Hello all.

Let me start by apologizing that my first post is an ask for help and not an introduction. I've been around forums long enough to know better but I'm in a rush right now.

Secondarily I know there's some cam advise on here, but my situation is quite specific and was hoping I could still get some advise as what to do with this motor in the car it's in from the guys who know the motors!

That being said, I'm looking for intake and cam advise on the following setup keeping in mind I want to keep my stock valve train (so no over .500 right?)

It's a '72 350 with long tube headers, true dual no crossover and an Edelbrock 4bbl.

The fun part: It's in a '72 Camaro and has TH350 behind it with 2.73 gears in an LSD housing. The 2.73 is great at keeping the revs down but gutless off the line. I do think it's got a mild cam, or the stock '72 is just pretty quick on stock once above 15mph. It pulls strong. (I'm used to 350 sbc )

SO, I am open to changing the gears/converter to suit a cam and exhaust needs to be redone so an x-pipe is no problem.

I'm looking for as much power as possible without changing the heads, I believe these have a 64cc chamber and flow pretty well from what I've read.

What kind of power can I get with which mods? It's a street car so off the line grunt would be great and I don't need to pull it past 5500rpm really. Is it worth having some taken off the heads? Is it worth putting in flat tops to raise compression (high octane pump gas no prob). How much more do I stand to gain by at least putting in flat tops in combo with a good cam and intake? And if I do change out the pistons what is the minimal block work that needs doing?

I'm in Europe and machine shops are few and far between and seriously expensive. I know out of cheap, reliable and power you can only choose a combo of two, but....

Would love to hear ideas and rough numbers on power for this off idle power band I'm looking for.

In summation:

'72 Olds 350 with 7a heads, long tube headers, true dual in a '72 Camaro street car with 2.73's

Lookin for advise on:

Cam (lopey idle )
Intake
Best way to get around 10.5:1 compression
Numbers that will yield roughly



Cheers!

 

What sort of fuel can you run with 10.5:1 compression?

I think you would be happy for much less $ by running a CR that your "affordable" fuel can tolerate, and making up the fun factor with final drive gears on the order of 3.4-3.7. Changing to a ~3.7 gear from ~2.7 is around a 35% boost in torque available at the rear axle. A higher-stall converter seems like it would add to the fun factor. Switch Pitch TH400... nah.

Others here with more experience can direct you on the cam selection better. Knowing your final drive gear ratio should help. Do you know the current compression [piston dish style/ size]?

 

I agree with Octania, get 3.42 gears, maybe a 2000 or 2500 stall converter.
I don't think you can get gas in Europe to run that 10.5 you want, hell you can barely get it here in US and it costs $10-$12 a gallon here in California.
I would do speed pro L2321 pistons with 6cc valve relief, which should net around 9.5 CR.
Talk to Mark - Cutlassefi about custom grind cam for your specific build.
I would also talk to Mark about improving the heads with some new springs, rockers etc.
JMO

 

Thanks and good call on the gears and stall converter.

"Switch Pitch th400...nah" I have no idea what you are referencing other than the named trans...

"your "affordable"" fuel? I don't understand. I've said that higher octane isn't an issue. But I was off on the CR. I want to run pump gas yes. So I guess 9.5 to 1 is where it's at max.

My pistons are stock and the heads too so that should be 64cc combustion chamber, probably slightly dished. So we're looking at about 8.3:1 I believe, the '71's were the first year of low compression.

 

First off, just what is available in Germany for gasoline so we won't be speculating.
Gears and converter are always cheap easy ways to improve performance. Combination of gear and converter are important in choosing a cam be it for an 8.5:1 engine or a 10.5:1 engine. So decide on where your going there first.

As far as running 10.5:1 on gasoline here in the states, I build engines quite often at that CR to run on 92oct pump gas. They make great power and live long lives. Its easy to do and takes a combination of the right parts and the ability to tune for it.

 

There ya go.

I'm an American currently in the Netherlands but it's the same all over the continent here, it's basically the same stuff as back home, some slightly higher octane stuff, just a different rating system.

Basically this is how it turns out:

US EU

87 91
91 95
94 98

I'd want to run a US 91 or EU 95 (easiest premium to find).

Our regular gas is 12-14 USD a gallon over here.

There is some E85 but that's not what I'm slightly modifying this motor for.

Still just looking for a good cam, intake and possibly piston advice.

If the CR now around 8.5 and I bump up to 9.5/10 that should be more than enough.

I want an aftermarket cam so I can just buy a set. If I get a custom grind I'm in trouble over here if something goes wrong. Nothings on the shelves.

cheers

 

Huh? Most aftermarket cams are a compromise. A custom cam won't cause any problems, you get a cam card with it just like an off the shelf one.
I see you want to run mid grade fuel. If so then I'd just mill the heads .040 or so. Then change the gear as mentioned. Add dual exhaust with headers, that will make a noticeable difference as well. Then an RPM intake with a 650 or so and it'll be a different car. Good luck in your project.