Overheating/Water issues

[lancec2c30]

I just got done installing the turbo system on my car, I took it around the block last week and noticed when I got back, some coolant had boiled out of the radiator.

Today I looked into it, I thought one of my head gaskets had let go. The temperature would come way up at idle, and when you revved then engine up with the cap of you could see bubbles in the ratiator, along with pushing water out.

But out of nowhere, the temp came down to normal for a second. But soon climbed back up.

So I did a compression test, all cylinder checked out at 130-135. I'm not sure how to interpret that. Is there still a chance a gasket could be bad?

The only other conclusion I tried to come up with was the head lifting under wot and pressurizing the coolant system. And now I have a bunch of air in it, causing my thermostat to work incorrectly?

Any help would be apreciated.

 

[twistedwankel]

I just got done installing the turbo system on my car, I took it around the block last week and noticed when I got back, some coolant had boiled out of the radiator.

The only other conclusion I tried to come up with was the head lifting under wot and pressurizing the coolant system. And now I have a bunch of air in it, causing my thermostat to work incorrectly?

Any help would be apreciated.

When I put a much larger volume turbo on my low compression 8:1 car with intercooler, ARP studs and full metal head gasket and ran at 15psi in 3rd or 4th gear the head would lift pushing water into radiator overflow when I was running the car flat out only. ARP studs use extremely high torque values. The mechanic didn't follow those numbers.

I retorqued all the nuts to the required high specs and the issue was solved EXCEPT for the following issues.

Never run high boost in OD or when the outside air is 55F or lower. An A/F ratio lean/rich meter permanently wired to the O2 sensor is a valuable tool.

In cooler air I ran only 10psi with the big turbo and had no issues.

Hope that helps.

 

[millhouse]

If you are running stock heads, I'm afraid head studs aren't necessarily going to fix your issue. The thin decks associated with the heads make them prone to lifting under boost…regardless of bolt type. An FYI, simply using head studs does NOT make them less prone to lifting. The real advantage of head studs is it being a more precise clamping method (easier to torque to spec without stressing the threads in the block).
What makes things worse is…once you've lifted a stock style head, it can be tough to get them to stay down. In the end…the best solution is to go with a thicker decked aluminum head.

As for the running high boost in OD…you shouldn't be running ANY boost in OD! This is the best way to fry your OD band or snap a shaft. OD is not a performance gear. The general rule of thumb with a turbo and an OD tranny is…don't let the tranny shift into OD at WOT, don't go WOT in OD and don't let the tranny downshift out of OD at WOT.

In regards to the temperature…if you have a decent tune, this should not matter. I could boost all day long in temperature ranging from 0-100*F with no ill effects. Get a good tune, run the appropriate octane for said tune and boost away.

 

[lancec2c30]

After you lift a head, I could see there being a problem if a person just threw a new set of gaskets on.
But if the heads are re surfaced there shouldn't be any more problems then before, should there?

 

[millhouse]

After you lift a head, I could see there being a problem if a person just threw a new set of gaskets on.
But if the heads are re surfaced there shouldn't be any more problems then before, should there?

Back when I had gt40p's I lifted the heads with due to a improperly installed boost controller (spiked to 18psi!), I never again could get those damn heads to not lift…even while running as low as 8psi. I went as far as to o-ring the block and install some stainless rings…still with no luck. FYI, the block and the heads were checked and deemed flat. From what I've seen/heard, this is not uncommon with thin deck stock and gt40/p heads.

 

[lancec2c30]

That's weird, I'm not quite ready to spring for aluminum heads yet, so i'll give these one more shot.