Installing splayed caps

I have been asked about the installation of splayed caps many times over the years. First of all this proceedure can be done in a Bridgeport, knee mill, CNC machine ETC.

I use flat bottom caps with 10 degree angle outer bolts because with the 10 degree outter bolts you should not get into the water jackets. I have had many calls about outter bolt holes getting into the water jackets only to find out its because of the 18 or 22 degree outter bolt holes.

Alot of classes out there are restricted to run OEM blocks and most racers like the weight savings of the OEM block and 383's we are now seeing over 500 plus HP and with the added stroke its best to go to a splayed center cap, Its always best to sonic test the cylinders for thickness before spending time and money on cap work.

Caps I prefer are caps from http://www.cipcoindustries.com/ or http://pro-gram.com/ Price on cipco caps are right at 160.00 a set Programs are right at 210.00 a set.

First process is to cut the register either with an end mill or I use a 2.5 shell mill on 2 bolt blocks the register has to be only cut appox. .120 deep measure of the pan and on 4 bolt blocks the register have to be cut appox. .140 deep. I like to see a .003 press fit. Both companies use a 10 degree outer angle.

READ THIS THREAD AND SUB LINKS
http://garage.grumpysperformance.com/index.php?threads/which-dart-shp-4-0-or-4-125.3219/#post-44637
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Next step is using a 1/2 in end mill at a 10 degree angle is to mill a flat spot.
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Next is to center drill
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Next drill holes using a the letter U drill appox. .800 deep
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Next would be taping with a spiral tap seems to work best.
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Line boring can be done with a line boring machine or I use the PLB-100 which seems to very fast and accurate, I cut the housing bores close to size.
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Once line boring is complete the caps are taken off and cut appox. .0025 to .003 off the bottom then then reinstalled and aligned honed to the last .001 caps are loosened retorqued to check for size and hone to size.
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Finish product
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Note: On the Cipco caps they are OEM height and you can use an ARP bolt kit and on the Porgram caps they are appox. .200 taller and would require a stud kit.

Hope this thread answers most questions about cap installation
 
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thanks for posting ,its sure to be useful, and the pictures are most welcome

http://www.jegs.com/i/PRW/228/1735002/10002/-1

http://www.competitionproducts.com/Main-Girdles/products/1073/

http://www.competitionproducts.com/Main-Caps-Main-Girdles-and-Valley-Girdles/departments/883/

http://www.jegs.com/i/PRW/228/1740002/10002/-1

http://www.jegs.com/i/Coleman-Racing-Products/193/C-307/10002/-1

http://www.ebay.com/itm/like/381470210584?lpid=82&chn=ps&ul_noapp=true

https://www.summitracing.com/search/product-line/milodon-main-cap-kits
http://www.superchevy.com/technical/eng ... main_caps/

http://garage.grumpysperformance.com/index.php?threads/block-choice.10472/#post-45976
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On oil pans I prefer studs, and an oil pan back plate
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you might want to Use with P/N 12553058 RH and P/N 12553059 LH oil pan reinforcement plates to distribute the bolt stress on the oil pan rail for 1985 and earlier oil pans P/N 14088501 (LH) and P/N 14088502 (RH).1986 and newer
I found these really rather good photos posted on the internet, of some of the machine work required for a well built engine

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splayed man caps on dart block
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honing lifter bores
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WELL HONED BORES TO QUICK RING SEAT LAPPING, and a good sealing surface
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BALANCING CRANK
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MAINS LINE HONED
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DECK PLATE HONE
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Ive occasionally been asked what you can do too reduce the slack in the timing chain if your blocks been line honed,
to straiten the main bearings and that resulted in a slightly closer crank to cam center-line distance,
that results in a slightly increased slack in the stock timing chain sets.
a negligible amount of metal is generally removed from the main bearing saddles in the block, they usually try very hard to minimize that, metal removal so standard parts still fit,during a line hone , but they do sell slightly tighter timing chain sets to correct excess slack if that's required.
SBCprintCustom2.jpg



cloyesunder.jpg


https://www.summitracing.com/parts/clo-9-3100-5
Timing Chain and Gear Set, Original True Roller, Double Roller, -0.005 in., Iron/Steel Sprockets, Chevy, Small Block, Set
for line honed blocks where the crank is .005 closer to the cam


https://www.summitracing.com/parts/clo-9-3100-10
for line honed blocks where the crank is .010 closer to the cam
Timing Chain and Gear Set, Original True Roller, Double Roller, -0.010 in., Iron/Steel Sprockets, Chevy, Small Block, Set
 
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I really appreciate advice from CNC. I have seen their posts on Dart's board, here, their own site as well as others. I will definitely choose to do business with outfits that provide support like that.
 
Crepitus said:
I really appreciate advice from CNC. I have seen their posts on Dart's board, here, their own site as well as others. I will definitely choose to do business with outfits that provide support like that.

