HKS 2mm Metal Head GAsket for SR20DE/T

[P11GT]

Yep, it the one i bought for my turbo conversion, but after discussing the situation further with other engineers, ive discovered that by fitting it, the compression would be far too low, i.e. 7.8:1 So its up for sale, as new, unused, can deliver anywhere. it will lower your standard compression by 0.5 NOT TO 7.8:1 like mine cos ive dne other things. asking price £200.00 UK Pounds ono. Email me if interestedor for more info.

heres the sales pitch............
HKS Metal head gaskets are constructed from multiple layers of steel to ensure proper head to block sealing, even under the most severe conditions. The special metal used in the construction of the head gaskets is resistant to both heat and corrosion. All gaskets are coated with a special fluorine rubber coating to provide the ultimate sealing.

[b-b00gie]

You've got mail

I was going to pick up one of these for my turbo project. But maybe I can help you get rid of it...

[b-b00gie]

Hmm... I just noticed the one I wanted was the HKS 1.2mm not 2mm... hmm..........

Will have to do a little research (aka talk it over with my SR turbo therapist...)

[P11GT]

your US spec G20 is 9.5:1 right? and thats what the FMAX and Hotshot are designed for, but lowering it a little more will make it easier to run slightly higher boost reliably. So with the HKS 2mm it'll be 9.0:1 which still isnt a great deal but better.

Ive opted for GTiR pistons which will bring it down to 8.3:1 more than enough, so the gasket wasnt needed.

[P11GT]

When turboing a NA car, the first thing that needs to be considered is how you gonna lower the compression. If anyone says you dont have to, then i think they arent giving good advice. By lowering it, youre relieving some of that extra stress that compressed air is putting into the block, so in effect, youre making the engine run more reliable.

[b-b00gie]

Originally posted by P11GT
When turboing a NA car, the first thing that needs to be considered is how you gonna lower the compression. If anyone says you dont have to, then i think they arent giving good advice.

This is totally not true. Especially with an SR20.

There's been a few people who've run SR20's w/ over 400whp on stock compression here. I wouldnt say thats the first thing that needs to be concidered. Below 300whp I wouldnt even concider it with our engines. Our engines can handle a lot more boost than other engines (honda, ford, etc..). I wouldnt concider detonation a problem with our engines unless you are running @ least 16 psi boost.


I am all for building up the bottom end even stronger just to be safe. I am going to be laying down 400-450whp @ 20 - 22 psi when I'm finally ready which is why I definately want to lower the compression.

I was going to be using 300ZX pistons so I'm not sure I can use the 2mm, it may be too much. I have to look into it. I think I was planning on the 1.2mm but I have to double check.

[P11GT]

One of the major problems i have over in the UK is that no one or not very many people have or done this sort of thing before, and if you ask them, they'll just shy away. Most people would say that the SR20 over here cant take that much power, but thats because thery aint tried it before. So i have to go round convincing people with what little info i can gather. But remember, my UK SR20 runs at 10:1 so your already ahead of me there, this is why its well recommended to lower mine. Nissan UK told me, thru my local dealer that the block/head would warp if i put the GTiR pistons in, i think because they think that the UK SR20 cant handle the power gain and it wasnt designed that way. I guess im out to prove them wrong, in a way.

[b-b00gie]

Yeah.. I wouldnt turbo @ 10:1 hehe.... not high power turbo.

Then again I'm not sure what your target is...

[P11GT]

well, i dont really have much of a clue, maybe you can help. Ive been told that the stock transmition can only handle around 200 BHP ATW so really, it'll be 220 ish at the engine, and i'd be happy with that. But could i go higher at a later stage without major surgery?

[b-b00gie]

Well it depends on how rough you are on the tranny...

250whp seems to be the stock limit. The problem is that some people beyond that level seem to crack the tranny case.


To remedy the problem you can have the tranny case welded. I can dig up some pics if you want to see where.


It is also a good idea to cryo treat and shot peen the gears. This makes them a lot stronger which you'll need at high HP levels..

[P11GT]

oooh, its starting to sound like surgery to me. i think ive done enough modifying if i can get about 200-200 ATW, i dont think i can be bothered to remove the tranny and have all that done, not even for the sake of 30 BHP. To be honest, if i get my to goal, and the car runs nice, i'll prolly only keep it for a while longer and sell it on....... maybe, dont know.

[jayntguru]

No one mentioned that a thicker than stock HG changes the quench area in the head and will modify the detonation resistant effects that the SR20DE normally has.

The only time you want to use a thicker than stock HG is when you have had material removed by having the block decked or the head shaved. This is why the HG's come in different sizes.

[P11GT]

Yeah, thanks for that. But in our cases, because were using force induction on a NA car, its a good alternative to lower the compression. It also adds stability, as with the quality of these gaskets, premature failier is less possible, and higher outputs can be achieved.

[jayntguru]

I just some quick math. looks like moving to a 2 mm HG is about .1 compression point decrease. Hardly worth the effort.

These thicker HG are meant to compensate for deck height changes due to machine work, not to lower your compression.

[JustinP10]

Originally posted by b-b00gie
Well it depends on how rough you are on the tranny...

250whp seems to be the stock limit. The problem is that some people beyond that level seem to crack the tranny case.


To remedy the problem you can have the tranny case welded. I can dig up some pics if you want to see where.


It is also a good idea to cryo treat and shot peen the gears. This makes them a lot stronger which you'll need at high HP levels..

I don't think it's the case that cracks, i thought it was the gears that actually break. The teeth get stripped off the gears, due to the internal flex in the transmission, from the increased hp?