Engine Block Cylinder Wall Thickness

grumpyvette

Administrator
Staff member
HOW FAR CAN YOU BORE A BLOCK?

before you begin to have a engine block bored more than about .030 over size its a good idea to have the blocks bore walls sonic tested
Have your machinist sonic check the block before you bore it.

calculate the remaining bore wall thickness, and if its not thick enough for safe use don,t bother
, bore walls are rarely if ever uniform in thickness from top to bottom or side to side, or concentric with the bore center line. and the STOCK O.E.M. production sbc block is well known to be fairly weak structually

REMEMBER PARTS TEND TO BREAK AT THE WEAK POINTS NOT THE STRONGEST AREAS THUS IGNORING THE THIN SECTIONS OF A CYLINDER BORE WALL BECAUSE MOST OF ITS FAIRLY RIGID IS NOT ALWAYS WISE!
its common for one wall in a cylinder to be significantly thinner than the other walls
this might sound like a unneeded extra expense but if your going to put several hundred dollars in machine work into a block you want to be fairly sure it won,t fail under stress wasting all that time and money, plus any resulting damage that might result.

boring a BIG BLOCK CHEVY block to more than about .060 over its original intended bore diameter,or sleeving the bore ,some times its the only way to save a block, but in many cases the O.E.M. blocks are so thinly cast that you'll have bore distortion and less than ideal bore, to piston ring sealing due to the cylinder wall thickness and /or less than ideal ring sealing, once the blocks really hot. making swapping to an aftermarket DART , world products or BOWTIE block with the thicker castings and better alloy metal,a better long term option, you cant tell how thick your cylinder walls are without sonic testing them as casting flaws, core shift and years of rust can make any block walls far thinner than you might assume them to be
let me point out a few facts, boring a cylinder takes 1/2 the bore increase off each side of the cylinder wall, and almost any big block will allow a careful machine shop to physically cut the finished bore size to be .100-.125 oversize , or a SBC .060 over bore,THAT IN NO WAY MEANS the remaining wall thickness thats left will be RIGID enough and STIFF enough to maintain a solid ring seal,or not flex and crack after repeatedly being stressed, at higher rpms and if the bore wall flexes to any significant degree it rapidly results in loss of effective compression rapid ring wear and potentially a cracked or busted cylinder wall.
yes you can have the block sleeved, but having more than two sleeves per cylinder bank on blocks that are not factory designed to have self supported individual cylinders generally results in a weaker block.
filling the lower coolant passages up to the level of the lower freeze plugs has a minimal effect on cooling but it reduces the UN-supported length of the cylinder walls making them stiffer.
KEEP IN MIND THAT YOU CAN PURCHASE BOTH NEW AND USED OEM AND AFTERMARKET CYLINDER BLOCKS, SO YOUR NOT STUCK USING, YOUR ORIGINAL PRODUCTION BLOCK WITH OVERLY THIN WALLS, IF ITS ALREADY RATHER THIN BUT REQUIRES A LARGER SIZE BORE


,https://garage.grumpysperformance.com/index.php?threads/sleeving-a-block.1516/#post-3467


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block prep.

you really should read these links for a lot more USEFUL info, on block pre prep one of the least discussed & acknowledged, and yet more common reasons engines fail , is related to micro metallic crud left in the engine while its being assembled, especially engine's built on newly machined...
garage.grumpysperformance.com


grinding block for stroker assembly

I finished grinding my block for 383 stroker assembly a couple of weeks ago. I found a tip to help cut down on metal dust particles. Take a magnet any type, and put it in a zip lock bag, then place the bag as close as you can to the area your grinding. I put mine in the direction of the flow...
garage.grumpysperformance.com

Engine Block Cylinder Wall Thickness

HOW FAR CAN YOU BORE A BLOCK? before you begin to have a engine block bored more than about .030 over size its a good idea to have the blocks bore walls sonic tested Have your machinist sonic check the block before you bore it. calculate the remaining bore wall thickness, and if its not thick...
garage.grumpysperformance.com

48378350d1683238904-bad-crack-between-cylinders-0opds.jpg


main-qimg-0887518726b7af4897c7e7f6512af04a-lq


ccrp-1204-hands-on-crack-repair-001.jpg

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bores must be honed with a deck torque plate to simulate the stress of a installed cylinder head stress , the torqued bolts exert on the bore walls, the torque plate induces and duplicates that stress so that the bore walls will be pulled into the same relationship when you hone the walls concentric, rings won,t seal correctly in a non concentric bore, aftermarket blocks with thicker and stiffer castings are less prone to bore distortion
a bit of reading here might be useful... get out a feeler gauge and look at how thick .060, .090, .120 actually is , and consider how easily a thin section of cylinder wall can flex and crack!
when G.M. or most manufactures "RATE" a block or any other component at lets say 350 hp what they are saying is that at that level of stress it should last a very long time, they are not suggesting that if its rated at 350hp, that at 360 hp its going to fall apart, only that the expected durability life span is being reduced, generally they build in some "cushion" usually 20%-25% or more because theres always going to be manufacturing tolerances and flaws
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when you have a block magnetically or dye checked for cracks , and sonic tested for bore wall thickness, don,t forget to check lifter bores, and lifter gallery areas, and main cap webs etc. just because its not easy to access does not mean cracks can be ignored
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when blocks are cast the molten metal can shift locations in the casting mold slightly, the machinery that machines the block is all indexed off
specific locations as its held in place, this results in some variation in the resulting casting thickness if the core mass has shifted marginally , thus most machine shops vastly prefer to work with ,
castings that maximize all casting metal thickness, in all directions from machined surfaces.

http://www.project33.com/Categoryarticle.cfm?ID=13&Category=Engine

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core shift results in one side of the cylinder bore walls tending to be noticeably thinner than ideal, this results in un-equal stress and more failures
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Chevy Performance BBC Bow Tie Race Engine Blocks | JEGS

Cast Iron Bow Tie Race Block Technical Notes
Precision CNC-machining means +/- 0.001'' tolerances
Standard deck (9.800'') or tall deck (10.200'')
4.240'' Finish Bore (4.600'' Maximum Bore, .250'' Minimum Wall Thickness)
A sonic bore check data sheet is provided with each block
Lifter bores are .300'' taller than standard blocks
Siamese cylinder bores
Improved cooling around number 1 cylinder
Accepts Mark IV or Gen V, Gen VI cylinder heads
Use Gen V head gaskets with Mark IV and Gen V cylinder heads
Use Gen VI head gaskets with Gen VI cylinder heads
Requires Mark IV design 2-piece rear main seal oil pans
Requires Mark IV design crankshafts
Can use Mark IV and Gen V, Gen VI camshafts, timing sets, lifters and timing cover
(aftermarket belt drive timing covers may require clearancing)
Blind-tapped head bolt holes; extra inner head bolt bosses provided
4-bolt SAE 8620 main caps splayed 16° on the three center mains
Priority main oiling wet sump system
Provisions for dry sump oil line provided
Honed camshaft and crankshaft bores
0.842'' lifter bores (maximum 1.06'') may be relocated
Distributor gear clearance at bottom of number 8 cylinder bore should be checked
Machined mechanical fuel pump pad
Tested to 1,200 horsepower!


READ THESE LINKS, YOULL MISS 80% OF THE INFO IGNORING THE LINKS

http://hotrodenginetech.com/how-to-build-racing-engines-cylinder-block-guide/


http://www.hotrod.com/articles/hrdp-1210-chevrolet-350-small-block-comparison/



http://www.chevydiy.com/ultimate-guide-building-chevy-big-blocks-cylinder-blocks-instruction/

http://garage.grumpysperformance.co...piston-to-bore-clearance-on-your-block.14251/



http://garage.grumpysperformance.com/index.php?threads/splayed-main-caps.1014/#post-3831



http://www.jegs.com/tech-articles/bbc-engine-specs.html



http://www.hotrod.com/techarticles/engi ... omparison/

Core shift is a result of a block, cylinder head, or other engine casting shifting in its mold when the molten metal is poured in. When core shift occurs the cylinder bores, lifter bores, main bearing and cam tunnels shift from their blueprinted positions. If the shift is significant, mechanical problems can occur and some cylinder walls may be critically thin. This is especially of concern if the engine is to be used for racing applications.

