6g74 - What gasket did you use?

[Gearheadvr4]

For a 6g74 that's already built what head gasket would you use. What if you have a larger than stock bore of 93.2. How do you bore out a stock head gasket to match?

If that's to much trouble then would you guys recommend a Cometic gasket? They make an oversized gasket for a 6g72 that works with a 6g74. The stock mls 6g74 is not for use on a turbo car.

[Ninja Performance]

OEM HGs, chamfer pistons.
I would stay away from the Cometic. It's a 3 layer versus the OEM 4 layer.

-Chris

[Chatzvr4]

OEM HGs, chamfer pistons.
I would stay away from the Cometic. It's a 3 layer versus the OEM 4 layer.

-Chris

+1. we just chamfered the pistons with a mls 6g72 gasket

[IPD]

i'm with those guys ^.

i intend to do the same with my stroker build.

[Gearheadvr4]

If I used a factory 6g74 which one do I need? I thought they wouldn't work because they are too thin and not really for turbo applications?

Unfortunately camfering the pistons is not an option. The block I'm looking at is already professionally built. The block is a diamante-style non-crossover 6g74 block (out of a kia) with 20 over Ross pistons.

[Rocket]

[quote]Using the wrong gasket and then chamfering the pistons is a bit pointless to say the least. But then if you haven't done your homework to find out what's available it's to be expected.[\quote]

Steve, I find the rest of your post to be pretty informative. This snippet though could be left off and you wouldn't rub so many raw even when you have good information. I don't personally know you. My guess a cantankerous old SOB that is just pretty gruff about everything. You have some good information to give sometimes, but the blunt attacks just cloud the issue and worthwhile things then get overlooked.

If there is an option to actually use a correct OEM MLS gasket I would think that would be much better than camfering pistions, but both are options that can be considered.

Steve, since he is .020 overbored will either of the stock gasket scenerios you listed work for him?

[Gearheadvr4]

The pistons are Ray’s custom Ross 6g74 pistons – 20 over, supplied by Scott Merkel. Block was Line bored to 2.6775. Does that help any? I don't know yet what any other measurements are.

No worries about offending me. It would take a lot to do that. No I have not done my homework at all. That's why I'm here to try and correct that.

[Ninja Performance]

I'm sure Ray will know how far out of the block these pistons sit. As for the size? these motors are designed and built in mm not inches.

so 2.6775 comes in as 68 and a bit mm........?
Maybe it was 3.6775 inch, that will be 93.4085mm .
20 thou over is roughly .5mm (.508mm)over the stock 93mm so should be 93.5mm.
In this part of the world we got rid of inches years ago. We buy oversize pistons in multiples of .25mm 10 thou inch is .254mm. It confuses things un nessecarily.
Line boring is actually align boring, which is what is done to main bearings (the block). Bores (cylinders) just get bored.

Realistically you can't rely on anything on the net, you need to do your own measuring or you get the wrong information.

Steve

Do you post sillyness just to see if you can get away with it? Seriously? I really wish you would stop before someone takes your info as fact. And you are correct, you can't rely on everything you hear on the net....ringlands.

-Chris

[Gearheadvr4]

I will try calling Ray and get his opinion. He's built a couple of these with those pistons so he would probably know.

The line bore info was just what I was told. Odd to me also that it was in inches. I don't have the block yet so I'm unable to make any measurements. I didn't think it would be so difficult to just get a couple of gaskets. Damn!!

Edit: Well I got up the nerve to call Ray and he said they chamfered a lot of those pistons anyways and he explained how I would be able to tell. So I'm back to waiting till I get the block in to see what I have. From the information I got from the seller,i dont believe they were chamfered. Since they are probably not I'm still in the same situation and have absolutely no idea what to do and cannot go forward till I figure this out.

[zelstin]

I will try calling Ray and get his opinion. He's built a couple of these with those pistons so he would probably know.

The line bore info was just what I was told. Odd to me also that it was in inches. I don't have the block yet so I'm unable to make any measurements. I didnt think it would be so difficult to just get a couple of gaskets. Damn!!

I'm sure Ray has the answers you're looking for, he's done more 6g7X strokers than anyone on the planet. Whether the info on the block is in standard or metric just depends on the machine shop that did the work. No biggie.