roulli Posted March 27, 2017 Report Share Posted March 27, 2017 Good evening, what is the best manifold gasket to reduce the risk of a vacuum leak around the PI manifolds? Payen gasket (tin on manifold side with fibre on the other side) looks rather thin to me? I have two of those in the drawer , one has some heavy rust spots... Moss, have an upgraded one, in the colored part of their catalogue. Are they really better? any other gasket? Should I smear some sealant to the manifold side, or is it too hot? Thanks for sharing your experience Best, Patrick Quote Link to post Share on other sites
Nigel Triumph Posted March 27, 2017 Report Share Posted March 27, 2017 Got to be Payen, available on eBay for a reasonable price. I've fitted these on my TR6 and GT6, never a problem. The cheap grey things blow apart by the exhaust ports after a while. For example: http://www.ebay.co.uk/itm/Gasket-intake-exhaust-manifold-Payen-JA510-/301888256009?hash=item4649f13809 Nigel Quote Link to post Share on other sites
Tom Fremont Posted March 27, 2017 Report Share Posted March 27, 2017 Hi Patrick, I've been using the MOSS uprated one with Webers / CANNON manifold and various exhaust manifolds. Never had a leak or other failure in circa 100,000 miles overall. These are homogeneous material; no metal layers. Cheers,Tom Quote Link to post Share on other sites
john.r.davies Posted March 27, 2017 Report Share Posted March 27, 2017 IMHO, more important than the choice of any good quality gasket is to ensure that the throttle bodies are square to the head and have flat surfaces. The 2.5 saloon manual uses a jig to align them (Special part No.S358), which may be more to do with lining up the throttle mechanism, but anyway. It's not mentioned in the TR6 manual. I made up my own, from a length of angle iron and six studs, that I aligned by fitting them to an engine that I hoped had never been dismantled before. But you may not be in that happy position! John Quote Link to post Share on other sites
roulli Posted March 28, 2017 Author Report Share Posted March 28, 2017 Thanks NIgel, Tom and John, I'm actually using a self made tool, to align the 3 manifolds, by means of fixing their inlet stubs between 2 stiff metal bars, prior tightening the bolts to the head. The manifolds have also been converted to sealed ball-bearings on the lever side. throttle plate bolts released and centered the throttle plates. sealed the throttle plates with Molycote using PU hoses from Revington between the balance tubes - without circlips though But I still could only tame the idle by reducing advance at idle. And I'm having a hard time to locate any leak with "Start Pilot" gas. Idle does hardly change, when I spray it into a manifold... So I wanted to concentrate more on the usual suspects: gasket and servo (rather new) So you mount your favorite gasket dry, then? Patrick Quote Link to post Share on other sites
Tom Fremont Posted March 28, 2017 Report Share Posted March 28, 2017 Hi Patrick, I install mine dry, but agree with some that Anti-Sieze paste on the exhaust manifold's mating surfaces is smart. Cheers, Tom Quote Link to post Share on other sites
Nigel Triumph Posted March 28, 2017 Report Share Posted March 28, 2017 I use a thin smear of Wellseal on both sides of the gasket, and copper grease on the studs. Nigel Quote Link to post Share on other sites
roulli Posted August 18, 2020 Author Report Share Posted August 18, 2020 Hi, I'm digging out this old topic, as I was searching for info about the best available manifold gasket for the 6, and I completely forgot that I had the same need already in 2017. So 3 years after I've fitted a "high performance" gasket from Moss. NowI ended up with a noisy exhaust gas leak under the bonnet. The result is impressive. The gasket became totally brittle and crumbled to pieces, when I tried to remove it. So at the end one can choose between: The so called "high performance" which is done after 3 years The cheapo 5£ cr...p that is even worse And the flimpsy Payen, which can't be trimmed due the fire rings. Patrick Quote Link to post Share on other sites
Tom Fremont Posted August 19, 2020 Report Share Posted August 19, 2020 Hi Roulli, Forgive a stupid question, but did you check the tightness of the manifold nuts after 500-1000 miles? They can loosen and in my experience need tightening at least twice if not three times in 2-3K miles. After that, no problem. When I did it there were no leaks; it was a pre-emptive measure. I think it's been 90K miles since my driver's was changed. Still haven't had a problem with the MOSS Heavy Duty gasket. Tom Quote Link to post Share on other sites
