How much power can the stock headgasket hold? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

TheSparo · 06-29-2005, 01:21 PM

i know i read this somehwere but i can't find it, am i correct in assuming 400whp? or is that too high? i would think it would go with the tolerance of the internals and tranny.. anybody have a close answer?
btw on a red top SR

evrae205b · 06-29-2005, 01:33 PM

That is a good question and would like to know the answer also. Although I'm probly going to get a metal HG before I put my motor in.

Dousan_PG · 06-29-2005, 01:35 PM

id upgrade around 320 imo
300 it holds a-ok
but above 3 i also would upgrade a lot..just because being safe is better then sorry.

TheSparo · 06-29-2005, 01:54 PM

ouch... has anybody been successful much higher than that?

Dousan_PG · 06-29-2005, 01:57 PM

mi sure people have done ok, no doubt
but like i said, better safe then sorry
id rather spend a few hours changing upgrading my headgasket then running my engine till it pops and being stuck in the middle of nowhere (ie: race track) and having to pay someone to replace it because i dont have the time or tools or tow money

so like isaid, spend the 100some-200some bucks and replace the stock headgasket

DrtyRat · 06-29-2005, 09:19 PM

not trying to thread jack but since we're on the subject are any aftermarket headgaskets better than others, if so why? just blew the head gasket on mine and i figure i might as well upgrade since my goal will be 300whp+.

NZO · 06-29-2005, 10:29 PM

The correct question is what power level and for what duration.

silviadriftr · 06-29-2005, 10:29 PM

I wouldn't go past 375whp. I ran mine for a few months around that range with no problems but after bumping the tune up to 398whp the head gasket went. It would have probably lasted longer but didn't do the fuel pump relay upgrade as needed over around 380whp. I have a couple of guys putting down around 430whp with head gasket and studs.

TheSparo · 06-30-2005, 06:14 AM

what fuel pump relay? never heard of it...

silviadriftr · 06-30-2005, 08:35 AM

Quote:

Originally Posted by TheSparo

what fuel pump relay? never heard of it...

Esentially, it uses the factory fuel pump wire to trigger the relay, and through the relay you run a 10gauge wire wich ties directly off the battery for more power. The original factory fuel pump wire is very small and under heavy prolonged loads of power the ecu will put the fuel pump in limp mode showing too high of an amperage draw. You can buy the rely kit from summitt for cheap or you can make your own.

06-29-2005, 01:21 PM	#1
TheSparo Zilvia FREAK! Join Date: Sep 2002 Location: Athens/Chattanooga/ Cookeville/Morristown, TN Age: 38 Posts: 1,141 Trader Rating: (0) Feedback Score: 0 reviews	How much power can the stock headgasket hold? i know i read this somehwere but i can't find it, am i correct in assuming 400whp? or is that too high? i would think it would go with the tolerance of the internals and tranny.. anybody have a close answer? btw on a red top SR __________________ 89 240 SR powered... ummm i promise its stock

06-29-2005, 01:35 PM	#3
Dousan_PG Post Whore! Join Date: May 2002 Location: Orange County, California Age: 45 Posts: 16,640 Trader Rating: (23) Rides Gallery: Dousan_PG Feedback Score: 23 reviews	id upgrade around 320 imo 300 it holds a-ok but above 3 i also would upgrade a lot..just because being safe is better then sorry. __________________ Aaron Pink GodziRa www.geocities.com/pink_godzira

06-29-2005, 01:54 PM	#4
TheSparo Zilvia FREAK! Join Date: Sep 2002 Location: Athens/Chattanooga/ Cookeville/Morristown, TN Age: 38 Posts: 1,141 Trader Rating: (0) Feedback Score: 0 reviews	ouch... has anybody been successful much higher than that? __________________ 89 240 SR powered... ummm i promise its stock

06-29-2005, 01:57 PM	#5
Dousan_PG Post Whore! Join Date: May 2002 Location: Orange County, California Age: 45 Posts: 16,640 Trader Rating: (23) Rides Gallery: Dousan_PG Feedback Score: 23 reviews	mi sure people have done ok, no doubt but like i said, better safe then sorry id rather spend a few hours changing upgrading my headgasket then running my engine till it pops and being stuck in the middle of nowhere (ie: race track) and having to pay someone to replace it because i dont have the time or tools or tow money so like isaid, spend the 100some-200some bucks and replace the stock headgasket __________________ Aaron Pink GodziRa www.geocities.com/pink_godzira

06-29-2005, 10:29 PM	#7
NZO Zilvia FREAK! Join Date: Mar 2002 Location: Reno, NV Age: 41 Posts: 1,424 Trader Rating: (0) Rides Gallery: NZO Feedback Score: 0 reviews	The correct question is what power level and for what duration. __________________ sentinelguild.com/nzo/PFCDB/

06-29-2005, 01:33 PM	#2
evrae205b Zilvia Member Join Date: Sep 2004 Location: birmingham AL Age: 43 Posts: 165 Trader Rating: (0) Feedback Score: 0 reviews	That is a good question and would like to know the answer also. Although I'm probly going to get a metal HG before I put my motor in.

06-29-2005, 09:19 PM	#6
DrtyRat Nissanaholic! Join Date: Jan 2005 Location: Miami,Fl Posts: 1,747 Trader Rating: (9) Feedback Score: 9 reviews	not trying to thread jack but since we're on the subject are any aftermarket headgaskets better than others, if so why? just blew the head gasket on mine and i figure i might as well upgrade since my goal will be 300whp+.

06-29-2005, 10:29 PM	#8
silviadriftr Leaky Injector Join Date: Oct 2003 Location: DOUGLASVILLE, GA Posts: 81 Trader Rating: (0) Feedback Score: 0 reviews	I wouldn't go past 375whp. I ran mine for a few months around that range with no problems but after bumping the tune up to 398whp the head gasket went. It would have probably lasted longer but didn't do the fuel pump relay upgrade as needed over around 380whp. I have a couple of guys putting down around 430whp with head gasket and studs. __________________ UNLIMITED PERFORMANCE WWW.TURBODAVE.COM http://www.mountainboost.com/415/silvia.wmv Record holding-473whp-sr20det stock cams and bottom end

06-30-2005, 06:14 AM	#9
TheSparo Zilvia FREAK! Join Date: Sep 2002 Location: Athens/Chattanooga/ Cookeville/Morristown, TN Age: 38 Posts: 1,141 Trader Rating: (0) Feedback Score: 0 reviews	what fuel pump relay? never heard of it... __________________ 89 240 SR powered... ummm i promise its stock