CamoKing Posted August 22, 2019 Report Share Posted August 22, 2019 Amateur question here...I have a set of Felpro gaskets for this '82, 720 w/Z22 engine . The head gasket went on 'dry'. I put some RTV on the timing cover to hold in place while assembling. Now wondering if RTV is necessary on the manifold gaskets?? Or, are today's gaskets generally designed to go on 'dry'? Thanks for any feedback on using RTV. Quote Link to comment
datzenmike Posted August 23, 2019 Report Share Posted August 23, 2019 If RTV was required Felpro would have put a tube in with the gaskets. If the mating surfaces are properly clean the gasket will do it's job. Using RTV is very unprofessional. It says...." I don't trust my work." Now in some cases, gaskets are no longer available, in other newer cars they never used them. In this, find a quality sealer. Quote Link to comment
CamoKing Posted August 23, 2019 Author Report Share Posted August 23, 2019 Thanks , Mike. These mating surfaces are very clean. If you overlook the pitting and rough casting, they're like new. I will allow the gasket to do it's job. No RTV. Quote Link to comment
Stoffregen Motorsports Posted August 23, 2019 Report Share Posted August 23, 2019 There are different sealants for the different areas of an engine too. Pet peev of mine - blue RTV. That stuff is worthless, and when you see it on every surface of an engine, you know it was pure amateur hour. RTV or other kinds of sealers are not "unprofessional" at all. Improper or over use is, but knowing which to use on what part of the engine and then applying it in a manner that doesn't stand out, that's the key. To answer your question about manifolds - It really depends on the manifolds. These are going on 50 years old now and the surfaces are probably not as flat as they were when new. If the surfaces have any imperfections (pits, scratches, somebody cleaned it with a Roloc disc, etc), then they need to be corrected, otherwise the gaskets will leak, RTV or not. 1 Quote Link to comment
Stoffregen Motorsports Posted August 26, 2019 Report Share Posted August 26, 2019 I keep circling back to the "unprofessional" response. While a purist may not want to see any sealer, a realistic approach is to not want leaks. A while back, I brought my 1964 Triumph Tiger Cub in to Mean Marshall's motorcycle shop in west Oakland to have him do some tuning. He is a purist and goes by the book, all the way. He's really good at what he does and has a reputation with vintage Triumphs. I had previously built the engine and sealed the crank case with ... um, crankcase sealer (Threebond 1211). It didn't leak a drop, which is unique for an old British bike. When I got the bike back he informed me that he tore the crankcase apart and resealed it with "proper paper gaskets". Guess what? it leaked. I'd say it's rather unprofessional to not recognize the pitfalls and to not utilize all the means necessary to have a leak free engine. Just as long as you don't see it. 1 Quote Link to comment
datzenmike Posted August 26, 2019 Report Share Posted August 26, 2019 A Triumph is not a Jap made vehicle and no comparison what ever. They don't leak. If they were to leak you did it wrong, thus unprofessional. If racing, fine to waste time on a redundant layer of protection, if just a regular car.... not needed. Quote Link to comment
Stoffregen Motorsports Posted August 26, 2019 Report Share Posted August 26, 2019 Again, if you say so... 1 Quote Link to comment
bananahamuck Posted August 26, 2019 Report Share Posted August 26, 2019 aluminum pits , pits leak ,, Use the correct sealant ,, Use very sparingly,, let set till somewhat rubbery ,, boom Quote Link to comment
datzenmike Posted August 27, 2019 Report Share Posted August 27, 2019 Pitting would have to be the width of the gasket used to leak. If that bad you would likely resurface or throw it away unless a chevy owner.. The cover was eroded the worst but I sanded them all down and used a home made gasket, dry. I guess I could have blobbed some RTV on it instead of fixing the surface, but that would be very unprofessional. Quote Link to comment
bottomwatcher Posted August 27, 2019 Report Share Posted August 27, 2019 I love permatex high tack gasket maker with the brush in cap. Sure makes life easier to slap the gasket in place and not fight it with only having two hands. The best part. No leaks! Quote Link to comment
