boxofbits Posted November 23, 2018 Report Share Posted November 23, 2018 Good morning Everyone Decided to replace the diaphragm and hoses on my TR4a..simple enough job you'd think, but when the new hoses are fitted it appears the valve sits too high and way above the bracket bolt fitting. I believe this is an original bracket and is bolted to the exhaust manifold stud. I've tried a hose from TR Shop and Moss but both appear to lift the valve too high. Has anyone else had an issue with this? Many thanks Kevin Quote Link to post Share on other sites
Lebro Posted November 23, 2018 Report Share Posted November 23, 2018 Just cut it down ? Bob. Quote Link to post Share on other sites
rcreweread Posted November 23, 2018 Report Share Posted November 23, 2018 I'm fairly sure the bracket doesn't go on the manifold stud but is bolted into a threaded hole on the inlet manifold - it looks like you mau have a TR4 inlet manifold not a 4A one and the TR4 didn't have a PCV arrangment so it isn't there. I'm not sure I would cut the hose down as has been suggested as I think the oil needs to flow from the PCV and if it's lower, it may not - easy enough to make a longer bracket I would have thought Cheers Rich Quote Link to post Share on other sites
stuart Posted November 23, 2018 Report Share Posted November 23, 2018 Does this help? Stuart. Quote Link to post Share on other sites
boxofbits Posted November 23, 2018 Author Report Share Posted November 23, 2018 Thanks for replies Bob- I did have cut down hoses on there before for a long time. But what I've found is, probably due to its insufficient height, some oil was present in the valve and on the diaphragm from the rocker cover, whereas I'd imagine they installed it at a higher level so that only hot vapourised oil/fumes would manage to get to the manifold? Rich & Stuart, I did look for another location but if as you say that's a TR4 manifold that might be the reason, however looking at Stuart's photo, the bracket does appear to be bolted to a manifold stud with a brass nut? The manifold I have is the one that came with the car in 1983 and does have the PCV inlet already there? The bracket is also the original one but only as far as I know. Is there any other way to identify a TR4 manifold from the 4a version in case this is the issue, and do you have any pics of the threaded hole in the manifold? Regards Kevin Quote Link to post Share on other sites
RogerH Posted November 23, 2018 Report Share Posted November 23, 2018 Hi Kev, mine is as per Stuart's photo. Attached to the manifold stud. Marco (Z320) has some good ideas on the PCV and how it works (or not) Roger Quote Link to post Share on other sites
Z320 Posted November 23, 2018 Report Share Posted November 23, 2018 2 hours ago, RogerH said: Hi Kev, Marco (Z320) has some good ideas on the PCV and how it works (or not) Roger Yeah, but my bracked is DIY and the hose is a repro from Bastuck / Germany and lovely shorter. Marco Quote Link to post Share on other sites
boxofbits Posted November 23, 2018 Author Report Share Posted November 23, 2018 2 hours ago, Z320 said: Yeah, but my bracked is DIY and the hose is a repro from Bastuck / Germany and lovely shorter. Marco The lower twisted one on mine is also Bastuck but I wouldn't say it's shorter, it seems to be the right height. It was the PCV bracket which was too low. Tightened the heater valve outlet in the head slightly to allow clearance for the bracket to sit upright. This has effectively lengthened and moved it rearwards at the same time, so the valve now fits with hoses supplied. I noticed when it was lower there was a lot of oil in the valve and the diaphragm was covered in oil. Think it's lack of height allowed a lot of unvapourised oil into it from the rocker cover. Thanks for the advice and the photo Stuart. Quote Link to post Share on other sites
rcreweread Posted November 23, 2018 Report Share Posted November 23, 2018 Kevin I may have got my comments wrong and I would bow to Stuart and Rogers superior knowledge in preference to mine. Unfortunately I'm not at home for a few days so can't check on my cars, but will do in due course. Re the difference beteen a TR4 and 4A inlet manifold, if you have a Moss TR parts catalogue, there are illustrations in there of the differences Cheers Rich Quote Link to post Share on other sites
RogerH Posted November 23, 2018 Report Share Posted November 23, 2018 Hi Kevin, have a look here https://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/exhaust/exhaust-manifolds/inlet-exhaust-manifolds-tr2-4a.html Roger Quote Link to post Share on other sites
