BBC build suggestions please

ridefast · Jul 7, 2015

Rebuilding a BBC for my wife's Sunday driver. I have torn down and reassembled a few small blocks, but this is my first full "build".

My goal is to build something that is mostly driven around town, but would once or twice a year see a 12-hr round-trip road trip. And to sound like a big 'ol dirty big block. Nice and thumpy. I think I'm looking for performance between 1500-3500rpm and I want it to have a semi-rough idle.

Couple things to keep in mind:

-It has peanut port heads.
-I have bored it .060 over.

Questions:

What style/shape of pistons should I be looking for given what I want to do with it? What kind of compression numbers should I aim for with these heads?

What kind of cam specs should I go for?

muddinmetal · Jul 7, 2015

Doesn't Piper know all about BBCs? :dunno:

SHELBS44 · Jul 7, 2015

muddinmetal said:
Doesn't Piper know all about BBCs?

hahahaha!!! yes yes he does :flipoff1:

zukimaster · Jul 7, 2015

I basically have the same engine your wanting to build in my Chevelle, mine is a .30 flat top, but I do have a set of closed chamber square port heads, I used a Comp Cams Xtreme Energy 274, rpm range is 1800-6000, has a very nice sound, but small enough where I only got a 1800-2000 Saturday night special convertor, and 3.31 gear. idles just fine in gear around 700 rpm's. I burn 87 octane gas, have drove to the rod run and back, and still runs around 8.20's at the dragstrip. just make sure to buy valve springs to match the cam. Edelbrock rpm performer is a great intake for that engine also.

muddinmetal · Jul 7, 2015

Since I am what is wrong with America, maybe you don't care about my first hand knowledge of big block chevys... It will be hard to keep the power way down low and have a choppy idle, but it can be done. What is the vehicle weight, stall, tire size, & gear ratio? Are you dead set on keeping peanut port heads? Flat tops are a must & even a small dome can be used & run pump gas with oval or square ports. More info please

ridefast · Jul 7, 2015

Vehicle is 1953 Chevy flatbed, NOT stock
Weight will likely be 3000-3500lbs
Don't know stall
700r4 tranny
Drive tires are 30"
Gears are 4.10
Peanut heads are staying, unless someone is willing to donate a better set.

muddinmetal · Jul 7, 2015

ridefast said:
Vehicle is 1953 Chevy flatbed, NOT stock
Weight will likely be 3000-3500lbs
Don't know stall
700r4 tranny
Drive tires are 30"
Gears are 4.10
Peanut heads are staying, unless someone is willing to donate a better set.

Xtreme energy 268 is a max, the 3.06 1st gear & 4.10s will help you a lot with most cam related drivability issues.

mna0121 · Jul 8, 2015

The rebuild will look almost exactly like the SBC's did just TQ specs will be different. Summit Racing sells a how to book, How to rebuild BBC. Get it use it you will be fine. Plan for a lot of coolant capacity and a well working cooling system. At .060 over she is going to rely on the radiator a good bit more. A natural aspirated BB is happy with a lot of cam duration, lot of fuel, hot spark and big headers. Single chamber mufflers but keep them behind the driver compartment, will make your ears ring after awhile. RTR

ridefast · Jul 8, 2015

What style/shape pistons should I be looking for?

Relatively cheap is key, but ... flat? domed? dished?

muddinmetal · Jul 8, 2015

ridefast said:
What style/shape pistons should I be looking for?

Relatively cheap is key, but ... flat? domed? dished?

As stated earlier, flat or super small dome, dished pistons in a n/a bbc are a recipe for an unreponsive engine. What casting # are your heads?

ridefast · Jul 8, 2015

oops, sorry about that...flats it is.

Will get head casting numbers tonight for you.

Would it be worth while to open up the valves to try and gain a little bit from the peanuts?

BUG-E J · Jul 8, 2015

Re:

creepycrawly · Jul 8, 2015

peanut port heads have 2.07 intake valves almost like a small block, but are not worth putting any money into...at least that's what a little iron muffin told me.

zukimaster · Jul 8, 2015

You will really thank yourself later to try and find a set of older model large oval port heads, it will make a ton of difference, I threw away no telling how many sets of those late model truck heads, about 4500 rpm's and they are done.

ridefast · Jul 9, 2015

Heads are casting # : 14092360

Yes, the gross, dumb peanuts.

halcat · Jul 10, 2015

zukimaster said:
I basically have the same engine your wanting to build in my Chevelle, mine is a .30 flat top, but I do have a set of closed chamber square port heads, I used a Comp Cams Xtreme Energy 274, rpm range is 1800-6000, has a very nice sound, but small enough where I only got a 1800-2000 Saturday night special convertor, and 3.31 gear. idles just fine in gear around 700 rpm's. I burn 87 octane gas, have drove to the rod run and back, and still runs around 8.20's at the dragstrip. just make sure to buy valve springs to match the cam. Edelbrock rpm performer is a great intake for that engine also.

I built a 69 COPO camaro clone. To the book, L72 engine, 4.10 gear, M22 trans.( even though it was never in a camaro I had it) and on 255 radials it ran 8.08. Your chevelle kicks ass. I have a 489 in my crawler now with a set of Brodex Racerite heads, small port big valves, that makes power way beyond all the old iron out there. If money is not there for new heads, stick with oval port, not peanut, heads. Go open chambered with a .250 dome piston. Stock bottom end is fine. Clean up in the valve area and port match the intake gasket. KEEP YOUR CAM MODEST. I had a 427 in a pickup with 44's with a mellings off road cam, 493 lift, that would blow your mind up to 5500 RPM's. With a stock bottom end, keep your cam below 6000 RPM's. Two bolt mains are fine. Your cam needs to peak torque at 3000 and hp at 5000, go to 6000 now and than tho, it sounds damn good. Build it and let's wheel!! See you on the trail.