The only way to guarantee cylinder wall thickness is to have the block sonic-tested, but this can be difficult when you go to purchase a used engine.


Core shift example


On engines with in-block cams, you can always take a look at the cam bearing bore. If it is noticeably offset in its machined boss, you should suspect core shift.
fordblockcast.jpg

the block pictured above is NOT A CHEVY, but it gives you some idea of what the block internal coolant passages and cylinder walls look like
read this
http://www.project33.com/Categoryarticl ... ory=Engine
and understand its deck and cylinder wall thickness you need to verify more than core shift, its not the average cylinder wall thickness its both the MINIMUM and WHERE in the bore wall the thin section is that matters as the head bolts distort the bore, far more in some areas than in others.

(1) yes youll need to have the block under stress with bolts, or studs and a torque plate to duplicate the stress on the bore walls , that a clamped cylinder head induces on the bore walls to get the hone done correctly

honeplate.jpg


http://www.prostart.com.au/crisis/350chev/350-p3.html

http://garage.grumpysperformance.com/index.php?threads/installing-splayed-caps.7267/#post-24529

http://racingarticles.com/article_racing-73.html

http://www.matweb.com/search/datasheetT ... =PDEVCON05



http://garage.grumpysperformance.com/index.php?threads/block-prep.125/



http://www.drillspot.com/products/31915 ... num_Liquid



http://www.hardblok.com/product-info/

what does it mean to fill the block?

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http://www.caribbean.basf-cc.com/en/pro ... 85-Ing.pdf
get the
block deck perfectly level on each bank before you pour is critical
24" carpenter levels are generally priced under $9

https://www.zoro.com/stanley-level-24in-42-468/i/G2998992/
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It might be a surprise to many guys but a $10, METAL CARPENTERS SQUARE can be used , to verify a block thats is significantly warped on the deck surface
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heres a cross section of a block used strictly for drag racing with about 80% of the coolant passage filled, you can fill a block up to the lower edge of the freeze plugs and add significant support with only a minimal effect on cooling as about 90% of the heats generated in the cylinders upper 2.5" of bore

Ive also seen guys forget to install a plastic or metal tube in the lower coolant passage to allow the block to drain when they partly fill blocks to add block rigidity on thin cylinder walls, so remember to do that if your filling the block to increase cylinder wall strength up too the lower edge of the freeze plugs as forgetting thats a common new guy mistake
watch this video, but remember , if you intend to partially fill a block to add cylinder wall rigidity, the block should be filled at least 48 hours prior to any machine work being done on the block, as the fill in the coolant passages will generally expands slightly as it sets and will change the bore dimensions slightly.
Id also point out that a DART after market blocks significantly thicker and stiffer and made from a stronger alloy than the OEM production block casting


on most cars used on the street your limited too filling to the bottom of the freeze plugs

Filling a block is when you use a concrete like substance fill, that you pour into the water jacket of your motor.
The idea is to strengthen your block from the inside.
One of the main benefits is to control bore flexing.
Most people do two different types of fill.
1. Street fill-you fill up to the bottom of the lower freeze plugs.
2. Race fill- you fill to the bottom of your water pump holes.
All fills should be done "Before" you do your machine work.[/color]

ok, generally you want an absolute minimum cylinder wall thickness, on a stock production block of .180 and .230 or thicker is generally considered to be ideal, anytime your bore reduces the cylinder wall thickness below .200 in my opinion, if you intend to race the engine, you should fill the block to the lower freeze plugs with a block coolant passage filler to reduce the unsupported cylinder walls tendency to flex, which reduces ring seal., and generally the semi-safe limit, with the block filled is at about .200-.180, below that, wall thickness, becomes a potential major problem and the blocks life expectancy, is usually lower,
Id reject a block as a race engine if the upper cylinder wall thickness is under about .145" as an absolute minimum,and only go below .180 if that thin wall area is supported by block fill now Im sure youll find guys who have raced thinner cylinder wall thickness, but its pushing your luck.
A great deal of the engines heat is produced in the cylinder heads and upper 2" of the cylinder bore, and very little comparatively in the lower engine so filling the coolant passages up to the lower edge of the freeze plugs has a minimal effect on cooling if you've got a good radiator and water pump ETC.you check this with a sonic tester AFTER FIRST verifying the TESTER accuracy on parts of the engine you can verify with a caliper.

you certainly don,t want to dump bunches of cash into a block that will likely crack if subjected to the stress of racing!
IF your a bit under that .180 minimum, you generally strengthen the cylinder wall by filling the coolant passages in the block surrounding the cylinder wall up to the lower edge of the freeze plugs with a block filler, I prefer a slurry of about 85% steel shot of size .180" -.200", and 15%- epoxy block filler , if you use more epoxy the epoxy won,t expand at the same rate as the block when its hot, filling the lower cylinder wall coolant passage up to the lower edge of the freeze plugs has little effect on cooling,because about 90% of the heat is generated in the top 3" of the bores stroke and heads (JUST REMEMBER TO INSERT A DRAIN TUBE SO THE EPOXY DOESN,T BLOCK THE BLOCK COOLANT DRAIN PASSAGE ON EACH SIDE)
SUMMIT SELLS G.M. BLOCKS you can use to build a 383 for $700 plus shipping , but ID suggest limiting power to about 500 hp with these
http://www.summitracing.com/parts/sum-150100
I personally thing anything less than .145 is pushing things even WITH a partially filled coolant passage area, ask
your self a couple questions, have you got a written quote on the required machine work? have you had the block walls sonic thickness checked, and found out what the bore walls remaining thickness will be after being bored and honed at both the top and bottom of each cylinder wall at every 90 degrees?
how much money have you already sunk into that block in machining costs, or what it the likely cost of a line hine, bore job , maybe adding splayed man caps and having the decks trued up and how much more cash with getting the stock block prepped correctly cost, will you waste that money , what if the block cracks after you get it assembled and start running it?
I think almost all of us start out making the same mistake of trying to get the block we already own re-machined to save costs ,not realizing in most cases its wasted effort and cash.
you could very easily dump $800-$1200 IN MACHINE WORK ON AN OEM BLOCK, AND STILL HAVE A VERY WEAK BLOCK CASTING,THATS FAR MORE LIKELY TO CRACK AND FLEX, IN COMPARISON TO A DART, or world products BLOCK.
if you spend roughly $1500 on a much thicker dart block you won,t be nearly as likely to have block failure related problems.
OR you can spend a bit more and get a far stronger and thicker DART BLOCK casting for about $1550.
yes $1550 or so is a LOT of money,and I know how difficult coming up with cash is! but this is NOT a cheap hobby and if you put $800-$1200 in an OEM block the fails and trashes the rest of your parts you hardly save any money


http://www.summitracing.com/search/prod ... e%20Blocks

http://www.precisionreloading.com/steel_shot.htm

(#4 or #2 shot, or BB size preferred) buy the 40lb bag

http://www.ballisticproducts.com/Steel- ... info/SH04/

there are several block fill products that are basically high strength mortar or concrete

http://www.hardblok.com/

http://www.labsafety.com/Magnacrete-Con ... _24531183/

is popular, for filling blocks up to the lower edge of the freeze plugs

Ive used a slurry of steel bird shot and liquid EPOXY for my blocks

http://www.precisionreloading.com/mm5/m ... STEEL_SHOT

http://www.alvinproducts.com/Products/Products.asp?id=1

but almost everyone uses moroso concrete/grout mix as its readily available, this generally has very little effect on the cooling as most of the heat is generated in the heads and the first 2" of the upper bore of the cylinders.

