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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Cometic Head Gaskets LEAKING!

  • Thread starter Thread starter soontobefastfox
  • Start date Start date Nov 2, 2007
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xr8d302

I bought a 27" monitor to compensate for my lack o
Apr 29, 2004
1,113
0
36
Medicine Hat, AB
Nov 5, 2007
#41
  • Nov 5, 2007
  • #41
Paul, I didn't want to say this on here...

but I'm pregnant.



You're the daddy.
 

soontobefastfox

Member
Nov 15, 2005
275
0
16
Troy, Michigan
Nov 5, 2007
#42
  • Nov 5, 2007
  • #42
xr8d302 said:
Paul, I didn't want to say this on here...

but I'm pregnant.



You're the daddy.
Click to expand...

uhh derailed?
 

xr8d302

I bought a 27" monitor to compensate for my lack o
Apr 29, 2004
1,113
0
36
Medicine Hat, AB
Nov 5, 2007
#43
  • Nov 5, 2007
  • #43
soontobefastfox said:
uhh derailed?
Click to expand...


Sorry man
 

soontobefastfox

Member
Nov 15, 2005
275
0
16
Troy, Michigan
Nov 5, 2007
#44
  • Nov 5, 2007
  • #44
xr8d302 said:
Sorry man
Click to expand...

no problem, you did succesfully lighten the mood in this thread
 

xr8d302

I bought a 27" monitor to compensate for my lack o
Apr 29, 2004
1,113
0
36
Medicine Hat, AB
Nov 5, 2007
#45
  • Nov 5, 2007
  • #45
yeah, that was my intention, good to know it paid off. Good luck with the gasket issue man!
 

BlownFiveLiter

have car, will race....wait, it doesn't run
15 Year Member
Nov 29, 1999
3,133
18
108
Chicagoland
Nov 5, 2007
#46
  • Nov 5, 2007
  • #46
xr8d302 said:
Paul, I didn't want to say this on here...

but I'm pregnant.



You're the daddy.
Click to expand...

You, back under my desk! I mean um... back over to 94-95!


Back on topic:

I wonder if the issue of leaking between the layers has anything to do with the R&D that Cometic did when they made the gaskets, like they need more torque than a regular head gasket? Say they used a 351 to test them with 1/2" head bolts and 100 lb. ft. of torque, versus the 302's 7/16" bolts and only 85 lb. ft.?
 

soontobefastfox

Member
Nov 15, 2005
275
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16
Troy, Michigan
Nov 5, 2007
#47
  • Nov 5, 2007
  • #47
xr8d302 said:
yeah, that was my intention, good to know it paid off. Good luck with the gasket issue man!
Click to expand...

Thanks! Looks like this winter I will betting ARP studs with bushings and Felpro MLS Permatorque gaskets. I'll see if I can send the Cometics back to Cometic and get my money back but we will have to see about that.

Not to bad but still a pain. I'm glad I am still doing a couple other fun mods this winter.
 

soontobefastfox

Member
Nov 15, 2005
275
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16
Troy, Michigan
Nov 5, 2007
#48
  • Nov 5, 2007
  • #48
StangGT1995 said:
You, back under my desk! I mean um... back over to 94-95!


Back on topic:

I wonder if the issue of leaking between the layers has anything to do with the R&D that Cometic did when they made the gaskets, like they need more torque than a regular head gasket? Say they used a 351 to test them with 1/2" head bolts and 100 lb. ft. of torque, versus the 302's 7/16" bolts and only 85 lb. ft.?
Click to expand...

Interesting point. That could be the problem. Couldn't overtorquing 7/16" bolts cause other problems?
 

gcomfx.com

Founding Member
Oct 22, 2002
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56
Republic, MO
Nov 6, 2007
#49
  • Nov 6, 2007
  • #49
Yeah, sorry about that guys. I was under the wrong impression about "he was building". It appears to me he "bought" an engine built just like I did. Which by the way my engine matched another setup in my engine builders shop. His cometics sealed just fine (with a turbo). Which is why I'm pretty confident in saying I bet it's a quality control issue. I hope to have mine back apart here pretty quick. Once we mill the pistons a little, I'll have more choices for gaskets as we can go thinner.

soontobefastfox - if you get yours fired up before I do, let me know which route you went and if it was successful or not. I'll do the same. Right now I'm saving up for a few other things while we're doing this all over. With Christmas coming up fast... it may be Jan. Good luck! If cometic gives you the run around... send them here. I can find out my engine builders order number to help refresh their memory if they still say they've never had issues.

Oh... almost forgot. I already have one kid. xr8d you know it was Guero. Look at the eyes and hair when it comes out.
 

soontobefastfox

Member
Nov 15, 2005
275
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16
Troy, Michigan
Nov 6, 2007
#50
  • Nov 6, 2007
  • #50
gcomfx.com said:
soontobefastfox - if you get yours fired up before I do, let me know which route you went and if it was successful or not. I'll do the same. Right now I'm saving up for a few other things while we're doing this all over. With Christmas coming up fast... it may be Jan. Good luck! If cometic gives you the run around... send them here. I can find out my engine builders order number to help refresh their memory if they still say they've never had issues.
Click to expand...