I don't much cap work any more since the Dart SHP blocks came out a few years ago.

This block is out a 76 Corvette which had a steel crank in and the rods were standard and mains were .009 under right from GM ( Not the first time I have seen this)

The block has been zero decked and I left the VIN numbers on the stamp pad bored and plate honed and I will be using the Dart 180 Pro-'s and a hyd. roller and looking for appox. 425 horse thtas why the splayed caps.

The Dart SHP blcks I machine need work

I at least line hone to the middle of the spec

Deck to zero

Bore if needed and plate hone

Chamfer the freeze plug holes and rear cam plug hole

Check and hone lifter bores as needed

Chamfer mian housing bores.

Tap oil galley holes deeper

Most builds I do up grade t main studs

All the solid roller cam builds I go to .903 lifters period.
 
its not all that un-common to find a cracked or damaged main bearing cap on a used or bargain block at a flea market or garage sale.
you obviously can,t use it that way, but replacement main bearing caps you can usually find on EBAY are available from guys that damaged block bore walls extensively or had blocks that can,t be bored any larger, due to excessively thing bore walls etc.
now splayed main caps offer superior strength, but obviously they cost more for your machinist to correctly install (not a great deal more because both will need line hone & index work)
Most of us learn by making mistakes, and you can be sure I made my share, and learned a good deal from each,
the first really serious SBC engine, back in the 1970s I built forced me to learn all about how crooked , and back-stabbing the machine shop I was dealing with at the time was.
I dropped off my nearly new 350 block and asked them to deck it 10 thousands, add splayed main caps , line hone and install new cam bearings and freeze plugs,
I was given a written estimate for a total of $480 for the work, which I foolishly paid up front, and told it would be 3-4 days.
a couple days later I called to see if it was ready to be picked up...they had not done much yet, but promised, it would be done in 3-4 days.....2 weeks later I get a call,
and the counter gal says were done, come pick it up, I was billed $870 -$480, or $390 MORE,
and they obviously billed me for decking the block which they had not done as you could easily still see the old gasket dis-coloration on the block,
not only that, the splayed main caps had obviously not been line honed,as they showed no honing marks, I pointed those little discrepancy's out ,
and was told if I wanted my block back the cost was $590 regardless.. I foolishly paid, got my block and left as I knew I was already out $480
I rarely build or suggest any serious 450 hp, plus SBC be built on a O.E.M. block
the first few rule's of GRUMPY'S engine assembly

(1) THINK THINGS THROUGH CAREFULLY ,
WRITE DOWN A LIST OF COMPONENTS ,
MAKE DARN SURE THE LIST IS COMPATIBLE WITH,
and AT LEAST SEMI-REASONABLY PRICED WITHIN YOUR BUDGET.
FOR WHAT YOU INTEND TO BUILD AND RESEARCH THE RELATED MACHINE WORK,
RESEARCH CAREFULLY THE COMPONENT INSTALLATION AND INTENDED USE ,
AND POWER BAND THE PARTS WILL REQUIRE
AND FIND AN EXPERIENCED MENTOR.

(2) if in doubt, about how to do anything, on an engine, do some detailed research,
find and compare at least 3-5 valid trust worthy sources info,
read the instructions over again, several time's very carefully
and if available watch several related videos.

(3) if any component will not easily function as designed or requires a good bit of physical force to install ,
or your not 100% sure your doing something CORRECTLY
STOP, FIND OUT EXACTLY HOW THE PARTS SUPPOSED TO FIT AND FUNCTION,& WHY! YOUR HAVING PROBLEMS
theres a reason, and you better verify your clearances are correct , and your following the instructions before you proceed.

(4) never assume the parts you purchased can be used without carefully , cleaning them prior too,
checking the physical condition, verifying clearances and using the correct sealant, lubricants etc.


(5) the quality of a component is generally at least loosely related to the cost to produce it,
and the amount of detailed research and quality machine work that went into its production.
if you got a significant reduced price, theres typically a reason.
it might simply be because a new improved part superseded the one you purchased,
but it might be a far lower quality imported clone with lower quality materials and machine work.
its the purchasers responsibility to research quality.

(6) if you did not do the work personally or at least take the effort to verify it was done correctly and personally verify clearances
ITS almost a sure thing that it was NOT done , correctly, and yes that mandates you fully understand what your looking at,
and how the components are supposed to function and have high quality precision measuring tools.

