Cometic head gasket better than Mopar?

[Chris W]

I ordered direct from Cometic. 148.00 and some change + shipping. Basically the same price.

Check again

http://www.turbo-mopar.com/forums/sh...617#post116617

$125. + Shipping

Chris-TU

[turbovanman²]

DOH!

[glhs875]

Check again

http://www.turbo-mopar.com/forums/sh...617#post116617

$125. + Shipping

Chris-TU

That's a good price if you can offer them in the same thicknesses as Cometic does. .027 to .120 in what I gather .003 increments (might be wrong on the increments). And can get them quick.

[Chris W]

That's a good price if you can offer them in the same thicknesses as Cometic does. .027 to over .100 in what I gather .003 increments (might be wrong on that). And can get them quick.

Just let me know what you need. They promised me to build anything I don't already have in stock in less then a week.

Chris-TU

[crazy1eye]

Check again

http://www.turbo-mopar.com/forums/sh...617#post116617

$125. + Shipping

Chris-TU

He, glhs875 was answering my ? concerning his custom made(.036") Cometic head gasket.

Please see posts #76 & #77

***edit*** He beat me to it.

[crazy1eye]

As for sprays/sealers...

quoted from Cometic's FAQ;

Why does Cometic recommend MLS gaskets to be installed dry?

Cometic Multi-Layer Steel (MLS) head gaskets go on dry because they are coated with a sealant. Each MLS head gasket is coated with a .001" thick viton rubber that is bonded to the outer stainless steel layers. Adding an additional sealer can hinder the performance of an MLS head gasket.

[Speedeuphoria]

I just ordered a custom Cometic gasket .036 thick. That will bring my compression ratio up to 8.2 to 8.4 to 1 from 7.98 to 1 with the #005 MP gasket (.068 thick), depending on what my combustion chambers cc to when I done with them. That will also decrease the quench area from .078 to .046. All together I think this will be a definite improvement in performance. My combo seems to be very detonation resistant, the tighter quench should help it even more. We shall see!

Kevin and I were talking about this the other day, and we agreed it would help you get better use out of the SC61. Raising the CR that is. Good luck and let us know how the spoolup/power is affected

[87csx2.4]

Kevin and I were talking about this the other day, and we agreed it would help you get better use out of the SC61. Raising the CR that is. Good luck and let us know how the spoolup/power is affected

Ahh lets just spray the sh_t out of it.

just ordered a custom Cometic gasket .036 thick. That will bring my compression ratio up to 8.2 to 8.4 to 1 from 7.98 to 1 with the #005 MP gasket (.068 thick), depending on what my combustion chambers cc to when I done with them. That will also decrease the quench area from .078 to .046. All together I think this will be a definite improvement in performance. My combo seems to be very detonation resistant, the tighter quench should help it even more. We shall see!
__________________

I think its gonna get you where you wanna be brian.

[glhs875]

I think its gonna get you where you wanna be brian.

I'll have to chain the head down to keep it on if I can get the compression ratio where I want it. I actually was only running 7.8 to 1. I thought my combustion chambers were 53cc. I remeasured them and got 55cc. After I did a little more work to them (deshrouding/reshaping) I ended up with 58cc on the one that's finished. I will check them again. If that's the case, will have to mill the head some to get to were I want to be even with the thinner head gasket. The 14cc dish on the T2 style pistons is just too much for a G head. We could use some 8cc dish forged pistons on the market for use with a G head.

[Aries_Turbo]

BTW, (a little late to this thread....) that knock gauge on page one (My setting is 40 posts/page) isnt going to cut it. Here is why:

the factory ecu setup samples the knock sensor voltage value only at certain times (after igntion) to see when there is detonation. this gauge samples the voltage at all times so there could be false knock.

the other reason that this isnt a good choice is due to the fact that when engine speed increases, engine noise increases. ie, if you have the knock box sensitivity set to "hear" the detonation at 6000rpms, the sensitivity will be set to high to "hear" it at 3-4000rpms. there is a reason that there is this table in the ecu. (see attached file)

the only thing that is compatible is the fact that the knock sensor itself is tuned to a certain frequency (6000-6300Hz) so the voltage output is already filtered to only "hear" the knock frequencies that our motors produce.

so basically, dont buy this gauge. buy a used OTC scanner or get a palm pilot and use Rob's Minidash program. you'll then be monitoring what the ECU determines is already knock.

Brian

[glhs875]

Got my new Cometic head gasket today. That was pretty fast for a custom part!! I measured it @ .037" thick. I'm sure it will crush when torqued and be the .036" that it's supposed to be. And the best part, it was $42.00 cheaper than quoted!!!

[TurboJerry]

Thinner ones/less layers are cheaper. 2 .040" V-8 gaskets are the same as 1 L-4 .067" gasket.

[Aries_Turbo]

on a local forum there was much discussion about the preparation of the deck/head surface when using a MLS/cometic gasket. does the cometic require any special/smoother deck surface? possibly the problem that warren was having?

Brian

[TurboJerry]

50 RA or finer. (smaller number) I get the heads to 20, but I've had no issues with the factory finish on the blocks yet. Seems like mopar does an excellent job for mass produced stuff..... BTW a pane of window glass is 3 to 4 RA......

[BadAssPerformance]

I took the MP gasket off, cleaned the block and head with a razor blade and a clean rag with brake cleaner on it, and put it on. No problems sealing to 30psi

[glhs875]

I took the MP gasket off, cleaned the block and head with a razor blade and a clean rag with brake cleaner on it, and put it on. No problems sealing to 30psi

Cleaning parts with brake cleaner is the bomb for sealing gaskets and when only silicone sealant is used instead of a gasket. Being a mechanic, I use it alot. Although I used brake cleaner too much one day in an inclosed garage and ended up in the hospital for a couple of days. It sucked all the oxygen out of the air and I went down on the floor and could not get up. Very scairy!!!

[turbovanman²]

Cleaning parts with brake cleaner is the bomb for sealing gaskets and when only silicone sealant is used instead of a gasket.

I buy 20L pails all the time for my shop,

[1FastCSX289]

BTW, (a little late to this thread....) that knock gauge on page one (My setting is 40 posts/page) isnt going to cut it. Here is why:

the factory ecu setup samples the knock sensor voltage value only at certain times (after igntion) to see when there is detonation. this gauge samples the voltage at all times so there could be false knock.

the other reason that this isnt a good choice is due to the fact that when engine speed increases, engine noise increases. ie, if you have the knock box sensitivity set to "hear" the detonation at 6000rpms, the sensitivity will be set to high to "hear" it at 3-4000rpms. there is a reason that there is this table in the ecu. (see attached file)

the only thing that is compatible is the fact that the knock sensor itself is tuned to a certain frequency (6000-6300Hz) so the voltage output is already filtered to only "hear" the knock frequencies that our motors produce.

so basically, dont buy this gauge. buy a used OTC scanner or get a palm pilot and use Rob's Minidash program. you'll then be monitoring what the ECU determines is already knock.

Brian

Brian, I was thinking of buying one of these. You know my situation. Dont you think it would be wise to run this with a little higher sensitivity and err on the safe side rather than go without one at all?

[Aries_Turbo]

sean, i guess you could buy one and set it up so it basically tells you what knock is over 4000rpms then you would be somewhat covered. set it up with one of those detonation turbe/earmuff things. that way you know when its actually knock.

Brian

[1FastCSX289]

sean, i guess you could buy one and set it up so it basically tells you what knock is over 4000rpms then you would be somewhat covered. set it up with one of those detonation turbe/earmuff things. that way you know when its actually knock.

Brian

Thats not a bad idea.