KB engine build

Posted By: supercomp

KB engine build - 02/21/14 07:04 PM

Getting ready to order a KB block and I,m wondering if I should build a 572 or 604. Reason being I only have some max ported by MCH B1 original heads with individual shaft jesel rockers. Will they support a 604 or would a 572 do just as well? And should the lifter bores be bushed? Any advice would be appreciated.
Allen

Posted By: pittsburghracer

Re: KB engine build - 02/21/14 07:31 PM

If you EVER plan on building it bigger than a 572 you better at least get it clearances now. I didn't and am limited on my Keith Black engine. I don't ever plan on going bigger so I went the route I did.

Posted By: MR_P_BODY

Re: KB engine build - 02/21/14 08:03 PM

Quote:

Getting ready to order a KB block and I,m wondering if I should build a 572 or 604. Reason being I only have some max ported by MCH B1 original heads with individual shaft jesel rockers. Will they support a 604 or would a 572 do just as well? And should the lifter bores be bushed? Any advice would be appreciated.
Allen

I would doubt they would work very well on a 604...
if they were the M/C then they would... but they
would still work to a lesser rpm .... thats a lot
of flow you would need for the 604 and the revs
EDIT
I would think the originals would even be on the small
side for a 572(even fully ported)..... JMO... I was
going with the M/Cs on a smaller ci but was gonna
have to rev it higher to make them efficient

Posted By: camastomcat

Re: KB engine build - 02/21/14 09:22 PM

I think the B1 572 or B1/MC 572, is the best option. Don't swing that much crankshaft until you have to. That said, if you ever think you might go bigger later, get the raised cam block. Also, be sure to get the drilled lifter bore/push rod oiling mod. For a straighter push rod angle, you might also consider the 2" spread lifter bore spacing too. JMO

Posted By: jim sciortino

Re: KB engine build - 02/21/14 10:24 PM

Useable rpm is your friend in a drag race.....

No need to purposely decrease it in a limited cylinder head situation, unless the goal is a low rpm engine.

Posted By: Tig

Re: KB engine build - 02/22/14 12:56 PM

You will be ahead of the game with a raised cam block if you're going to go 604 with a wedge head. With a standard spaced cam tunnel, you can't get any decent lift without fouling the rods with a 4.75 arm. Lift can be addressed by rocker arm ratio but that creates there own little problems. Better off deciding now, belt drive is a lot more expensive than non raised cam tunnel.
We've not ran bushed lifter bores and they're holding up fine. Our's is 580ci btw. Nice reliable, low maintenance 850 ish HP. 6700 shift. 7200 max rpm. see sig.
HTH's

Posted By: supercomp

Re: KB engine build - 02/22/14 03:25 PM

This is is going in a S/C dragster. Thanks for everyone,s advice.

Posted By: racerhog

Re: KB engine build - 02/22/14 09:47 PM

Check with Keith @ KB and see what he thinks of the 604's....

Posted By: Mulehead

Re: KB engine build - 02/22/14 11:25 PM

Street Hemi KB 4:500 crank.Just something to look at

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