New (non leaky) Cometic Gaskets
#1
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Thread Starter
New (non leaky) Cometic Gaskets
We have been selling the Cometic 3 layer gaskets for a few years now. We have heard all the rumors about leaking. We tell people it's a 50 50 crap shoot whether or not your going to have a problem even if you have a fresh machined clean head and block surface.
When we had a couple leak on us, we attempted to understand why. Well, we figured it out. The gasket they offer for the 2.5L is actually for a 8v 928 engine. It has a bolt in the water passage near the front of the head in a different location then the 944/951 8v. They attempted to make the gasket work for both. Problem is when they do their compression grove (like a bead roll but done in a stamping tool) around that 928 bolt, it actually pushes
the compression grove off the edge of the head and block on a 944/951. Barely, but enough to not compress the grove and allow it to leak.
When we told them about this, they understood and agreed to build a new tool specifically for the 944/951. They sent us a clear Mylar sheet with a line drawing of the gasket on it so we could offer our advice on grove location and any other suggestions. It took a couple months of continuous prodding, but we now have a new tool!
Not only does it have the compression grove in the water passage where it should be, but it has them around each head stud, and the little arc that everybody asks about in the gasket is also gone. That was for a 928 dowel pin.
We have our first few samples coming to review. Upon approval, we will then order and stock the gaskets in all bores sizes and in .040" and .050" 3 layer, and .060" and .070" 5 layer.
This problem does not exist on the 3.0L block gasket (S2, 968, 89 2.7.)
We hope this is a final fix for Cometic and allow us to sell and use them with more confidence.
When we had a couple leak on us, we attempted to understand why. Well, we figured it out. The gasket they offer for the 2.5L is actually for a 8v 928 engine. It has a bolt in the water passage near the front of the head in a different location then the 944/951 8v. They attempted to make the gasket work for both. Problem is when they do their compression grove (like a bead roll but done in a stamping tool) around that 928 bolt, it actually pushes
the compression grove off the edge of the head and block on a 944/951. Barely, but enough to not compress the grove and allow it to leak.
When we told them about this, they understood and agreed to build a new tool specifically for the 944/951. They sent us a clear Mylar sheet with a line drawing of the gasket on it so we could offer our advice on grove location and any other suggestions. It took a couple months of continuous prodding, but we now have a new tool!
Not only does it have the compression grove in the water passage where it should be, but it has them around each head stud, and the little arc that everybody asks about in the gasket is also gone. That was for a 928 dowel pin.
We have our first few samples coming to review. Upon approval, we will then order and stock the gaskets in all bores sizes and in .040" and .050" 3 layer, and .060" and .070" 5 layer.
This problem does not exist on the 3.0L block gasket (S2, 968, 89 2.7.)
We hope this is a final fix for Cometic and allow us to sell and use them with more confidence.
__________________
Mike or Dave Lindsey
www.lindseyracing.com
U.S. 1-877-943-3565
Other 1-405-947-0137
Mike or Dave Lindsey
www.lindseyracing.com
U.S. 1-877-943-3565
Other 1-405-947-0137
#2
re: When and how much??
Ok
I have been the victim of two non sealing MLS head gaskets.
What I would like to know is do you now guarantee the gasket will seal and not leak within reason?
Is installation the same dry no sealant required?
What are the advantages of the 5 layer vs the three layer?
lastly the gaskets are not listed on your web site so when will they be available and how much will the three layer cost and the five layer?
thanks,
-BB
I have been the victim of two non sealing MLS head gaskets.
What I would like to know is do you now guarantee the gasket will seal and not leak within reason?
Is installation the same dry no sealant required?
What are the advantages of the 5 layer vs the three layer?
lastly the gaskets are not listed on your web site so when will they be available and how much will the three layer cost and the five layer?
thanks,
-BB
#3
Race Director
Mike/Dave,
Sounds great, and as always I see you are again at the forefront of constantly improving and providing products for the 944/951. Thanks for your continued model support and put me down for 2 when available.
PATRICK
Sounds great, and as always I see you are again at the forefront of constantly improving and providing products for the 944/951. Thanks for your continued model support and put me down for 2 when available.
PATRICK
#4
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Thread Starter
Your not alone!
If you want a guarantee, you would want to discuss that with Cometic. We are not going to be guaranteeing their product.
You should not have to use sealant on a gasket designed to be installed dry. That means there is a problem. We're surprised nobody figured this out before. You can use some 5900 loctite around concerned areas if you want. Hopefully this new version won't need it.
We see 951 turbo heads vary from 56 to 62cc. If you milled your 56, your even less. This means you actual compress can vary about .5 depending on the head you have. There is no way to tell by part numbers. We use a thicker gasket if need be to target the desired compression ratio. They only make the materials so thick, and .050" is it for a 3 layer. So thicker requires more layers. We have been using 5 layers on a few engines already. One we are driving now and its just fine. The thicker gaskets are nothing new for Cometic. Making a "REAL" 951 gasket is.
We will list them once we have them to ship.
If you want a guarantee, you would want to discuss that with Cometic. We are not going to be guaranteeing their product.
You should not have to use sealant on a gasket designed to be installed dry. That means there is a problem. We're surprised nobody figured this out before. You can use some 5900 loctite around concerned areas if you want. Hopefully this new version won't need it.
We see 951 turbo heads vary from 56 to 62cc. If you milled your 56, your even less. This means you actual compress can vary about .5 depending on the head you have. There is no way to tell by part numbers. We use a thicker gasket if need be to target the desired compression ratio. They only make the materials so thick, and .050" is it for a 3 layer. So thicker requires more layers. We have been using 5 layers on a few engines already. One we are driving now and its just fine. The thicker gaskets are nothing new for Cometic. Making a "REAL" 951 gasket is.
We will list them once we have them to ship.
Trending Topics
#8
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Thread Starter
Anybody buying a 2.5L style gasket from Cometic will be getting the same improved thing. It's
not exclusive to us. We will just have plenty to choose from in stock without the wait.
not exclusive to us. We will just have plenty to choose from in stock without the wait.
#10
Rennlist Member
it took a week from the day i called n ordered n they had to make it n shipped to my house
#11
Site Sponsor
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Join Date: Aug 2002
Location: A great big building in the woods, FL.
Posts: 6,527
Likes: 0
Received 4 Likes
on
3 Posts
I ordered two about a year ago and it took 3 weeks for delivery. I only used one and I still have one on the shelf.. I wander if they will do an exchange.
#13
Drifting
Hmm, the new 951 thats shipping out beginning of next week, has a cometic gasket.....hope I dont have any issues.
#15
Burning Brakes
Do you happen to have any idea whether Cometic may be inclined to warranty their old product? Like yourself I'm sure there are many of us who paid good money only to have them fail. With all due respect, it seems to me a reputable stand up company would step up to the plate and replace them at their expense considering the additional cost those of us that had problems incurred to redo a HG job. Tony G figured it out awhile ago