Planning a new 383 build that is now going to be a 400

Re: Planning a new 383 build!

the dog bone , roller lifter ,retainer is supposed to stay in place, just above the lifter bores, but its got a strong tendency to move with the lifters hence the required retention spider spring.
If your planing on exceeding about 400-430 hp, based on use of a standard production sbc engine casting build-up, and BEFORE you spend a good deal of money in machine work on a stock OEM PRODUCTION block, you might want to know the stock block castings are not ideal, FROM A STRENGTH STAND POINT,yes we all know a dozen guys who swear they built 500 hp sbc combos using a stock block as the basic block,but maintaining 500 hp for a few seconds on a dyno, to verify its peak power level, is not the same as beating on the engine frequently on a near constant basis, in a semi race application, stress is cumulative! what they don,t admit ,or realize is that the the blocks designed for low cost production ,not high performance strength, the main caps have a tendency to flex the cylinder walls don,t remain rigid at near max torque loads and the block was designed to operate at or below 5500rpm at or below 400hp
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!
Feeler-Gauge.jpg

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Re: Planning a new 383 build!

grumpyvette said:
the dog bone , roller lifter ,retainer is supposed to stay in place, just above the lifter bores, but its got a strong tendency to move with the lifters hence the required retention spider spring.
Click to expand...
The reason I was asking is this engine isn't going to turn more than 5500. But it is going to have a lift over 500, if the retainer does move, can it be kept in place my a spider spring that is stronger? I am just wondering, I am thinking about designing a spider that can control that movement and keep the lifter orientation from moving. If the spring that holds the retainer was thicker and made of Stainless, it may control that movement and I was possibly thinking of drilling a hole in the spring, drill and tap the retainer dogbone, possibly use a long enough bolt to raise the dogbone a lil to allow for the movement you spoke of above. Not raising it much, say 1/32 or 1/64 of an inch. I am just brain storming here, maybe it done before and didn't work, maybe not. 1/32 is just .031 and 1/64 is .015, I am thinking thats all.
 
Re: Planning a new 383 build!

why go thru the work, and effort when the retrofit rollers with the link bar are a decades old and well proven system, thats known to work!
keep in mind the factory dog bone design was meant to be cheap, and easy to install, but it was never designed to run under near the rpm or stress levels or at anywhere near the valve lift range that the link bar design has been well proven to handle .
there,s not a single cam manufacturer I know of that suggests using the factory link dog bone and spider retainer on the more aggressive performance cams ,or higher rpm applications, higher lift cams.
yes the factory lifters and lifter retention system is perfectly adequate below about .520 lift and yes it does mater , to the engines long term durability what cam lobe design and valve spring load rates and valve spring installed heights are used.

luntihylift.jpg

retrohydraulicrollerlifters.jpg
 
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Re: Planning a new 383 build!

I was just thinking outloud, if the dogbone isn't capable of handling the stress in a performance engine I will nix the idea.
 
Re: Planning a new 383 build!

Ive seen several fast cars that used the stock dog bone lifters but Ive seen far more failures with the stock vs the aftermarket lifter designs, so I NEVER use the stock, dog bone lifters
 
Re: Planning a new 383 build!

Does anybody know if all the Main caps on Dart's SHP block are the 7/16 bolts/studs, or are the middle 3 caps smaller on the outside bolt/stud? Am compiling a list of parts and need to make sure I am getting the right studs for the mains. We haven't decided on the block yet, whether to use a Chevy bowtie, Dart SHP, or the World Motown block, I know the bowtie has 3/8 bolt/stud on the middle 3 outer caps, the motown has 7/16 bolts on the middle 3 outer caps, but the SHP blocks I don't know about all the info online doesn't say.
Bob
 
Re: Planning a new 383 build!


The main caps 2, 3 and 4 have 3/8" bolts on the outside.

All the other main cap bolts are 7/16"

 
Re: Planning a new 383 build!

get the DART block, Ive yet to see a bad one but Ive seen a few world blocks with machine work issues
READ THRU THE LINKS
ITS VERY LIKELY TO HELP SAVE YOU MONEY< AND AVOID EXPENSIVE PROBLEMS
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when a blocks cast and then machined its almost unheard of for all the cylinder bore walls to be both equal or have the bore center line centered in each cylinder sleeve. the result is that its typical for the cylinder wall to vary in thickness from side to side and from top to bottom, having a cylinder wall in a stock production block casting thats .230 thick at one point but taper to .110 is hardly rare, so you need to have the blocks cylinder walls sonic tested. thin sections near the lower end of the cylinder are a bit less critical because theres a bit less heat generated there and a block can have the coolant passages filled with either epoxy and steel shot slurry or concrete to add support to the lower cylinder wall without compromising a great deal of the engines ability to transfer heat to the coolant as about 80% OF THE HEATS GENERATED IN THE CYLINDER HEADS AND UPPER 2" OF THE CYLINDER BORE.
the DART blocks are designed with much thicker castings and use a stronger alloy of cast iron, both add considerable strength

read these related threads

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Re: Planning a new 383 build!

