Compression Ratio Question on Power Pack Heads

[buzzard]

I have a set of Power Pack 60cc heads that I may have rebuilt for my 327. The engine has stock flat top pistons. When I use some of the online compression calculators, I come up with 10.29:1. More than I want on pump gas on the street. Is this right?

I put in:

4 in. bore

3.25 in stroke

4.166 gasket bore

.039 gasket thickness
60 cc chamber

0 dome volume ( Is that right for stock flat top pistons?)

I used .016 deck clearance. I don't know and that is the default

Is this correct? Also, what can I do to lower compression a bit. How thick can I get head gaskets? If I double the .039 and put in .078, I get a 9.29:1, which is right about where I'd like to be. Somewhere between 9.25 and 9.75 seems ideal.

Do my #'s look accurate? Is there something I can do other than find 64cc camel humps?

[12packo94s]

in a standard gasket .051 is pretty much as thick as it gets
from fel pro

if you wanna go to copper then you can ge allthe way up to .093 they also have a .080 and .073 offered from sce

[manyolcars]

The information I have seen suggests that many, many common heads are more powerful than the old Power Packs

[Bass]

I would NOT use those heads on your 327. They will only end up restricting it. Surely you can find something better to use....I just passed on a pair of complete 462 heads at the Fredricksburg swap for $75. (I would have bought them but I spent all my cash on a pair of Halibrands)

They're still out there...you just have to go hunt 'em down. Have you ever even been to a swap meet? http://www.jalopyjournal.com/ubbthreads/images/graemlins/tongue.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[Bigcheese327]

Truly. I just took better heads than that off my 327. Get a set of fuelie heads, or even *gasp* aftermarket aluminum jobbies. Save the Powerpacks for the restorers.

[buzzard]

Bass, I went to a swap meet once before I got into the car business. Now I work every Saturday. Plus, they start 'em too early in the morning!

I picked these up for $36. We'll see what I can find in 461's or 462's.

[Hot Rod To Hell]

Another thing to consider is that you do not have true "flat" tops. There are valve reliefs in them, which will lower the compression ratio some. And I have to agree with all the other guys, from a performance standpoint those heads suck.

[Bass]

Just fuckin with ya Steve...the Rosankey swap is in a couple weeks. You gonna make it? I'm willing to bet you could find something to use there.

[buzzard]

I'm taking the day off that Friday, or quitting Thurs. night. Either way, I'll be there. Haven't had a day off (other than closed Sun.) in nearly 2 months. Been working 11-13 hour days, so I deserve to go blow some $$$.

[AHotRod]

Buzzard,
1.Factory deck height for a 327 is .029
2.Our Fel-Pro head gaskets are .039 compressed (installed)
3.Flat top pistons w/2 valve reliefs are -3.4cc
4.Flat top pistons w/4 valve reliefs are -5.4cc
5.You should be at 9.5-1 with 4 valve pistons .030 over size.
Hope this helps you out!
Glenn

[Roothawg]

Powerpack heads are good for restorers...that's all.

[Fourdy]

What is the designation for the power pack heads. casting #? casting shape on the heads, humpback, triangle etc? Thanks

Fourdy

[buzzard]

Power Packs are 59-60cc heads from '58 to I think '63. Mine are 896's. Does that answer your question?

Glenn, thank you very much for the info. That is exactly what I needed to know.