roulli Posted August 19, 2020 Author Report Share Posted August 19, 2020 Hi Tom, the question isn't stupid at all. I sincerely don't recall whether I checked the tightness of the nuts after 500-100mls, but I re-tightened them eventually a few times. I will be looking into the studs and bronze-nuts, a few of them are "bond" together and its the stud that screws out of the head... But its not that the nut is completely blocked, it's just that the friction is lower in the head-thread. But generally talking I'm amazed on how brittle the HP gasket has become. However the part under the inlet manifolds is much less brittle, than the parts that suffered from the exhaust heat. The question is then, if the manifold gasket failure is always due to non-tight fasteners, then a std cheapo gasket might do the same job and I shouldn't look for the best gasket, but for the most robust way over time to get the manifolds bolted firmly . Spring washer don't seem to work well under this hot conditions. I used new ones they loose spring force easily I wonder how robustness in this area has become inherent in modern cars - it can't be rocket science.. --> I replaced recently the particle filter on our daily driver and Volvo use self-locking nuts on the the flanges of the filter - not the nyloc type of cours but the one with the oval end. Should I replace the bronze nuts with steel nuts and use copper grease on threads. The bronze nuts get compressed / deformed, where they mate with the spring washers Regards Patrick Quote Link to post Share on other sites
Nigel Triumph Posted August 19, 2020 Report Share Posted August 19, 2020 (edited) 5 hours ago, Tom Fremont said: Hi Roulli, Forgive a stupid question, but did you check the tightness of the manifold nuts after 500-1000 miles? They can loosen and in my experience need tightening at least twice if not three times in 2-3K miles. After that, no problem. When I did it there were no leaks; it was a pre-emptive measure. I think it's been 90K miles since my driver's was changed. Still haven't had a problem with the MOSS Heavy Duty gasket. Tom That would also be my question. I've never had a problem with the Payen JA510, though they are harder to find now. Nigel Posts crossedover! Edited August 19, 2020 by Nigel Triumph Posts almost simultaneous Quote Link to post Share on other sites
John L Posted August 19, 2020 Report Share Posted August 19, 2020 (edited) The important thing here is are the flanges the same thickness, and are all the manifold flanges flat and square, more so on the fabricated exhaust manifolds. Perhaps the ones that don't leak are all square, and the others perhaps not. The gasket Payen JA510 is available from Hertitage Gaskets, in Slough. John Edited August 19, 2020 by John L Quote Link to post Share on other sites
astontr6 Posted August 19, 2020 Report Share Posted August 19, 2020 8 hours ago, roulli said: Hi, I'm digging out this old topic, as I was searching for info about the best available manifold gasket for the 6, and I completely forgot that I had the same need already in 2017. So 3 years after I've fitted a "high performance" gasket from Moss. NowI ended up with a noisy exhaust gas leak under the bonnet. The result is impressive. The gasket became totally brittle and crumbled to pieces, when I tried to remove it. So at the end one can choose between: The so called "high performance" which is done after 3 years The cheapo 5£ cr...p that is even worse And the flimpsy Payen, which can't be trimmed due the fire rings. Patrick The JA510 has the tin plate backing precisely to stop the break up of the gasket! I have used JA510 gaskets for over 40 years never had a problem and as for trimming the fire rings. I don't know where that idea came from as they are the key sealing part of the gasket? How flat are your flange facings as no gasket will seal a warped face? Bruce ( ex Payen /Coopers apprentice, who worked on the original tooling) Quote Link to post Share on other sites
