Redog

Are there any out there other than Speed-Pro or whatever brand are on the Summit website and Mondello?

I've heard of 12:1 pistions of the 350, but I can't find them

Mondello's pistions will get me up to 10.35 : 1 if I use the 5 heads. I want to go higher and use the "C" heads

J-(Chicago)

Anything over 10:1 and you probably won't be able to run pump gas anymore.

70cutty

There is 12:1 pistons but they are custom made not something you can just call and order. I don't remember but I think the company is called Diamond and they will probably be around $600-800 for the set.

redoldsman

Aren't "C" heads from a 455?

citcapp

Yes C heads are bid block heads not small block

Redog

Well I'm looking for about 450 HP.

Yes "C" heads are BBO heads, but with the CR drop, this can be recovered with higher compression pistons.

The Edelbrock top end package with the 7111 mani, and 7112 cam, along with a 600-800 CFM carb and 3" collector headers it claims to pull 400 HP and 397 ft/lbs. You need at least a 9.5 : 1 CR to pull this off.

I was talking to a friend of mine. This guy has a 71 Cutlass with a 350 SBO, "C" heads, Mondello JM 20-22 cam and a set of 11.1:1 pistons and he's telling me with my set-up I'm looking at 350 at the crank and adding upper and lower windage trays and roller rockers and a good tune I may be in the 400 HP range.

I always figure on 20% hp loss in the tranny. It seems that most people say anywhere between 17% to 23% loos in the tranny, so I just say 20% being right in the middle. I have a build 400 turbo than chrips 2nd.

I'm looking to mill the heads, probably no more than .020 which will bring the CC's of the head down to 76 and I'm planing on using the .028 head gasket on Mondello.

I want to use Mondello as little as possible. I bought an intake gasket from them, a $15 gasket cost $13 more to ship to me and it took 10 days Sorry that's BS.

With 443 HP at the crank, I will get my goal of high 12's in the 1/4 mile

70cutty

this would be a good starting point, contact arias and see what they say.
http://www.ariaspistons.com/custompistons.html

captjim

With a 4.087 bore (.030 over) and stock stroke, .040 piston to head and a 76 cc chamber, you will need an 18cc DOME to get right at 12 to 1. Then, you will have the piston to valve issues. I don't know how much you can safely mill off of a BBO head, perhaps someone who does will chime in. You can mill a SBO head down to 58cc, that with a flat top gives you 11.9. Might be cheaper and easier in the long run. But, the heads will need a fair amount of work to flow 450 hp.

But, the good news is you don't need anywhere near all that to run a high 12. 300 RWHP will do it in a 3800 lb car with a good suspension. So, flat tops with a 65 cc chamber in a 350 head gets you 10.5 or so. A nice cam in the 230 @ .050, spend a little $ on quality head work and you are there pretty easily.

Redog

^^ Hmmmmm.. Really

I already have 5 heads, and I'm buying "C" heads off another member.

I'll still buy the "C's" but maybe just hang on to them and work my 5's

Is the cc on the 5 : 64 or 68?

That 230 @ .050, is that intake or exhaust? Still a noob with cams

captjim

230 is just a ballpark number. I recently finished up a mild-ish 355. 10.45 to 1 with flat tops and a 66 cc chamber, 2.02" intakes ans 1.560" exhaust, I spent a little on the heads, had them ported for low lift flow, good valve job, dividers welded. I live in Fl and it is just too dang hot down here to race, but I am expecting a high 12 with a 3.42 gear in a 3800 lb car. We'll see if it does it or not. I figure the HP around 400, TQ around 425. Cam is a Voodoo 60803, .510/.522 227/233 on a 110. I installed it a degree and a half advanced, on a 103.5 IC. The car has terrific response and plenty of vacuum. I DO mix the fuel, though. I decided the trade off was worth it as this is just a fun little weekend car, not a DD.

380 Racer

At least 68-70 ccs. My # 7s were milled .045 down to 62 ccs.

Redog

OK I have an idea of how this build will go now

I'll probably go down .02 on the head bringing it to 64 cc and using the thinner gasket that I mentioned above will bring up CR to 10.74 : 1, if I use the reg gasket I'll be at 10.39 : 1.


I used this calc to get the numbers. Is .020 the correct deck clearance?

1
4.087
3.385
4.220
.028
64
0
.020

http://www.csgnetwork.com/compcalc.html

captjim

The Speed Pros sat down .024 on mine, so yeah, that is a good number. However, if you use the .028 gasket and mill deck the block, you can end up with .040 piston to head, which is considered ideal, and a touch more compression.

J-(Chicago)

When do you plan on having the delta done?
We gotta bring the b body bombers to the strip and get them some respect.