jacob80 Posted August 17, 2009 Share Posted August 17, 2009 Hey guys, Well we have just rebuild our L28ET and right off the bat, the turbo drain flange gasket is leaking. As far as gaskets, how do you properly install a gasket? Do you use sealant on oil gaskets or nothing at all? Do you use sealant on water gaskets or none at all? This has always been kind of a gray area to me so if anyone could give me some insight on this that would be greatly appreciated, thank you! Quote Link to comment Share on other sites More sharing options...
Robert Posted August 21, 2009 Share Posted August 21, 2009 Hey guys, Well we have just rebuild our L28ET and right off the bat, the turbo drain flange gasket is leaking. As far as gaskets, how do you properly install a gasket? Do you use sealant on oil gaskets or nothing at all? Do you use sealant on water gaskets or none at all? This has always been kind of a gray area to me so if anyone could give me some insight on this that would be greatly appreciated, thank you! On oil gaskets, simply use some engine oil (new unused). This makes them seal great! On water gaskets, normal grease works great. Thats how I do it. Do NOT mount them dry! Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 21, 2009 Share Posted August 21, 2009 The drain flange on a turbo housing is HOT! As a general rule never use sealant when attaching parts on an exhaust system. Reason being is that any sealant will eventually vaporize and will leave a void (leak) afterward. MOUNT IT DRY since it's a compression seal. I can only remember 2 places to use sealant when assembling an L28; to fill a slight void where a gasket just does not reach. 2 small traces of sealant are called for when installing the rear main bearing cap and 2 small traces at the front cover. THAT'S IT. You can use gasket "tack" to hold the front cover gaskets in place but it's not a sealant. If you NEED a sealant on a gasket to make it seal then there is a problem with the parts you're assembling. Either the parts are warped or gouged. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted August 21, 2009 Author Share Posted August 21, 2009 So use oil on gaskets where the gasket will be sealing oil? Such as the oil pan? I have never heard of this, and grease on water gaskets? Quote Link to comment Share on other sites More sharing options...
Robert Posted August 21, 2009 Share Posted August 21, 2009 So use oil on gaskets where the gasket will be sealing oil? Such as the oil pan? I have never heard of this, and grease on water gaskets? Thats a good old way tested and retested. An interesting view on hot parts from mr rolling parts, but Ive always used engine oil on turbo flanges without problems... Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 21, 2009 Share Posted August 21, 2009 Thats a good old way tested and retested. ... I'd be interested in these published "test" that you mentioned. Where are they? I've read the FSM and the How To Rebuild books on the L series engines and I've never seen anything about putting "grease" on the either the water gaskets, oil gaskets, or front cover gaskets.... Just how does it actually improve the sealing? Quote Link to comment Share on other sites More sharing options...
Robert Posted August 21, 2009 Share Posted August 21, 2009 I'd be interested in these published "test" that you mentioned. Where are they? I've read the FSM and the How To Rebuild books on the L series engines and I've never seen anything about putting "grease" on the either the water gaskets, oil gaskets, or front cover gaskets.... Just how does it actually improve the sealing? Well, If youre such an expert, you tell me. More seriously, this is simply based on 10 years experience. Ive had several oil and water leaks where I simply greased or oiled the gaskets, and the problem is gone and never returned. Feel free to mount any gasket dry, I dont care, and you and all others can say whatever you would like, this is simply my experience, and probably many gaskets can be dry mounted, but I dont see the reason to take the risk. I dont know the Theory, but adding grease or oil cant hurt anything in my opinion, and in my experience It can make the difference of completing the race, or ripping your hair out in the Pit. Oh, and Im shure different gaskets need different mountings to. Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 22, 2009 Share Posted August 22, 2009 Feel free to mount any gasket dry, I dont care, .. Superstition. Chances are the seals would have been fine otherwise. I've heard that some people pee on paper gaskets they don't leak afterwards either. Science works differently. That's why I asked about "tested and retested". Just because it does not harm does not imply it's better. Quote Link to comment Share on other sites More sharing options...
