Chev SB heads

rblong · #1 (**permalink**) 05-24-2005, 01:05 PM

I hope it is OK to post this here, since the motor is in a Camaro and not a Cobra, but everyone is always so much help and sounds like there are a good number of Chev SB folks - so here it goes.

My son has saved up to do some more "upgrades" to his SB chev. We build the engine up a couple of years ago and rebuilt the existing heads because he did not have the cash to upgrade at the time. He asked me to post a question of what heads you guys would recommend to add to his SB. His motor currently has
comp cam # XE262H. Adv - in 262, ex 270
@.050 - in 218 ex 224
lift - in 462 ex 469

Headers w/3 inch pipes, single chamber flowmaster mufflers, 373 12 bolt possi, Muncey 4 speed, msd blaster, holley performer intake, 350 4 bolt bored 40 over, Demon 650 carb, non roller hydraulic lifters, stock heads that came with the 1980 350 block out of 4 barrel truck. Stock flat top pistons, rods and crank were reused.

What might be a good bolt on option?

Thanks for your help
Bruce and Jordan

Hotfingrs · #2 (**permalink**) 05-24-2005, 02:16 PM

I've always liked the Air Flow Research heads...something in the 190cc intake size would work for this engine. Other wise do a check for Trick Flow and Edelbrock aluminum heads, and compare flow characteristics for the 3, and pick the best......

ItBites · #3 (**permalink**) 05-24-2005, 03:26 PM

For Chevys, I'd check out DART. They make the best heads for BBCs, but I don't know their product line for SBCs...

xlr8or · #4 (**permalink**) 05-24-2005, 05:04 PM

The Edelbrock Performer RPM heads are a nice easy bolt on. They do have a slightly smaller combustion chamber than the stock heads so you may see as slight increase in compression rate. You will also be moving up to the 2.02 valves which will let it breath better. When you switch to the aluminum heads you may need to change the pushrods as well. If I remember correctly Edelbrock suggests a pushrod that is .10" longer.
I have used them on a few engines and been very happy with them but any of the suggested heads will make that engine "wake up and breathe" better than it did.

rblong · #5 (**permalink**) 05-24-2005, 08:01 PM

Thanks everyone for your suggestions. Now time to start comparing!

Bruce

Carnut427 · #6 (**permalink**) 05-24-2005, 08:26 PM

Best bang for the bucK: http://www.sdpc2000.com/catalog/2174...-Head-Kits.htm
Vortec heads require a different intake because the bolt pattern is different, and use center bolt valve covers rather than the old standby perimeter bolts. Vortec heads flow better than the best Chevy heads of yesteryear!
For more on Chevy performance, have your son check out Chevytalk.com, Performance Related section.

rblong · #7 (**permalink**) 05-24-2005, 08:37 PM

More great info - great prices!!! Now to show my rookieism some more. 64CC versus 70 or 72? I understand the different sizes of combustion chambers, and think I remember smaller burns faster? But how do you choose for my application?

Bruce

vettestr · #8 (**permalink**) 05-24-2005, 10:44 PM

Well great info already from the group and here is my 2 cents to try and help. With your cam and exhaust system combined with your low static CR the most compatible type would be. Try a small runner volume like in range of 160 to max of 180 CC's. A crushed head gasket height of 0.041 and piston will be about 20 to 0.040 down the hole so 64 CC vol. head or even the 55 CC head will bring up the final CR. The 50 CC heads for sure if the aluminum heads are in budget. Stay with smaller intake valve diameter or smaller to keep signal strong = 0.194 and 0.160 Ex.
Do some simple intake gasket matching and open roof and last 1/2 inch of Ex. up to help a bunch. If not experienced stay away from porting as you can hurt them easy. Use a dual plane intake manifold and try smaller runners here also. Play with carb spacers to shore up the small intake and GIVE HER TIMING until she rattles and back off 3 degrees and lock it down. Try static of 18 degrees with mechanical in by 2500 RPM to a total of 38 degrees. It will take a 780 CFM carb if vac sec. and small intake runners to retain airflow speed/signal.
Good set of used Dart iron eagle or the smallest Pro 1 alum heads will do the job.

Carnut427 · #9 (**permalink**) 05-26-2005, 03:09 AM

As vettestr mentioned, if the deck hasn't been milled, most small block pistons are .020 or so down in the bore. When you add a .041 thick head gasket, you loose too much squish (or quench, whichever you want to call it). To remedy this, use a Part # FEL1094 Shim-type head gasket, .015 in. Thick, 4.100 in Bore, for use with Iron or Aluminum Heads. Can not be used on 400ci engines. Embossed shim with precision coating does not cause any brinneling on aluminum heads. 1 gasket per package. Price: $18.95 . Using these gaskets will give you the disirable .035-.040 squish, which allows you to run a little higher compression without detonation. The squish is the air/fuel mix being squeezed out of the area where the flat area of the head & piston come towards each other. This squish creates turbulence in the combustion chamber, cooling off hot spots and keeping the fuel & air correctly mixed. You then choose the head cc to match your piston to give you the compression you want. THEN choose a cam that will give you a DCR of around 8:1 for iron heads and up to 8.4:1 for aluminum heads. Do all this correctly and you've got yourself a screamer, no matter what brand it is.
Good Luck,

Dan