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Fastest65 04-29-2010 10:14 AM

BBC, Hyd Roller Question Please
Getting my build components narrowed down and need any
thoughts on a cam I picked out. I will have a 454 pushed out
.060" over, 4 bolt, high vol ol pump, double roller timing chain,
291 rect port heads with 2.19/1.88, L2399F60 pistons,Stealth intake,
780cfm w/vacuum secondaries. The cam choice finally is the Compcam
#11-430-8 hyd roller. If anyone has any experience with this puppy can
you please throw it my way.
Plus I know this is a rough guess, but what kind of HP do you think I
will be pushing? I am hoping around 500-550 am I dreaming???

Guy Hiltz 04-29-2010 02:24 PM

You'll get an answer quicker if you post the cam specs;
280 adv duration
224 dur @ 0.050
0.566 valve lift
110 LSA
Also posting your compression helps others with recommendations.
The carb may be a bit small,but otherwise you have a decent combo.Although big blocks respond well to bigger cams.Realistically,you might be in the 450-475 hp range.
Also,whats it going in ??

Fastest65 04-29-2010 02:38 PM

It is going in a 65 Malibu, 4spd, 12 bolt.
Are you saying I could get more cam and get a little
nastier engine? With the L2399F60 and the 291 heads
I think I'll be around 10.0.

Guy Hiltz 04-29-2010 02:57 PM

Heres the heads;
3964291 1969

1970 396
454 375
450 2.19/1.88 109.037 Similar to #3919840 with spark plug seat changed to tapered, "peanut" plug but early castings had standard, "N" reach plug. Last closed chamber cast iron square-port head. Produced in both plug designs for service replacement of 1965 through 1969 applications.
Heres a chart with piston specs;
It looks like you might be trying to use an open chamber piston in a closed chamber head,so you'll have to check for clearance.Also looks to be close to 10.0:1 cr.So a bigger cam is possible,but again you would have to check for P to V clearance.You could use a cam with a slightly wider LSA and have more lift.If you want nasty,use as big a cam as possible.

Fastest65 04-29-2010 03:13 PM

Cam/Piston Stuff...Guy Hiltz Thanks
I want to stick with my 291's and stick with a proper
piston for close chamber. My 291's have brand new springs
good to .600 lift. Yes I want nasty as hell, but do not want to exceed
CR for pump gas. In the process of buying the L2399F60's shopping for best
price. The Comp #11-678-5 looks like a nice cam too. Except it is a solid.
With flat tappet I know one has to use the proper break-in oil Compcam has
some, but once she has gone through the 2000 rpm for 20 mins can use then use regular oil without Zinc? like 20-50 or 5-50 full syn?

ericnova72 04-29-2010 03:40 PM

I would say keep adding the zinc at each oil change but at a lesser amount, like 4-6 ounces with each oil change just as a preventative as modern oils have removed the zinc that used to be there all the time. Cam break-in is the most critical time but it still needs to be there all the time.

If you are going to run solid lifters in a BBC know that the heavy valvetrain and staggered lifter layout makes these engines real hard on cam lobes. I would consider it MANDATORY that you use a face-oiling lifter, these have a tiny oil hole lasered right thru the center of the lifter face to constantly oil the lobe. I wouldn't even bother picking up a wrench without them.

The 2399F60 is an open chamber piston, you will likely have to rework the head chamber or the piston dome to make them fit with your closed chamber heads. The 2349F60 piston is the correct piston for the closed chamber head but but is higher compression out-of-the-box than you want, you will have to just mill the domes down a little to get the compression down to 10-1. This would be easier to do than hand clearancing the open chamber pistons IMO

Fastest65 04-29-2010 04:02 PM

ERICNOVE72, THANKS piston/cam stuff
crap..maybe if I did not Zero deck the block she would drop to
pump gas level using the L2349F60. This is what I was leading to
in other questions about the 496 stroker route. after a guy decks
the block, mills pistons are up at the cost of a SCAT stoker
kit. which I can get for $1700.
Or use the L2365F60 and rebuild my 049 heads????? Want to stick with
these 291's though becasue they are clean, with SS 2.19/1.88 rect port.
There has to be something out there that would yield a 9.8 or 10.1
for a piston in a .060 454 ???

ericnova72 04-29-2010 04:35 PM

Main problem you are fighting is the closed chamber, back when they were factory installing this head cheap high octane gas was in every station you stopped at.

I would want to stay with the 291 head also for the power they can produce, you are just going to have to work it a little to get a pump gas compatable ratio. It is still too high with the correct 2349 piston even with the undecked block, but the fix is easy, just machine the dome down. 1/2 hour job, shop shouldn't charge more than $50 to do this - if you or a buddy doesn't have the ability or the equipment (lathe or mill). This would be the route I would take.

The closed chamber head will present the same problems with compression ratio on a 496, maybe more so as virtually all stroker combo's are configured for the much more common(and aftermarket standard) open chamber.

The 2349 piston fix is real simple, even a caveman could do it. An ambitious and motivated person could even do it with a flat file and a buttload of time if they are mildly skilled with hand tools, a pair of calipers and pay attention to what they are doing. ;)

Fastest65 04-29-2010 04:39 PM

milling 2349 pistons
But still how much should be taken off?

Guy Hiltz 04-29-2010 05:41 PM

I dont know if you are aware of this or not,but any Comp Cam roller cam whose part # ends in 8 is not made on a billet core.They are made from an austempered ductile iron,which does not have the strength that a billet core does.You can order a billet core from Comp by substituting the # 9 for the # 8.

Fastest65 04-29-2010 05:51 PM

Guy Hiltz Cam Stuff Thanks
Not sure where you are getting the 8 and 9 from.
My cam picks were the 11-430-8 hdr roller or the
11-678-5 solid flat tappet. Or maybe the 11-250-3
less break in with the roller and the 11-250-3 is hyd
flat old school...just not sure if it is nasty.

ericnova72 04-29-2010 05:57 PM


Originally Posted by Fastest65
But still how much should be taken off?

Listed as a .210" flat topped dome, rough estimate in my head from having done this before on other pistons and from comparisons to other 454 pistons and the dome size listed at each compression ratio tells me .090-.100" removed from the 2439F60 would be very close. Final amount cut dimension number would depend on how exact you want to be on the ratio and the exact measured cc of a chamber in your actual head as they will always vary some from the published spec because of the nature of casting tolerances back then. The head chamber could be smaller than listed but the usual pattern is they are bigger than listed.

ericnova72 04-29-2010 06:00 PM

Part # 11-430-8 is on an austempered iron core, these have a somewhat poor reputation for cracking. 11-430-9 is on a billet steel core, very strong.

Guy Hiltz 04-29-2010 06:06 PM

You may find a better fit piston as far as compression goes,I found a SRP piston for a close chamber that will put you just a bit over 10.0:1,go here and scroll to the bottom,# 141636;

Guy Hiltz 04-29-2010 06:07 PM


Originally Posted by ericnova72
Part # 11-430-8 is on an austempered iron core, these have a somewhat poor reputation for cracking. 11-430-9 is on a billet steel core, very strong.

Thanks,thats exactly what I meant.

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