splayed main caps



splayed main caps

Postby grumpyvette » January 11th, 2009, 8:29 pm

I was asked," whats the difference between 2,4, and a splayed bolt block"

Image

on a normal chevy engine with 4 bolt main caps the caps look like this, notice the front cap is a two bolt main cap which is normal even on four bolt block where all the other caps have four bolts
the better machine shops pin or sleeve the main caps to prevent movement
Image
Image

Image

on a two bolt block all the caps look like the front cap like this block below
Image

racing blocks have SPLAYED 4 bolt main caps like this

Image

Image

Image

Image

http://www.superchevy.com/technical/eng ... main_caps/

which are even stronger

BTW you can CONVERT standard two bolt blocks to SPLAYED 4 bolt with a KIT and a MACHINE SHOP to REFIT AND HONE THE MAIN CAPS
theres MILLIONS of guys running 350 two bolt blocks with few problems, if your block has only two bolt caps you have two options, you can add ARP studs if you want to increase the caps holding strength about 30%-50% or you can convert that two bolt block to splayed 4 bolt caps if your really concerned , but unless your over about 450hp I would not be even slightly worried , if your using a standard sbc 4 bolt block with ARP bolts or studs

Image
typical two bolt cast crank 350

http://www.flatlanderracing.com/callies_maincaps.html
Image
http://www.flatlanderracing.com/maincaps_oliver.html
ARP ,two bolt main cap STUDS will work ok at the 400hp-450hp level, but are not ideal.
but heres some splayed caps, if your interested,
be aware that your going to spend between $400-$550 in most machine shops by the time you figure on the $200 for the caps themselves and added to the machine work expense, to get them correctly installed on a 2 bolt block,in your case its more than likely wasted money,because by the time you buy a 2 bolt block, pay for the machine work required too add splayed man caps and have the block decked , bored, bores honed and line honed the cost can frequently be close to the cost of a DART BLOCK with its much thicker and more rigid casting, but if you feel better knowing they are there...... well all I can say is I bite the bullet and get them installed simply because with everyone's plans changing over time and a shot of nitrous as a future option in most high performance engines they add a good deal of strength, but in the long haul the DART BLOCKS A BETTER VALUE
this is a great example of project cost creep, yes you'll more than likely NEVER use the extra strength, on most common engine builds used on the street as most of those engines true hp level unless nitrous or a supercharger is being used fall in that 450hp and under range.,and yes its more than likely wasted money,if you already have a 4 bolt block with ARP fasteners. but many of us just look at it and say, hell, its a good investment in the bottom end strength... and Ill feel better knowing their there!, the money would be better spent in almost every case on better quality rods in most cases simply because rods and rod bolts fail far more often than caps do! its insane in most cases to go to the expense of splayed caps on the block if your still running stock connecting rods, invest in good quality (H) style rods with 7/16" ARP rod bolts and a STEEL CRANK before worrying about SPLAYED MAIN CAPS
BUT I'D ALSO POINT OUT THAT AT ABOUT THE 500-550 HP LEVEL THE BASIC O.E.M. BLOCK CASTING ITSELF LACKS THE REQUIRED CASTING STRENGTH, SO THAT JUST ADDING SPLAYED CAPS IS WASTED MONEY AND YOU'LL WANT TO UPGRADE TO A DART AFTERMARKET BLOCK
DART MAKES THE CORRECT BLOCK
TALK TO THE TECH GUYS BEFORE ORDERING

http://www.dartheads.com/products/engin ... all-blocks

http://www.racenet.net/eng/arp-main-studs.php

http://www.milodon.com/instructions/mai ... d-bolt.pdf

http://www.vhrpartsandaccessories.com/s ... let/Detail
HERE the STUDS that should be used to replace the stock main cap bolts, they ate far stronger, ... don,t forget a good MILODON windage screen and a high volume oil pan, they are very important to insuring long engine life at high rpm levels



0945400 – PRW Billet Steel Main Girdle
PRICE: $ 169.50
THERES ALSO THE OPTION OF USING MAIN CAP STUD GIRDLES
Image

the better machine shops, will suggest you have the option too pin or sleeve the main caps to help prevent main cap movement
Image
Image
PRW Billet Steel Main Stud Girdle, Chevy 454, 1045 Billet Steel Girdle, including PRW steel studs, nuts & washers