http://moroso.com/catalog/categorydispl ... Code=22008


BTW you generally fill the coolant area BEFORE the BORE/HONE WORK

http://www.ndtsystems.com/Automotive/automotive.html

http://raceology.com/2004/11/sonic-test ... y-how.html

http://www.geinspectiontechnologies.com ... index.html

http://www.qualitest-inc.com/2000b-utg.htm

http://www.popularhotrodding.com/engine ... index.html

http://www.qualitest-inc.com/pr-82.htm

http://www.popularhotrodding.com/tech/0 ... index.html

http://books.google.com/books?id=-csSm0 ... q=&f=false

http://www.checkline.com/sonic_testers/

http://www.racecarmagazine.com/Articles ... .asp?ID=26

http://raceology.com/2004/11/sonic-test ... y-how.html

http://www.abqindustrial.net/store/soni ... -c-40.html

http://www.dakotaultrasonics.com/



http://garage.grumpysperformance.com/index.php?threads/installing-splayed-caps.7267/#post-24529

This is where the aftermarket performance engine blocks generally have a huge advantage over the standard production blocks, core shift and casting thickness is generally much better controlled on the better aftermarket performance engine blocks like DART sells as an
EXAMPLE
.

and yeah! at first the $1500-$3000 for a block seems absurd,
but it comes machined if you order it that way, (EXTRA COST OPTION IN MOST CASES) and its a whole lot stronger,stiffer,thicker and less likely to self destruct under hard use than a factory block., and its NEW not something that's been sitting around rusting and being over heated for 30-40 plus years, like some sbc cores, and the dart block cylinder walls can easily be twice as thick or more than a Chevy block and made from better materials.
here is where you, or your machine shop can screw things up on ring to bore seal, when you hone the bores,get and use block deck hone plates, during the hone process , keep in kind you want to use the same (STUDS OR BOLTS) the machine shop used and the same torque settings they used when the cylinders were honed with deck plates or the distortion of the bore and ring seal won,t be identical (exactly round)or ideal , aftermarket blocks can and usually do have significantly thicker cylinder walls, the thicker the cylinder wall the less the distortion , that effects ring seal will tend to be,under the load the bolts or studs used to fasten the heads to the block produce which will tend to distort the block

STEEL SHOT GUN PELLETS AND EPOXY WORKS AS A COOLANT PASSAGE FILLER
http://easy-strike.com/prod_liquid.html

http://www.adperformance.com/index.php? ... 82_105_309

http://www.adperformance.com/index.php? ... =69_82_106

http://www.circletrack.com/techarticles ... index.html

http://www.scatcrankshafts.com/PDFs/ScatWorld.pdf

http://www.arengineering.com/articles/sonicbig.html

http://www.hotrodpitstop.com/engine-block-prep.php


http://www.e30m3project.com/e30m3perfor ... sonic2.htm
 
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If your looking for a block to start with you'll generally want to look for a 4 bolt block, as they tend to be slightly stronger than the two bolt blocks,IN MANY CASES BUT NOT ALL,OBVIOUSLY 4 studs or bolts SHOULD provide greater clamping strength than two bolts or studs but the thickness of the block web area varies a great deal, and just having 4 bolts is no guarantee its stronger, unless you add splayed main caps to the two bolt blocks, but ANY production block is significantly weaker than the bowtie and DART BLOCKS available know.Ive long ago lost count of the guys that dumped weeks of work and hundreds ,sometimes THOUSANDS of dollars into converting stock engine blocks to 4 bolt main caps or splayed main caps or had the blocks decked and line honed or bored cylinders, and honed ,or sleeved and then were forced to throw all that expensive machine work in a dumpster when the block cracked under use.
the stock blocks are designed for about 350-400hp and under 6000rpm, and while we all know guys who have built successful engine combos making a good deal more power the fact is the blocks significantly weaker than a DART AFTERMARKET block thats both a good deal thicker and has a stiffer and stronger alloy in the casting.

TW the question always comes up, "how do you seal the rings/pistons to the bore so the fluid you use to measure the piston dome volume does not leak past the rings?

OK, most shops either use a piston bridge and dial indicator or maybe a custom fixture to place the flat or quench deck of the piston exactly 1" below the top of the cylinder bore, and they use a burret when ccing the bore volume vs the theoretical CC volume of a perfect flat bottom cylinder
most shops use a bit of moly grease, smeared 360 dregees around the and on the bore walls with the piston at bdc
and they rotate the crank up from BDC to 1" below TDC, then they use a few tissues and Q-tips to remove all excess grease above the piston or left on the bore wals , some shops pour a bit of melted PARRIFIN on the piston and wipe it into the piston to bore clearance and then they remove all excess off the piston before they measure the piston dome or recess in the piston, from that 1" down the bore location, with a burette of fluid, paraffin has the advantage that it rapidly melts and will burn off in use if a small amount is left in the oil, most oil already has a bit of paraffin in it,

you may need to use a floor jack to lift the engine to have the blocks deck read level, use a solid but reasonably soft spacer under the block if thats required to prevent damaging the blocks lower surfaces, a large block of wood may work,

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Valve To Piston Clearance??

A buddy of mine is about to drop off a set of fresh 215 closed chambered heads that I’m getting for next to nothing. Question here is does anyone know if the 2349 speed pro ls6 closed chamber replacement piston will work with them? I have a short block sitting here with those pistons ready to go...
garage.grumpysperformance.com
remember the formula for a cylinders volume is the radias (1/2 the diameter) squared times 3.147 times the depth (in this case 1"
1 cubic inch = 16.3871 cc's
so for example if the bore diameters 4.25" youll multiply 2.125 x 2.125 x 3.147 to get the cubic inch volume them multiply the result by 16.3871 to get the cc's
thats the expected volume above a flat top piston, you'll generally use a bit more because the valve clearance notches add 6-8 cc volume on a flat top piston or use a bit less fluid from the burret if the pistons got a dome.
obviously the difference is the dome volume
I generally use a 100cc-250cc BURRET and a 6" square sheet of LEXAN (they generally sell 12" square sheets so you get four to use to measure heads and piston volume ones you carefully saw then drill the 4 quarters) use with a small counter sunk hole drilled in the center over the bore for the burret to drip fluid through, a very small thin bead of grease or silicone around the bore to seal the lexan from leaking fluid is advised and of course the blocks deck must be both level and clean, before the blocks used to measure the piston dome volume,

this is a good time to use a 24" steel carpenters square and a set of feeler gauges to verify the block decks square and level,
71vdNbnjE2L._SL1500_.jpg



https://www.amazon.com/SimbaLux-Ple...710&sprefix=6+square+1/2+lexan,aps,273&sr=8-9

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read these links



ccing my heads

HELP I hope some can help me with a prob I am having. I started to cc my heads so i check all and found that they need to be ground. I have one at 64.3 so I started grinding one of them to be at 64.3 or there abouts. I ground a lot off and got a reading of 62 so I ground more off and came up...
garage.grumpysperformance.com

unshrouding valves, and polishing combustion chambers

I think you missed my point It was a pun intended towards Skipwhite performance..... Short of the long story Skipwhite performance build a motor for me in 2015 fast forward 2018 They built junk from what I have ran into, Grumpy and the gang have gave me all kinds of advice and help so far...
garage.grumpysperformance.com

Valve To Piston Clearance??

A buddy of mine is about to drop off a set of fresh 215 closed chambered heads that I’m getting for next to nothing. Question here is does anyone know if the 2349 speed pro ls6 closed chamber replacement piston will work with them? I have a short block sitting here with those pistons ready to go...
garage.grumpysperformance.com



Sonic Checking Your Block

Author Andy Finkbeiner Photos Ron Valera

Image3.jpg


Modern technology is great for us hot rodders. A few years ago, you practically needed a top security clearance before you could get your hands on technology like this. Now you can whip out the VISA card and order yourself a sonic checker like the one shown above.

Sonic checking is a fairly common term in the engine building business but many people might not fully understand just what it is all about. When the engine builder asks if you want to spend another $75 to have the block sonic checked, some people might think he is just trying to get more money from you. Actually, the engine builder is probably trying to save you from wasting a lot of money on a block that might not be any good. After all, most of the engine blocks in our musclecars are at least 30 years old now and have been through a lot.

