Cometic gaskets
03-09-2006, 02:22 PM
#12
Re: Cometic gaskets
Originally Posted by Big Block Billy
A legendary engine builder, Lee at Lab engine strongly recommends them.
I like Felpro, but Cometic really is the cutting edge in performance gasket technology.
Cometic provides so many more different bore sizes and thicknesses than anybody.
Whatever the cost, they are worth every cent ! BBB
I like Felpro, but Cometic really is the cutting edge in performance gasket technology.
Cometic provides so many more different bore sizes and thicknesses than anybody.
Whatever the cost, they are worth every cent ! BBB
03-09-2006, 10:35 PM
#13
Registered
Thread Starter
Re: Cometic gaskets
Originally Posted by Linster
Cometic says yes as long as you measure them and they come up to .015 thicker than the compressed thickness. I dont know if I would, too much work if one leaks.
The key is to not let any debris get between the layers. That might be hard after using once. If I was going to reuse, I probally would apply copper coating to the gasket. A friend of mine does that every time. I just use them bare and open the package right before I install it to keep it clean.
The key is to not let any debris get between the layers. That might be hard after using once. If I was going to reuse, I probally would apply copper coating to the gasket. A friend of mine does that every time. I just use them bare and open the package right before I install it to keep it clean.
Where do I find the acceptable compressed thickness figure?
03-09-2006, 11:05 PM
#15
Registered
Join Date: Mar 2005
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Re: Cometic gaskets
One good thing about cometic gaskets is that they handle detonation really well. I was running 10.2;1 compression on my engines, and the detonation actually damaged the pistons before the head gaskets.
These things are good !
These things are good !
03-10-2006, 06:41 AM
#16
Off the Radar
Platinum Member
Join Date: May 2001
Location: Short Pump or Colonial Beach, VA
Posts: 1,097
Likes: 0
Received 1 Like
on
1 Post
Re: Cometic gaskets
Originally Posted by 2112
Where do I find the acceptable compressed thickness figure?
03-10-2006, 11:46 AM
#17
Registered
Join Date: Jan 2004
Location: San Diego, California
Posts: 2,777
Likes: 0
Received 6 Likes
on
6 Posts
Re: Cometic gaskets
One of the keys to having all the time success with Cometic head gaskets is to make sure the block and head surfaces are correctly finished , free of nicks and gouges or scratches and to make sure you use a good cleaner like alcohol or such to clean both surfaces before assembly and make sure you do not get carried away with head bolt thred sealer-lubricants that will squish into the gasket seal area when installing. Also inspect the viton(black) coating for gouges, abrasion and such because it is this coating which actually fills in the tiny voids in the surfaces when the gaskets are torqued. Proper torque in proper pattern in at least three steps is also advised. We have been using exclusively Cometic head gaskets for over three years on all our 496 engines and kits without one failure or problem. They are in my opinion definitly the best head gasket for marine use. Yes we do use them over on the dyno motors several times and checking the uncompressed height is a must when you do this.
Ray @ Raylar
Ray @ Raylar
03-20-2006, 01:29 AM
#18
Registered
Thread Starter
Re: Cometic gaskets
Did we come to a consensus regarding the need to retorque after intial run in period? Always needed to do this on new conventional style fel-pros.
Re: Cometic gaskets
03-20-2006, 09:58 AM
#20
Registered
Join Date: Jun 2005
Location: Cayman Islands
Posts: 136
Likes: 0
Received 0 Likes
on
0 Posts
Re: Cometic gaskets
I've heard nothing but good things about Cometic gaskets. They are the latest technology but I think they've been around for several years but were used primarily in race bike applications. I've noticed lately that now Mr. Gasket and Fel-pro are making the MLS gaskets as well, at competitive prices.
I agree with Ray that particular attention needs to be given to the finish of the deck and heads.
The Cometics actually come with instructions which tell you that the finish needs to be like 5 ra (I think its 5). Ra is basically the smoothness of the finished surface. I not sure what method is used for this so talk to a machinist/engine builder. I recently read an article on the new Fel-Pros which indicated that the Fel- Pro gasket require less of a smooth surface because they coat the outer layers with Viton which fills in minute surface imperfections. I also noticed that the Fel-Pros are made of Stainless Steel layers. I'm not sure about the Cometics. Anyone know whether the Cometics are stainless? I have a set that I'm hoping to use in salt water so I'm thinking the stainless is the better way to go.
I agree with Ray that particular attention needs to be given to the finish of the deck and heads.
The Cometics actually come with instructions which tell you that the finish needs to be like 5 ra (I think its 5). Ra is basically the smoothness of the finished surface. I not sure what method is used for this so talk to a machinist/engine builder. I recently read an article on the new Fel-Pros which indicated that the Fel- Pro gasket require less of a smooth surface because they coat the outer layers with Viton which fills in minute surface imperfections. I also noticed that the Fel-Pros are made of Stainless Steel layers. I'm not sure about the Cometics. Anyone know whether the Cometics are stainless? I have a set that I'm hoping to use in salt water so I'm thinking the stainless is the better way to go.
