Stock vs. steel vs. aluminum main caps

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younggun2.0

younggun2.0

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I am getting very close to starting my 470" stroker build. At what point is changing main caps needed? I am building a 10.5:1 pump gas engine with solid roller cam. Looking for 550-600 hp. Car will see street duty and be abused heavily.
 
younggun2.0 said:
I am getting very close to starting my 470" stroker build. At what point is changing main caps needed? I am building a 10.5:1 pump gas engine with solid roller cam. Looking for 550-600 hp. Car will see street duty and be abused heavily.
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sounds very nice ......I assume this is for the green dart??

is there a build thread anywhere.
 
.................The time is now.....400 block 511 stroker callies crank, diamond pistons...my buddy has had problems with the main caps moving around on the same build twice 1st time with a dyno'd 513 hp 620 tq, had ARP bolts , now with ARP studs and stepped up to 650 hp and 670 tq built by pro's it will be gone thru over winter again...I would never want his grief or expense....kim............
 
oldkimmer said:
.................The time is now.....400 block 511 stroker callies crank, diamond pistons...my buddy has had problems with the main caps moving around on the same build twice 1st time with a dyno'd 513 hp 620 tq, had ARP bolts , now with ARP studs and stepped up to 650 hp and 670 tq built by pro's it will be gone thru over winter again...I would never want his grief or expense....kim............
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The bottom end will be studded and if need be a girdle. I have read that billet aluminum caps help to dampen the hammering from the crank and help with cap walk. I was quoted $750 to machine/align bore replacement caps. If this is going to help with longevity then I'm ok with the extra cost
 
For 550-600 hp, I wouldn't think they'd necessary for a streeter. I'll be interested what smarter folks have to say.

btw, what ever happened to the early Valiant. I enjoyed watching the progress of that.
 
mopowers said:
For 550-600 hp, I wouldn't think they'd necessary for a streeter. I'll be interested what smarter folks have to say.

btw, what ever happened to the early Valiant. I enjoyed watching the progress of that.
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I plan to race, beat, flog, and terrorize the public streets with my next build! I want a bullet proof bottom end. Picture the last engine you plan to build! A street war machine! That is what I want! I want people to be dazzled by my pretty paint and shiny **** then see me run and wonder wtf just happened! Come hell or high water I'm gonna embarrass people and do what can't be done! I'm taking back the streets for mother mopar! My collar is blue as the ocean and my dreams as big as the known Galaxy! Fasten your seat belts kids! I'm goin to push the limits and achieve my dreams! I work my hands bloody to make my fantasy reality! It's gonna take time but my home built crap is gonna run hard and shed tears! So what caps guys? Pretty simple lol
 
As for the valiant! I still have her! I have the mag 360 ready to drop in and go. This winter I will make progress. The lady needs a play toy
 
younggun2.0 said:
I plan to race, beat, flog, and terrorize the public streets with my next build! I want a bullet proof bottom end. Picture the last engine you plan to build! A street war machine! That is what I want! I want people to be dazzled by my pretty paint and shiny **** then see me run and wonder wtf just happened! Come hell or high water I'm gonna embarrass people and do what can't be done! I'm taking back the streets for mother mopar! My collar is blue as the ocean and my dreams as big as the known Galaxy! Fasten your seat belts kids! I'm goin to push the limits and achieve my dreams! I work my hands bloody to make my fantasy reality! It's gonna take time but my home built crap is gonna run hard and shed tears! So what caps guys? Pretty simple lol
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:laughing: That is awesome! All I gotta say is- Take videos!!
 
For what you're doing, and what you're working with, you are fine with stock caps and studs. You're not strong enough IMO for aluminum caps. If you "need" a girdle - you need a better block.
 
txstang84 said:
It's a pretty cool little Val...he's doing some solid mods to it. I think it's gonna be a sweet little ride.
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alum. main caps are for stopping the block from splitting between the mains and cam, due to the hammering of a stout stroker. had a friend that ended up going that route, his was all out drag car running 9:60`s w/ the carb backed off some to keep it together. a girdle will help w/ that problem some, but is more geared towards stopping the caps from walking, which will contribute to the block splitting. a big block Chrysler will benefit from a main girdle probably more than about any other engine due to their design. go to hughs website and look it up. I even had mine chryo treated along w/ a main girdle. at around 700ish h.p. (plus or minus), I don't expect any trouble w/ it in a street n strip rest mod.[-o<
 
I am not a pro builder but I would run the aluminum caps with a girdle. I understand cap walk but if the weakest part is above the crank why put a hard steel cap under the crank. I would think that the added hardness under the crank would only add to the transfer of force to the top of the crank, thus to the weak link in the block. I lucked out and got a set of BCR caps and girdle on the cheap (not a 100% solution to the problem) but If that had not of happened I would have bought an aftermarket block.
 
I've put alum. caps on a 440/496 stroker.
Never been able to run it yet but have been thinking of adding a girdle as well.
The solid cammed engine will see a roots supercharger on top of a pair of INDY 440-1 heads.


20101923-BlowerMotor-AlumMainCaps.jpg
 
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