Sonic checking is a method for measuring material thickness when you only have access to one side of the part. For instance, if you want to know how thick a cylinder wall in an engine will be, you would have to cut a hole in the wall in order to use a pair of calipers. The sonic checker is able to measure the thickness by sending out a sound wave and then measuring the time that it takes for the sound wave to get to the other side of the wall. Modern electronics allow this complicated task to be accomplished in a hand held device.

How thick the cylinder walls need to be is a fairly difficult question to answer but we do have some clues. Most production V8 blocks have cylinder wall thicknesses that range from 0.090 to .250 thick. Ford motors tend to be the thinnest while some Chevy blocks are the thickest. The thickness of the cylinder wall becomes more important as you start to make more horsepower, so a block that works in a passenger car application might not be suited for Winston Cup duty. If you can find a production block that is at least 0.200 thick on all cylinder wall thrust surfaces you’ve found a good one. Walls that thick should be good for at least 500 or 600 horsepower. If you’re going to be making more power than that then it is probably best to step up to a factory race block. Typically the race blocks are designed to maintain a 0.250 thick cylinder wall at the maximum overbore. They might start out with a wall thickness close to 0.400 as delivered.



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Here is the sonic checker from Dakota Ultrasonics. This unit sells for $990 and is designed to be used for various automotive tasks. It can measure thicknesses from 0.025 to 20 inches in a variety of materials but is especially good at measuring cast materials.

Image5.jpg


Here is where you really need a sonic checker! Nine engine blocks to choose from but which one is the best? A sonic checker allows you to examine each block for core shift and casting flaws. Obviously, what you want to do is to pick the block with the least amount of core shift. Minimum core shift will be indicated by having fairly consistent thickness measurements for each cylinder.



Contact Information:

Dakota Ultrasonics

1650B Mansfield Street

Santa Cruz, CA 95062

(831) 465-8585
http://www.dakotainst.com/


HAVE THE HEADS AND BLOCK CHECKED
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RELATED INFO

block prep.

you really should read these links for a lot more USEFUL info, on block pre prep one of the least discussed & acknowledged, and yet more common reasons engines fail , is related to micro metallic crud left in the engine while its being assembled, especially engine's built on newly machined...
garage.grumpysperformance.com

grinding block for stroker assembly

I finished grinding my block for 383 stroker assembly a couple of weeks ago. I found a tip to help cut down on metal dust particles. Take a magnet any type, and put it in a zip lock bag, then place the bag as close as you can to the area your grinding. I put mine in the direction of the flow...
garage.grumpysperformance.com

Engine Block Cylinder Wall Thickness

HOW FAR CAN YOU BORE A BLOCK? before you begin to have a engine block bored more than about .030 over size its a good idea to have the blocks bore walls sonic tested Have your machinist sonic check the block before you bore it. calculate the remaining bore wall thickness, and if its not thick...
garage.grumpysperformance.com

48378350d1683238904-bad-crack-between-cylinders-0opds.jpg


main-qimg-0887518726b7af4897c7e7f6512af04a-lq


ccrp-1204-hands-on-crack-repair-001.jpg

most SMALL BLOCKs can be bored .030-.040, after that they tend to get rather thin in places, BIG BLOCK blocks will go .060 with no problem, some few will big block castings will go 0.100 and but you cant make a blanket statement because there are some blocks with core shift or just not enough material that are too thin to start with. if you are going to sink a lot of money in a block and machine work, and if you plan on making a lot of power you need to have the block sonic checked, and in almost every case if your goal exceeds 550 hp the DART aftermarket block is preferred as its got a much thicker casting,
IVE HAD EXCELLENT results with standard 4 bolt blocks from the late 1968-72 time frame, we bored them to 4.310 without thinking twice, (.060 over size) IVE built engines that exceeded 650hp, with 4.25" stroker cranks and 13.7:1 compression ratios,that ran on only race gas, but those blocks are now 35-40 years old and who knows what the coolant passages and stress levels have been subjected too, the DART aftermarket and BOWTIE blocks are significantly thicker and stronger castings than any of the standard production car blocks, and machine work is expensive, if you are thinking of exceeding 600-650 hp you'll be better off buying and using a decent aftermarket block as they are significantly stronger and thicker castings , thicker decks, thicker webs thicker cylinder walls, etc, priority oil passages,etc. they are made from a better alloy and less likely to have problems
dartcylinder.jpg

AFTERMARKET BLOCKS LIKE DART PRODUCES HAVE FAR THICKER CYLINDER WALL CASTINGS
http://www.dartheads.com/products/engin ... ig-blocks/

http://www.adperformance.com/index.php? ... =69_82_106

viewtopic.php?f=51&t=588&p=764&hilit=sonic#p764

http://www.arengineering.com/articles/articleframe.html

http://www.arengineering.com/articles/sonicbig.html

http://www.ndtsystems.com/Automotive/automotive.html

http://www.testequipmentdepot.com/reed/ ... 2a058b0ec6

100_6020.JPG

8811.jpg



(this link below suggests a 0.125 cylinder wall thickness as a absolute minimum, on a high performance application, while 0.180, is what most shops suggest, as a safe lower limit on a race engine)
http://books.google.com/books?id=_i_XVV ... q=&f=false

well worth reading thru

have the block sonic tested, if you've got any doubts and have it honed with a deck plate, as a general rule cylinder wall thickness should ideally be a minimum of .200-.250 thick, getting much thinner,due to boring it larger, allows too much distortion for proper ring seal, and yes we all know guys who get away with .180 occasionally, but remember just because something, sometimes doesn,t fail the first few dozen or even the first few hundred times, its used, doesn,t mean its operating correctly, Id suggest getting an aftermarket block if you want a larger bore, and your pushing those limits on a stock production block, simply because the decks and cylinder walls are significantly thicker and the basic casting design is stronger, and if the stock casting fails at high rpms you might loose all your components, machine work, etc, certainly making the up front higher cost of the aftermarket block looking far more reasonable if looked at in that light.

the stock OEM components are rated by chevy, to with stand 350-400hp and 5700rpm-6000rpm,obviously we all know guys that have pushed their components to exceed those limits, but stress is cumulative, and the harder you push or the more frequently you push past those limits the more likely you are to experience component failures
look at the rated hp

http://www.sallee-chevrolet.com/ChevyBa ... 05123.html

the DART SHP Chevy Small Blocks are significantly stronger castings in the stressed areas and are rated UP TOO 600hp, the little m blocks are even stronger

http://www.dartheads.com/products/shp-c ... locks.html

http://www.dartheads.com/products/engin ... locks.html

it would make very little sense to build an engine thats intended to produce over about 500-550 hp on a STOCK PRODUCTION Chevy block simply because the main caps will walk or the lifter bores will crack or the cylinder walls will begin to flex ETC. at some point, and that point will be noticeably lower in the power curve than an aftermarket block , thats been properly machined, Ive got splayed 4 bolt main caps and use all ARP hardware in my block and Im still reluctant to push it much past those limits, because I see the results far to often in my shop, when guys insist on spinning the nearly stock engines to 7k plus or dropping a 150-200hp worth of nitrous,or use of stock bolts on an engine without the proper mixture and ignition controls and all forged components.

