Head Gasket again

[greenbusa]

Well I did it again, my head gasket is leaking boost into the water jackets. I can ride it all day at 10psi and no problems, anything over 15psi and it pukes water out of the overflow. this has happened 3 times in the last 3 years, each time I put a new cometic gasket in it and it will last about a year of hard riding. I've checked the head/block for flatness and has never been more than .002 off by checking it with a known straight edge and a feeler gauge. This time I had the head/block surface ground and the machine shop only had to take off .003(.002-head/.001-block) I'm adding .020 more spacer under the block to make up for it and drop the compression a little more. While I was doing this I had a valve job done on the head and they found 4 bent valves not bad but bad enough they said they would'nt seat properly. I'm also changing the exhaust cam to an intake cam and degreeing them to 110/110. While I was taking the turbo off I shined my flashlight into the wg dump and noticed a light showing through a bolt hole on the turbo(I'm attaching a few pics of it). It's a VR stage 2 with dbb gt2871 and Velocity welds the holes shut from inside( the holes where the exhaust plate bolts on) and then welds the dump pipes directly to the turbo, I don't know why they do this instead of welding them to a plate that bolts onto the turbo. Anyway, it looks like one of the holes eroded through the weld from inside and I had a 1/8"x3/16" hole in the bolt hole, this had to be a boost leak. AND the rubber boot that holds the tb to the head was split almost half way around, which was probably another boost leak. I have everything almost finished and should have it back together this weekend and it should run a whole lot better, even with all these problems it was still making 332 on the dyno! Tell me what y'all think about these pics. Hopefully I can break 400 hp this time, a few months ago it made 382 with 18-20psi, that was all the boost we could get with the wg springs we had but now I have a new ams1000 going on it when I put it back together

[Coryonbusa]

Yeah, take the exhuast side off and weld all those holes up.

Wouldn't think that would be your head gasket problem though???

Are you using the pro mod studs instead of the factory bolts?

[greenbusa]

I knew it was not the head gasket problem, I just found the hole when I was pulling the motor. I have ape studs

[buzard]

use a stock head gasket  (if you don't already). run good fuel when going 10lbs or higher? c-16. it costa alot, but not as much as a melted motor or the hassle of changing a head gasket.
nice find on the header leak.

[Moparict]

use a stock head gasket  (if you don't already). run good fuel when going 10lbs or higher? c-16. it costa alot, but not as much as a melted motor or the hassle of changing a head gasket.
nice find on the header leak.

I'm not trying to sound like a smart ass.  I just want an explanation, being as I'm a self confessed idiot.  Why the stock head gasket over a Cometic?  Is there a point where a Cometic is better?

[Busabob]

I'm not trying to sound like a smart ass.  I just want an explanation, being as I'm a self confessed idiot.  Why the stock head gasket over a Cometic?  Is there a point where a Cometic is better?

Was told by my head porter to use a stock suzuki one also .Said it was made of spring steel and was better? But my stock one blew originally???   

[Dan.J]

Have had a Cometic on mine for 3 years now......Lots of passes/street miles ABUSE Sill hanging in there

[buzard]

japanese know what they are doing when they build parts to put in the bikes. they spend millions to reasearch and improve what is already out there on last years bikes. i run factory parts whenever possible. they last in my bikes with zero failure to date.

[shannigan]

I had similar problems about 2 years ago with my race bike, I also checked evry thing trice when i finally desided to add  ARP studs to the motor problems stoped still have the APE ones in the drawer. I'm not saying that is it but that cured my problem BTW i was running about 24psi of boost.

[sportbikeryder]

So what did you do differently with the ARP studs as opposed to the APE? Torque them higher?

[gilberjj]

Sometimes detonation is the reason for blown head gaskets.  When I was racing my Supra at the strip, the fuel pump failed, causeing a lean condition. The head gasket popped, but the motor was fine.  Just a thought...

[Nem]

Sometimes detonation is the reason for blown head gaskets.  When I was racing my Supra at the strip, the fuel pump failed, causeing a lean condition. The head gasket popped, but the motor was fine.  Just a thought...

+1
or banging the limiter on boost will do it too