Cometic or ????

[TurboWh1]

Is everyone basically running cometic head gaskets? What other options are out there? Tired of the coolant / oil leaks

 

[TurboBuRick]

That's what I use but if there is issues with oil and coolant leaking from head gaskets, cosmetics are not going to help.

Are you sure these leaks are from the head gaskets?

 

[BEATAV8]

There's other stuff out there but all I will use is cometic. If there's a coolant or an oil leak its because something is wrong. Head surface, deck surface, cleanliness, or fasteners.

 

[BOJANGLES]

everybody has their own opinion, I used RJC "bulletproof" kit, quit using cometic in my motocross days. couldn't seem to keep a head sealed with a cometic until we went back to factory honda gaskets.. and my quad engine was 14:5:1 compression! my .02 (would be no cometic)

 

[jasjamz]

SCE Titan, Felpro 9441 PT, Victors.....
But as said... I copper coat them and dont have any issues.

 

[TurboWh1]

Surface on both the head and block are good and double verified good. I’m pressure testing the heads this week just to rule that out. Currently running Cometic # C5691-040. The studs were sealed with thread sealant as well. Coolant has always been present at the lower front and rear studs on both heads. Not a lot of coolant but you could always see green at the top of the nut. The oil issue is of my #1 priority. Its making a mess and I’m just tired of it. I did get some recommendations for SCE and the 1000 Felpro gasket. I have no experience with either of those. I did run the stock GM gaskets back in the day. They worked well with no leaks.

 

[TurboWh1]

Pics of the gasket when I removed the head.

 

[BEATAV8]

Sealing the threads...... For 100% success 100% of the time use Loctite 545 hydraulic thread sealant. This stuff never leaks.

 

[TurboWh1]

Sealing the threads...... For 100% success 100% of the time use Loctite 545 hydraulic thread sealant. This stuff never leaks.

A friend of mine recommended the same thing but isn’t it a pain to remove the stud if you ever need too?

 

[BARRACUDA1968]

I just went through this with Cometics. Never had a coolant leak but they leaked oil pretty bad. I separated them and copper sprayed each layer. From what I have read some guy's have good luck with them and some don't. I got tired of the mess and went to Felpro 9441pt. No leaks.

 

[BARRACUDA1968]

I just went through this with Cometics. Never had a coolant leak but they leaked oil pretty bad. I separated them and copper sprayed each layer. From what I have read some guy's have good luck with them and some don't. I got tired of the mess and went to Felpro 9441pt. No leaks.

 

[TurboWh1]

I just went through this with Cometics. Never had a coolant leak but they leaked oil pretty bad. I separated them and copper sprayed each layer. From what I have read some guy's have good luck with them and some don't. I got tired of the mess and went to Felpro 9441pt. No leaks.

The Felpro 9441pt are like a stock gasket from what I recall? When I ran the OEM style gaskets I never had an issue, even running head studs. My only concern is high boost situations. I was considering Felpro 1000 or SCE head gaskets...

 

[bison]

Rtv thin smear:

I'd do in between the layers in this area also. The oil won't have a leak path if done this way. You need a tiny bit. That's all


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[forcefed3.8's]

I used to copper sparay the cometics, and they always leaked oil. I now do what Bison said, small smear of ultra black on both sides of the gasket. I never had a coolant leak. Could be leaking out of the stud, GM Cadillac tabs seal that up.

 

[TurboWh1]

I really liked the cometics if they weren’t leaking. You do not take the gasket apart and apply between layers correct? Just buy new, right out of the box, RTV both sides at the upper corners?

Also, is Cometic part #C5691-040 correct for the 109 engine? I see they have extra holes for additional head bolts. I’m guessing a stage motor application.

 

[BEATAV8]

A friend of mine recommended the same thing but isn’t it a pain to remove the stud if you ever need too?

Not with 545. It's a sealer, not a locker.

 

[TurboWh1]

Not with 545. It's a sealer, not a locker.

Thats good to know. I'll have to track some down... My dads tool shop probably has some I can borrow

 

[BEATAV8]

Thats good to know. I'll have to track some down... My dads tool shop probably has some I can borrow

for prep just chase the threads in the block nice and clean with a thread chase or a tap. wire brush the threads on the studs nice and clean.

 

[TurboWh1]

So is the concencus, Cometic still my best option? I don't beat on my car too often and I'm usually conservative when I do.

 

[jasjamz]

So is the concencus, Cometic still my best option? I don't beat on my car too often and I'm usually conservative when I do.

I would use a Felpro 9441 PT and studs. Torque them. Let it sit overnight. Check them again the next day.