chevblockparts003.jpg



a reasonably common result of boring the block walls too thin to support the rings, especially without partly filled water jackets on an OEM block bored more than .060 oversize, or if you fail to sonic test the block wall thickness, but keep in mind a rod letting go, a failed rod bolt or a piston destroyed by detonation could result in similar damage


an example of a sonic test on a stock block bores .060 over bore


SonicTest01a.jpg


notice several areas, A-E where the block walls less than .100 thick




thinwall.jpg

thinwall1.jpg


sleeving the bore,some times its the only way to save a block, but your very unlikely to need this type of work on a well assembled DART or AFTERMARKET BLOCK, all these examples were bored to under .100 thick


theres hundreds of ways to destroy an engine, but a common route is trying to compress solid objects in the combustion chamber,where theres not nearly enough clearance,or having the valve train bind up due to clearance issues or reveing the engine above its valve control limitations.
failure to keep the pistons from hitting the valves, bending valves, ,over reveing the valve train and having un-controlled valve movement, or having chunks of piston,that detonation can break loose, being compressed against the heads,can result in the cracked cylinders, and bent rods like the pictures below show
crackedbore.jpg

crackedbore1.jpg

bustedvalve.jpg


blockcrack.jpg

brokemaincap.jpg

main%20web%20crack.jpg

broken400cap-1.jpg

the crank or block can have the correct bearing clearance but still be slightly bent or the block may be warped and result in the bearing wear , keep in mind main bearing caps can crack or be improperly machined, this is FAR less common on DART AFTERMARKET BLOCKS
I think the 400 SBC 4 bolt blocks have a bad reputation that's probably not fully deserved , the rumor is that the web area of the block is weaker and the outer bolts further weaken the block, but I think its more a case of the extra bolts don,t significantly add to the block rigidity .
the 350 and 400 SBC OEM production blocks were designed to handle 350-400hp max,and when pushed well past that stress level its just logical that they occasionally fail.
if a two bolt block fails the normal response seems to be that
'we should have installed the angled aftermarket main caps'
if a four bolt block fails the normal response seems to be that
'we should have installed the angled aftermarket main caps, because the damn four bolt blocks weaker'
the truth is that by the time your making 500hp neither block with stock main caps keeps the main caps from moving under full loads and adding the splayed main caps while helpful is not a cure, its a band-aid at best, the aftermarket DART block has much thicker castings in the block web area and better and stronger alloys used.


http://webtools.delmarlearning.com/samp ... _ch139.pdf

http://www.thirskauto.net/BearingPics.html

https://www.hotrod.com/articles/hrd...parison-19-dart-machinery-little-m-sportsman/


Neither plastigage or a full set of micrometers or other ways of checking crank to bearing clearances will detect a bad align bore or a crankshaft with runout.

But there are some simple ways to check both.

http://www.herboldracing.com/2010/02/19 ... ank-runout

173207.jpg

Here are a set of main bearings that 400 miles o them and you can see there was an alignment issues the rear main bearing is missing but was in good shape.



BADMAINLINE.jpg

crack1.jpg

crack2.jpg

blockcrackm1.jpg

blockcrackm2.jpg


clean any block you buy and look for obvious cracks and if you have doubts get the machine shop to mag or dye test the block or heads
lifter bores
and lifter gallery
,piston bore walls,
block main cap web support areas
heads between the valves in valve seat area
look for stripped head and manifold and oil pan mounting bolt threads,
in threaded holes and cracks in block radiating from the holes
blockcr1.jpg

blockcr2.jpg
blockcr3.png


blockcr9.JPG

blockcr4.jpg

blockcr5.jpg

blockcr6.jpg
blockcr7.jpg

blockcr8.jpg

ASK LOTS TO QUESTIONS & SHOP CAREFULLY,

if you check you'll find that stud girdle use does little or nothing for the individual main cap strength but it does marginally increase main cap stability and block flex.
now the potential difference is probably not worth the expense, in that your generally spending cash that would be better used in the purchase of the stronger aftermarket block casting from a known source like DART.
look through the links and read the sub links
the billet splayed main caps on the aftermarket block is the stronger route, but Id bet 90% of the guys building their first engine think they will save money using the O.E.M. block they already own.....well, until... they add up all the machine work costs and price of parts like aftermarket splayed caps, ARP main studs ,the labor costs from the machine shop, etc. but by that time the machine shop owner is smiling all the way to the bank, and youve just figured out the true cost of that cheaper O.E.M BLOCK
girdle1gh.jpg

main%20web%20crack.jpg

broken400cap-1.jpg

failure to check for cracks or use of a O.E.M. block at power levels its not designed for can and frequently does result in engine failure, most O.E.M. SBC blocks are rated at no more than 400hp, we all know guys pushing them to 500hp but much beyond that its a crap shoot and the blocks eventually going to flex and fail.
 
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DART BIG M BBC BLOCK
Features:
  • Siamesed Extra-Thick Cylinder Walls: Resists cracking and improves ring seal (minimum .300'' thick with 4.625'' bore).
  • Scalloped Outer Water Jacket Walls: Improves coolant flow around the cylinder barrels to equalize temperatures.
  • Four-Bolt Main Bearing Caps: In steel or ductile iron have splayed outer bolts for extra strength.
  • Crankshaft Tunnel: Has clearance for a 4.500'' stroke crank with steel rods without grinding.
  • True ''Priority Main'' Oil System: Lubricates the main bearings before the lifters.
  • Oil Filter Pad: Drilled and tapped for an external oil pump.
  • Rear Four-Bolt Cap: Uses standard oil pump and two-piece seal - no adapter required!
  • Lifter Valley Head Stud Bosses: Prevent blown head gaskets between head bolts.
  • External Block Machining: Reduces weight without sacrificing strength.
  • Simplified Install : Fuel pump boss, clutch linkage mounts and side & front motor mounts simplfy installation on any chassis.
  • Dual Oil Pan Bolt Patterns: Fits standard and notched oil pans.
  • Bellhousing Flange and Rear Main Bearing: Reinforced with ribs to resist cracks.
  • Note: Does not include cam bearings, freeze plugs, or dowels

Racing Articles
Sonic Testing - What, Why, How
by Don Terrill ©2004

In the racing world a sonic tester is used to measure the thickness of metal in areas that can t be accessed for direct measurement, the most common being cylinder walls and roll bar tubing. For this article I m going to focus on the engine block s cylinder walls.

Relative to the induction system, there isn t much power to be had in the short block, but one of the most important areas is ring seal. The interaction between the rings and the cylinder wall is critical. Rings can handle some irregularity, but there is no question, the better the cylinder wall, the better the power.

How a sonic tester works:

Just like a bat or a radar gun, the sonic tester sends out a sound wave and then calculates the thickness of the metal by measuring the time for the reflected wave to return.

Calibration is the key to accurate readings. For the best results you should find two pieces of like material (cast iron), one thinner than typically readings and on thicker, to use as standards. You need to be able to physically measure these pieces and then compare them with the tester to make adjustments. You can try to find areas on the block for calibration or take a sledge to a blown up block and make your own. I was “lucky” enough to have a customer forget to put antifreeze in his block over the winter, which supplied me with the perfect donor block.

Where to test:

Major thrust â Located opposite the rotation of the motor. Facing the front of the engine, if it turns clockwise, the major thrust is the left side of each bank (V8). This is the location of the largest loads and thus it would be nice to see the thickest cylinder walls.
Minor thrust â Located opposite the major thrust and on the same side as the rotation of the motor - Typically the right side of both banks.
Front and back of block â This would be the front of the front cylinders and rear of the rear cylinders. Most manufacturers put a good amount of material in these areas, probably because they had the room.
Between cylinders â This is typically the thinnest section of the cylinder because of closeness of adjacent cylinders and the need to allow room for coolant. I ve actually seen blocks run with less than .100 on the pin sides.

What s a good thrust side thickness? .300+
What s ok? Over .250
What s bad? Under .200 on a thrust or under .100 on a pin side â I d call this a nightmare

What can go wrong? Egg shaped cylinder walls and worse, a cracked cylinder wall. A good way to know how good a block is without a sonic tester is to see how out of round the cylinders get after a season of racing, good blocks will take next to nothing to clean up, bad ones may take .002+ every season.

Fixes:

Grouting the block - Filling a block with grout is no replacement for having a good block. Grout can be helpful, but for other reasons that I will discuss in a future article.
Sleeving the block - There are so many things that can go wrong with sleeving a block that it s not worth the risk in my opinion.
Offset boring â Offsetting the boring bar away from thin spots may help a fuzz, but unless you re doing a large overbore you just can t make enough difference.
A better block â In the end this is the only true fix, with a few more pounds on the nose of the car being the only negative.
 
