Crap! I hope my head bolts need to just be re-torqued. The Green Machine has been running on the hot side lately. my brother-in-law suggested I watch for bubbles in the rad during warm up. this morning I took off the cap and watched, when the thermostat opened I got a foamy bubbly layer on top of the coolant . does this sound like a leaky head gasket to you all?

_________________

If the gasket was really blown, coolant would be gushing out with the cap off, t-stat open or not.
I don't have alum6 experience, but retorquing would be a good place to start.
A little foam can be from additives (stop leak?) - maybe check the rad (is the whole core hot or are there cold spots w/t-stat open?), then flush it out.
How hot is it getting? Is coolant disappearing? White smoke out the pipe?
Do you have access to an HC probe to sniff the rad with?

_________________
O==\=/==O

"A mechanic is Somebody."
- Jim Preston

I drained the coolant and refilled it with distilled water, ranit untill the thermostat opened, drained it again and refilled with distilled water a second time(antifreeze is not alowed at raceway park). last year(before raising compression) I had no trouble keeping cool. It rarely if ever got more than 1/3 of the way into the normal range. Now it runs up around half to the very top of the normal range.
Has anyone else running higher than stock compression had this problem?
I am running a V8 A/C Volare rad. It is still only a 2 core but is much wider than stock.
Saturday coming home from Englishtown I kept it down to 65mph(2300rpm) and it ran way up almost on the very top of the normal range.
anyone have any suggestions?

_________________

Pluged heater core maybe? How is your bottem hose? Not collapsing is it? Just some ideas.

Mine's doing the same thing, though running hot as opposed to halfway in the normal range as I am used to. Ive probably got a vacuum leak from the intake gasket or the carb's running lean. Will find out soon.

_________________
I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

Had that happen once...
Blew the 'wafer' between the intake and exhaust manifold with the exhaust gases venting directly at the block...pulled the stack, installed the hyperpak and dutra duals and have been happy ever since....Of course that stack just went onto the 'other duster' so we'll see if it happens again...

yipes...

-D.idiot

If your suspecting head gasket, you can also check compression and take a look at your plugs.

OK I don't think it is the head gasket any more. It dosen't bubble at all when warming just for a few seconds when the thermostat opens.
I did however snug the carb nuts/bolts and the intake/exhaust nuts all went 1/8-1/4 turn. I think now I may have been experiencing a lean condition caused by a vacuum leak. It did seem to run cooler this morning but we will see when it hits 80* on my way home. If I want to richen the mixture which way do I turn the screws? its in right?
Thanks for all the replies I really appreciate all the help.

_________________

the mixture screw only affects idle. If you're lean while cruising then you'll need to change the jets. Before you go to all that trouble though, I'd make sure all the vacuum leaks are fixed...

_________________
My truck is a Frankenstein creation
Built from the dead carcasses of others
And brought BACK TO LIFE!