CART0410 Posted June 15, 2007 Share Posted June 15, 2007 I have a 1973 240Z with a L28 Turbo motor running 13Lb’s boost. Over the winter I had to replace the head gasket. Since then I have gone trough 2 OEM NISMO exhaust manifold gaskets (PN# 99996-N1044). My torques are correct the only difference is I had the manifold Jet Hott coated. I am thinking about going to a copper gasket for round 3 and removing the coating from the mounting flange. Does anyone know where I can get a copper gasket for my P90 head it has the square exhaust ports. I would appreciate any opinions or information on this situation. I am in Columbus, OH and it sucks when your Hot Rod is down in the summer……..Thanks -Don Quote Link to comment Share on other sites More sharing options...
johnc Posted June 15, 2007 Share Posted June 15, 2007 I ran that gasket for years on a 320 hp NA 3L engine (N42) head with a Jet Hot 2000 coated header. Never had an issue but a turbo application might be different. Four additional things I did to help the gasket survive: 1. Cut the header flange between 1 & 2 and 5 & 6. 2. Spray both sides of the gasket with Permatex Copper Spray-a-Gasket. 3. Put a small bead of Permatex Ultra Copper around the exhaust port openings on the header. 4. Used grade 10.9 studs and stainless metal lock nuts. Quote Link to comment Share on other sites More sharing options...
GeeZ Posted June 15, 2007 Share Posted June 15, 2007 I ran that gasket for years on a 320 hp NA 3L engine (N42) head with a Jet Hot 2000 coated header. Never had an issue but a turbo application might be different. Four additional things I did to help the gasket survive: 1. Cut the header flange between 1 & 2 and 5 & 6. 2. Spray both sides of the gasket with Permatex Copper Spray-a-Gasket. 3. Put a small bead of Permatex Ultra Copper around the exhaust port openings on the header. 4. Used grade 10.9 studs and stainless metal lock nuts. Where did you find the studs and lock nuts? I am having an issue to leaking gasket between 5 & 6. Thanks Quote Link to comment Share on other sites More sharing options...
johnc Posted June 15, 2007 Share Posted June 15, 2007 Industrial supply like McMaster-Carr (http://www.mcmaster.com). Quote Link to comment Share on other sites More sharing options...
speeder Posted June 20, 2007 Share Posted June 20, 2007 With a cast iron turbo exhaust manifold, the best way is to not use a gasket. Get your manifold milled straight at the head mating surface, put a bead of the high temp copper silicone around each runner opening and install with no gasket. Do not use this technique with tubular headers. Believe it or not, this does work! Maybe something to do with even heating of the two pieces (head and manifold) by metal to metal contact. The ZX turbo manifold's runners have a tendency to flex and move around when heated. Upgraded studs and nuts wouldn't be a bad idea, either - member Pallnet sells a set I think. I obtained one of his sets as a drawing prize at SEZ and it is of the best quality. By now those old stock studs are probably ready to be retired. This is the only long-term solution to turbo exhaust manifold leaks I've found. The stock Nissan gaskets don't last, and the soft, metal -cored Fel-Pro ones are better, but only slightly. I looked for, and never found, a copper exhaust gasket for the L. Quote Link to comment Share on other sites More sharing options...
GeeZ Posted June 21, 2007 Share Posted June 21, 2007 I am confused a bit. Other's on this site say that the Fel-Pros are junk and the Nissan OEM is the one to use. So is the Nismo part any better than OEM or Fel-Pro? Is there a consensus? The Fel-Pro item at Autozone is $11 the OEM is twice the price. And all have to be special ordered. Thanks. Quote Link to comment Share on other sites More sharing options...
johnc Posted June 21, 2007 Share Posted June 21, 2007 The gasket referred to at the start of this thread is the Nissan Motorsports (Garlock brand) composition gasket. Nissan Motorsports is the competition department for Nissan here in the USA and is not Nismo. They do sell Nismo parts but they also have their own parts line that they have developed and been selling for 30 years. Nissan Motors also sells an OEM style gasket that's available through Nissan dealers. Autozone and other auto parts stores generally sell FelPro brand gaskets. There is no concensus on which gasket is "the best." Each has its own strengths and weaknesses. I've had lots of success with the Nissan Motorsports (Garlock) gasket on normally aspirated race engines. Those engines get torn down every 50 to 100 hours and the gasket doesn't leave a bunch of crap on the head or the header. It seals well and handles a race environment. Quote Link to comment Share on other sites More sharing options...
