Estimate on how much to mill heads?
#718706
06/07/10 11:44 PM
06/07/10 11:44 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
|
OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
Even though when I bought my CNC Hughes Victors they said their work included milling the heads back to the original chamber size (75 cc is what Edelbrock advertises), they looked "big" to me. So, tonight I measured the two end chambers of one head and came up w/ 82 cc for both (fractionally more for the one chamber that shows more drop-out from the CNC program). Can anyone give me a reasonable estimate of how much should be milled to reduce the chamber volume per 1 cc? Now that I know they're actually bigger, I think I'll just take 'em down to 78 cc, same as w/ my Stage VIs, and leave the CR at 10.8. P.S. What got me thinking I needed to measure my heads was noticing that Hughes has recently changed their CNC Victor description to say their program increases the chamber size and for additional $ they'll bring the chamber down to what ever your target volume is. I wonder at what point they realized that 75 doesn't equal 82?
|
|
|
Re: Estimate on how much to mill heads?
[Re: BradH]
#718712
06/08/10 02:02 PM
06/08/10 02:02 PM
|
Joined: Jan 2003
Posts: 75,043 U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
|
Quote:
I think Indy's spec of milling .006" for each 1 cc is close enough, considering they have similar chamber shapes and volumes --> 4 cc = .024"
think it would need that much ? an open chamber 906 Rule of thumb is .005 for every 1 cc ????
|
|
|
Re: Estimate on how much to mill heads?
[Re: JohnRR]
#718714
06/08/10 03:23 PM
06/08/10 03:23 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
|
OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
Quote:
Quote:
I think Indy's spec of milling .006" for each 1 cc is close enough, considering they have similar chamber shapes and volumes --> 4 cc = .024"
think it would need that much ? an open chamber 906 Rule of thumb is .005 for every 1 cc ????
Think wide (open chamber) vs. deep (closed chamber).
|
|
|
Re: Estimate on how much to mill heads?
[Re: jamesc]
#718717
06/08/10 04:43 PM
06/08/10 04:43 PM
|
Joined: Jan 2003
Posts: 75,043 U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
|
Quote:
the indy chamber is smaller and has less effect when milled, with the 906 you're getting a lot of chamber reduction when cut.
That's right , for some reason I was thinking that the smaller chamber wouldn't need as much
|
|
|
Re: Estimate on how much to mill heads?
[Re: BradH]
#718721
06/09/10 10:34 AM
06/09/10 10:34 AM
|
Joined: Jan 2003
Posts: 75,043 U.S.S.A.
JohnRR
I Win
|
I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
|
Quote:
Unfortunately, one of the "gashes" is right on the edge of the combustion chamber where the gasket "fire ring" would be.
have it welded ?
|
|
|
Re: Estimate on how much to mill heads?
[Re: JohnRR]
#718722
06/09/10 10:59 AM
06/09/10 10:59 AM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
|
OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
Quote:
Quote:
Unfortunately, one of the "gashes" is right on the edge of the combustion chamber where the gasket "fire ring" would be.
have it welded ?
If necessary... but I hope that's not required.
|
|
|
Re: Estimate on how much to mill heads?
[Re: BradH]
#718723
06/09/10 11:11 AM
06/09/10 11:11 AM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
Quote:
Unfortunately, one of the "gashes" is right on the edge of the combustion chamber where the gasket "fire ring" would be.
how about a large bore gasket like 4.560? it would also help lower the compression.
|
|
|
Re: Estimate on how much to mill heads?
#718724
06/09/10 12:00 PM
06/09/10 12:00 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
|
OP
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
Quote:
how about a large bore gasket like 4.560? it would also help lower the compression.
I'll consider all options at this point.
Still feeling really STOOPID for having let the freakin' head fall over in the first place. Some things are so easily preventable... and yet they still happen.
|
|
|
|
|