Robert Posted August 22, 2009 Share Posted August 22, 2009 Superstition. Chances are the seals would have been fine otherwise. I've heard that some people pee on paper gaskets they don't leak afterwards either. Science works differently. That's why I asked about "tested and retested". Just because it does not harm does not imply it's better. Like I said this is based on experience. A quick example is once I mounted a thermostat gasket dry, and it leaked. Some grease solved it. I dont know the theory. Pee on your gaskets all you want Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 22, 2009 Share Posted August 22, 2009 Like I said this is based on experience. A quick example is once I mounted a thermostat gasket dry, and it leaked. Some grease solved it. I dont know the theory. Pee on your gaskets all you want Pee? Nah, my method is still dry:) Though I will confess that thermostat housing is THE ONE PLACE I've ever used sealant. 2 yeas ago on one of the L26's I had a leak and I was too lazy to take the time to match the surfaces so I grabbed the good old RTV and put it on both sides of the new gasket and slapped it back together. On a full engine rebuild (like jacob80 had) a re-builder BETTER make sure that all surfaces are flat before assembly! In that case, "extra" sealant is just not a tradition to get a seal. Quote Link to comment Share on other sites More sharing options...
Robert Posted August 22, 2009 Share Posted August 22, 2009 I think we can conclude that we have different opinions. I thrust grease and motor oil on my gaskets, and on all the different engines Ive built over the years, Ive hardly ever had a leak. On my latest L24E with turbo build, all gaskets got oil and grease, no leaks. The surfaces was only cleaned and grinded with some ~600 paper. Quote Link to comment Share on other sites More sharing options...
woldson Posted August 22, 2009 Share Posted August 22, 2009 Outside of certain gaskets, ie. head gasket, exhaust stuff, etc, I really think you guys are just spitting hairs here. (The last felpro head gasket had rtv on it) Anyhoo, I personally use rtv on a lot of seals, mostly because when I go to remove them years later, they come off, (apart), easier. On American auto trannies, I let rtv set up on the seal for some time before tightening, never had one leak. If it works for you, great! No need to get into a huff over this one. Quote Link to comment Share on other sites More sharing options...
woldson Posted August 22, 2009 Share Posted August 22, 2009 One more tid bit, on any seals like cam seal, crank seals and "o" rings, I grease them with clean hands and grease. This is in order not cause micro abrasion in the rubber. Quote Link to comment Share on other sites More sharing options...
jacob80 Posted August 22, 2009 Author Share Posted August 22, 2009 Outside of certain gaskets, ie. head gasket, exhaust stuff, etc, I really think you guys are just spitting hairs here. (The last felpro head gasket had rtv on it) Anyhoo, I personally use rtv on a lot of seals, mostly because when I go to remove them years later, they come off, (apart), easier. On American auto trannies, I let rtv set up on the seal for some time before tightening, never had one leak. If it works for you, great! No need to get into a huff over this one. I've never used RTV on anything cause I've been told to stay away from it. Is there problems that arise with using RTV as a sealant? Just trying to straighten things out here Quote Link to comment Share on other sites More sharing options...
Mario Posted August 22, 2009 Share Posted August 22, 2009 I think everybody is right, from experience I have used oil , and not oil in fact I have used every thing. I think is the quality of the gasket and the irregularity of the parts. If it works used it. Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 22, 2009 Share Posted August 22, 2009 If it works for you, great! No need to get into a huff over this one. No huff on a NEW engine build; an engine build SHOULD be a precision undertaking and gaskets (like Nissan did) will last 30 years and 400,000 miles. That's a fact and everyone loves their Nissan engines that were built that way. A rebuilt (to Nissan specs) will perform similarly well; no question. If you build everything on the L28 to spec and install Nissan quality gaskets DRY; it too will last for generations. The only way a seal starts to have a problem is if something is worn beyond spec and that happens when worn engines are overhauled. Overhaul shops are on-the-clock and assemble lots of simply "cleaned" parts, not "new" parts. They also use the cheapest gasket products they can find. That why engines from so called overhaul shops never last like a new engine and some (like in jacob80's case) start seeing small leaks "right off the bat". I'm an amateur engine builder. I cannot create the quality that Nissan did on their production lines in my garage. I can tell you that when I take the time to follow the factory books for measurements, my engine built 10 years go now has an extra 150,000 miles and still running great without leaks. My other 5 engines I've re-built in the garage in last 10 years also doing really well; no leaks at all since rebuild. All I can say as an amateur is that following the book, taking time doing measurements; and buying quality seals and bearings sure seems to work out well. If there was a GOOD technical reason someone can come up with to not follow the book, I'm listening! Quote Link to comment Share on other sites More sharing options...