PRW Billet Steel Main Girdles are engineered to help eliminate the block flex and cap walk that occurs as a result of stress while under extreme loads, including nitrous oxide power bursts in high performance engines. PRW main girdles are manufactured from premium quality 1045 billet steel. These kits include high quality steel studs, spacers and nuts. (limited machining may be required for proper fitment).
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: splayed main caps

Postby grumpyvette » April 27th, 2009, 2:52 pm

Grumpyvette: I had asked you before about the strength of a 2 bolt versus 4 bolt main SBC blocks especially those with 1 piece rear main seal. I have also spotted girdles for 2 bolt blocks and valley girdles also. Please see http://www.horsepowersales.net and evaluate and comment please about using these valley girdles and crankshaft main cap girdles concerning strenghening the block. Your thoughts please.

the first thing ID point out is that the chevy small blocks are far less prone to cracking from flexing than the ford small blocks and that anytime you exceed about 550-600hp your much better advised to use an aftermarket DART BLOCK with its much thicker cylinder walls, main webs ,and block endwalls, before spending hundreds of dollars on machine work, but the chevy block will stand up to a good deal more abuse than the sbf generally will if its correctly machined, read thru the links, JOBYs turbo build on a STOCK short block lasted for quite awhile under higher loads
Id bet 90% of the guys building a SBC based engine never give the basic block or foundation strength a second thought UNTIL they find out thru part failure that the basic OEM blocks are just not meant to be rigid and solid enough to allow you to build an engine that exceeds about 500hp without expecting it to eventually have major problems.
The reason so many people get away with using stock OEM blocks is BOTH that darn few SBC engines that people claim make 500 or more horse power actually do, and many that do are seldom run in the rpm range where they make that power level for more than a couple seconds, at a time. you really see the way the stock OEM block casting flexes in applications like stock car racing , where the stress is prolonged and the main caps tend to be subjected to more repeated and higher stress.[/b]

READ THRU THESE LINKS

viewtopic.php?f=51&t=6162&p=19172&hilit=main+caps+dowels#p19172

viewtopic.php?f=86&t=3203&p=8527&hilit=girdle+caps#p8527

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

viewtopic.php?f=51&t=7646
lets put it thisway, Ive built over 175-200 engines in 39 years and Ive never seen a block crack thru the lifter gallery unless it was the result of a rotating assembly grenading and that was usually at over 6000rpm, with obsurd levels of nitrous used, chevys crack cylinder walls, main caps, main cap webs, and decks on occasions but even the stock chevy blocks take alot more abuse than stock sbf seem to from what Ive seen
Image
cleaning up the threaded holes is mandatory if you want consistent clamp loads
http://www.dartheads.com/products/engine-blocks

http://forum.grumpysperformance.com/viewtopic.php?f=69&t=636&p=850#p850

http://www.adperformance.com/index.php?main_page=index&cPath=69_82&zenid=0aaf0a17ddbd33634a85e31f4062f2a0

http://forum.grumpysperformance.com/viewtopic.php?f=51&t=47&p=56&hilit=+dart#p56

http://forum.grumpysperformance.com/viewtopic.php?f=51&t=439

viewtopic.php?f=51&t=5945

http://forum.grumpysperformance.com/viewtopic.php?f=51&t=976

Image
Image
Image
Image
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
the better machine shops pin or sleeve the main caps to prevent movement
Image
Image
PS, what does that lifter valley brace really do that the correctly bolted in place chevy intake maninifold not do, IE, it prevents the cylinder banks from easily flexing thru the lifter gallery
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: splayed main caps