Okay, Tommy went and did what I told him not to, bought a block. Its a Chevy Bowtie, but I think we lucked out, from the casting number H-D 10051184, it looks like a Bowtie Sportsman with 350 mains. I found this online :


12480047 Block, Bow-Tie Sportsman "350 Main Size"
This iron block is fully CNC machined from the H-D 10051184 casting. It has siamesed cylinder walls, cast nodular caps, four bolts on all five main caps; the outer bolts on the three center main caps are splayed 20 degrees. Grade 8 bolts secure the caps. It features priority main oiling and 9.025" deck height. The blocks come finished bored at 3.980" and the maximum recommended bore is 4.150". This block features a two-piece rear main seal; "350" main size (2.45"). It features lifter bore heights (.842"), same as P/N 24502503

I did look and it does have the four bolts on all the main caps, but I do have one question. With the bores being siamesed I will need to have the 400 steam ports drilled in the heads won't I?
With this block being saimesed, what is a acceptable wall thickness Grumpy
 
Re: Planning a new 383 build!

busterrm said:
With the bores being siamesed I will need to have the 400 steam ports drilled in the heads won't I?
With this block being saimesed, what is a acceptable wall thickness Grumpy
Click to expand...

I found this on AFR's website, looks like it pertains to your question.

http://www.airflowresearch.com/sbc_faq.php#400blocks

4) 400 Blocks:

Steam holes are recommended for all 400 block applications (GM blocks only). Use a 400 Gasket as a template and drill the three holes, nearest the spark plug side of the head, straight down. The other three which are very near the head bolt holes should be drilled at a 30° angle away from the bolt hole. The center hole will intersect water about 1" down and the two outboard holes to a depth of 2 1/4". Use 1/8 drill.

But then Brodix says "No"

http://www.brodix.com/faq/faq.php

Q. Do you recommend steam holes on BRODIX heads?
A. No, the BRODIX water jacket is more efficient than previous heads. Just make sure all holes are properly lined up and drilled in head gaskets to efficiently pass water.

 
Re: Planning a new 383 build!

Hey Rick, do you have a spare 400 head gasket? I know that your engine is assembled, but thought you might have spare! I am going to have to buy a set of steel shims for the quench to be correct on this engine. I was hoping you might have an extra I could use for a template. I will probably use it to also drill the gaskets I buy, unless I can get them with the steam holes already in them. I did some research on the wall thickness, and we have couple thin spots but they are still thick enough to be safe. The sonic test report show that all cylinders are good half way up the bores, thinnest spot in the middle is .246 in the number 4 hole. Thinnest spot at the top of the bores is the number 8 hole at .249. At the bottom of the bores number 3 is .232 and number 6 is .229. So we are good with the bores as far as thickness is concerned, the mag testing is negative for cracks, cam bore was honed, main bores were honed also, lifter bores were all honed and within specs. The pan face was trued up, the tranny was trued up also, along with the timing cover face. It has the lifter valley machined for roller cam, and has the spots at the cam tunnel entrance for an roller cam retainer. So, I guess I will have to drill and tap those for the retainer plate. I am unsure about the decks, the deck was taken to 9.01, I may just take it to my machine shop and have it zero decked so I can buy a standard head gasket. That is still up in the air though.
 
Re: Planning a new 383 build!


No, the only head gaskets I bought were the SCE copper .021" thick and I used them. SCE says to use them with an O-Ring, but I installed them with the Permatex Copper Spray. Grumpy has done this many times without any failures.

Your wall thickness sounds good, my first block bored .060" over had a wall thickness .064" in one location.

Why would you have to mill off .010" so you can use standard head gasket? They come in so many different thicknesses.

 
Re: Planning a new 383 build!

yeah, and it would justchange the compression atad, it can play in your favor depend upon the piston and head's chamber size and your compression ratio goal.
i try to avoid decking block, so there is some more room for valve to piston clearance"big lift".
I have a spare 350 gasket if need be, but no steam hole i guess.
 
