hosrom_951

If you want the ultimate head gasket, i would say a copper head gasket would do, since you can't really 'break' it, but it could fuse the cylinder head with the block if you seriously mess up with the tuning.......

And you can re-use it......

tedesco

I see that most of the posts refere to impropper tuning and to E85 being used. I think if I would have been running gas any damage would have been much more seriouse (about 20 octan less here in europe!). As mentioned preveiously the problem first of all was running 30psi due to a lost line to the wastgate. I did not intend to run 30psi. When something goes wrong I would not expect the tuning of the engine to be right. I am just looking for something a bit more robust if any of you have a constuctive suggestion.
If any of you say that head geskets are generally no problem on our engines that either because they are runing stock or they don´t try to explore the limits. I am convinced that almost on any type of engine the head gasket is a weak spot. Also on STs car the gasket "leaked" during a dyno pull attempting to break the 600HP mark. I guess this was not due to improper tuning.

special tool

Let me clear some things up.

I will go ahead and consider myself the expert with reguard to the particular thread title here on this board.

-The strongest headgasket is the Cometic steel. I have used them all at over 35 psi boost (high load, not just first gear, girls)
-The headgasket problems I had on the dyno were ALWAYS with a stock gasket (Widefire is stock, for all practical purposes).
-The Cometic gasket can be TOO STRONG!!! That is, under detonation, the stock gasket will forgive you by "blowing" - the steel gasket WILL NOT!
Despite all bull**** spouted by knuckleheads on this board who don't know what the hell they are talking about, the steel gasket WILL INDEED INDUCE FAILURE AT THE NEXT WEAKEST LINK UNDER IMPROPER MOMENTARY COMBUSTION!
This means that you will blow out your alusil cylinder walls (I should know, I have blown 5 of them strictly from this in the quest for high power).
These are engines that are all built, installed, run, tested, removed and torn down with the same hands that are typing this post (not Joesshmoe's, sister's, garbageman's, brother's-who worked for Kelly Moss bull**** uncle.....okay?).
-Because of this, I recommend to most guys to install the Widefire, ESPECIALLY, if you are tuning or racing road course at upper power levels.
I would only advise the Cometic for a tuned car WHEN YOU ARE VERY SERIOUS ABOUT MONITORING YOUR CAR'S TUNE. (I am talking every day here, not every week, such as in a REAL race car environment) You cannot afford any detonation with a stainless steel gasket on your car with a 2.5 liter alusil Porsche block.
-CONVERSLY, if you have a stock car, and you feel confident and emotionally secure enough that you will never try to exceed 18 psi boost on a suitable turbocharger, than you cannot do better than the cometic gasket in this particular instance.

eniac

Nice post and I agree with you 100%. I also run very high boost on a much more limited budget then yours. I do tune almost daily but with a pieced together MAP system I choose to stay with a "stock" widefire gasket. That said I have been running 23-27 psi for the past 3 years on the same widefire gasket I bought from Huntley long ago. I have blown out a wastegate, grenaded a turbo, had 3 other turbos fail on me, went through the routine of securing every single vacuum line, and am still on a quest to find a bolt on TB that wont leak over 23psi. There are plenty of problems associated with running high boost. Those listed are minor compared to a rod exiting the block. Until I have a perfect AFR and a good supply of 116 unleaded(too bad nitromethanol is so dang expensive) I will certainly be leaving the "fuse" in.

One more note: I have pegged my boost gauge at 30+psi on 93 octane before. Obviously I let off when I noticed but this happened a few times with no noticable damage whatsoever. The stock(widefire) gasket on a somewhat tuned motor really can take quite a bit of abuse. I also have the original studs for now. These will be changed eventually but there is absolutely no reason to right now.

toddk911

You run those levels on pump 93?

Tms951

The cometic is the best, also studs that won't stretch would be good too. Newer carslike Audi turbo cars use MLS head gaskets from the factory.

eniac

Noo...at least not by choice. I use the car for many different things, including road trips. For around town I can afford a good xylene mix or use the 110 sold down the street from me, I have yet to break open the 55g drum of C16 in my garage . For road trips I turn the boost down to 20 and run 93 as I sometimes have no idea what gas station I'll be filling up for my trip back home.
My AVC-R comes in handy for this with a simple A/B setting.

A couple time I hit >30psi when a wastegate hose popped off before I realized it. Another time was when I first switched from my old Huntley Stage IV MAF to a Link MAP. I drove around town slow till I got a decent AFR then hopped on the highway. I hadn't accounted that the MAP would help the car spool quicker so left all the boost settings the same. I gave it some heathly throttle, felt a huge rush of power, looked back for merging traffic/police, then at my boost gauge which was pegged at 30psi.

I also have 83# injectors and 2 stages colder on the spark plugs. I'd run 3 stages colder but ehh, I live in Michigan.

tedesco

Aha, so that´s good information. I think I will give the cometic gaskets a try even though I might crack a cylinder. Still have three sets around and another two engines. Engines is build with lightened and balanced crank, rods, pistons, rings, modified oil girdel, 14mm head studs, slightly ported heads, reworked valves and guides, new springs, all new bearings still a few things to come. I hardly ever drive without monitoring and loging A/F ratio and other engine parameters. That is also why I could say that fuel was still ok and boost at 2.09 bar and max rpm with that boost. I can not honestly blame the components I used if a host blew off and as a result something goes wrong. In the end it is me to blame as I did not lock the lines properly. I was just angry that it came off. Still there was no noticable damage done on the engine. Only noticed the slightly pressureised expansion tank so something blew into the water. No coolant lost. I just would not trust the head gasket anymore and want to change it.