Robert Price Posted November 4, 2021 Report Share Posted November 4, 2021 Having had the 6 a few weeks decided to remove the oil cooler, so bought a new Mocal housing and Mahle OC38 filter used on past TR's, 20/50 Vavoline. Fitted the latter, Started up the car oil pressure rose to 100 psi bit more than with the oil cooler on, Checked for oil leaks and oil was coming out between the Mocal housing and block. So took it off, seal was in place ok. Now the centre of the Mocal has a sprung seal so I screwed in the bolt pulling the seal down before refitting, was this wrong? As on restarting the car oil pressure rose dropped back to 20 psi rose again and so on. Now before I did this work everything was excellent pressure wise etc. and I know the engine is very good, so is it to do with this inner sprung seal within the housing, and should it be fully out and let the bolt compress it? Otherwise I cannot think of anything else, I am thinking now if it aint broke dont fix it! Rob Quote Link to post Share on other sites
Mike C Posted November 4, 2021 Report Share Posted November 4, 2021 Been a while since I installed my Mocal. I recall a lot of people had leaks due to double gasketting- failure to remove the old gasket before installing the new one. Is your oil pressure rising and falling inexplicably? Might be something stuck in the engine's PRV or a problem with the filter's internal PRV. Make sure that you have good thread engagement with the filter on the Mocals centre nipple- mine was only one turn or so ex factory and a filter cartridge blew off on a cold start. I had to remove/replace the nipple with something longer. Quote Link to post Share on other sites
Tim D. Posted November 5, 2021 Report Share Posted November 5, 2021 I've fitted this attachment on a number of 6s. As far as I am aware you don't touch the sprung centre section. You just bolt the attachment onto the engine. Tim Quote Link to post Share on other sites
Robert Price Posted November 6, 2021 Author Report Share Posted November 6, 2021 Tim has confirmed my mistake on re assmbling the filter housing with the centre seal pulled down, which explains why the pressure became unstable and did not occure during the first fitting. But because of the leak I decided to look at the pressure relief valve and found a washer under the spring and I am wondering if the spring is uprated also. This may have been done because of the oil cooler fitted to keep oil pressure up? So that may be why my oil pressure on start up has gone up to 100 psi and caused the leak from the filter housing gasket. The oil filter conversion for the oil cooler was the older type with a fixed inner O ring and certainly did not leak, so do I put the cooler back on with new hoses or change the relief spring and try another new adapter having returned the other one now, what a pain. Rob Quote Link to post Share on other sites
KiwiTR6 Posted November 7, 2021 Report Share Posted November 7, 2021 On 11/5/2021 at 10:16 AM, Mike C said: Been a while since I installed my Mocal. I recall a lot of people had leaks due to double gasketting- failure to remove the old gasket before installing the new one. Is your oil pressure rising and falling inexplicably? Might be something stuck in the engine's PRV or a problem with the filter's internal PRV. Make sure that you have good thread engagement with the filter on the Mocals centre nipple- mine was only one turn or so ex factory and a filter cartridge blew off on a cold start. I had to remove/replace the nipple with something longer. I had exactly the same issues with my adaptor.... Quote Link to post Share on other sites
Mike C Posted November 8, 2021 Report Share Posted November 8, 2021 The nipple engagement was a near disaster. I was lucky . I was testing the new adapter in the garage with a cold engine and my eye on the oil pressure gauge when I revved the engine the oil pressure suddenly dropped so I immediately switched off the engine. When I checked the filter had blown off. I I'd been on the open road and not watching the OP gauge it would have cost me the engine. Quote Link to post Share on other sites
Robert Price Posted November 8, 2021 Author Report Share Posted November 8, 2021 Just ordered new Mocal adapter, standard pressure spring, copper washer currently missing from the pressure retaining nut and K&N gold filter, we shall see what happens later this week. Rob Quote Link to post Share on other sites
roy53 Posted November 8, 2021 Report Share Posted November 8, 2021 On 11/5/2021 at 7:34 AM, Tim D. said: I've fitted this attachment on a number of 6s. As far as I am aware you don't touch the sprung centre section. You just bolt the attachment onto the engine. Tim +1 Try removing the washer from the release spring. Pressure should drop but hopefully not to far. The washer is used to raise the pressure. These do weaken over time , i would purchase a new spring. Roy Quote Link to post Share on other sites
Andy Moltu Posted November 9, 2021 Report Share Posted November 9, 2021 The washer was a modification often suggested in the past. Presumably the theory was that higher oil pressure must be better. A flawed theory as the optimum pressure is just that. Too low and the risk of inadequate protection, too high and risk of leaks. Some 6 pot blocks have deeper grooves (than others) for the outer ring seal to sit in. Not an issue with the original oil filter as you tightened up until it sealed. The early spin on conversions were solid, came with 2 inner O rings to make the inner seal and - the thinner for use with blocks with a deeper groove, the thicker for those with a shallower outer seal grove. However sometimes youhad to use an extra thick outer seal for some blocks (a standard seal and a half seal made by splitting a standard seal with a Stanley knife. The latter adaptors spring loaded the centre of the adaptor to resolve this issue but sometimes it can be tricky to retain the inner seal whilst you mount it. Blob of vaseline helps retain it. Quote Link to post Share on other sites
