Head gaskets Fel pro or Cometic?
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From: Orange county n.y.
Head gaskets Fel pro or Cometic? Ok i have a head gasket leak on my car now, right now it has Felpro 1041 gaskets and i was thinking about Cometics going in. I spoke to a very reputable sponser and he told me Felpro's seal much better than Cometics. Any Opinions??
The block and head surface need to be exact for cometics. Anything over .001" could cause a leak. Some people have better luck when they copper spray them. You'd have to ask Fel-pro what they use as a coating for sealant. I believe the Cometics have a .001" layer of Viton.
Cometics should be used only on brand new engine combo's because that way the deck on the block and heads are straight. Like said above the smallest variance will cause a leak.
I am going to use cometics on my build,the heads are freshly milled and the block only has 15k miles on it,i should be okay,if i had higher mileage or used heads i would not be using the cometics.I only want to do it once.If you decide to use cometics be sure to check and double check cleanliness and torque specs,sequences,i know i will when i do mine.
Originally Posted by SideStep
I have used Cometics on my last 3 head swaps... None were new motors (LS1s), all used Copper Sealant, NONE have leaked...
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My .02 here.... Both gaskets are excellent....both also have their plus's and minus's.
The Cometic is the better choice if very high cylinder pressure will be the norm (nitrous especially, forced induction, etc.), BUT, there is no question it is less forgiving to an install unless everything is close to optimal. A perfectly flat machined head and block deck and a very smooth finish on both is mandatory....not to mention a clean meticulous assembly with no small pieces of debris, left over old gasket etc.
A Felpro on the other hand is much more forgiving and will seal almost regardless of finish, has a tolerance for a slight warp in block and/or head, but ultimately doesn't have the capacity to put up with ludicrous cylinder pressure for an extended period of time....it can literally start to push and work its way up the head studs, but if you see that upon a disassemby, its highly likely the motor was detonating badly which causes immense shock waves that just kill the gasket (among other things....bearings, pistons, etc.).
BTW, Im not saying a Felpro wont hold up to some boost, because it will, its just that your window of having head gasket issues if some detonation finds its way into the equation is probably not as comfortable as it would be with a multi layer steel sandwich (the Cometic).
Once again....pro's and cons to both....either are good choices but one might be better than the other armed with this information as well as knowing the type of engine you are building and the abuse it will ultimately see.
Hope this helps...
Tony M.
The Cometic is the better choice if very high cylinder pressure will be the norm (nitrous especially, forced induction, etc.), BUT, there is no question it is less forgiving to an install unless everything is close to optimal. A perfectly flat machined head and block deck and a very smooth finish on both is mandatory....not to mention a clean meticulous assembly with no small pieces of debris, left over old gasket etc.
A Felpro on the other hand is much more forgiving and will seal almost regardless of finish, has a tolerance for a slight warp in block and/or head, but ultimately doesn't have the capacity to put up with ludicrous cylinder pressure for an extended period of time....it can literally start to push and work its way up the head studs, but if you see that upon a disassemby, its highly likely the motor was detonating badly which causes immense shock waves that just kill the gasket (among other things....bearings, pistons, etc.).
BTW, Im not saying a Felpro wont hold up to some boost, because it will, its just that your window of having head gasket issues if some detonation finds its way into the equation is probably not as comfortable as it would be with a multi layer steel sandwich (the Cometic).
Once again....pro's and cons to both....either are good choices but one might be better than the other armed with this information as well as knowing the type of engine you are building and the abuse it will ultimately see.
Hope this helps...
Tony M.
Tony,
Good information, have you used the SCE titan gaskets? I am planning to use them on my H/C job, they are purported to be a good compromise between copper and elastic gasket types for good usage in a street application. Just wondering what your opinion is, if any, regarding these alternatives to cometics.
Good information, have you used the SCE titan gaskets? I am planning to use them on my H/C job, they are purported to be a good compromise between copper and elastic gasket types for good usage in a street application. Just wondering what your opinion is, if any, regarding these alternatives to cometics.
I'll be using Fel-Pro cam only i must hope for the best. I don't think anythign will go wrong. But if anything should happen i dont believe the gasket would be the one to blame- atleast i sure hope not. They have been around for a while, and i have heard also that Cometics are great for new setups.
Originally Posted by frodo84
Tony,
Good information, have you used the SCE titan gaskets? I am planning to use them on my H/C job, they are purported to be a good compromise between copper and elastic gasket types for good usage in a street application. Just wondering what your opinion is, if any, regarding these alternatives to cometics.
Good information, have you used the SCE titan gaskets? I am planning to use them on my H/C job, they are purported to be a good compromise between copper and elastic gasket types for good usage in a street application. Just wondering what your opinion is, if any, regarding these alternatives to cometics.
I dont have any experience with them so I wouldn't be able to pass judgement on them one way or the other....