Re: Planning a new 383 build!

Not actually going to do it, just a thought. Grumpy sent me a link where I can get a .028 shim gasket, and with that I will use the copper gasket spray. Was wanting quench to be 42 , but can't find any .032 gaskets, the .028 grumpy put me on is the closest. Quench will be .038 with that one. I may not do anything Rick. I was just wanting to use composite gaskets instead of a shim head gasket.
 
Re: Planning a new 383 build!

busterrm said:
Not actually going to do it, just a thought. Grumpy sent me a link where I can get a .028 shim gasket, and with that I will use the copper gasket spray. Was wanting quench to be 42 , but can't find any .032 gaskets, the .028 grumpy put me on is the closest. Quench will be .038 with that one. I may not do anything Rick. I was just wanting to use composite gaskets instead of a shim head gasket.
Click to expand...

They are expensive, but SCE does have copper head gaskets that are .032"

http://www.summitracing.com/parts/sce-0 ... /chevrolet
http://www.summitracing.com/parts/sce-t ... /chevrolet


 
Re: Planning a new 383 build!

you never asked for a link to a .032 chevy small block head gasket, you asked for a .028 gasket
BTW, When a head gasket thickness is listed its supposed to be the compressed gasket thickness
keep in mind it assumes you use the factory heads with the matched factory head bolts torqued to the factory suggested torque settings,this can be important in determining quench distance.


.028
http://www.summitracing.com/parts/NAL-10105117/


.030
http://www.summitracing.com/parts/cgt-c ... /chevrolet

.032

http://www.summitracing.com/parts/sum-1 ... /chevrolet

.036
http://www.summitracing.com/parts/cgt-c ... /chevrolet

http://www.gmpartsdirect.com/performanc ... D=697.html

.038
http://www.speedwaymotors.com/Super-Sea ... ,1587.html
 
Re: Planning a new 383 build!

I guess I am searching those sites wrong or something, I always get limited results. Thats what this forum is for I guess.
 
Re: Planning a new 383 build!

Block is here(we've had it but was at mach shop) had the machine shop check all the stuff. Boring of the cylinders is fresh, with the sonic testing he got with the block I feel confident we have a good block. Mains are straight, decks are square, lifter bores are good. This block has all five mains with four bolts. We have decided on a crane roller cam for it. Even though we have aluminum heads, I wanted to keep the dynamic CR down around 8.25, some of the cams we have been looking at were pushing it up in the 8.35-8.45 range. The rotating assembly is going to be forged he kept wanting to go cast steel and I pushed him to decide on forged. It should be here in the next week or so. The block is already clearanced for 3.75 stroke but I am going to do a mock up assembly when the cam gets here to check all the clearancing points. The rod and main bearings are going to be clevite coated bearings.
Hey Rick when you did your 400 did you use plastic gauge on both sides of each bearing to check the journals? What I mean is, did you check on the rod and block sides then on the rod caps and block caps? With the bore we have I am going to get a ID mic from work and check the bore and pistion sizes for clearances. Will check the pistons with my standard mic. With the crank and rods being new I suspect my clearances are going to pretty close like they should be, but going to check them anyway.
Once we check all the block clearances and bearing clearances, off to the machine shop for rotating assembly balancing.
 
Re: Planning a new 383 build!

Oh yeah, they asked me if I wanted a mock up to check the deck height, so I agreed. I use this machine shop all the time and they didn't charge me for it, so I thought I'd get their opinion and then do my own when we do the mock up assembly with our rotating assembly. They came up with a . 010 in the corner bores. So I can go with .028 or .030 to get my quench in the ballpark. But, I will do a check on all the cylinders when I do the mock up assembly.

It looks like the Crane Hyd roller 119831 is going to be our cam. With our SCR of 10.67, DCR will be 8.23, which is right about where I wanted it to be. We are still undecided on the heads, The are going to be AFR 195cc/65cc, but I want the comp version and he wants the street version.
With our cam decided, I just feel we will get better performance with the comp heads flow rates at full lift.
AFR 195 street:
276 at full intake
210 at full exhaust

AFR 195 comp:
288 at full intake
227 at full exhaust

DD2000 rates it at 494/483hp @6K and 487/475tq @ 4.5K, I factor in a 3% high puts us at about 480hp/473tq with comp version, and 468hp/460tq with street version heads.

With the flow and the comp heads having 2.08 intake valves I just feel it will perform better and breath more efficiently.
 
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