My motor is 500 miles old and I have the problem . It started on the dyno , when doing a power curve run . The extra load put on the motor [ Mustang dyno ] when doing the power curve , I think is what started it .

 

How do you know it's headlift and not a cooling system problem? Are you showing signs of coolant in your oil or deposits in your coolant?

 

I have carbon deposit in the overflow tank.

 

Its only doing it when I boost it to redline . 13 to 13.9psi from 6000rpm to redline . I get the same aount of water in the overflow [ 1/2inch ] every time . It doesnt do it when not boosting and the car doesnt run hot during boosting runs

 

I am good friends with Clark @ JWT... I trust what he tells me. The car was road raced at the 550whp level.. and never had a single problem. It was driven hard on the freeway, and flogged on the dyno.. Clark thinks that it has more to do with localized boiling in the cylinder head, creating steam pockets.. which displace the coolant into the overflow tank. He's talked with a few of the JGTC guys.. they have done all sorts of elaborate burp tank setups, and running much higher coolant system pressure.

Travis

 

Also... you guys with carbon deposits in the coolant system.. are you using stock head gasket's? The sealant that Nissan uses on thier gaskets, isn't the best in the world.. the gaskets suck, honestly..

 

true, it isn't carbon deposits, it is part of the stock head gasket breaking off. the stock head gaskets have dimpled rings around the cyliders, which makes it easy for the coating they put on to break off in the bending process when the gasket mates. the coating loosens during this. thus making it easy to break off later when you get a combustion leak.
bottom line, if you get black specks in your over flow, you have a problem!! they come from somewhere.

 

That's what alot of us are running. I am. It's called a radiator breather tank or radiator purge tank, take your pick. It definitely helps but guys like Gman2004 are running those and still having the problems.

 

Maybe we're just maxing out the cooling capacity for a street car?

 

I am still having problems.....only @16 psi. I am going to try Scott's mod and see what happens.

 

is this the 8th wonder of the world?

8.) How can we prevent pressurizing the cooling system on a F/I'd vq35???


um...larger head studs..why don't we test this and see that it solves the problem before we overthink this and develop "fixes" that we don't need

OH NO!!!!!! we're doooooooooomed ...

come on guys, these are the same exact problems encountered on many other motors that have been pushed...for example, the sti motors were having the same problems, they swapped out the head studs for larger diameter, torqued em down and the problem is solved, guys run 45psi on those motors without any sign of head lift!

oh yeah, sleeving helps the cylinders too , true, we are working with an open deck...so don't run it insanely high unless you want to get it sleeved...

my $1.50

 

Unfortunately not everyone works in the tuning/motor building industry and can pay little or nothing to get work done on their cars therefor if someone can come up with a fix other than having to pull the motor and installing larger head studs I am jumping all over it.

 

Tell you what Jorge, you are a good guy, drive out here for a week, you and me will pull your motor and install the studs..then you'll be golden

(I am serious too)

 

I believe you too. You are a good guy!

 

Actually it is nice to have because I only have to burp the system once with the purge tank in there and it will burp itself after that. It only took about an hour to install and we all know how much fun burping the cooling system is.

 

When I refilled my cooling system I didn't take any measures to get the air out. I filled the cooling system up and let the car run with the heater on and I watched the breather tank purge the air for me.

 

Wondering if people solved their problem? I just got a new Koyo radiator and my car overheated today for the first time w/ the coolant filling up the overflow after the new radiator install. Took all the air and stuff out. Not sure what to do.

 

Holy old thread!

If you just changed out your rad, and immediately overheated, than the cooling system was not properly purged.

 

Not immediatetly, but maybe been a week or so no problem overheating. Then today going home drove it a little hard is when it happened. This is on Lo boost, this usually only happens on Hi boost. BTW thanks for the great price on the Koyo!

 

How did you bleed the cooling system? +1 on what Sharif said, your probaly isn't properly purged of all the air. When you turn on the heater does it get hot right away, or does it take a while and not get as hot as it should (like when it was stock)

LMK,

-George
GT Motorsports