Prepping for a head gasket replacement.

[TweeT91109]

So I have done a little bit of searching and found a bunch of stuff on how to prep for a head gasket replacement. Everything from using a a straight edged blade (gasket removal tool), to using different grits of sand paper, even scrubbing with a wire brush and purple power. So i'm just replacing a head gasket using a replacement Toyota gasket, and ARP head studs. When I removed the head it left, what i'm assuming is just left over composite material. I want to remove this left over material before I do replace the gasket. But with the things I have listed i'm worried about a few things, like if I were to use a razor blade, nicking the surface of the head, i'm not to worried about the block being that its cast iron. Or using a sand paper, I wouldn't want to take of any material of the head itself and create an uneven surface.

So my question is what are your guys opinions on the option listed above. I'm not looking to get any machine work done, being that it is a stock oem composite replacement gasket. And ill be using new ARP hardware to torque everything down to 78ft. lbs after a few heat cycles, then again probably 100 miles then 500 miles later. But just wanted to get some insight from the pros. And thanks in advance guys.

 

[IJ.]

Personally I'd just have both surfaced to the correct RA value for the HG you're using, cheap insurance against repeating the job in a few months time.

 

[TweeT91109]

Personally I'd just have both surfaced to the correct RA value for the HG you're using, cheap insurance against repeating the job in a few months time.

But this would require a machine shop to do this correct?

And its just a 7mgte replaceable gasket from Drift-motion.

 

[suprarx7nut]

I've done a few HG jobs now. (3 total) on 7M's and one every one, I had the head machined flat (cheap and easy to do) and I simply cleaned the block. I never used sand paper for fear of creating gradual valleys and an uneven surface. Of course on all of these I used the toyota OEM HG. If you are using a MHG, you need to have both machined.

If you are shooting for a stock rebuild and dont have the money or the time or the space or the tools... to have the block removed and machined then I'd say your plan sounds just fine. I'd avoid using sandpaper and have the head machined and checked out.

 

[TweeT91109]

I've done a few HG jobs now. (3 total) on 7M's and one every one, I had the head machined flat (cheap and easy to do) and I simply cleaned the block. I never used sand paper for fear of creating gradual valleys and an uneven surface. Of course on all of these I used the toyota OEM HG. If you are using a MHG, you need to have both machined.

If you are shooting for a stock rebuild and dont have the money or the time or the space or the tools... to have the block removed and machined then I'd say your plan sounds just fine. I'd avoid using sandpaper and have the head machined and checked out.

i am going for a stock rebuild. And I have the money to have the block decked and the head machined its just I don't feel like theres a point to doing that much work just for a stock gasket. It it were a metal head gasket I wouldn't spare a dime in preparation for it, cause I know how much its needed. But again i'm only in a for a stock gasket replacement, and wanted to know how everyone feels about using the listed items, and see if my raised concern just wasn't pointless.

If I do go ahead and have the block decked, and head machined I might as well get MHG. Or just reuse my old one, from another motor.

 

[CyFi6]

Don't forget that just because you get it machined doesn't mean it will be good for a mhg, a lot of machine shops seem to cut surfaces pretty rough and that's not what you want for a mhg.

 

[TweeT91109]

Don't forget that just because you get it machined doesn't mean it will be good for a mhg, a lot of machine shops seem to cut surfaces pretty rough and that's not what you want for a mhg.

true that. and ill probably just do what 1j suggested and have the block and head just cleaned. I think the only problem ill have is figuring out what "RA value" ill need to have the block and motor machined to.

 

[IJ.]

Don't forget that just because you get it machined doesn't mean it will be good for a mhg, a lot of machine shops seem to cut surfaces pretty rough and that's not what you want for a mhg.

true that. and ill probably just do what 1j suggested and have the block and head just cleaned. I think the only problem ill have is figuring out what "RA value" ill need to have the block and motor machined to.

Personally I'd just have both surfaced to the correct RA value for the HG you're using, cheap insurance against repeating the job in a few months time.

 

[TweeT91109]

Thanks for the quotes buddy, but how will I know what RA value to have the block and head machined to?

 

[IJ.]

Thanks for the quotes buddy, but how will I know what RA value to have the block and head machined to?

I'm not familiar with that particular gasket have you asked the supplier what they recommend?