Thicker Head gasket to bring down compression
#1909197
09/09/15 01:31 PM
09/09/15 01:31 PM
|
Joined: May 2008
Posts: 984 San Diego CA
65 Hemi
OP
super stock
|
OP
super stock
Joined: May 2008
Posts: 984
San Diego CA
|
I have 2 motors that I'm thinking about putting on the street 90% and 10% race. Has anybody ever run the .095 Cometic head gaskets to lower their compression for pump gas. What's the down sides? They will never be full effort race motors. One is a 493" aluminum Indy block with -1 heads and the other is a 500" iron World block with -1 aluminum heads. Thanks in advance for the input.
Doug
MOPAR or NO CAR!!! 1965 Dodge Coronet soon a 6.1 Hemi with a Magnson blower 810 hp on pump gas 1964 Dodge Polara 582" Indy alum Block 426-1RA heads, 1933 Plymouth PE all Steel, LT1 4L60E 1959 Plymouth Savoy 33,000 mile survivor Old cars are never done. They are ongoing projects!
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: 65 Hemi]
#1909228
09/09/15 02:10 PM
09/09/15 02:10 PM
|
Joined: Feb 2005
Posts: 20,203 PA.
pittsburghracer
"Little"John
|
"Little"John
Joined: Feb 2005
Posts: 20,203
PA.
|
Where is your compression at right now?
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: pittsburghracer]
#1909286
09/09/15 03:23 PM
09/09/15 03:23 PM
|
Joined: May 2008
Posts: 984 San Diego CA
65 Hemi
OP
super stock
|
OP
super stock
Joined: May 2008
Posts: 984
San Diego CA
|
493" aluminum is at 13.46:1 and the 500" iron block is at 12.4:1. I have 2 other race cars and race motors so these will very seldom see the track if at all. Where is your compression at right now?
Doug
MOPAR or NO CAR!!! 1965 Dodge Coronet soon a 6.1 Hemi with a Magnson blower 810 hp on pump gas 1964 Dodge Polara 582" Indy alum Block 426-1RA heads, 1933 Plymouth PE all Steel, LT1 4L60E 1959 Plymouth Savoy 33,000 mile survivor Old cars are never done. They are ongoing projects!
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: 65 Hemi]
#1909331
09/09/15 04:28 PM
09/09/15 04:28 PM
|
Joined: Jan 2003
Posts: 4,291 Morrow, OH
markz528
master
|
master
Joined: Jan 2003
Posts: 4,291
Morrow, OH
|
I got .125 inch. Downside is $400 for the gaskets. Never again.......
67 Coronet 500 9.610 @ 139.20 mph 67 Coronet 500 (street car) 14.82 @ 94 mph 69 GTX (clone) - build in progress......
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: 65 Hemi]
#1909341
09/09/15 04:39 PM
09/09/15 04:39 PM
|
Joined: Nov 2004
Posts: 6,890 North Alabama
Monte_Smith
master
|
master
Joined: Nov 2004
Posts: 6,890
North Alabama
|
If you just plan to DRIVE it on the street, pump gas and even high compression is not a big deal. Anything will drive on pump gas, with the timing a little low. When you choose to stick your foot in it is the issue. So you would either need the timing to be really low all the time, or lower the compression.
At the Pump Gas Drags, we ran some really high compression stuff, WITH a lot of nitrous and had no issues, just had the timing really low. But that's a RACE scenario. For just cruising, it still be snappy, plus safe for the assorted blast here and there.........I would lower the compression
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: Monte_Smith]
#1909353
09/09/15 04:57 PM
09/09/15 04:57 PM
|
Joined: May 2008
Posts: 984 San Diego CA
65 Hemi
OP
super stock
|
OP
super stock
Joined: May 2008
Posts: 984
San Diego CA
|
Monte, would you lower compression by a thicker head gasket or do you think that is just a band aid. I just hate to mill the pistons down and re balance them. These motors have good part and I hate to be penny wise and dollar foolish! I just don't want to be running around all the time to chase race gas. I want to hop in and drive 50-100 miles. Both of these will always be NA motors. Like I said I have 2 race motors 583 Aluminum Hemi Indy 426-1 RA motor and a 583 B1MC motor for my race cars. Thanks y'all for the input. If you just plan to DRIVE it on the street, pump gas and even high compression is not a big deal. Anything will drive on pump gas, with the timing a little low. When you choose to stick your foot in it is the issue. So you would either need the timing to be really low all the time, or lower the compression.
