Cometic head gaskets or not?

We currently are running Blown alcohol circuit boat, BBC powered, & are in the process of rebuilding a fresh engine. It would be nice to go away from 'O' rings & reciever grooves but dont know if the cometics will handle it. BBC 509 ci, 1471 rootes, 10.6 static comp, 28 lbs boost, thoughts please but real experience would be a great bonus, thanks guys.

 

X2 ^^^

It might work for a little while.... but when it fails you will be sorry $$$$$

 

Not claiming to be an expert, but we planned on o-Rings and copper head gaskets in our recent build; blown alcohol 565 with about 10 lbs boost in a drag boat. The consensus at the shop was MLS style gaskets are perfect for our application. Not exactly apples to apples... but it's working for us. A couple of the turbo cars that race out of the same shop run well over 30 lbs boost with no problems.

 

Your problem will be water, not holding compression.
The wet guys are cutting the rivets out of the cometics, taking them apart and copper gasket spraying each layer, then puting them back together and running them. If you are willing to do all that, they will seal juat fine. Compression and water. Even some of the big engine builders have started doing that. And since the EPA made FelPro change their format for MLS, people have even been doing that to their Fel Pro MLS.
I started using the SCE ICS Titan deals and copper spraying them. (The ones with their own 0-ring) Those babies are really nice too.

 

I have heard that plenty of guys are running them on turbo deals with 30 plus # drag application but dont know anyone running in the blown circuit stuff.
Wannabe, do you know personally the guys using them in blown stuff and how long are they holding up for? What boost & RPM, thanks. I understand the water deal but I also wonder if they are machining the surfaces smooth enough for the MLS

 

Whatever route you take I would suggest this advice:
Make sure the deck surface finish of the block and heads are correct for the gasket you choose.
Keep your detonation in check with enough fuel and correct ignition timing.
And use the inside head bolts.

 

Sodak, check ,check, check & check

 

I have had great luck with cometics on a SBF with 42#'s of boost with water. You need to have the deck and head finished to there specs and you shouldn't have an issue

 

I tried the cometic gaskets in my motor (572" mopar with 16-20 psi), I couldnt get them seal water. My sleeves stick out of the deck .004 and they didnt like that.

We are running SCE gaskets ICS head gasket now, its a copper gasket with an O-ring built right in the copper, they work great for me. I dont think they would take much more though.

 

Did you use copper-coat or any other sealants on them?

EDB

 

No sealants for combustion pressure, just a little silicone for water, the water holes dont quite match my heads.

 

Thanks.

EDB

 

We took my heads off today, and the gaskets looked good, had a little discoloring between 4-6 and 3-5, no signs of material movement though.

 

Just curious but do your heads fit tight on the dowels?

 

Yea, my dowel pins fit good and tight.