Edelbrock heads- mill or not

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draginmopars

draginmopars

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picked up a set of used 6077 heads

004-2.jpg


replaced some valves, did a valve job, plus a little porting

building a 1970 spec 340 engine

cam is 268* at .484"

.040 over pistons are .035" above deck
using a 1008 fel pro gasket at .040" compressed
heads are .060" recessed chambers

was thinking of trying to get some quench
mill .030"

as is, comp will be 10.75
milled increases to 11.47

trans is 4 speed


What do you think ?
 
You might have detonation problems at 11.47 If there wharped you have little to no choice Ide leave them alone unless needed.
 
tekslk said:
You might have detonation problems at 11.47 If there wharped you have little to no choice Ide leave them alone unless needed.
Click to expand...

thats the thing

they need cleaned up
have some areas have bad scratches

if i get them lightly surfaced
cost the same as mill some off.
 
I run a 11-1, 360 on 93. The solid lifter cam is size able @ 248@ .050.
I would not push it with the small cam. Mill to clean it up nice and straight.
 
You should be fine I had my Edelbrocks on my 11.9 to 1 416 never had a detonation problem ran 93 octane all the time..
 
draginmopars said:
picked up a set of used 6077 heads

004-2.jpg


replaced some valves, did a valve job, plus a little porting

building a 1970 spec 340 engine

cam is 268* at .484"

.040 over pistons are .035" above deck
using a 1008 fel pro gasket at .040" compressed
heads are .060" recessed chambers

was thinking of trying to get some quench
mill .030"

as is, comp will be 10.75
milled increases to 11.47

trans is 4 speed


What do you think ?
Click to expand...

10.75 will be too much as well...this is why we port the chambers...it helps the ports to flow better, and get the compression where you want it. If you had started with the 60775 heads you could have used a .070 thick cometic gasket allowing good piston to head squish...then do a good valve job blended into the bowl, and port the chambers to 68cc for 9.75:1 compression.
Brian
 
Thanks everyone for the info

ou812- the reason i'm using these heads,
they are some I got a real good purchase price on

Didn't need them at the time
but couldn't pass on the deal

at this point

the short block is together

I can port the combustion chamber to 70cc
which would change the comp to 9.77-1
and /or put in a large duration/lift cam

what do you think
open to all suggestions

car will be a weekend cruiser
 
ou812 said:
10.75 will be too much as well...this is why we port the chambers...it helps the ports to flow better, and get the compression where you want it. If you had started with the 60775 heads you could have used a .070 thick cometic gasket allowing good piston to head squish...then do a good valve job blended into the bowl, and port the chambers to 68cc for 9.75:1 compression.
Brian
Click to expand...

You think 10.7 is to high ? I thought you could run higher compression with alu heads , or do the open chambers not allow for as high compression ?
 
jerry6 said:
You think 10.7 is to high ? I thought you could run higher compression with alu heads , or do the open chambers not allow for as high compression ?
Click to expand...

Yes for that small cam it is. You have to balance static compression and cam timing.

For me, less compression means more initial timing, safer total timing where the engine wants it to be, and if done correctly more airflow from the ports. It's all in how you open the chambers up.
 
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