Postby grumpyvette » February 16th, 2011, 8:21 am

I was recently asked if adding SPLAYED 4 bolt main caps Image

to a O.E.M. 2 bolt block,Image


Image
was a good worth while upgrade, this is one area where experience teaches you a few things
the short answer is that the route you take depends on both your budget and GOALS for the engine.
adding splayed main caps to a standard 2 bolt O.E.M. block does significantly strengthen the clamp loads holding the crank in place with those main caps, if your main caps on the block move under high stress loads the bearings take an exceptional beating , tend to loose oil pressure and cooling and eventually will fail but your still anchoring the main caps to a significantly WEAKER and thinner block casting made from weaker cast iron alloy and main block web area compared to an aftermarket block like DART sells.
main caps with inner sleeved main cap bolts tend to have much reduced main cap movement under stress.
a O.E.M. SBC block will frequently have cylinder walls that are less than .100 thick with a .030 over bore while a dart block will still have a .250 cylinder wall thickness with the same bore size
the cost of adding main caps will vary a great deal in machine costs but main caps alone cost about $160-$270 , mandatory main studs and splayed side bolts add an additional $150 or so, then the machine work can easily add $350 or more, so your looking at a cost of about $750--$850 in most cases, and your still dealing with a thin cylinder wall casting and weak main block webs.
don,t forget that when ordering main cap studs you'll want the ARP main studs DESIGNED to mount a windage screen with the stepped extensions that allow you to adjust the windage screen to be 1/8" from the rotating assembly arc.
yes IM well aware we all know some guy, some place, whos been pulling well in excess of 550hp while using a O.E.M block, and yes that's been done all the time, but stress is cumulative, and pulling 550-600hp a couple times on a dyno for bragging rights or racing once or twice a year is not nearly the same thing, as lets say an engine thats used almost weekly at the strip, or a guy whos using a 150 shot of giggle gas (NITROUS) on his 400hp street engine or a circle track car where the average rpm levels and duration of stress is far longer, if you talk to those guys youll see far more main cap fretting, bearing wear, and bearing problems...its not like a block will always fail if subjected to 550hp, its that its on borrowed time, because it was designed to handle 350-400hp and yes there a safety margin in strength built in, but time stress and casting variations WILL eventually detect the flaws, thru component failures that are far less likely to occur with the stronger block castings

now if your only going to try to strengthen the block and reduce main cam movement at the 450hp-500hp level that most street sbc engines see only occasionally because you spend 99% of your time well below peak rpm levels this is a worth while addition to block strength, but if you going to add a heavy nitrous shot, a turbo or supercharger that adds significant cylinder pressures its basically throwing $700 plus in the dumpster in my opinion, that $700 PLUS would be FAR BETTER SPENT on a significant part of the price on a good aftermarket block, especially if you consider the other extra machine work thats more than likely required like boring, honing, decking, lifter bore indexing etc. if your truthful with yourself and actually do check all the factors and machine work costs its usually actually LESS expensive in the long run to buy the aftermarket performance block if your power goals exceed about 550HP from a SBC

Image
Image
Image
Image

Image
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.
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.
Image

http://www.summitracing.com/parts/ARP-234-5606/
Image

http://www.summitracing.com/parts/DRT-31161211/

http://www.summitracing.com/parts/HRS-H350S/

http://www.summitracing.com/parts/ARP-234-5602/

http://www.summitracing.com/parts/ARP-234-5604/

READ THESE

viewtopic.php?f=51&t=976

viewtopic.php?f=51&t=3363

viewtopic.php?f=51&t=588

http://www.chevelles.com/techref/ScreenInstall.pdf

viewtopic.php?f=53&t=343&p=419#p419

viewtopic.php?f=51&t=3363

viewtopic.php?f=51&t=2851&p=7377&hilit=splayed#p7377
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: splayed main caps

Postby grumpyvette » July 27th, 2011, 7:56 am

http://www.pro-gram.com/tech_info.jsp

http://www.pro-gram.com/catalog.jsp

Pro-Gram Engineering has had the pleasure of serving the automotive community for 22 years and is proud to claim the title of the world's largest and best manufacturer of aftermarket main bearing caps. Dedicating ourselves to the principle of "quality, not quantity, is our #1 product" enables us to provide a superior part in design, manufacture and material. These principles have allowed us to provide parts to all facets of the automotive performance industry including NASCAR's Nextel, Busch and Craftsman series, NHRA Drag Racing, NTPA Tractor Pullers, Offshore and Drag Boat Racing as well as industrial and military applications.

Quality, as defined by Webster, is "the degree of excellence of a thing"; Pro-Gram Engineering strives to maintain an excellent quality in our materials and production methods.

