Custom Head Gasket

[jdmser]

Has anyone ever had a custom head gasket made? With the price of the rb20 Tomei head gasket, especially the 83.5mm ones, I've found it would be cheaper to have a custom one made. What material would you go with and why? Who would you go to for this? This would be for a motor that will be seeing mid to high 20s psi.

[BoostFab]

i got a cometic 1.5mm they don't sell these normally.

[Carryl]

im running an FET sports 2mm

[Cjmartz2k]

Why the hell would you need a 2mm head gasket? Did you shave the hell out of the head to make it flat or something?

[sil_eightyRPS13]

i also have a tomei 88mm x 2mm ready to go when my cometic bites the dust...

[Sil240]

jdmser-

You bored your 20 out to 83.5??????That's crazy stock bore is 78mm, that would be a 5.5mm (0.2145") overbore!!!!

I did a 79.87 just about 2mm/.068" overbore and my machinist was reluctant to go more due to cylinder wall thickness.He said that if I went more and I wiped the motor then I would have to sleeve the motor after that.

Becarefull of cylinder distortion.

Checkout Cometic or Fel-pro and see if they will make it for you.I've sent an e-mail to find out if Fle-pro carries anything for the RB's.

What thickness do you need?

[ripracer]

Sil40 What pistons did you have made for that bore, and what did they end up running you?

[Sil240]

I have custom JE pistons, pins retainers and rings.I got raped for $1000

So if you need them, tell them they've already made them.I had to send them a sample piston, one of my good pistons.

[jdmser]

No, 83.5 is the size of the rb24 gasket that Tomei sells. I will be boring mine out to 82mm and would like to keep the hg diameter a little tighter. I have read on Cometic's site that all you have to do is call with the part number and the diameter and thickness you want and they'll make it. I'm just a little leary because I've heard some people had bad expierences with they're head gaskets. I also just got a quote from JE to make my RB24 pistons and it will be right around a grand with pins, locks, and rings. Ross racing quoted the same price so now I have to choose.

[BoostFab]

No, 83.5 is the size of the rb24 gasket that Tomei sells. I will be boring mine out to 82mm and would like to keep the hg diameter a little tighter. I have read on Cometic's site that all you have to do is call with the part number and the diameter and thickness you want and they'll make it. I'm just a little leary because I've heard some people had bad expierences with they're head gaskets. I also just got a quote from JE to make my RB24 pistons and it will be right around a grand with pins, locks, and rings. Ross racing quoted the same price so now I have to choose.

i hope you know what you're doing, 82mm bore is pretty close to the water jacket.

[jdmser]

I'm no expert but, I been reading everything I can find. I know that the guys that go 83mm have had cylinder wall cracking issues. I would imagine that if 82mm was too much Tomei wouldn't make the pistons. This isn't a daily driver either it's a cruise/strip car. I average less than 5k miles a year on it. If I do get into the water jacket it will be a good excuse to sleeve the block. I've also thought about having the block cryo treated after the machine work is done.

[jdmser]

I just want to post an email I wrote to Tomei USA and the reply to it about the rb24 pistons from Tomei. I plan on keeping a journal and posting all the information on here about my rb24 build.

I have acquired a RB26 crankshaft and rods in an atempt to build my RB20 intoa RB24. I have recently been told that 82mm may be too big of an overboreon a RB20. Are there any issues that would have to be adressed when usingyour 82mm pistons?

Hi Tom,

We have been selling our 82mm pistons for well over 10 years.There is no issue with using them on the RB20 or we would not advise thatcombination.You only need to worry about the clearance on the crank and rods for theblock.

-- Sincerely Allen LorenzoTOMEI POWERED INC.1737-3 Tsuruma MachidaTokyo 194-0004 JAPANTel: +81 42 795 8035Fax: +81 42 799 7851http://[email protected]