RB oem headgasket install... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Zacho · 10-11-2009, 10:21 PM

Okay guys, heres my situation

I removed the head to install tomei oil restrictors, and I am replacing the headgasket with another OEM gasket. The motor has NOT overheated. I will be using a combo of permatex gasket remover, putty knife, and some solvent to get the surface free of any old gasket.

My question is, using the OEM gasket and ARP studs, should I be okay not decking the head/block? I just don't think I need to without a blown HG or not having overheated. Can anyone share some opinions? I read on a thread here that I should spray some permatex copper spray lightly on it when it goes in and I should be fine.

Thanks.

eklips3 · 10-12-2009, 12:10 AM

thing is , is doesn't matter if your engine has overheated or not it will always warp , some in more severe cases that others. this is because that the RB heads are aluminum and the RB blocks are cast iron ... both dissipate heat at different time frames .

but thinking about it ,,, if you are using the OEM headgasket and you say it hasent overheated then you should be fine . but i strongly suggest getting your head planed just to be on the safe side.

and about that copper spray ..i've heard about it .. all it does it controls heat transfer between the head and block . you dont have to do it with a OEM head gasket , dont have to do it with a metal headgasket either . its your call if you want to do it . i havent come across anyone or read any threads if it's actually worked or not.

Sileighty_85 · 10-12-2009, 12:18 AM

Deck the head. It's like $30 to do so.

GSXRJJordan · 10-12-2009, 01:18 AM

Quote:

Originally Posted by Sileighty_85

Deck the head. It's like $30 to do so.

Seriously! And if you're staying stockish boost, taking a little material off will raise compression a tad, which is good.

eh? · 10-12-2009, 06:16 AM

Nope you don't need to machine the head or block. Just clean the surfaces and you'll be fine.
The oem hg will seal better on untouched blocks & heads than some MLS hg's on decked blocks & heads..

Sileighty_85 · 10-12-2009, 09:51 AM

Quote:

Originally Posted by eh?

Nope you don't need to machine the head or block. Just clean the surfaces and you'll be fine.
The oem hg will seal better on untouched blocks & heads than some MLS hg's on decked blocks & heads..

How do you know the prev. owner didnt over heat it?

I would at LEAST take it to the shop to check if its warped out of tolerance.

eh? · 10-12-2009, 02:53 PM

Quote:

Originally Posted by Sileighty_85

How do you know the prev. owner didnt over heat it?

I would at LEAST take it to the shop to check if its warped out of tolerance.

Yes at least check it but don't go willy nilly and mill the head just yet. Wait until you install a MLS hg and without question deck the block and head.

Out of personal experience the RB hg will seal some fuked up heads. I had a head that was resurfaced so bad it needed to be milled .014" by another shop. I had no idea as compression was 180psi and there was no leakage/mixing. Ended up blowing the HG after running 19psi with a ripped FPR sense line.

I've used quite a few oem RB hg's and I'm amazed at how well they seal along with the power they can take.

10-11-2009, 10:21 PM	#1
Zacho Zilvia Member Join Date: Jun 2007 Location: Canada Posts: 217 Trader Rating: (5) Feedback Score: 5 reviews	RB oem headgasket install... Okay guys, heres my situation I removed the head to install tomei oil restrictors, and I am replacing the headgasket with another OEM gasket. The motor has NOT overheated. I will be using a combo of permatex gasket remover, putty knife, and some solvent to get the surface free of any old gasket. My question is, using the OEM gasket and ARP studs, should I be okay not decking the head/block? I just don't think I need to without a blown HG or not having overheated. Can anyone share some opinions? I read on a thread here that I should spray some permatex copper spray lightly on it when it goes in and I should be fine. Thanks.

10-12-2009, 12:10 AM	#2
eklips3 Zilvia Addict Join Date: Apr 2008 Location: Calgary Canada Age: 31 Posts: 626 Trader Rating: (3) Feedback Score: 3 reviews	thing is , is doesn't matter if your engine has overheated or not it will always warp , some in more severe cases that others. this is because that the RB heads are aluminum and the RB blocks are cast iron ... both dissipate heat at different time frames . but thinking about it ,,, if you are using the OEM headgasket and you say it hasent overheated then you should be fine . but i strongly suggest getting your head planed just to be on the safe side. and about that copper spray ..i've heard about it .. all it does it controls heat transfer between the head and block . you dont have to do it with a OEM head gasket , dont have to do it with a metal headgasket either . its your call if you want to do it . i havent come across anyone or read any threads if it's actually worked or not. __________________ 1992 240sx (RB20. [email protected])

10-12-2009, 12:18 AM	#3
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Deck the head. It's like $30 to do so. __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

10-12-2009, 06:16 AM	#5
eh? Zilvia Member Join Date: Apr 2005 Location: Orlando, FL Age: 40 Posts: 283 Trader Rating: (0) Feedback Score: 0 reviews	Nope you don't need to machine the head or block. Just clean the surfaces and you'll be fine. The oem hg will seal better on untouched blocks & heads than some MLS hg's on decked blocks & heads..