Gtx3071 Install

[slippylotion]

I'd say it's not a common fault with the head gasket, it would have been from the 25psi forced in for it to try and hold. Nissan head gaskets don't normally hold that amount of boost for long. Toyota is better in that regard as they have a metal gasket from factory.

Can you get a/market metal gaskets for it?

[Sunkist]

im pretty sure the head gaskets on vq25 are multi layer metal gaskets.. arent they?

[slippylotion]

If that's the case head bolt stretch then. Fit an ARP stud kit.

[wolverine]

If you reach >1000psi during combustion, can someone explain what difference running 15psi, 20psi or 25psi will make to the headgasket if the tuning is spot on.

[Sunkist]

If that's the case head bolt stretch then. Fit an ARP stud kit.

i have a feeling thats what happened. same thing happened on the '400kw vq30' put ARP studs in and away he went.

[Sunkist]

If you reach >1000psi during combustion, can someone explain what difference running 15psi, 20psi or 25psi will make to the headgasket if the tuning is spot on.

i think over time its a lot of stress on the head studs and they will stretch and eventually blow out the head gasket.. as scotty said he reckons its been there for a while but today it just let go

[scotty nm35]

Mmm, that doesn't explain Gleeson's almost stock car with exactly the same issue.

I was looking at the pathfinder mod, I think I may be able to do my own version. This issue is documented as a common 3.5 problem when boosted. http://www.jimwolftechnology.com/wolfpdf/VQ35-VQ37_COOLANT_SYSTEMS_HEAD_GASKETS_HEAD_BOLTS.pdf

[Sunkist]

thats pretty interesting. when do you wanna go up to cambelfield..

and it could explain gleesons, previous owner couldve boosted it without tuning or anything.. we dont know but can only assume.

they did do cosmetic mods on it, whats stopping them from adding a boost t

[PN-Mad]

Maybe Gleesons car overheated? Don't know the circumstances, but faulty clutch fan and over heat?

Might have been suspect from Japan too.

Good work Scotty. Seems to make good power. Good quick trouble shooting too.

[scotty nm35]

Mine has overheated many times too, like I said, the rear of the heads doesn't cool too well so if it gets hot, that will be the failure point.

I'm still not sure which path to take, probably best to buy a s/h motor and drop it in but the 3.5 build would be nice, so would the 2.5dd high comp turbo'd.

[iamhe77]

Don't you have a spare 25det?

[scotty nm35]

Yep, it has a top end tick though, not sure what the issue is with it, or whether it will handle 350kw.

[sky^rkt]

damn sorry to hear scotty wil be good to see the results with a new motor in it

[scotty nm35]

Im leaning towards Paul's suggestion of an ARP stud kit and just replace the gaskets after checking the heads are straight. It will take some time though...

[Sunkist]

Im leaning towards Paul's suggestion of an ARP stud kit and just replace the gaskets after checking the heads are straight. It will take some time though...

Let's go

[scotty nm35]

Haha, keen as ey Aaron.

I would need to get Nissan to order the gaskets and wait for the stud kit to come from the US, hopefully the same thread size etc...

[slippylotion]

Can you go a larger thread size in these at all? I know the serious SR builds tap out to a larger stud size. Might be worth a look for the punishment you'll more than likely put it through ?

[sky^rkt]

how big are the standard studs? quit possible to put larger studs if you get the right length, my rb30 is drileld n tapped for 1/2 inche studs the bastard should hold!

[scotty nm35]

http://www.jimwolfte..._HEAD_BOLTS.pdf

Ours are the 26 hc rockwell early VQ35de bolts I'm fairly sure. Ours have one bump on them anyway.

I'm sure the ARP studs will crap all over them anyway.

[scotty nm35]

Here are the L19 ARP head studs, exactly what I need.

http://my6thgen.org/f17/arp-l19-headstuds-597/