datzenmike Posted August 27, 2019 Report Share Posted August 27, 2019 So basically it's to hold a gasket it place??? Glue? It's really hard to argue that a gasket sealer leaks less than just a gasket doing it's job. RTV makers spend millions of advertising dollars convincing you that you need their product to do what the gasket is already made for doing. Incredible genius!!! There are places where it is good to use like where gaskets meet at a right angle and in some cases the gasket is no longer made or used and relies solely on a film of sealer such as a differential or transmission case. Funny how engines are built and run for hundreds of thousands of miles with no help from any sealer but suddenly a new gasket needs it? If it makes you comfortable to use this stuff go ahead. I'm pointing out that you don't. In almost all cases when something comes apart it's a knee jerk reaction to get out the RTV. Quote Link to comment
alexg89 Posted August 27, 2019 Report Share Posted August 27, 2019 so id like to chime in on this.. Lets say i have a head thats been ported and the gaskets are to small.. do i try to enlarge the small gasket or what do i do ? Quote Link to comment
datzenmike Posted August 27, 2019 Report Share Posted August 27, 2019 You don't want a gasket extending out into any port and flapping in the wind. Exhaust ports have a metal ring around and to protect them from eroding from the hot corrosive gasses. I can't see anyone porting past a gasket match of this ring. Same with the intake though there is no ring, but the port and the manifolds don't always line up well from shifting of the cores when casting. You usually port out the the edge of the gasket on the head and the manifold, but in the case of an intake you can take it out farther and trim the gasket to match. Quote Link to comment
Stoffregen Motorsports Posted August 27, 2019 Report Share Posted August 27, 2019 11 hours ago, datzenmike said: Pitting would have to be the width of the gasket used to leak. If that bad you would likely resurface or throw it away unless a chevy owner.. The cover was eroded the worst but I sanded them all down and used a home made gasket, dry. I guess I could have blobbed some RTV on it instead of fixing the surface, but that would be very unprofessional. Very professional, Mike. But we're not always taking about a small t-stat housing that you can hit on a belt sander. Try belt sanding a front cover or intake manifold. Even with a block of wood and emery cloth, these surfaces can't always be brought back to perfect. You've said it yourself before, these engines and parts are nearing 50 years old now. Quote Link to comment
datzenmike Posted August 28, 2019 Report Share Posted August 28, 2019 The litmus test for throwing away a part is when you find yourself putting RTV on it. My sheet of glass and sand paper is 30 x 20" wide 1 Quote Link to comment
Stoffregen Motorsports Posted August 28, 2019 Report Share Posted August 28, 2019 Because swap meets are littered with junk that was supposed to have been thrown away...?! This has turned into a pissing match. I'm out. 1 Quote Link to comment
datzenmike Posted August 28, 2019 Report Share Posted August 28, 2019 Of course use RTV if it's that fucked and you can't level it or have no choice, or ....don't use the part. Using on smooth clean surfaces is redundant if you have a gasket is my point. Far and away surfaces may be old but need just a new gasket. Quote Link to comment
Rays74 Posted September 10, 2019 Report Share Posted September 10, 2019 As a 40+ year motorcycle and small engine mechanic I've had lots of experience with different types of sealers......used with gaskets and without (many engine case halves are assembled using only semi hardening sealants such as Yamabond 4, Hondabond 4 or Theebond 1184 all gray colored). I tend to error on the side of caution and use a very thin layer of sealant ( I say thin as in not seen when the part is assembled it's only there to supplement the main gasket not replace it) on most critical gaskets and it has worked very well for me for this many many years. Of course the sealants I use are gray colored as to not be seen so easily and anything that happens to squeeze out gets wiped off immediately with a rag or perhaps a drop of gasoline on a towel (easily done before it sets up, impossible afterwards) ....... I don't understand the fascination with using neon orange or blue RTV so much so that it squeezes out of the surfaces you're trying to seal! LOL As a Datsun owner and rebuilder of my own engines I can tell you they all were built the same way using either Yamabond 4 or Threebond 1184 on their gaskets, they don't leak and thats the way I like it 😉 Just one mechanic's way 1 Quote Link to comment
datzenmike Posted September 10, 2019 Report Share Posted September 10, 2019 What squeezes out squeezes in. This RTV 'worm' was in this head's water jacket. Likely a chevy owner, they think a gasket comes in a tube. Quote Link to comment
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