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just for grins IM posting this info to try to show why you don,t want to use a OEM 400 block thats been improperly machined.
a great deal many more problems can be avoided entirely, if you take the time to think things through and do a bit of research into what works and what tends to fail, than you'll generally find by rushing into a project with the stock OEM engine block and waving your check book under the nose of the local machine shop owner!
Start by getting the block carefully cleaned and the block wall thickness sonic tested, then dye test for cracks , the last thing you want is to spend hundreds of dollars on a block thats already cracked or so thin in places its sure to crack under stress, or one that has bore walls so thin they flex and cause ring seal issues.
yes testing and inspections, and cleaning cost money, but its better to find problems early then after you spend hundreds of additional dollars on a junk block.
in this case a guy on a different site posted pictures of what the result was when he used a stock OEM 400 block that had been bored .060 over size and honed without deck plated during the hone process.
this guy put hundreds of dollars into block machine work , and while tightening the head bolts he heard a (POP SOUND) and the torque changed, inspection showed the bolt tension caused the thin block casting that was bored .060 over size to crack.
you could easily pay $400-$800 for a clean 400 block, and add another $500-$1200 in machine work, think about that, then think about the far stronger DART block cost, and its far less likely to have similar problems

the answer, to what machine work and parts you'll need and what main cap design is best for your application, will of course depend on what you intend to DO- WITH THE COMPLETED engine , yes a common upgrade is to use the stock main caps and ARP main studs, they can be used but the difference in tension may require the block gets line honed to maintain the correct crank bearing alignment compared to the factory main cap bolts ,and this generally works ok up to the 450-475 hp level, and yes there's stronger billet aftermarket main caps, splayed main caps and main cap girdles that can be used to increase the blocks strength and rigidity, but the aftermarket blocks use thicker castings of a sightly better design making them significantly stronger and a splaid main cap is structurally a stronger design.
Most OEM production SBC blocks are factory rated for under 400 hp use, we all know people that have pushed the limits to 450-500 hp but theres a huge difference, in stress, levels a block sees, between the malt shop hero who got his car dyno tested at 475 hp who spends 97% of his time cruising around to impress his buddies with the cars lumpy idle, and racing once every few months , and some guys racing a stock car, for several 50 lap races at 6500 rpm every Saturday night, in what you can reasonably expect from the main cap durability and main cap stability because stress is CUMULATIVE !
you can get away with amazing amounts of abuse SHORT TERM, that will EVENTUALLY cause major parts , durability issues & failures


girdle1gh.jpg

400blockfail.jpg

look closely the red arrow shows the threads were repaired with a heli-coil thread insert, while thats not necessarily a huge problem the CRACK that goes thru the STEAM HOLE (GREEN ARROW) IS POTENTIALLY A MAJOR ISSUE

400blockfail1.jpg

Bolthelicoilrp.jpg


http://garage.grumpysperformance.co...ing-cast-iron-can-make-a-preacher-cuss.12647/
notice that the piston rings don,t show contact wear on the cylinder walls ,adjacent to the bolt holes (LOOK IN THE RED BOXES) where the bolts tension pulls the cylinder walls outward, this could be compensated for if the block was honed with deck plates in place but the cause is extremely thin and flexible cylinder walls, the correct route is use of the far stronger and thicker casting used in the DART aftermarket block

Ive got zero doubt that adding main cap girdle adds rigidity, You can certainly make a great deal of horse power, but the rpm level stress goes up rapidly past 6000 rpm, and Id point out that the block casting design is the key to strength, in many designs, EXAMPLE, an olds blocks main web strength is not noted as nearly as strong as some of the other engines, so no matter what you do your stock casting is not going to be as strong as a good aftermarket block, like a DART,splayed 4 bolt main on a chevy big block, or a cross bolted block like some fords, hemis and LS1-LS7 engines so Id still recommend staying under 6000rpm, and last time I checked theres no OLDS ARP,connecting rods with 200,000psi rated 7/16" rod bolts, think thru your component selection with the intended rpm range in mind, theres no reason to spin some engines to higher rpms that the designs made to safely operate at.

before you dump a $1000 dollars or more into machine work on any block have the bore walls thickness checked and the block MAG TESTED for FLAWS & CRACKS , failure to spend the time and money required to do so can cost you a great deal of wasted time and money!
preparation+mag-check.jpg

mag check for cracks in the block


NOT A TA said:
For those who never witnessed Magnafluxing this is how its done. Electromagnet is located so the area you want to test is located between the posts. Then some "magic dust" (in my best Cheech impersonation) is puffed ofer the area to be checked and the dust jumps right to the crack. Even if the crack is very small (like the one on my head) it will show right up. The crack in this pic was easily seen by the naked eye but it made for a nice easy pic to display the process. The lightweight head in the pic had been sleeved for the bolt hole previously so thats why theres a circle of magic dust around it. The dust knows it as a crack. This head will be pinned to repair the crack. If the opportunity arises to get pics of "pinning" sometime I'll get some.
DSCN0004-2.jpg

girdle69.jpg


look closely youll see the lack of basic olds main web thickness, to anchor the main cap studs is a potential problem
girdle699.JPG

have your block carefully sonic tested , read the links , you can get away with rather tin bore walls in less stressed areas , but if you find any place under about .o90 I would not put any more cash into the block (personally Id want thicker) if you intend to seriously thrash the engine, stress is cumulative, like bending a steel coat hanger over 90 degrees then back strait, the first couple times it handles the stress, but repeat the process over and over and at some point the wire just breaks off

GRAB YOUR FEELER GAUGE SET AND LOOK HOW THICK , even 0.125 is
and remember the bore wall is subjected to hundreds of PSI of cylinder pressure 50-70 times a second,
Feeler-Gauge.jpg

Cylinder-Pressure-Lrg.gif

if we calculate that 700 psi at peak cylinder pressure a 302, 327, 350, 383 has about a 4" bore so roughly 12.6 square inches of piston surface , over 8800 ft lbs of force on the crank and thats not counting inertial loads

an example of a sonic test on a stock block bores .060 over bore




notice several areas, A-E where the block walls less than .100 thick
http://garage.grumpysperformance.com/index.php?threads/engine-block-cylinder-wall-thickness.976/

http://garage.grumpysperformance.com/index.php?threads/main-cap-fit-in-block.5945/

http://garage.grumpysperformance.com/index.php?threads/block-choice.10472/

http://garage.grumpysperformance.com/index.php?threads/splayed-main-caps.1014/

http://garage.grumpysperformance.com/index.php?threads/machine-work-costs.3169/

http://garage.grumpysperformance.com/index.php?threads/checking-blocks-heads-for-cracks.3363/

http://garage.grumpysperformance.com/index.php?threads/torque-plate-honing-makes-a-differance.588/

http://garage.grumpysperformance.com/index.php?threads/bits-of-dimensional-info.134/
RELATED THREADS

viewtopic.php?f=53&t=341

viewtopic.php?f=69&t=7267&p=24723&hilit=splayed#p24723

viewtopic.php?f=51&t=976&p=1827&hilit=sleeved+main+caps#p1827

http://www.hastingsmfg.com/ServiceTips/ ... ishing.htm

viewtopic.php?f=51&t=125&p=12993&hilit=caps+walking#p12993

555build1-09058-2.jpg

JUST COMPARE TO A BIG BLOCK CHEVY

hemimain.jpg

JUST COMPARE TO A CROSS BOLT FULL SKIRT HEMI BLOCK

http://garage.grumpysperformance.com/index.php?threads/finding-a-machine-shop.321/#post-55314
moparw2.jpg

moparw1.jpg

JUST COMPARE TO A mopar wedge FULL SKIRT girdle that uses all the oil pan bolts in the BLOCK

the better machine shops pin or sleeve the main caps to prevent movement

sleevecap1.jpg

sleevecap2.JPG

RELATED INFO


http://garage.grumpysperformance.com/index.php?threads/finding-a-machine-shop.321/#post-55314

http://garage.grumpysperformance.com/index.php?threads/sleeving-a-block.1516/#post-3467
 
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Indycars posted this great info



http://www.hotrod.com/techarticles/engi ... omparison/

If you look at the Chevy block on page 2, this is remarkably close to my experience. I bored a
350 in² SBC .060", which is .030" on a side. My thinnest wall was .064" on cylinder #4.

If the Chevy block in the Hot Rod (Page 2) article was bored .060" over, it's thinnest cylinder
would be .062".