GeeZ Posted June 22, 2007 Share Posted June 22, 2007 The Nissan Motorsport gasket is backordered and according to Courtesy Nissan in Richardson, Tx, they don't know when it will be available. I ordered the Fel-Pro today from O'Reilly's. Also, I picked up a tube of VersaChem's Mega Copper Gasket Maker. Suppose to support temp up to 700 deg. F. Also, I am using a couple of hex head bolts (from McMaster-Carr.. thank you, John C) in a couple of places where the Turbo Tom intake or exhaust manifolds don't allow enough room for Pallnet's longer studs and wider base nuts. I'll know this weekend if this works. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted June 22, 2007 Administrators Share Posted June 22, 2007 This gasket has a steel core, the kicker is the exhaust ports of the gasket are sandwiched in a steel, just like a head gaskets†fire ring†surrounding the chambers. I’ve not seen these used on Turbo applications, but my guess is that with an iron turbo exhaust manifold that is truly flat, this gasket would hold up just fine. Too bad this gasket is no longer in production. I have been using these gaskets exclusively on all of my customers and personal L-6 engines with headers. If the header flange is thin and prone to warping, I will double these up and wa la, no more leaks. They also work great for square port headers used on round port heads. This gasket was removed from a running round port head, square port header combo and all the exhaust ports looked just like these, no leaks. Quote Link to comment Share on other sites More sharing options...
Careless Posted June 24, 2007 Share Posted June 24, 2007 lol, that gasket is probably even reusable. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted June 24, 2007 Administrators Share Posted June 24, 2007 lol, that gasket is probably even reusable. I have successfully reused these gaskets on my own N/A car with header, no leaks. As long as the intake manifold doesn’t tear the paper gasket material when removing it, yes, they are reusable. This one tore when intake was removed, no longer useable. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 23, 2007 Share Posted July 23, 2007 Ooo Oooo, question! IF I choose to go with the semi-popular method of NO GASKET and I use a bead of some exotic high temp sealant around the exhaust ports, what to I do for the intake ports? Afterall, if I leave out the exhaust manifold gasket, I have no intake gasket either. Right? Quote Link to comment Share on other sites More sharing options...
speeder Posted July 25, 2007 Share Posted July 25, 2007 The referenced "exotic" high temp copper silicone adhesive is about 5 bucks for a tube at any neighborhood parts store. I cut a soft fel-pro intake/exhaust gasket's intake sections off and glue them to the intake runners with Gaska-Cinch adhesive. Probably your run of the mill weatherstrip adhesive will work for this. When installing the intake manifold I coat the head side of the gaskets with anti-seize and have removed/installed the intake several times without having to change its gasket(s). Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 26, 2007 Share Posted July 26, 2007 Last night I cleaned up all the surfaces of the intake, exhaust and head with a long, straight, sanding block and some 200 and 320 grit emery cloths. The exhaust manifold is about 0.002 - 0.003" low in the middle two ports which should not be much of a problem considering there are three bolts on the center section of the manifold. Mt last port, #6, looks like it had a bad casting from the factory. The seat area at the bottom of port 6 on the ex manifold is only about 1/8" wide. I think that's where it was leaking. Anyhow, I am doing away with the gaskets and going to try to assemble both manifolds to the head with Ultra Copper High Temp Silicone. Hopefully it will work. I am not too worried about failure as I plan on pulling the motor for rebuild in a month or two anyhow. I will report on how the Copper Silicone holds up. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted September 1, 2007 Share Posted September 1, 2007 The copper silicone goop worked well for me for at least three weeks on both the intake and exhaust manifolds with NO gasket. I have removed it for now as I am replacing the head gasket. I am going to use a gasket on the manifolds this time because I have one. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted September 1, 2007 Administrators Share Posted September 1, 2007 Cygnus, Thank you for the follow up. ... I cut a soft fel-pro intake/exhaust gasket's intake sections off and glue them to the intake runners with Gaska-Cinch adhesive. Probably your run of the mill weatherstrip adhesive will work for this. When installing the intake manifold I coat the head side of the gaskets with anti-seize and have removed/installed the intake several times without having to change its gasket(s). I really like Ricks idea of no gasket for the "iron" exhaust manifolds and just the intake portions of the gasket held on with Gask-a-cinch and anti-seize on the other side for reusability, (Gask-a-cinch is great stuff for front cover and other thin paper gaskets). Using the intake portion of the gasket should help reduce heat transfer from the head to the intake manifold. Quote Link to comment Share on other sites More sharing options...
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