(7) ITS ALMOST ALWAYS FASTER AND LESS EXPENSIVE , AND PRODUCES BETTER RESULTS IF YOU,
BUY FEWER HIGH QUALITY PARTS & DO THINGS CORRECTLY THE FIRST TIME

together correctly
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http://www.harborfreight.com/36-piece-3 ... 60669.html

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related

read the links its worth your time and effort
https://www.engineprofessional.com/EPQ3-2020/mobile/index.html#p=16

http://garage.grumpysperformance.com/index.php?threads/finding-a-machine-shop.321/#post-59253


http://garage.grumpysperformance.co...ing-parts-and-a-logical-plan.7722/#post-68651

http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/page-2#post-61958

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

http://garage.grumpysperformance.co...ing-a-383-sbc-combo-planing.12168/#post-58778

http://garage.grumpysperformance.co...gine-to-match-the-cam-specs.11764/#post-55651

http://garage.grumpysperformance.com/index.php?threads/bare-minimum-tools.11026/#post-51823

http://garage.grumpysperformance.com/index.php?threads/parts-prep-cleaning.6255/#post-51146

http://garage.grumpysperformance.com/index.php?threads/383-information-overload.11137/#post-49857

http://garage.grumpysperformance.com/index.php?threads/big-block-chevy-info.710/#post-49737

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-52466

http://garage.grumpysperformance.co...ting-started-in-the-car-hobby.339/#post-60187




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just be sure what you order matches what you need, and be aware youll most likely need to get the replacement rear main cap align honed to get it to fit and the clearances correct to match the existing block its being mated too.
a good machinist that knows what hes doing will have zero issues doing that but its likely to cost a couple hundred bucks between cleaning the block, new cam bearings freeze plugs and line honing the main caps and honing the bores of the cylinders after verifying they are strait and consistent in size and have no taper, and use deck plates while honing the bores, so you may as well order ARP main cap studs that fit a windage tray while your spending the time in the machine shop
always accurately measure the crank main journals, and remember the crank and block bearing sizes on a 400 sbc and 350 smc are different as are the early 283-327 sbc

Ive occasionally been asked what you can do too reduce the slack in the timing chain if your blocks been line honed,
to straiten the main bearings and that resulted in a slightly closer crank to cam center-line distance,
that results in a slightly increased slack in the stock timing chain sets.
a negligible amount of metal is generally removed from the main bearing saddles in the block, they usually try very hard to minimize that, metal removal so standard parts still fit,during a line hone , but they do sell slightly tighter timing chain sets to correct excess slack if that's required.

SBCprintCustom8.jpg



cloyesunder.jpg


https://www.summitracing.com/parts/clo-9-3100-5
Timing Chain and Gear Set, Original True Roller, Double Roller, -0.005 in., Iron/Steel Sprockets, Chevy, Small Block, Set
for line honed blocks where the crank is .005 closer to the cam


https://www.summitracing.com/parts/clo-9-3100-10
for line honed blocks where the crank is .010 closer to the cam
Timing Chain and Gear Set, Original True Roller, Double Roller, -0.010 in., Iron/Steel Sprockets, Chevy, Small Block, Set


spacerbearing5a.jpg


ID SUGGEST USE OF ARM MAIN CAP STUDS AND SWAPPING TO BILLET SPLAYED MAINCAPS IF YOU REGULARLY WANT TO EXCEED 6400 rpm and 450 HP
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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
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if you have a two bolt main cap block and you don,t want to go to the considerable expense og having the block converted to splayed aftermarket main caps the option of adding a main cap stud girdle, and ARP main cap studs, may appeal to you as it adds a bit more block strength & rigidity, but its not going to be as strong as a aftermarket DART block or the splayed main caps and it can limit the oil pans and windage tray options

girdlem.jpg
main%20web%20crack.jpg

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OEM main caps on most blocks are cast iron and have a tendency to fracture under lower stress loads than machined steel splayed main caps,that have outer bolts anchored in the blocks thicker outer section, this can be an important consideration if you intend to use nitrous or push an engine well in excess of 4000fpm in piston speeds

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

http://arp-bolts.com/

RELATED THREADS THAT SHOULD BE READ
http://garage.grumpysperformance.co...bearing-studs-torque-stretch.9409/#post-34238

http://garage.grumpysperformance.co...4-bolts-or-stds-good-enough.10632/#post-45801

http://garage.grumpysperformance.com/index.php?threads/installing-splayed-caps.7267/#post-24723

http://garage.grumpysperformance.com/index.php?threads/decking-or-truing-up-the-block-deck.16152/

http://garage.grumpysperformance.com/index.php?threads/splayed-main-caps.1014/#post-16462

http://www.jegs.com/i/Dart/301/3277...7&cadevice=c&gclid=CMfnmqaG2tMCFUm1wAodg-4J8A

http://garage.grumpysperformance.co...eventing-leaky-head-bolts-studs.50/#post-1253

https://www.engineprofessional.com/EPQ3-2020/mobile/index.html#p=17

http://garage.grumpysperformance.co...block-cylinder-wall-thickness.976/#post-22976

http://garage.grumpysperformance.co...gine-block-main-cap-movement.6162/#post-19172

http://garage.grumpysperformance.com/index.php?threads/main-cap-fit-in-block.5945/#post-18302

http://garage.grumpysperformance.co...-help-with-main-bolt-question.2851/#post-7377
 
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