Wish I would have known these facts before I spent $200 on boring a block I'm not going to use
for a performance application.

HotRodBlockTests_Pg01.jpg

HotRodBlockTests_Pg02.jpg

HotRodBlockTests_Pg03.jpg

HotRodBlockTests_Pg04.jpg

HotRodBlockTests_Pg05.jpg

HotRodBlockTests_Pg06.jpg


 
I was recently asked what block casting numbers a guy should look for,
to insure that the block he was going to base his engine on was more likely to have the thicker casting,
and cylinder wall depth that would safely allow a .030-or even a .060 over bore?
well youll ideally want a pre-1970 block for either the SBC or BBC engine.
keep in mind that block is now almost 50 years old you have no idea how in was stored or treated previously,
or how much internal coolant passage rust damage is hidden in the block's internal passages after all that time.

pre-1970 block casting technology tended to use MARGINALLY thicker casting's,
that the post 170 blocks with their slightly improved casting tech.
but core shift was more likely so its a bit off in its bore wall consistency,
a no-win situation, you could have thicker castings, that were slightly off-set ,
making it just as weak as a later thinner casting.
the truth here is if your intention is to bore any stock block over .030,
you should first sonic test the bore wall thickness and consistency.
that being stated, a DART or similar aftermarket WORLD PRODUCTS block,
will have a significantly thicker casting with a stronger alloy.
if your going to throw $70-$1000 plus in precision machine work into a performance engine,
your much safer financially in the long term doing that on the much stronger aftermarket or bowtie block.

http://garage.grumpysperformance.com/index.php?threads/casting-numbers-vin.93/#post-29983

http://garage.grumpysperformance.com/index.php?threads/block-choice.10472/

http://garage.grumpysperformance.com/index.php?threads/blueprinting-a-block.49/

http://garage.grumpysperformance.com/index.php?threads/sbc-cylinder-wall-thickness.7646/

http://garage.grumpysperformance.com/index.php?threads/which-dart-shp-4-0-or-4-125.3219/

http://garage.grumpysperformance.com/index.php?threads/block-choice.10472/

http://garage.grumpysperformance.com/index.php?threads/darts-new-sbc-block.47/

http://garage.grumpysperformance.com/index.php?threads/why-build-a-bbc-vs-a-sbc.1009/
 
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Have you ever bought yourself an Ultrasonic tester for checking cylinder wall block thickness Grumpy ?
It would be nice to have one.
I clicked on on of your older links.
Seen $595 price tag.
 
yeah, as usual, 90% of the infos in the sub links

https://www.chevydiy.com/build-big-inch-chevy-small-block-engines-cylinder-block-guide/

https://www.chevydiy.com/the-complete-cylinder-block-guide-for-chevy-small-block-engines/


http://www.superchevy.com/how-to/en...-big-block-casting-changes-through-the-years/

https://www.hotrod.com/articles/hrdp-1210-chevrolet-350-small-block-comparison/

http://garage.grumpysperformance.com/index.php?threads/help-with-identification.14880/#post-83702

http://garage.grumpysperformance.co...s-to-casting-numbers-and-info.632/#post-55259

http://garage.grumpysperformance.com/index.php?threads/vin-casting-info.10474/#post-44012

http://garage.grumpysperformance.com/index.php?threads/casting-numbers-vin.93/#post-29982

https://www.enginebuildermag.com/1996/11/performance-small-block-chevy-engines/
Your Old 350 Block Sucks
Written by Mike Finnegan on August 19, 2012


There’s a limit to what you can do with old-school GM passenger-car parts, and the breaking point is relatively low when it comes to the Gen I small-block Chevy cylinder block. Sure, you can bore the block to within an inch of its life and fill the water passages with concrete before stuffing a 4.00-inch stroker crank into it and make decent power for a while. The fun won’t last long, though, when the block cracks, leaks water, or flexes enough to pinch the main bearings or lose the head-gasket seal. To find the beef of the stock 350 and the aftermarket alternatives, we had Pfaff Engines sonic-test six different blocks with 350-style main journals (some are available with 400 main journals) and standard deck heights to see how far they could be bored and how thick the decks were. We also put them on the scale and called every manufacturer to find out how much work it is to drop a big arm into each one. The results were surprising, but we are savvy small-block Chevy shoppers now.

Dart Machinery SHP

Model PN 31161211
Block Composition SAE grade G3000 cast gray iron
Bore 4.120-inch (unfinished); 4.165-inch max
Maximum Stroke Clearance 3.750 out of the box using steel rods; 4.000 with some pan-rail clearancing and a small base-circle camshaft (0.900 diameter)
Deck Height 9.020 inch
Deck Thickness at Thinnest Point 0.430 inch
Maximum Recommended Horsepower 600
Weight 170 pounds
Price $1,578.57 from DartHeads.com
hrdp-1210-Chevrolet-350-Small-Block-Comparison-04-Dart-Machinery-SHP.jpg


Chevrolet Performance


Watch SBC Dual-Plane Shootout
Model PN 101051237 late-model, one-piece rear main seal (adapter available for two-piece seal)
Block Composition Cast iron
Bore 4.040 inches (stock bore is 4.000 inch)
Maximum Stroke Clearance 3.750 inches with steel rods
Deck Height 9.020 inch
Deck Thickness at Thinnest Point 0.456 inch
Maximum Recommended Horsepower 360
Weight 157 pounds
Price $789.95 at SDPC.com
hrdp-1210-Chevrolet-350-Small-Block-Comparison-09-Chevrolet-Performance.jpg


small_block.gif

https://www.chevrolet.com/performance/engine-components/small-block/production-based-blocks

SMALL-BLOCK PRODUCTION BASED BLOCKS
10243869
ORIGINAL 305 V-8 PRODUCTION BLOCK (RE-INTRODUCED FOR SPRINT CAR SPEC RACING)

cp-2017-site-components-sb-production-based-blocks-image-01-02.jpg

cp-2017-site-components-sb-production-based-blocks-image-01-01.jpg

cp-2017-site-components-sb-production-based-blocks-image-01-02.jpg

cp-2017-site-components-sb-production-based-blocks-image-01-01.jpg

cp-2017-site-components-sb-production-based-blocks-image-01-02.jpg

  • Original, standard-bore block
  • Uses production Small-Block components
  • Fully machined
  • Original 2-bolt cast-iron main cap design
10105123
350 BARE BLOCK (1986 – LATER STYLE), 1-PIECE REAR MAIN SEAL

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  • Cast-iron 4-bolt block
  • 4.000” bore
  • Machined for hydraulic roller or flat tappets
88962516
383 BARE BLOCK (1986 – LATER STYLE), 1-PIECE REAR MAIN SEAL


  • Cast-iron 4-bolt block
  • 4.004” bore
  • Torque plate honed
  • Clearanced for 3.800” stoker crankshaft
  • Machined for hydraulic roller or flat tappets
10066034
350 BARE BLOCK (PRE-1986 STYLE), 2-PIECE REAR MAIN SEAL


  • Cast-iron 4-bolt block
  • 4.000” bore
  • Can be used for 302, 327, or 350 engines
 
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We can't even use a Big shot of Nitrous Grumpy in Ricks T-bucket 400 SHP Block engine. Be past 600 Hp rating.

Dart Little M is expensive now.
SHP a Good value not high Hp.

Big Blocks for Fast Drag Race.
 
rick would have zero issues with a 100hp-200 hp shot of giggle gas.
in that engine, but he should easily run low 11 second times,or better,
even without any nitrous once the suspensions sorted out.


even if the T-bucket weights about 2200 lbs with a full tank of fuel
and Rick in the car he should have at near 400 rear wheel hp

http://www.wallaceracing.com/et-hp-mph.php
 
rick would have zero issues with a 100hp-200 hp shot of giggle gas.
in that engine, but he should easily run low 11 second times,or better,
even without any nitrous once the suspensions sorted out.


even if the T-bucket weights about 2200 lbs with a full tank of fuel
and Rick in the car he should have at near 400 rear wheel hp

http://www.wallaceracing.com/et-hp-mph.php
100 +500 =600 .
200 + 500 = 700 Hp.