At the Pump Gas Drags, we ran some really high compression stuff, WITH a lot of nitrous and had no issues, just had the timing really low. But that's a RACE scenario. For just cruising, it still be snappy, plus safe for the assorted blast here and there.........I would lower the compression
Doug
MOPAR or NO CAR!!! 1965 Dodge Coronet soon a 6.1 Hemi with a Magnson blower 810 hp on pump gas 1964 Dodge Polara 582" Indy alum Block 426-1RA heads, 1933 Plymouth PE all Steel, LT1 4L60E 1959 Plymouth Savoy 33,000 mile survivor Old cars are never done. They are ongoing projects!
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: dogdays]
#1909414
09/09/15 06:32 PM
09/09/15 06:32 PM
|
Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Run E85 and keep the compression.
R. If you have E-85 in the area(if its easy to find) thats all I would do... change over the carb to E-85 which is probably about the same cost as the head gaskets EDIT this is based on if you have enough fuel pump to supply 30% more fuel
Last edited by MR_P_BODY; 09/09/15 06:35 PM.
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: 65 Hemi]
#1909445
09/09/15 07:36 PM
09/09/15 07:36 PM
|
Joined: May 2008
Posts: 984 San Diego CA
65 Hemi
OP
super stock
|
OP
super stock
Joined: May 2008
Posts: 984
San Diego CA
|
The issue with E85 is the stations are few and far between. 2 within a 35 mile radius and one had water in their e85 when I ran it before. Also with the humidity here I had a little trouble and even tried blowing nitrogen on top of the tank when the car would sit for 3-4 weeks durning the winter.
Doug
MOPAR or NO CAR!!! 1965 Dodge Coronet soon a 6.1 Hemi with a Magnson blower 810 hp on pump gas 1964 Dodge Polara 582" Indy alum Block 426-1RA heads, 1933 Plymouth PE all Steel, LT1 4L60E 1959 Plymouth Savoy 33,000 mile survivor Old cars are never done. They are ongoing projects!
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: 65 Hemi]
#1909446
09/09/15 07:37 PM
09/09/15 07:37 PM
|
Joined: May 2008
Posts: 984 San Diego CA
65 Hemi
OP
super stock
|
OP
super stock
Joined: May 2008
Posts: 984
San Diego CA
|
The issue with E85 is the stations are few and far between. 2 stations within a 35 mile radius and one had water in their e85 when I ran it before. Also with the humidity here I had a little trouble and even tried blowing nitrogen on top of the tank when the car would sit for 3-4 weeks durning the winter.
Doug
MOPAR or NO CAR!!! 1965 Dodge Coronet soon a 6.1 Hemi with a Magnson blower 810 hp on pump gas 1964 Dodge Polara 582" Indy alum Block 426-1RA heads, 1933 Plymouth PE all Steel, LT1 4L60E 1959 Plymouth Savoy 33,000 mile survivor Old cars are never done. They are ongoing projects!
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: Monte_Smith]
#1909555
09/09/15 10:51 PM
09/09/15 10:51 PM
|
Joined: Dec 2006
Posts: 2,122 Byron, NY
W.I.N. Racing
top fuel
|
top fuel
Joined: Dec 2006
Posts: 2,122
Byron, NY
|
If you mill the pistons .040 to put them in the hole more, or put .040 of head gasket on it...........what's is the difference other than making the top of the piston thinner. I would run a thicker gasket and then you always have the easy option of returning the compression
'01 P1500, Blown/Inj BAE,/Veney ,Bruno/CS2,Dana 60 '01 Dodge 3500 S Cummins Auto, Fresh air kit, 4" Exhaust, '05 Dodge Magnum R/T - Too Much to list '60 Willys CJ5 '01 International LPX - Project,DT466, Allison '64 Plymouth Valiant, Inj 528 Hemi, 2spd
|
|
|
Re: Thicker Head gasket to bring down compression
[Re: 65 Hemi]
#1909568
09/09/15 11:04 PM
09/09/15 11:04 PM
|
Joined: May 2008
Posts: 984 San Diego CA
65 Hemi
OP
super stock
|
OP
super stock
Joined: May 2008
Posts: 984
San Diego CA
|
Thanks for all the input. I will order the gaskets and rest easy when I install them.👍🏻
Doug
MOPAR or NO CAR!!! 1965 Dodge Coronet soon a 6.1 Hemi with a Magnson blower 810 hp on pump gas 1964 Dodge Polara 582" Indy alum Block 426-1RA heads, 1933 Plymouth PE all Steel, LT1 4L60E 1959 Plymouth Savoy 33,000 mile survivor Old cars are never done. They are ongoing projects!
|
|
|
|
|