Thanks! I may not be until January also, I am very busy at the moment. I talked to a couple engine builders and they do not sell or recommend Cometic for this reason. They said use the MLS Felpro Permatorque gaskets, which is what I am going to do along with head studs.
 

rd

Founding Member
Jan 12, 2000
3,316
63
109
Ocean Springs MS
Nov 6, 2007
#51
  • Nov 6, 2007
  • #51
Some old info on the oil pump seizures.

My first sbf did this, a 260 two barrel back in 1970.

It turns out the oil pump screen was only stretched across the bottom of the pickup where there is a solid metal portion of the bottom of the pickup.

The screen is crimped at the perimeter. This is, I am told, by design, so that if the screen is totally plugged, the suction will lift the rear of the screen and allow oil to flow.

Yep, it took awhile for me to figure out how big chunks of valve stem seal got in the oil pump....

Cleaned it, put in a new pump shaft, and drove the daylights out of that 65 Mustang for 3 years....
 

gcomfx.com

Founding Member
Oct 22, 2002
3,690
0
56
Republic, MO
Nov 6, 2007
#52
  • Nov 6, 2007
  • #52
Ouch, that's not good. But it's cool the engine kept going once you cleaned it out. BTW - when the shaft broke. Aprox. how long did it run before you caught it and shut it down? Just curious.
 

Pokageek

Active Member
Jun 10, 2005
2,767
0
46
MA, USA
Nov 9, 2007
#53
  • Nov 9, 2007
  • #53
Ok I am curious, so why would one use cometic or whatever the name is - gaskets if they have a potential to fail? Is there something special about them?
 

Rick 91GT

Mustang Master
Nov 29, 1999
9,692
95
99
PA
Nov 10, 2007
#54
  • Nov 10, 2007
  • #54
Pokageek said:
Ok I am curious, so why would one use cometic or whatever the name is - gaskets if they have a potential to fail? Is there something special about them?
Click to expand...

A MLS (Multi Layer Steel) style gasket has the best sealing strength and it will take more abuse then a convential gasket. These are perfect for high cylinder pressure car, boost, N2O or high comp NA. They give you a little extra protection if you get greedy, although you can blow them. They are also re-usable, drill out all the rivot but one and clean then very good, coat them with the Chrysler spray I mentioned and you can put them right back on and use them again. Most guys do not use them over but I have done it at the track successfully.
 

soontobefastfox

Member
Nov 15, 2005
275
0
16
Troy, Michigan
Nov 11, 2007
#55
  • Nov 11, 2007
  • #55
Rick 91GT said:
A MLS (Multi Layer Steel) style gasket has the best sealing strength and it will take more abuse then a convential gasket. These are perfect for high cylinder pressure car, boost, N2O or high comp NA. They give you a little extra protection if you get greedy, although you can blow them. They are also re-usable, drill out all the rivot but one and clean then very good, coat them with the Chrysler spray I mentioned and you can put them right back on and use them again. Most guys do not use them over but I have done it at the track successfully.
Click to expand...

Exactly, I wanted them because of their superior sealing strength. Also I plan to run a procharger in the future and wanted high performance gaskets that could support high cylinder pressures. Another reason was at the time Cometic was the only MLS gasket company I could find (now Felpro has MLS gaskets, which I plan to use).
 

gcomfx.com

Founding Member
Oct 22, 2002
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Republic, MO
Nov 12, 2007
#56
  • Nov 12, 2007
  • #56
Also, some of us wanted to be cheap and change the gaskets to get the right piston clearance on a decked engine. You need a thicker gasket to try this.
 

soontobefastfox

Member
Nov 15, 2005
275
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Troy, Michigan
Jun 5, 2008
#57
  • Jun 5, 2008
  • #57
Finally got my stang running. I decided to go with Fel-Pro 1011-1 gaskets because I don't plan on running to much boost (~10-12 psi).

Thanks for all the help guys. Sorry for bring this back from the dead.
 

gcomfx.com

Founding Member
Oct 22, 2002
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Republic, MO
Jun 5, 2008
#58
  • Jun 5, 2008
  • #58
Guess I should follow up as well. I ended up going with a whole new block (properly decked). No more Multi-layer gaskets here. Just a good ole Fel-pro and it seems to be holding just fine.
 

gcomfx.com

Founding Member
Oct 22, 2002
3,690
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56
Republic, MO
Jun 30, 2008
#59
  • Jun 30, 2008
  • #59
I am still having a few issues with the tune/transmission conflict. We fixed the 3rd gear blow out by going back to stock settings. Now we have to fix the shifts. The car basically cuts out on each shift.

I did run a new best yesterday.

12.58 @ 108 on ET Streets and 3.55 gears. The car stumbles on the shifts and has a weird miss issue in 2nd gear at 5,000 rpm. Definitely more to be had....

Pics and vids soon. I won the burnout contest at the track rental. I finally got my nitto d/r's hot enough to stick!!!!!!
 
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