Metal Headgasket thickness

[510-SR20DET]

Questions for all SR20DET experts,
I have S14 Sr20det which took a poop on me because i let it sat for too long without start up. Why? beat me. so I sent it to a shop to replace the head gasket and rebuild the engine. And they told me the Apexi Head gasket 87mm 1.1 thickness is too thin.
Base on previous research i had, stock or 1.1 is what most people are running. Im running 19 psi and planing to retune with 22psi (Gt2871r).
Are these guy know what they saying or my research is wrong? 1.1 is too thin? They suggest me to use 1.5 or 1.8.
How thick is your HG? psi?

[lightsource]

just out of curiosity, you were running 19psi w. a stock hg?

I'm going to be running a cosworth 1.1mm @ 12 to 14psi on a t25.

[510-SR20DET]

just out of curiosity, you were running 19psi w. a stock hg?

I'm going to be running a cosworth 1.1mm @ 12 to 14psi on a t25.

no way dude, that's suicide mission. I had Apexi 1.1. i get the same HG again but this time the shop said its too thin.

[lightsource]

no way dude, that's suicide mission. I had Apexi 1.1. i get the same HG again but this time the shop said its too thin.

haha alright, I was gonna say...

But anyway, dude if you were running a 1.1 and your head hasn't been shaved down or anything like that why would you need anything bigger than 1.3 if you were running 19psi successfully?

I say go with what works.

[macey]

im a believer on using the standard 8.7:1 compression ratio. i have just finished building my tomei motor and i have used 20 over thou pistons and used a 0.9mm head gasket. this size was what tomei told me to run as it keeps that compression ratio.

-macey

[jspaeth]

I ran 340 whp GT2871R @ 17 psi on stock headgasket for 2 years, no problems.

Now I am at like 375 whp @ 18-19 psi on APexi 1.1 mm.

If you have the bottom end and head decked appreciably you should find out how much and compensate (relative to 1.1 mm) for it.

0.004" is about 0.1 mm......

[510-SR20DET]

I was successfully running 402 whp on 100. Now im rebuilding the motor so the head and block are getting deck and all sort.
This is a different shop which i never go to. There are alot of Sr20 that they are working on. They built the motor for Calvin Wan the drifter for Falken, seem like they have knowledge on SR but it does not match on my research.

[kamilitaryman]

Questions for all SR20DET experts,
I have S14 Sr20det which took a poop on me because i let it sat for too long without start up. Why? beat me. so I sent it to a shop to replace the head gasket and rebuild the engine. And they told me the Apexi Head gasket 87mm 1.1 thickness is too thin.
Base on previous research i had, stock or 1.1 is what most people are running. Im running 19 psi and planing to retune with 22psi (Gt2871r).
Are these guy know what they saying or my research is wrong? 1.1 is too thin? They suggest me to use 1.5 or 1.8.
How thick is your HG? psi?

If a shop is suggesting/telling you that you must go thicker than why even argue? Was any material removed from either the head or block? If so, you have to make up for that loss of material with a thicker head gasket. Once your head is torqued down, that 1.1 would become even thinner. Cometic is nice if you're running over 19psi.

[rc1honda]

Sound like the shop is just trying to go the safe route. The thicker gaskets are the same price as the thinner ones, so it's not a scam or anything.

By using a thicker headgasket you will lower your compression ratio. Ultimatley you can theorectically run more boost safley with a lower CR.

But really 1.1 is fine and shoudln't hurt anything. 1.5 or 1.8 should run fine to. If the shop is going to be decking the head and block then it might be a good idea to go with a thicker gasket but again it's not nessesary.

[jspaeth]

If you are getting only your head milled a few thousandths, just stick with 1.1 mm.

If you are getting your head and block decked, find out how much TOTAL is being taken off, then add this amount to 1.1 mm.

Remember 0.004" = 0.1 mm roughly.

[510-SR20DET]

I already bought the HG and brought to them. That's the thing.
I know ALOT people running 9:1 compression so whats that? are they using 2.0 thickness? see, dont make any sense.

kamilitaryman (http://zilvia.net/f/members/kamilitaryman.html) - Do you do whatever shop tell you to do? goodluck with that.

Cometic HG is hit and miss, some people have problem with it ( just a few though) for SR20 Apexi or Tomei is the way to go.

[kamilitaryman]

I already bought the HG and brought to them. That's the thing.
I know ALOT people running 9:1 compression so whats that? are they using 2.0 thickness? see, dont make any sense.

kamilitaryman (http://zilvia.net/f/members/kamilitaryman.html) - Do you do whatever shop tell you to do? goodluck with that.

Cometic HG is hit and miss, some people have problem with it ( just a few though) for SR20 Apexi or Tomei is the way to go.

Read below:

[kamilitaryman]

I already bought the HG and brought to them. That's the thing.
I know ALOT people running 9:1 compression so whats that? are they using 2.0 thickness? see, dont make any sense.

kamilitaryman (http://zilvia.net/f/members/kamilitaryman.html) - Do you do whatever shop tell you to do? goodluck with that.

Cometic HG is hit and miss, some people have problem with it ( just a few though) for SR20 Apexi or Tomei is the way to go.

No I do not. I tell them what I want done and listen to their input if they got any. I make the final choice. No need to get defensive kid. After all, YOU'RE the one asking for advice here....not me.

[brian3676]

The only reason they should say that is if they had to shave a lot off the head or block to get it flat. If they did not 1.1 is fine

[kamilitaryman]

The only reason they should say that is if they had to shave a lot off the head or block to get it flat. If they did not 1.1 is fine

Exactly, thank you.