David Floyd

Suspect I've blown a head gasket already 2600 miles.

Was told that a modified 968 gasket was use on my 106mm bore, so I bought a couple of 968 gaskets for cheap.

After measuring the 968 gasket fire ring at 106mm for a 104mm 968 block, then should I have a 108mm fire ring for my 106mm block??

Anyway I want to buy one of your super duty head gaskets.

Let me know a price and what you know of the fire ring sizes.

Danno

Yeah, I've known tuners who've blown multiple wide firering headgaskets just weeks apart. Sent you an email on these headgaskets... <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />

OZ951

David,

Thats a shame to hear you are having problems especially after waiting so long to get that motor back in your car and being gentle with it for the last 2000mi. Was the head O-ringed or not ?

fast951

David,

Sorry to hear about the Head Gasket. Was your engine sleeved? I wonder why you blew the headgasket? Which Cyl? Make sure the sleeves are still in place (ie didn't move on you).

John

Konstantin

how was this 968 headgasket modified??????
how can you make a 968 headgakset form 106 to 108mm? Is this possible?
can you check the diameter of the "modde" gasket?
I am VERY curius or maybe you just have a stock 106 mm gasket. Thats wouls explain the blown head gasket!

Konstantin

Sean Hall

David,
Did you blow the headgasket on the track? If so, how long were you on the track for? How much boost?

Maybe I should invest in an EGT guage before I take my car to the track.

Thanks,

Sean

Sean Hall

...Once EGTs get past a certain point, say bye-bye to your headgasket; and if your engine is o-ringed, you'll break/melt something else.

The question is, what EGT is that point for a 951? Most people say an EGT of 900C is 'melt-down' time... For our cars, it might be lower though.

Anyone running an EGT gauge on their car?

-Sean

David Floyd

Thanks for the replies.

Let me just say I am not 100% sure it the headgasket yet.

After returning home last night from a 100 mile trip, I was went to check the oil and saw coolant all over the coolant tank area, headgasket jumped into my head. Very little was I under boost but I did notice some stumbling in upper RPM,s, the TechEdge wideband did not show any lean condition.
Will investigate further this weekend.

Let me answer some questions.

Yes, it is o-ringed
Yes, it is sleeved
Not sure how the 968 gasket was modified, the fire ring diameter is a concern to me.
Not on the track, the engine has 2600 miles, 2000 of which was very easy at 10 psi and the last 600 at 15 psi and has been pushed very little.

With any luck it will a loose hose or a bad radiator cap, but the way my luck has been going
<img border="0" title="" alt="[Frown]" src="frown.gif" />

NerfRacing

speaking of head gaskets, will a blown head gasket cause a rough idle, aside from the plumes of white smoke and coolant all over the place? i was thinking maybe a seared ring too?

guardsred951S

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by NerfRacing:
will a blown head gasket cause a rough idle, </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Well, if you're seeing plumes of white smoke, then that means coolant is getting into the combustion chamber right?. I'm sure this would do something to the idle, since the only thing that's supposed to be in there is fuel and air and maybe a little oil from el turbo.

Bill

Just a note, there can be other adverse affects from a blown head gasket.

When water is mixed with combustion gasses, it creates a very caustic acid.

If left uncared for it, can eat away the head, turbo impeller and the exhaust system.

I have seen the area around the valve seats completely eaten away, leaving the valve seat standing proud about a 1/4 of an inch. This car was run for many miles though.

Sean Hall

FYI,
This vendor has the Autometer EGT Sensor and gauge for a pretty good price:

<a href="http://www.horsepowerfreaks.com/ShowProductsMain.asp?SubCategoryCd=GEGT" target="_blank">http://www.horsepowerfreaks.com/ShowProductsMain.asp?SubCategoryCd=GEGT</a>

-Sean

SamGrant951

i plan on installing the Autometer Ultra-Lite EGT when I install my boost controller and new wastegate in a few weeks, thanks for the link-best price so far.
Also whats the consensus on where to mount the bugger?

DangerIsland

Geez, all these cool gauges, I'm making a list of all the ones I'd love to have, I'll add EGT to it!

Does your EGT go way down when you have a blown lead leaking into the cyl.? I would assume so, with all that water vapor in there.

michael2e

Sorry to hear about the continued travails, David. Any coolant in the cylinders or over-pressurized cooling system? Hard to believe it with the o-ringed head. good luck.btw, did you change studs during the rebuild?