Hi
So my question is about 6 months ago had c heads ported and got a custom hyd flat tap cam dur. 240/240 .536/.536 110 lsa. Told them was going to be 9.5.1 cr cause I wanted to keep it on pump gas. The more I have been thinking about the cr and the more I think about the fun factor the more I wonder would it be worth it to raise the compression and if did how much to make it worth it. Also would cam still work. Pistons, crank, and oil pan are all installed. The most cr I can get rate now without any machine work would be about 9.75.1 with .017 head gasket. So if I wanted a higher cr would either Take apart short block or mill heads and would it really be that big of a difference in performance to go to a 10.0.1 or 10.25.1 cr and what type of octane increase would there be?
Stock balanced rotating assembly/n crank
Air gap intake
Quick fuel 850 do
1 7/8 headers
3.73 gears
No converter yet

 

How far in the whole is the piston?
with iron heads 9.75 is about the most you can run with out alot of problems.
even at that you will still need to use premium fuel about 94 octane.
To me a cam with split duration will work much better for you with factory heads. I would say 6 to 8 degrees more duration on the exhaust side with 550 to 570 lift.
just IMO

Gene

 

Way in the hole. .037
Speed pro 2323 pistons
77cc heads
Heads flow
Intake .600 lift 278cfm
Ex. .600 lift 200cfm
Why dual pattern vs. single?

 

With the right combination you can run 10.0:1 with iron heads on 92 or better.
And why the RPM? Your current combo really doesn't warrant that intake imo.

 

I have both performer and air gap. Any ideas what way to go with this. Cam? Cr? Intake?

 

Don't want to go with roller. $$$. But open to opinions to best utilize heads for combo. 70%street/30%strip

 

I'm running 10.3:1/ported C heads/.640 lift/ 240 duration
I run 93 gas. Runs fine.
Are your combustion chambers polished. IMO its a good idea if you go north on the CR.
I have a new 3 way radiator with a well fit fan shroud and ceramic coated headers. All helps to keep motor cooler.
I'm in CT not TX.

George

 

What are the flow numbers at .550 and .650?

 

Intake .550 272cfm
Ex. .550 196cfm
In. .650 280cfm
Ex. .650 203cfm

 

I have 2 455s with ported C heads and 10.25:1 compression that run on 94 octane pump gas with no issues.

 

Talk to me Dave. What are are you running for a cam? Is my setup crap or what. Read a lot on here and it makes me second guess things. I got a guy that is 64 yrs old doing the motor for free, he is got tons of knowledge overall. My dad's buddy. But I'm helping him. I'm not going to pay someone other than for machine work. He will make sure I don't screw up, he is an ase certified mechanic that's built a lot of big blocks. Mostly Chevy. So I tell him what I'm doing and he is handling the tech side of things. Very knowledgable! So my point is I'm no idiot, just need help from dedicated olds people on what route to go.

 

Ok so with those numbers why are you using a cam that only has .536 lift?
What octane premium do you have available?
Btw I offer hyd roller cams with lifters for $725.00 to anywhere in the U.S.

 

It would have to be a hyd. Flat tapper. Can't afford a roller. Any recommendations?

 

91 octane but a couple miles away sells 110 and 115 if needed to mix just don't want to get to crazy on running race gas

 

10.0:1 on 91 is doable.
Yes I can do something approaching .600 lift with a 1.65 or 1.7 rocker. What springs do you have?

Finalize your compression ratio then we can go further on a cam recommendation.

 

Not sure paper work for heads just says 140lbs 310@.500 .570CB

 

I do have 1.65 roller tip rockers

 

It coil binds at .570? If so those won't even work with your current cam.
Lobes I have in mind would give you .586 with the 1.65 rockers.

 

My mistake rockers are 1.6 ratio. Does that make a difference with the springs I have?

 

Depends on where the springs go into bind. It they really bind at .570 you're in trouble no matter what.