I am collecting parts for a 5oo something c.i. build and wonder if it is time to upgrade the bottom end.My goal is for a reliable 600hp and 600tq motor that never sees above 6000 rpm in a heavy car.May have a 100shot now and again
I have always used stock caps with a stud kit and let it roll.I know you can go crazy with a girdle and alum caps but is it really necessary at this level?
I am considering a partial fill to the bottom of the freeze plugs.
The spinning assembly will be considerably lighter than stock.
I expect 10 diff answers so how about what you are running and your power level and how long it has been together.Miles or passes.
Thanks,
George

Numerous 9 and 10 second cars with stock caps and bolts and stock caps and ARP stud kits.

600 HP and 6,000 RPM should be good with stock caps and ARP studs.

When I started my 500 'B' block I got the BCR caps/girdle because I originally intended to go with 350+ cfm ported heads, a tunnel ram, and a biger roller cam to try and make 750+ HP and 7,000+ RPM, but I toned my goals down a bit with a single plane intake and a milider cam, so I only expect to see about 700hp and 6500+ RPM.

The old 451cid engine using stock caps was fine at 580 HP @ 6,100 RPM, but I chassis dynoed it a few times up to 7,000 rpm with no problems.

My street 518 C.I. low deck makes over 700 hp on pump gas, on what maybe a happy dyno, I bought the Mopar ductile iron main caps and ARP main bolts ad had them installed along with a align hone to make them fit properly. going on four years of racing some(400+ passes shifting at or above 7000 rpm, knocking on wood, ) and street driving some, 1200 or more street miles I think the key is to avoid detonation and look at all of the bearings every so often

cab's got it....detonation can instantaneously inflict huge damage to the bottom end...and the more power you make the more severe the destruction.

if you are racing you have to determine whether the cost of keeping a stock block alive is worth the extra cost of bullet-proofing the bottom end...and even then it's how the top end is tuned that makes the real difference. For me I'd rather build an aluminum rod motor with a stiff cradle around my crank than stiff rods inflicting a pounding into a bottom end designed to effectively "flex". I'd rather have a dead-blow hammer banging into a strong anvil than the other way around...but opinions vary

George, at 600hp you'll probably have a fairly mild converter in it so the shock loads onthe line won't be as severe as they might be in a stick car or a TB/high stall FB racer....even with the weight a converter cushoins the radial and axial loads on the crank. at that power level I think you'll be ok. Ductile caps are good insurance as is a Girdle but at 600 I think you're probably ok......a 500" motor that peaks around 600hp is going to have atorque peak fairly low (maybe 4200rpm) in the powerband, the lower the RPM, generally the better in terms of crank flex and block longevity.

If you decide to stick to stock caps you may want to reconsider the 100HP nitrous setup. Pretty much any 500 inch setup even using Eddy heads will make 600 HP plus. If you hit it with nitrous now you are 700HP plus That is when those stock caps are going to fail. Now is the time to overbuild the bottom end or tone it down. You have to decide yourself. I have never met anyone that said OH my car make to much power I want to take some away. We all get used to a HP level then the car seems slow. That is when you will decide oh its just a 100 shot and that is when those caps will fail. Been there seen it hundreds of times. If you are going to build a motor That is on what I call the Bump Line "600 HP" that is the limit of stock caps for longevity and being able to sleep at night. If you are looking for assurance from members that your motor wont fail at 600HP in the cap area you may be foolish as I have seen far too many fail at that level. You either need to tone it down and be happy or do a little more to the bottom end and be happy that way. I can not stress enough to use a good foundation "sonic test and mag the oil hole to web area" to insure you start with a good piece.

www.bcrproducts.com

Greg