rcreweread Posted November 23, 2018 Report Share Posted November 23, 2018 18 minutes ago, RogerH said: Hi Kevin, have a look here https://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/exhaust/exhaust-manifolds/inlet-exhaust-manifolds-tr2-4a.html Roger Roger - as I recall, the Moss catalogue shows more versions of the manifolds in the pre-amble section to the parts page you have linked to, and it clearly shows the difference between a 4 and 4A manifold Cheers Rich Quote Link to post Share on other sites
RogerH Posted November 23, 2018 Report Share Posted November 23, 2018 Hi Rich, the Moss WebCat does not have all the little comments and tips shown in the paper cat Roger Quote Link to post Share on other sites
Z320 Posted November 23, 2018 Report Share Posted November 23, 2018 on my car it looks like this, PCV valve is a repro, spring is a modyfied WECK spring, bracket is DIY, hose from Bastuck I use this funny but very reliable spring bepause the repro spring was only bended wire. About the PCV I wrote everythink that is worth to write; I am very pleased with it. Quote Link to post Share on other sites
boxofbits Posted November 23, 2018 Author Report Share Posted November 23, 2018 4 hours ago, rcreweread said: Kevin I may have got my comments wrong and I would bow to Stuart and Rogers superior knowledge in preference to mine. Unfortunately I'm not at home for a few days so can't check on my cars, but will do in due course. Re the difference beteen a TR4 and 4A inlet manifold, if you have a Moss TR parts catalogue, there are illustrations in there of the differences Cheers Rich No problem, thanks Rich Quote Link to post Share on other sites
boxofbits Posted November 23, 2018 Author Report Share Posted November 23, 2018 (edited) 2 hours ago, Z320 said: on my car it looks like this, PCV valve is a repro, spring is a modyfied WECK spring, bracket is DIY, hose from Bastuck I use this funny but very reliable spring bepause the repro spring was only bended wire. About the PCV I wrote everythink that is worth to write; I am very pleased with it. Tbh the valve sits too low like mine did, and that's why the lower hose is kinked virtually flat at the bottom. Oil will get into it at that level like my own. The best way around it is to fit the proper hoses, see where the valve sits, and then make a bracket to suit that height and position. The spring on the original part was only sprung wire, similar to voltage regulators, but works fine. Kevin Edited November 23, 2018 by boxofbits Quote Link to post Share on other sites
Z320 Posted November 24, 2018 Report Share Posted November 24, 2018 (edited) Hi Kevin, you are right, my PCV valve is a little low, but be sure, it works very well, there is absolute NO oil in the lower hose. It is set high enough to let the separated oil flow back to the engine. And it separates all the oil... I guess yours was much too deep so the oil in there was higher than the rim on its ground, which should avoids this. And as your diaphragm looks like it perhaps was glues with oil to the cover. Than the valve cannot work and you have up to the the full vacuum from the inlet on the rocker box cover. That sucks! The workshop manual tells to clean it from oil every 12.000 miles with alcohol, mine is always dry. Ciao Marco Edited November 24, 2018 by Z320 Quote Link to post Share on other sites
Z320 Posted November 24, 2018 Report Share Posted November 24, 2018 A few words about what I realised about the PCV when I had a very close look on it some years ago. The Positiv Crankcase Ventilation valve works as a Continious Crankcase Ventilation valve (perhaps a better name but not common?) It is a low pressure regulator valve to reduce the low pressure from the inlet manifold (which goes down to vacuum) to a always constant low pressure. I measured about 60 mm water pillar. That sucks the gases always out of the engine - and always with oil. The PCV valve is made of metal, has got a flame trap inside and works as a oil separator, standard on every car today. Thre is always oil in it because of this reason and to get the oil back to the engine it mus be set higher than the point where it is connected to the engine. And it has a rim inside to avoid the oil flow to the inlet manifold. The rim is to wide and too low, I made a modification on it. The upper side of the diaphragm has to be free from oil, if it glues on the cover there is alway the full low preasure on the engine. A lovely item... Quote Link to post Share on other sites
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