I was wondering if this is possible. I have an 85mm bore and have been using the Cometic gaskets. Needless to say, they do not seal. I know the B20 gasket is an 84mm bore. I was just going to have the B20 gasket cut to fit the 85mm.

I know the usual rule is to use the gasket for the block, but since the b20 gasket has the already bigger bore, then I would need to cut out less material hoping to have a better seal.

The big question is... are the b20 gaskets the same as the B18 other than bore size?

 

here should be no problem, I have used the B-20 gasket on 84.5 and 85 mm bores.

 

do you need to have it cut to 85mm (CNC machined).

the other question is are you using a B18 or B20 block? Does this matter? Since the only real differences are the bore sizes.

By the way thank you very much for replying. No one has answered this question on the hybrid board. So i figured to try the tech.

 

Everytime I have compared a B18B and a B20 headgasket the only difference I could see was the bore sizes. If that helps any.


[Modified by SLPR, 12:10 PM 10/7/2002]

 

thank you. That is exactly what I was looking for.

The only thing I do know is that the Cometic LS/VTEC gaskets don't work. I've gone through like 4 of them. 3 didn't make it past start up, and one lasted like 10 minutes.

Head and block checked 2times by different shops.

 

I ordered an 85mm Cometic crvtec gasket. The thing doesn't line up with a stock B20 head gasket at all. I called Cometic and told them, they faxed me a print of what their crvtec gasket is supposed to look like. Their print matches the gasket they sent me. I think their design is flawed.

The Cometic is based off of a dohc vtec gasket, maybe that is why everyone has problems with them.

What happens when you use a vtec gasket on an lsvtec motor? Does it work?


[Modified by Inlinefour, 2:46 PM 10/7/2002]

 

I have been on the phone with Matt from Cometic with this same problem. I have the "new and improved" gasket and it doesn't work either. I told then that I thought they were going about this process all wrong.

My thoughts are that they are trying to combine the B16/18 vtec head gasket with the b18/b20 non-vtec headgasket. I told them that I was looking at all 3 gasketsb16vtec/b18nvtec/b20nvtec and that their gasket looks more like a b16 head gasket with a bigger bore. It looks nothing like the B18/B20nvtec cooling holes are different, and I believe one or 2 of the oil holes do not line up properly.

Matt was supposed to talk to Bill (engineer) i believe and see what the story is. I haven't gotten back to him yet. I was supposed to call him on friday and he went home early. And Bill was gone. I forgot to call back today and see what the follow up was, but they are definately aware of the obvious problems.

The Gasket itself should fit, and the vtec oiling hole will play no apparent role due to the fact that the block doesn't have this hole and the head is plugged. The real issue is that the coolant holes in the gasket match up with the head. In my situation, I also have a block guard, so it will be more important. But since others are having problems, I would say that the coolant holes and the oil holes are not lining up properly and thus not sealing. Just my personal opinion.

But I just ordered my B20 HG and we'll see what happens. I'm getting pretty good at removing and replacing the head. Too bad each time I do it, I'm not going any faster. Oh well it will be nice to actually drive the damn car eventually.

I'll be talking to Matt at Cometic tomorrow... I won't forget.


[Modified by Shft@9GSR, 10:19 PM 10/7/2002]


[Modified by Shft@9GSR, 10:20 PM 10/7/2002]

 

I spoke with Jason at Cometic about it last week. I explained the issue, but I didn't really get anywhere with him. He did send me prints of their gasket though, which verified that their design is wrong.

 

Has anyone compared these Cometic gaskets to each other:
CM-C4194 LS/VTC HYBD 85mm/030"
CM-C4175 B18A/B 85mm/030"

I'm wondering if the 4175 gasket has the same appearance of a B16A Vtec gasket that the 4194 gasket seems to have. If not then perhaps the 4175 would seal better on our LSVT and CRVT engines? Has anyone seen the two side by side?

If not I suppose I will order one up to have a look.


[Modified by SLPR, 6:50 AM 10/9/2002]

 

As I have not used the Cometic gasket on any LS/VTEC's, just the factory ones, what leaks?
I have used one on a 85mm GSR and that worked fine. Is the sealing ring around the cylinders to small, or to close to the cylinder edge? Those are the only differances I could find in a comparison, other than the oil hole for vetec,and slightly off oil drains, which should not leak. Thanks

 

I haven't seen the B18a/b gasket. Maybe that is the whole problem. The Cometic tech that I talked to (matt) said that the person who did the work for the Hybrid gasket no longer works for the company.

But thinking about this whole situation...why would there really need to be a specific application for LS/VTEC when all that is required is the bore size for the motor applied to a NON VTEC headgasket configuration?

 

That's exactly what I have been thinking. What happens when you use a vtec gasket on an lsvtec motor? Does it leak?

 

Yea this is exactly what I am thinking. I think Cometic got confused in the begining and assumed that the Vtec cyl head and Vtec headgasket need to stay together on a LSVT engine.......when really the head gasket should match the bottom end. After all the time I have used oem B18B gaskets on LSVT engines I really think using the Cometic C4175 (respective number according to thickness and bore size) instead of the C4194 is the solution here.


**I have some gasket versions on order, once they are all in and once I get a C4194 gasket I will compare and measure accordinly. I'll post what I find**


[Modified by SLPR, 11:41 AM 10/9/2002]