the gasket from pami is a pain in the a** ask anyone with a big bore pami motor and they will tell you about the 2 or 3 times the head gasket sealer let go. done right the first time with the german silicone it's ok but even pami admits they are working on a better gasket that won't need the silicone. it took 2 tries to get mine sealed up[img]i/expressions/face-icon-small-sad.gif[/img]

 

The gasket from Pami comes as bare metal. Sealant comes in a tube. Customer applys the sealant. It is re-usable because you can strip it down to the metal and re-apply a new layer of sealant. I am not saying this is better just another type of gasket.

You won't gain compression with the gasket. Both stock and Pami / TVI gaskets should be good for 12:1 compression. Gasket thickness (after sealant is applied) is virtually identical.

As for the head bolts, I think there are a few on the forum that have had theirs strip (Angry???) Gary at TVI actually offers an add to bore out your stud holes so larger diameter studs can be used in addition to the metal the studs are constructed of being stronger (harder Rockwell Scale.)

Oh and yes, Jeffroe is right. Sometimes the metal ones can be a pain.

 

what about if youre up in the 12.5 compression area, do you think the stock gasket will hold it

 

The stock head-gasket is reusable, just pray paint it witth High-Heat paint, then put it on and torque it down when its still tacky.[img]i/expressions/face-icon-small-wink.gif[/img][img]i/expressions/face-icon-small-smile.gif[/img]




anyway, it works for me. [img]i/expressions/face-icon-small-happy.gif[/img]




BIggerisbetter.

 

I've got plenty of faith in the Rotax engineers to use their head gasket on any stock bored motor, wouldn't hesitate a bit.

 

Its not your compression ratio you need to worry about. It is detonation that blows head gaskets. Since detonation causes pressure spikes hundreds of times higher than normal, that is what does the damage. With that being said your 12.5:1 compression ratio engine will be more prone to detonation. As long as you address this issue with higher octane and a safe tune you should be alright. Copper gaskets are more resistant to being blown out by detonation but that just makes it a stronger link in the chain. Usually the next weakest link is the piston. Which one would you rather replace??

 

This head gasket thing really has me irked! Annihalater just told me that after rushing parts in to him in vegas so he could have a nice weekend once again turns into disaster. He already had a blown head gasket and he went and purchased Gary's new bolts and that supposedly wonderful copper gasket. Well Guess what?!, it blew out the first run up the hill!! What the hell is it going to take to not blow out these head gaskets on a 105mm bore?! I don't see how it could be detonation problemsm he runs a crazy mixture of race fuel so he is at least at 107 or 110 octane. someone HELPPPP!!!!!!!!! I can't affor these problems and I need input fast!!

 

can you tell where it is blowing at? and did you use the sealer they recommend?

 

Assuming that the hard parts are in good shape, the failure is most often due to improper assembly, not because of the gasket. An alluminum gasket would be best, but copper can be made to seal if proper care is taken. If your builder knows what he is doing, it should never fail a second time[a first failure could always be a mistake, a second failure is just stupidity]. I've seen local builders claim that they know what they are doing, but install the piston backwards; buyer beware.

I recomend staying away from the 105 bore unless you use a Team Pami cylinder. Almost any builder can seal the 102 bore, but the 105 seams to give them fits.

 

Well how about using a o-ring?