Material: With the influx of lesser quality goods and materials to the US, Pro-Gram Engineering solely uses materials certified as produced in the US. This allows us to guarantee the quality of the materials used in our parts, which are critical in any performance application.
Equipment: The machinery and equipment used to manufacture our products is continually being maintained and upgraded to ensure the highest precision available.
Location: Pro-Gram Engineering manufactures all of it's goods here in the US. Our manufacturing facility is located in Barberton, OH, which allows us to have direct influence on our product quality and manufacturing methods.
Personnel: Pro-Gram Engineering proudly employs highly skilled men and women from the surrounding communities. The combined machining and manufacturing experience at our, and your, disposal is in excess of half a century. While already highly skilled and competent, Pro-Gram engineering's employees are continually trained in new manufacturing methods and techniques as well as CAD design and software. Pro-Gram Engineering's technical support team of Ken and Dan Anderson have been working and serving the automotive racing industry as father and son for 13 years while Ken has served the automotive community at large for over 43 years.

Along with Pro-Gram Engineering's own product line, we proudly offer other high quality parts from a select group of manufacturers including Diamond Racing, Oliver Racing and ARP to name but a few. These parts, and manufacturers, are known for the quality and consistency that we expect and require of ourselves.

Pro-Gram Engineering's dedication to quality has given us the privilege of supplying some of the world's best race teams and engine builders. It is an honor to continue working with MOPAR Performance, Bill Davis Racing, Rousch Yates Racing, Arrington Racing, Coughlin Bros. Racing, the Butler Performance Group and M&W Engine Service of Australia as well as numerous aftermarket engine manufacturers.

Image
In any application where your tightening a nut on a stud , such as on the outer threaded ends of main cap studs or head bolt studs, youll want to use a lube on the threads that gives consistent torque reading from your torque wrench indicating the correct bolt or stud TENSION, oil and MOLY assembly lube and various thread sealants do not always do that,the end in the blocks course threads have thread sealant, the fine threads on the outer end require a totally different lubricant
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: splayed main caps

Postby grumpyvette » September 20th, 2011, 9:53 am

"I was told that a two bolt BBC can be converted to a four bolt while still retaining the stock two bolt caps. This is accomplished by counter boring the stock cap where the additional bolt would go on a standard 4 bolt block and then drilling and tapping the block to accept the additional fastener.
This would be a way to add some additional clamping strength to the main caps without the added expense of having to buy and fit aftermarket caps.

Has anyone ever seen this done? "


HERES A PICTURE
Image
Image
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
Image
Image


you can see the modified two bolt caps above
are not nearly as well anchored to the block as correctly modified splayed main caps below
Image





thats NOT a BILLET or solid steel main cap, Id bet theres little too no effective strength added as the outer bolt clamping on that limited amount of a cast part can,t exert much clamp force before distorting the cast main cap or perhaps causing it to crack under load,
even 4 bolt main cap cast caps are not super strong
Image
Id bet you would gain more if limited to the original cast main caps just using ARP main cap studs
drilling extra holes in the block web in that area is not usually beneficial
Image

on some engines they have main cap girdles available
Image

milodon sells replacement splayed main caps, for under $250, the splayed outer bolts would add significantly more strength and any time you are swapping to 4 bolt main caps on a two bolt block your very likely to need the block line honed as the extra bolts change the way the clamp forces distort the main webs in the block
Image
http://www.summitracing.com/parts/MIL-11200/?rtype=10


STOCK OEM 4 bolt 454 blocks are not all that expensive
and a 2 bolt block with ARP main studs can support a surprising amount of hp, I don,t think its financially worth the effort to convert a 2 bolt block rather than swapping to ARP studs or a 4 bolt block, the conversion machine work and splayed main caps are likely to make selling a current block and purchasiing a factory 4 bolt block a better option
Image
http://www.summitracing.com/parts/ARP-135-5402/
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: splayed main caps

Postby grumpyvette » July 16th, 2012, 10:20 am

CNC BLOCKS N/E;3556266 wrote: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


Image

Next step is using a 1/2 in end mill at a 10 degree angle is to mill a flat spot.

Image

Next is to center drill

Image
Next drill holes using a the letter U drill appox. .800 deep

Image
Next would be taping with a spiral tap seems to work best.

Image
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.

Image
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.

Image

Finish product

Image

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.
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida


Return to Blocks

Who is online

Users browsing this forum: No registered users and 1 guest