We have Theory.

Then we have Street Drag Racing Grumpy.
Where it's at .
 
rick would have zero issues with a 100hp-200 hp shot of giggle gas.
in that engine, but he should easily run low 11 second times,or better,
even without any nitrous once the suspensions sorted out.


even if the T-bucket weights about 2200 lbs with a full tank of fuel
and Rick in the car he should have at near 400 rear wheel hp

http://www.wallaceracing.com/et-hp-mph.php
Don't forget about the Weld in Rollcage Rule for T-buckets and convertibles like my 87 C4 Vette Roadster. Fastest you can run in both is 13.50 ET without.
 
at times you have to wonder what some guys are thinking...
one of the guys I know locally had built a 496 BBC stroker engine about 6 years ago
, his water pump failed and as a result, he cracked a cylinder wall when the block overheated,
now he used a standard O.E.M. chevy mark VI late block, with a one piece rear seal, bored .060 over standard bore diam.
the machine shop he brought the block too quoted him.. almost $1980 total price ,
parts and labor to machine the block and install the replacement bore sleeve.
yes that inclueded two new connecting rods and two new, pistons, all new rings, and bearings and a gasket set.
having the crank polished, and block sleeved and decked.
but its just block repair and a few parts, he would be the one doing the reassembly,
personally I think Id be looking for a replacement block, (most likely a DART block)
as the majority of the quote related to block machine work.
yeah, no question, its several hundred dollars cheaper to have the existing block re-sleeved and repaired,
but once its repaired will he be sleeping as well as if he found a replacement O.E,M. block or upgraded to a
DART performance block.

http://garage.grumpysperformance.com/index.php?threads/sleeving-a-block.1516/#post-68903

https://www.hotrod.com/articles/how-to-sleeve-an-engine-block/

http://www.superchevy.com/how-to/engines-drivetrain/1804-re-sleeve-save-matching-numbers-block/

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/#post-7077

http://garage.grumpysperformance.com/index.php?threads/thrust-bearing-wear.619/#post-10925

http://garage.grumpysperformance.com/index.php?threads/another-496bbc.5123/#post-15557

http://garage.grumpysperformance.co...-about-your-potential-dream-bbc-combos.14607/
 
I honestly don,t understand how some people blindly trust other people they have never met or talked with,
If your shopping for used parts, having a list of casting numbers in a reference book and a couple precision measuring tools,
would sure help reduce the number of times junk is passed off on inexperienced guys,
when they are about to spend hundreds of dollars on an engine block, with a totally unknown or verifiable history or its condition is virtually unknown.
this guy paid $340 for what might be an un-useable block...its certainly at .060 at or near its max bore diameter/
one of the local guys was visiting a local car show and asking around trying too find , big block chevy performance parts at bargain prices.
he was shown a bare block and told it was a 454 high performance engine block,
it turned out to be a low performance 427 block that was already .060- over the stock bore size
the block was freshly pained bright orange and only who knows if the fresh paint conceals cracks,
but the bores look in reasonably good condition, and freshly honed,
my guess is the guy had the local machine shop bore and hone the block,
but the owner was told the bore walls were marginal, so he decided to sell the block rather than proceed with further machine work.
of course, the previous owners phone number , who guaranteed the block was (LIKE NEW) is invalid, and he has zero recourse if the blocks junk....
I strongly suggested he have the block sonic tested and professionally inspected after a good cleaning.

http://www.tooltopia.com/fowler-72-646-300.aspx


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http://www.tooltopia.com/fowler-72-646-300.aspx








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CAREFULLY
.. reading links and SUB LINKS is almost mandatory on this web site!
if you want all available useful related info

http://garage.grumpysperformance.co...earances-and-journal-surface.9955/#post-38385

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/#post-26440

http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/

http://garage.grumpysperformance.com/index.php?threads/can-you-reuse-bearings.5544/

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-68194

http://garage.grumpysperformance.co...in-height-compression-height.5064/#post-66240

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.com/index.php?threads/assembly-lube-summary.6352/#post-68508

http://garage.grumpysperformance.co...ear-articles-you-need-to-read.282/#post-57371

related threads

http://garage.grumpysperformance.com/index.php?threads/vin-casting-info.10474/#post-44012


http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-68876

http://garage.grumpysperformance.co...-state-muscle-or-project-car.4318/#post-18620

http://garage.grumpysperformance.co...nk-durring-short-blk-assembly.852/#post-21611

http://garage.grumpysperformance.co...-state-muscle-or-project-car.4318/#post-18620

http://garage.grumpysperformance.co...c-piston-ring-info-youll-need.509/#post-12277

http://garage.grumpysperformance.co...ing-piston-to-bore-ring-seal.3897/#post-10316
 
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https://www.ebay.com/itm/182156058501?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

http://garage.grumpysperformance.co...-bragged-about-in-this-big-block-chevy.15931/

https://www.amazon.com/TM-8811-Ultr...ocphy=9012039&hvtargid=pla-570103806143&psc=1

https://www.ebay.com/itm/1PC-AR850-Digital-Ultrasonic-Wall-Thickness-Gauge-Meter-Tester-1-2-225-0mm-SPK2/263252405488?_trkparms=aid=555018&algo=PL.SIM&ao=1&asc=20131003132420&meid=5135251171ce4ea7b652b6b6d3b5a899&pid=100005&rk=5&rkt=12&mehot=co&sd=182156058501&itm=263252405488&pmt=1&noa=0&pg=2047675&_trksid=p2047675.c100005.m1851

http://arengineering.com/tech/how-to-sonic-checker/

Sonic Checking Your Block

Author Andy Finkbeiner Photos Ron Valera

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Modern technology is great for us hot rodders. A few years ago, you practically needed a top security clearance before you could get your hands on technology like this. Now you can whip out the VISA card and order yourself a sonic checker like the one shown above.

Sonic checking is a fairly common term in the engine building business but many people might not fully understand just what it is all about. When the engine builder asks if you want to spend another $75 to have the block sonic checked, some people might think he is just trying to get more money from you. Actually, the engine builder is probably trying to save you from wasting a lot of money on a block that might not be any good. After all, most of the engine blocks in our musclecars are at least 30 years old now and have been through a lot.

Sonic checking is a method for measuring material thickness when you only have access to one side of the part. For instance, if you want to know how thick a cylinder wall in an engine will be, you would have to cut a hole in the wall in order to use a pair of calipers. The sonic checker is able to measure the thickness by sending out a sound wave and then measuring the time that it takes for the sound wave to get to the other side of the wall. Modern electronics allow this complicated task to be accomplished in a hand held device.

How thick the cylinder walls need to be is a fairly difficult question to answer but we do have some clues. Most production V8 blocks have cylinder wall thicknesses that range from 0.090 to .250 thick. Ford motors tend to be the thinnest while some Chevy blocks are the thickest. The thickness of the cylinder wall becomes more important as you start to make more horsepower, so a block that works in a passenger car application might not be suited for Winston Cup duty. If you can find a production block that is at least 0.200 thick on all cylinder wall thrust surfaces you’ve found a good one. Walls that thick should be good for at least 500 or 600 horsepower. If you’re going to be making more power than that then it is probably best to step up to a factory race block. Typically the race blocks are designed to maintain a 0.250 thick cylinder wall at the maximum overbore. They might start out with a wall thickness close to 0.400 as delivered.









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Here is the sonic checker from Dakota Ultrasonics. This unit sells for $990 and is designed to be used for various automotive tasks. It can measure thicknesses from 0.025 to 20 inches in a variety of materials but is especially good at measuring cast materials.

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Here is where you really need a sonic checker! Nine engine blocks to choose from but which one is the best? A sonic checker allows you to examine each block for core shift and casting flaws. Obviously, what you want to do is to pick the block with the least amount of core shift. Minimum core shift will be indicated by having fairly consistent thickness measurements for each cylinder.



Contact Information:

Dakota Ultrasonics

1650B Mansfield Street

Santa Cruz, CA 95062

(831) 465-8585

http://www.dakotainst.com/
 
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