Block prep for metal headgasket..?

[Malcolm]

Well at present my 3S head is being skimmed for the metal headgasket, but I need to work out what to do with the block.

Now I know some people suggest having the block skimmed too, but I don't want to strip down my block to have that done (I don't even want to remove it from the gearbox). I know quite a few people have installed metal headgaskets without having the block skimmed, so what have you done instead?

Today I block sanded the block with 800 grit wet sand paper. It's pretty smooth now, but the parts that meet water passages in the head still appear to be pitted. It still looks like it should seal though


The other thing I want to know, is do I use copper gasket spray on the headgasket or not? Many people recommend using it, and as many seem to not recommend it, so what have you done, and did it work?

Thanks

[ChaosAD]

I put a trd metal gasket on my mates bluetop when he blew the headgasket. Skimmed the head and spent ages with the gasket scraper and then fine sandpaper getting the block mint. Sprayed some copper headgasket sealant on both sides as I had some left over, let it go tacky then fitted the hasket and head.

Still sealing mint, but then it diddnt have very bad pitting on the block.

[Malcolm]

probably wasn't running boost either

I'm leaning toward using the gasket sealer if noone tells me otherwise.

When you were done sanding the block was it all one colour without any marks at all on it?

[vvega]

if you have a pitted block you need to get the blocked skimmed

sorry man that just the right way to do it

v

[Malcolm]

I will take pictures tomorrow to show where it's pitted - it's not over the whole thing, it's just areas which don't have the full pressure of the head on them, the parts around + between cylinders are mint

[Si]

on a side note, i have that diff in now, works fine chur all_fours

[Malcolm]

good stuff, 2 wheel skids now?

[Si]

not quite, clutch is on tis way out, and add to that the 245's on the back, means the supra is a grip monster

[Malcolm]

excellent
245's make the mr2 grip pretty good too (unless you try to turn...)

[Si]

im getting rid of them anyways, 17s are dirt cheap both for the rims and tires,

[SUBARUCONVERT]

Emery paper its back to a nice finish, if theres any pitting dont bother tryin to make it work, it wont.

[Bazda]

Get the block skimmed, tell them your running a metal head gasket.

Use the copper spray stuff that VHT make i think, I just used it a week ago when I put my head on with a TRD metal gasket.

[Malcolm]

have you run it yet with the VHT copper spray on it? I have a can of it waiting if I decide to use it.

Anyway, I took some pictures (sorry, they're big for clarity). I got the head back but wonder whether it's a good enough finish. I can feel the grooves if I run my fingers over it, but only just.
Head:


Now the block, which actually feels smoother than the head (having sanded it with 800 wet sandpaper)


What is probably of more concern to me than the pitting is the swirl marks presumably from when it's machined from the factory.

[Crucible]

The other thing I want to know, is do I use copper gasket spray on the headgasket or not? Many people recommend using it, and as many seem to not recommend it, so what have you done, and did it work?

I do at least one head job a month Ive always fitted "Regular" headgaskets dry and never had any come backs. I use brakleen or kero and a fine oil stone to prep decks, You can tell with the headgasket sitting on the dowels wheather there is going to be a sealing problem.
Copperspray prevents the gasket shifting under torque and is supposed to conduct heat better.......well "In theory" but thats all.
Worked with a guy that used the VHT stuff on all h/g jobs and he had no comebacks as long as proper procedures were followed.

I cant see any probs with those pics, but then again Ive never used metal headgaskets only regular ones. The deck would have to be mint if the gasket hasnt got any beading to seal......... Yep Mill the deck

TNT

[Malcolm]

I do at least one head job a month Ive always fitted headgaskets dry and never had any come backs, if you doubt the block in an area get a reconditioners opinion. I use brakleen or kero and a fine oil stone to prep decks, You can tell with the headgasket fitted if there is going to be a transfer problem.

Are those metal headgaskets, or composite type ones? Also are you talking about prepping the deck with a grindstone or manually?

Copperspray prevents the gasket shifting under torque and is supposed to conduct heat better.......well "In theory" but thats all.
Worked with a guy that used it on every h/g job and he had no comebacks as long as proper procedures were followed.

I thought it is supposed to help seal the parts because it fills imperfections in the surfaces

[solberg Fan]

Measure the block and see if it has any warp in it. I had a copper gasket made up for me, skimed the head, no pitting on the block used the VHT copper stuff and put it together. Had no compression in two cylinders, went straight into the water jackets.
The only reason was that the block was a little warped. The head and Block must be straight and true when using metal gaskets. In my case a normal gasket fixed the problem.
If i were you i would measue the block and then decide what to do.

[Crucible]

I must of been editing above when you were posting.....

Oil stone like what you sharpen carving chisels with, I just realised you were talking about metal gaskets and changed my first post, and I was reffering to standard beaded gaskets NOT metal ones at first

copperspray would take up small imperfections but not much as its more like a tacky spray than a sealant......

Have you got a pic of the headgasket?

tnt

[Crucible]

Measure the block and see if it has any warp in it. I had a copper gasket made up for me, skimed the head, no pitting on the block used the VHT copper stuff and put it together. Had no compression in two cylinders.

What is the advantage of flat unbeaded copper or metal gaskets? are you trying to increase quench efficiency or compression ratios or what?. Are they superior to standard gaskets in what way???

Ive never used them before? only on some diesels but they were shimmed type gaskets to get the correct compression ratio back after milling.

[Malcolm]

the big advantage with metal gaskets is that they are more resistant to blowing under high cylinder pressures, as you would find in turbocharged cars, particularly those running high boost.


old on the top, metal on the bottom

[Crucible]

the big advantage with metal gaskets is that they are more resistant to blowing under high cylinder pressures, as you would find in turbocharged cars, particularly those running high boost.

Ahhh ok......that makes sense, the only area which is under the most stress from combustion I thought would be the sealing ring around the cylinder which Standard type gaskets have anyways, Can you get higher torque settings with steel gaskets? are you using arp bolts?

just as a matter of interest.

tnt