astontr6 Posted November 9, 2021 Report Share Posted November 9, 2021 On 11/6/2021 at 10:08 AM, Robert Price said: Tim has confirmed my mistake on re assmbling the filter housing with the centre seal pulled down, which explains why the pressure became unstable and did not occure during the first fitting. But because of the leak I decided to look at the pressure relief valve and found a washer under the spring and I am wondering if the spring is uprated also. This may have been done because of the oil cooler fitted to keep oil pressure up? So that may be why my oil pressure on start up has gone up to 100 psi and caused the leak from the filter housing gasket. The oil filter conversion for the oil cooler was the older type with a fixed inner O ring and certainly did not leak, so do I put the cooler back on with new hoses or change the relief spring and try another new adapter having returned the other one now, what a pain. Rob Mocal have produced 2 types, the first type gave trouble with seal as the large outer O ring was not compressed enough to affect a seal? I had to turn down the Centre section so that the outer sealing section entered much deeper (+0.025"). After years of use I visited Mocal for a new sealing kit only to be told that they do not supply parts for that unit as it was troublesome? Then had to buy the later version but they did give me trade price. Bruce. Quote Link to post Share on other sites
Robert Price Posted November 10, 2021 Author Report Share Posted November 10, 2021 A TR specialist has also suggested fitting an extra washer under the adapter bolt head in case the bolt is bottoming out. My car was built in late 1969 so maybe some of these early cars based on what others have commented on could have slighty different fittting tolerences compared to later cars. Anyway parts due to arrive today, including new pressure spring (standard). Looking at the adapter for the oil cooler its outer sealing ring is identical to the latest one, but I will measure the casting and compare its flange for sealing with the new one when it has arrived. Rob Rob Quote Link to post Share on other sites
Robert Price Posted November 10, 2021 Author Report Share Posted November 10, 2021 (edited) Parts arrived today, new standard spring 17coils, (old one 21 plus washer), New Mocal adapter plus K&N filter, all worked perfectly no leaks pressure about 85/90 on start up, so I can forget about that for now. I did notice comparing the old type adapter to the new that the rim body which goes against the seal/block is narrower on the new design, but it works, thank you to those who replied. Choke cable next no fast idle cable! Rob Edited November 10, 2021 by Robert Price Update Quote Link to post Share on other sites
SpitFireSIX Posted November 11, 2021 Report Share Posted November 11, 2021 Hi, If you are getting over 80PSI on start-up, I would reconsider your oil viscosity choice. 20W looks the wrong choice; maybe 10W or 5W/0W would be a better choice? Cheers, Iain. Quote Link to post Share on other sites
astontr6 Posted November 12, 2021 Report Share Posted November 12, 2021 On 11/10/2021 at 9:57 AM, Robert Price said: A TR specialist has also suggested fitting an extra washer under the adapter bolt head in case the bolt is bottoming out. My car was built in late 1969 so maybe some of these early cars based on what others have commented on could have slighty different fittting tolerences compared to later cars. Anyway parts due to arrive today, including new pressure spring (standard). Looking at the adapter for the oil cooler its outer sealing ring is identical to the latest one, but I will measure the casting and compare its flange for sealing with the new one when it has arrived. Rob Rob Rob! the key issue is the center boss as to how far it will allow the outer flange to enter the Cyl. Block section to compress the large O ring in the block to affect a good seal? Mocal told me that they had sorted out that problem? Bruce. Quote Link to post Share on other sites
Robert Price Posted November 12, 2021 Author Report Share Posted November 12, 2021 lian it is usual for a TR6 to have anything up to 95 psi on a cold start, 20/50 is the grade I always use although some people do use other grades, but the pressure soon comes down when the engine gets hot. My issue Bruce I think was caused mainly by excessive spring pressure on the relief valve as on fitting a standard spring but also a replacement spin on adapter just to be safe and it worked which is the main thing. Rob Quote Link to post Share on other sites
SpitFireSIX Posted November 18, 2021 Report Share Posted November 18, 2021 (edited) Hi, Good its all sorted. 95PSI on a cold start is not good, but 20W will do that as its a poor, but popular & wrong choice for many. To each his own. Sorry There. Cheers, Iain. Edited January 1, 2022 by SpitFireSIX speeling Quote Link to post Share on other sites
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