What's Involved In A Head Gasket Change?

[wilch]

Hi guys, just wondering what's involved...

Does the head need to be decked? Or does anything of the sort need to be done when changing the head gasket over and bolting the head back on?

Thanks

[CRSRB25DE]

The head should be surfaced as flat and smooth as possible when using a MLS head gasket.

[wilch]

Thanks CRSRB25DE

Does anyone know how much approx the surfacing should cost?

[SECURITY]

you can get away with using a blade to get the layer of crap off the block and head surface.

sand the block back with some sand paper (coarse-ish wet and dry will be fine).

next thing would be to check the flatness of your head with a straight edge. if it comes out straight you can just sand it back with some coarse wet and dry.

get yourself some metho and clean both surfaces with a clean rag before putting the head gasket on.

if the head doesnt come out flat, take it to a machine shop and they'll charge you around $50 for it, its worth it if you're bothered to wait a few days.. this is what my head looks like after the machining:

[wrxhoon]

Why do you want to remove the cyl head? If its just to change the h/gasket just leave it as it is, if it blows then remove and replace with a metal gasket. While the head is off you may want to service it and check the block for warping as well.

[madness]

Why do you want to remove the cyl head? If its just to change the h/gasket just leave it as it is, if it blows then remove and replace with a metal gasket. While the head is off you may want to service it and check the block for warping as well.

Don't listen to him, If your head gasket went the first thing ill be checking to if its cracked, warped ect....

Then go from there, the last thing you want to do is change it and the same problem happens again...

I love this "While the head is off you may want to service it and check the block for warping as well"

To check the block i think you need the block out....

[wrxhoon]

To check the block i think you need the block out....

Who told you that? Of course you can check the block for warpage in the car when the cyl head is off.

[SECURITY]

to check the block for cracks you'll need it out. but checking it for warping is fine while its sitting in the car.

and if he wants to swap for a metal head gasket before his current one blows then whats wrong with that?

he's probably got his reasons.

[wrxhoon]

and if he wants to swap for a metal head gasket before his current one blows then whats wrong with that?

he's probably got his reasons.

Nothing.....

If i was to do that i would do a total rebuild though .... Each to their own.

[wilch]

Why do you want to remove the cyl head? If its just to change the h/gasket just leave it as it is, if it blows then remove and replace with a metal gasket. While the head is off you may want to service it and check the block for warping as well.

Currently running a GT30r turbo on 16psi (light tune)...

The fact I'm still running the stock gasket makes me worried, and hesitant to track the car.

I've been given conflicting information from different sources. Some say it's perfectly safe to run 16psi on a stock RB25det w/ stock gasket, others say I'm stupid and asking for trouble.

I don't know who to believe....

[sh@un]

Wil, damaging your head gasket is only a concern if your engine is being subjected to pre-ignition/detonation when run hard for extended periods (which causes massive spikes in peak cylinder pressure, hammering the gasket).

Nissan head gaskets on RB turbo engines do their job very well. I'm assuming the gasket hasn't been fiddled with at some stage, but if your tune is spot on- then don't worry about it.