Cometic HP head gasket

[Lunch_Box]

I am in the middle of the my engine back together and my next purchase will be a rebuilt head and a head gasket. I am going to be running a T3/T4 T67 on my 2.4L and this turbo comes to life at 30-40 Psi. My question is will the cometic head gasket be able to hold what I am going to be throwing at it? Both the head and block will be decked so the surfaces will be flat and smooth. What other options do I have for a head gasket if the cometic isn't up to the task?

 

[GVR4592]

The Cometic will hold at least 32 psi thats the highest I can say from personal experience. It may hold a lot more but I have never ran more than that. The most important thing with any steel headgasket is make sure the head and block surfaces are mirror finish or it wont seal properly. Most maching shops are not capable of milling them to a super smooth finish and most people don't know any better. If you are running boost that high you need to make sure that the surfaces are as smooth as you can get them. Lots of guys claim that the copper spray makes a big difference too, but having never used it I can't say if it works but it may be worth checking out

 

[TSIfreek]

I have been told not to use the copper spray on the cometic Hgs because they already have a viton seal. The things that keeps the steel HGs alive is 1 flat and glass smooth block and head surfaces, 2 ARP studs, 3 alot of fuel (850s) or higher and 2 fuel pumps braded lines and 3 run C16 and keep it out of detionation and you should not have a problem. At that high boost level I would run sometype of lab top management to control your timining more precisely.

 

[99gst_racer]

What about using a solid copper gasket; like an SCE gasket? Then you could o-ring the block and spray a few coats of Hylomar on each side of the gasket. Alot of my high compression, 1000+ HP customers do this with much success. Just an idea - has any DSMers tried this?

 

[TSIfreek]

I have heard guys O- ringing the head or block with good results. Just not that many run the copper gasket becuase of coolant leaking issues more so than the steel HGs . 95% of the guys on this board dont run anything over 25 psi so it will be difficult for oppinions to pop up on this subject.

 

[Lunch_Box]

I have been told not to use the copper spray on the cometic Hgs because they already have a viton seal. The things that keeps the steel HGs alive is 1 flat and glass smooth block and head surfaces, 2 ARP studs, 3 alot of fuel (850s) or higher and 2 fuel pumps braded lines and 3 run C16 and keep it out of detionation and you should not have a problem. At that high boost level I would run sometype of lab top management to control your timining more precisely.

Well I will be running a DSMlink 2, 950cc injectors, ARP head studs, 8an feed and 6an return, tsunami fuel pump, and on that hogh of boost of coarse C16.

 

[Lunch_Box]

What about using a solid copper gasket; like an SCE gasket? Then you could o-ring the block and spray a few coats of Hylomar on each side of the gasket. Alot of my high compression, 1000+ HP customers do this with much success. Just an idea - has any DSMers tried this?

Another option I was thinking of was running a stainless steel o-ring in the head and a factory head gasket.

 

[99gst_racer]

Another option I was thinking of was running a stainless steel o-ring in the head and a factory head gasket.

I've never heard of o-ringing with a MLS gasket. I dont think most MLS gaskets will hold at 40 psi. And that is why many guys switch to copper. And most guys dont have luck with copper unless they o-ring the block or head too.

 

[Awdboost]

I'm using an o-ring block with a mitsu MLS head gasket and copper spray. No problems.. I've heard bad thinks about Cometic and Cometic HP.

 

[Forces32psi]

i was running the STEEL o-ring in my block and a cometic head gasket and my fp RED.. now ive stepped up to the NEW mitsubishi 5 layer steel gasket and the steel o-rings in my block.. i havent used the copper spray on either head gasket and i havent had any issues w/ sealing..and this new setup is a FP 3575, fpcam3's and a 2.3 stroker motor..

 

[99gst_racer]

i was running the STEEL o-ring in my block and a cometic head gasket and my fp RED.. now ive stepped up to the NEW mitsubishi 5 layer steel gasket and the steel o-rings in my block.. i havent used the copper spray on either head gasket and i havent had any issues w/ sealing..and this new setup is a FP 3575, fpcam3's and a 2.3 stroker motor..

I'm using an o-ring block with a mitsu MLS head gasket and copper spray. No problems.. I've heard bad thinks about Cometic and Cometic HP.

Thats very interesting. How many PSI are you guys running?

 

[GRNDSM]

My Cometic HP was fine up until I started running around 35-36psi of boost . That was when it started to "push" coolant.

 

[Forces32psi]

my car isnt ready to run yet...

hey leon im guessing your block is o-ringed allready??? i plan on running 36+ psi...IF i need to ::::snicker:::::::

 

[GRNDSM]

Nope, no o-ringing on my block. I had mirror like finish on both sides of the gasket. And truly, I can't complain. It lasted me over 50 passes and countless dyno pulls. That might be just an average life expectantly when running that much boost.

When I had my 40psi run last year, it hasn't pushed coolant...

 

[Lunch_Box]

My Cometic HP was fine up until I started running around 35-36psi of boost . That was when it started to "push" coolant.

Were you running the stock rad cap when it started to push coolant? What are you going to be running now that you are ushing coolant?

 

[Lunch_Box]

I've never heard of o-ringing with a MLS gasket. I dont think most MLS gaskets will hold at 40 psi. And that is why many guys switch to copper. And most guys dont have luck with copper unless they o-ring the block or head too.

I have been doing some searching and one guy said that he has had the best luck with SS o-ring in the head and a felpro head gasket. What company makes a copper head gasket for the G4CS?

 

[wickedtsi]

Why don't you get a SCE Titan ICS gasket. You don't have to worry about your block being a mirror finish and it seals better than an MLS gasket.

 

[Lunch_Box]

Why don't you get a SCE Titan ICS gasket. You don't have to worry about your block being a mirror finish and it seals better than an MLS gasket.

Where can I find more info on this?

 

[GRNDSM]

Were you running the stock rad cap when it started to push coolant? What are you going to be running now that you are ushing coolant?

No this was with a Power Industries cap (1.2bar?).

 

[Lunch_Box]

No this was with a Power Industries cap (1.2bar?).

So are you going to be getting another Cometic HP or going a different route?

 

[99gst_racer]

What company makes a copper head gasket for the G4CS?

G4CS?? I dont show an SCE listing for that.... What is your bore size? I'm showing listings for the 4G63's and the 4G64's.

 

[wickedtsi]

Where can I find more info on this?

I opened thread in this forum about this gasket titled "New gasket better than Cometic". You can also go to http://www.scegaskets.com/index.html that is SCE's web site. The part # for the Titan ICS is T91526, it is .062 thick.

 

[wickedtsi]

My bad that is for the 4G63, for the 4G64 all I see is the solid copper. You might want to call them to se if they make it now.

 

[Lunch_Box]

G4CS?? I dont show an SCE listing for that.... What is your bore size? I'm showing listings for the 4G63's and the 4G64's.

Bore size is 87mm.

 

[Lunch_Box]

My bad that is for the 4G63, for the 4G64 all I see is the solid copper. You might want to call them to se if they make it now.

On there site under the part number you gave me it says that the gasket has a bore size of 87.3mm. When I was looking into an Cometic I was told to go with 87mm for the 2.4L block and 86mm for the 2.0L block. Also the part number you gave me is for the SCE self sealing gasket, not the ICS gasket? What kind of boost have you taken your car too?