woldson Posted August 23, 2009 Share Posted August 23, 2009 I believe that it is a preference issue, not so much reliability issue. Technology has improved dramatically over 20-40 years. Oil on gaskets is an old thing, (not saying that it is better or not), rtv rocks if used correctly. Neoprene gaskets can be found to replace gaskets that were cork, why.... You don't want to glob rtv! speculation on break down causing O2 sensor problems, "chunks" in the pick up screen in the pan...etc. Some parts will advise using rtv in corner that were known to leak. Really all points are valid, without talking about gasket quality. It is just a preference thing. You may also consider that how often has any part been apart on any given engine that requires a seal, that was improperly cleaned? Slight abrasions to mating surfaces, pits and slight distortions can easily be made up by a modern product. Yes that engine was/is amazing! I plan on using many stock components when reassembly, new of course;). I really don't think this is a hill to die on. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 24, 2009 Share Posted August 24, 2009 "I dont know the Theory, but adding grease or oil cant hurt anything in my opinion, and in my experience It can make the difference of completing the race, or ripping your hair out in the Pit. " I could throw in an example where Intel got reeeeeeeeeeeeeeeeeeeeeeeally upset when hydrocarbons got into their air system becuase someone used anti-seize on gaskets and traces contaminated the system, resulting in $$$ of cleanup and purge. I'm with Woldson on this one: Technology has changed in the past 30+ years, and there are different ways to install stuff now. In many cases people simply don't read instructions and take shortcuts, resulting in leaks. Using anecdotal evidence as a basis for genaral instructions across the board is dangerous as well. Some kid reads 'put grease on gaskets to make them seal' and soon you have a kid with a greased head gasket wondering why it blew out at the fire ring... Generalizations are bad, as a general rule... Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 24, 2009 Share Posted August 24, 2009 Technology has changed in the past 30+ years, and there are different ways to install stuff now.... Generalizations are bad, as a general rule... I agree that there are vastly improved sealing techniques today; which makes me all the MORE IMPRESSED with what Nissan was able to do in the 1970's. They made an engine that was legendary for longevity in a time of paper and cork gaskets. Well done! I disagree that slathering oil onto gaskets has anything to do with new modern sealing technologies that are available today. If anything it reminds me of a few American shade tree mechanics I knew working on Chevy's in the 70's. Absolutely take advantage of new technology! Used and applied correctly it's good stuff. Just make sure you understand the "why" as well as the "how" of the application. Quote Link to comment Share on other sites More sharing options...
Robert Posted August 24, 2009 Share Posted August 24, 2009 "I dont know the Theory, but adding grease or oil cant hurt anything in my opinion, and in my experience It can make the difference of completing the race, or ripping your hair out in the Pit. " I could throw in an example where Intel got reeeeeeeeeeeeeeeeeeeeeeeally upset when hydrocarbons got into their air system becuase someone used anti-seize on gaskets and traces contaminated the system, resulting in $$$ of cleanup and purge. I'm with Woldson on this one: Technology has changed in the past 30+ years, and there are different ways to install stuff now. In many cases people simply don't read instructions and take shortcuts, resulting in leaks. Using anecdotal evidence as a basis for genaral instructions across the board is dangerous as well. Some kid reads 'put grease on gaskets to make them seal' and soon you have a kid with a greased head gasket wondering why it blew out at the fire ring... Generalizations are bad, as a general rule... As this is a datsun L forum, I dont think Intel will get too pissed if we use oil on our gaskets.. And I really cant see the reason for reading a book during assembly of most engines, with exceptions of very new and advanced engines, and in some cases tightening torques etc (like newer BMW`s with magnesium blocks and so on), unless you are totally green, in which case you would be stupid If you just put it together and see how it works. Just my opinion. So use the book if youre not shure of what youre doing, or not shure on something can be the new rule of thumb Quote Link to comment Share on other sites More sharing options...
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