Main Menu

75cc or 84cc Aluminum Heads

Started by edison1970, April 23, 2021, 11:22:28 AM

Previous topic Next topic

0 Members and 1 Guest are viewing this topic.

edison1970

Which size would work best on a 440 with 6 pak pistons that is strictly street use?  Would the 75cc heads bring the compression too high? Edelbrock E-Street  heads is what I was looking at. Confused on what the compression would be.
Thanks

Chryco Psycho

Why spend more for less , use 440 Source Stealths for 1/2 the price instead or use Trick Flow & get a better head

RUNCHARGER

I agree: Go Trickflow, better quality, better flow.
Sheldon


edison1970

Main reason is cost. I found a brand new set of the 75cc for cheap. A lot less than the 440 source heads.

RUNCHARGER

#4
Oooh: In that case yes. I prefer the smaller chambers anyway. In the off chance you have too much compression it is a lot easier to get a thicker headgasket than it is to mill the heads if your compression ends up too low (more likely).
Sheldon

Chryco Psycho

Makes me wonder why they are being sold !

jimynick

Quote from: Chryco Psycho on April 25, 2021, 10:56:32 PM
Makes me wonder why they are being sold !
Hahaha, that's because you graduated from the "You don't get much for nothing" school Neil, and have been there and done that.  :cheers:
In the immortal words of Jimmy Scott- "pace yourself!"


edison1970

Mama didn't raise a fool. Brand new in unopened box with head gaskets, head bolts and plugs. I have always been the guy that looks at a glass half full. And never passed on a good deal.

Chryco Psycho

What kind of head gaskets , I will only use MLS & usually Cometic between iron & Alum .
Make sure you have a machinist check the heads over QC is not a strong point for Eddy .

jimynick

"Mama didn't raise a fool." Of that I have no doubt and my comment was not meant to be insulting. It's just the old conundrum that if it seems to good to be true, it often is. If you got a deal, then God bless and more power to you. Neil has a point regarding the QC of Edelbrock heads, and ask the machinist to check the RA of the finish, as too coarse a finish can "grab" and since the aluminum heads and iron block expand at a different rate, it the gasket binds on either surface, it can sheer and that's no fun either. Good luck with it!  :cheers:
In the immortal words of Jimmy Scott- "pace yourself!"

Pinionsnubber

Quote from: Chryco Psycho on April 26, 2021, 08:56:39 PM
What kind of head gaskets , I will only use MLS & usually Cometic between iron & Alum .
Make sure you have a machinist check the heads over QC is not a strong point for Eddy .

I work with Fel Pro 1009, good for compression 12:1


Strawdawg

Quote from: Pinionsnubber on April 27, 2021, 08:32:22 PM
Quote from: Chryco Psycho on April 26, 2021, 08:56:39 PM
What kind of head gaskets , I will only use MLS & usually Cometic between iron & Alum .
Make sure you have a machinist check the heads over QC is not a strong point for Eddy .

I work with Fel Pro 1009, good for compression 12:1

You missed the point.  Aluminum grows at a different rate than iron when heat is added to the equation.  Ideally, one wants the difference to be negated by the smoothness between the two different metals without damage to the gasket or loss of seal.  MLS allows this without potential failure down the road.  The 1009 is still a composition gasket I think.
Steve

Chryco Psycho

 :iagree:

I do not like to replace head gaskets for no reason , 1009 is composition & will fail in time , if you live where I used to the temps varied from - 45 to + 30 C & then add running temp of close to 100* C so the expansion & contraction was extreme , 1009 gaskets will fail , why take the chance , install Cometic & it will stay sealed .

Pinionsnubber

Ok, thanks
Three RB-Engines have be running the 1009 for 5-6 years withaout any problems .
I`ll do it differently, thanks .

DrEamer

..... and this in the just so you know category,  Trick Flow has changed from specing MLS Cometic gaskets in favor of the Felpro's. My guess is that the Cometic's surface finish requirements may have been causing issues. Anyway, just putting the info out there for your consideration.