roulli Posted August 19, 2020 Author Report Share Posted August 19, 2020 I'm using the OE Triumph exhaust manifold. But I'll check its straightness with a ruler. I do have 2 Payens JA510 in the drawer for some time. But I haven't used them just because of the fire rings, which are basically a good idea... but I've always been trying to make sure that manifolds, head runners and the gasket in-between mate without a "step". This requires that the gasket needs to be trimmed. If one pays attention, the gasket will protrude a few mm into the "flow channel" , which is not so optimal in terms of blue printing the engine. This trimming is not going to work on the JA510, as the fire rings will fall off and it cannot work as intended. Patrick Quote Link to post Share on other sites
TRTOM2498PI Posted August 19, 2020 Report Share Posted August 19, 2020 (edited) These gaskets are not as good as they once were, and last time I checked, the improved/uprated ones from MOSS were NLA ? Bastuck in Germany sell a fantastic gasket, which is far better than anything available in the UK, period. I have seen the Payen ones break down after a few months of being fitted over recent years. The quality is just not there. Blowing exhaust manifold gaskets are more prevalent when using aftermarket exhaust manifolds and inlet manifolds. There is a difference in thickness in manifold flanges (exhaust manifold Vs inlet manifold). The exhaust manifold flange is must thinner than the inlet manifold. The issue here is if you do not relieve metal from an aftermarket inlet manifold (Cannon for example), it will not bolt up squarely to the head, and cause a manifold leak. If you tighten the manifold nuts up properly from the beginning, you will not have to re-torque them again, nor will you have any issues with manifold blow with this gasket. Cheers. Edited August 19, 2020 by TRTOM2498PI Quote Link to post Share on other sites
JochemsTR Posted August 19, 2020 Report Share Posted August 19, 2020 after changing to EFI, I removed the upgraded Moss one. All looked good !! I used a new one, and been on it ever since. Each about 3000mls and counting. I never re-torqued the manifold/exhaust nuts. Patrick mentioned it, the Moss Upgraded one, can be modified/sanded to meet the Inlet and Outlet ports. Jochem Quote Link to post Share on other sites
Tom Fremont Posted August 19, 2020 Report Share Posted August 19, 2020 I have CANNON manifolds on both my '250s with the MOSS gasket. ( Bad news if it's NLA. ) Thickness of the manifold flanges seems to be the same, as the clamp bars are parallel to the head. I have another engine build in the pipeline, so am interested in the BASTUCK gasket - where to buy? Roulli, I wonder if your exhaust gas temperature is too high. Other issues would occur, I suspect... Tom Quote Link to post Share on other sites
ntc Posted August 19, 2020 Report Share Posted August 19, 2020 Dry fit any type and it will not last long. Quote Link to post Share on other sites
roulli Posted August 19, 2020 Author Report Share Posted August 19, 2020 Tom, here's the link to the Bastuck gasket: https://shop.bastuck2.de/index.php?cat=10000&hg=11800 product code is: MD9TR6 https://www.bastuck.de/gb/classic/triumph/ But if you like the Heavy Duty one from Moss, Moss Europe sell them, I received one this week... FInally I had a look at the Payen JA510, that was lying around for years and the fitting was not so bad. Not really a need to trim So i ended up fitting this flimsy gasket, where I still wonder how such a thin gasket can deliver a good seal. But if so many people are contented with it, plus Payen normally know what they're doing... then it should actually work. Couldn't help to smear some Dirko sealing compound around the runners of the PI inlet manifolds to avoid air leaks. I'll also check for re-torquing more regularly... Thanks for all the advice Patrick Quote Link to post Share on other sites
astontr6 Posted August 20, 2020 Report Share Posted August 20, 2020 18 hours ago, JochemsTR said: after changing to EFI, I removed the upgraded Moss one. All looked good !! I used a new one, and been on it ever since. Each about 3000mls and counting. I never re-torqued the manifold/exhaust nuts. Patrick mentioned it, the Moss Upgraded one, can be modified/sanded to meet the Inlet and Outlet ports. Jochem If the tooling is made to the correct dims on the BL engineering drawing? There s/b no modification needed. But it seems to me that the ports in some of the Cyl. heads and exhaust manifolds are over size. Whether this has been done by PO's or Current owners is a question that needs to be answered or have the exhaust manifolds and inlet manifolds been made oversize originally? if so they should have been rejected! Bruce. Quote Link to post Share on other sites
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