[Formulajones]

Originally Posted by Formulajones

Yes they are now. Originally the AFR 305's he used on the first 502 were out of the box and milled to 110cc for a 9.6:1 compression.

Same heads I have that flow 370 cfm so more than capable of hitting the power level he showed me.

What's interesting about this, is that 9.6:1 is well below an acceptable pump gas compression level with aluminum heads. Some might even say it loses some efficiency at that compression. This is generally considered a safe level with an iron head LOL.

But the chevelle ran solid 10's at nearly 3700 lbs. race weight and was street driven with this combo.

It gave me a new appreciation for a low compression build.

[STEELCITYFIREBIRD]

Does the fact that these engines have HUGE lungs factor in someway?

[Formulajones]

Originally Posted by STEELCITYFIREBIRD

Does the fact that these engines have HUGE lungs factor in someway?

BBC's do have an advantage, in stock form the heads are superior to stock Pontiac stuff so they are much easier to make steam with.

The AFR's helped even more. Same head I have here currently running on a 454. 305's, out of the box with CNC combustion chamber flow 368 cfm on the intake side and 275 on the exhaust side.

Either way it fits the theme of low vs high compression builds. There is a lot of power hiding in this engine with more compression. As shown in the videos posted, Dave took the car from mid 10's to deep into the 9's with a compression bump and new camshaft to compliment the compression ratio.

["QUICK-SILVER"]

Originally Posted by "QUICK-SILVER"

I remember that Taylor article from years ago. It went more like how much you gained on a 455 when going from 8:1 to 9:1 and seems like it was 50hp. Then seems like the hp was cut in half with every point after that.
From fading memory
8 to 9 = 50
9 to 10 = 25
10 to 11 = 12.5

Clay

Went and found the article that had the '50 and 50' statement in it.
It is not the article I was partially remembering.

It appears to be full of mis-quotes and some non-sense pulled out of thin air.
The dude using that one sentence out of the article as fact....I'm calling BS
https://www.hemmings.com/magazine/mu...r/1281457.html

Clay

[1968GTO421]

Originally Posted by "QUICK-SILVER"

Went and found the article that had the '50 and 50' statement in it.
It is not the article I was partially remembering.

It appears to be full of mis-quotes and some non-sense pulled out of thin air.
The dude using that one sentence out of the article as fact....I'm calling BS
https://www.hemmings.com/magazine/mu...r/1281457.html

Clay

Thanks,Clay. I was wondering about that and you confirmed it.