Jim Allen Posted July 28, 2014 Report Share Posted July 28, 2014 On cleaning up my by-pass oil filter it occurred to me after so many years of lay up that the pressure relief valve may not work if it is ever needed on my TR2. So if I'm replacing the filter head can I go to a full flow system from the later cars or aren't they interchangeable. And is that a good idea or should I just stick with what I've got? If so how can I test the pressure relief valve or if I dismantle it how do I reset it so that it will work when needed? Any help much appreciated Jim Quote Link to post Share on other sites
Fireman049 Posted July 28, 2014 Report Share Posted July 28, 2014 Hi Jim ~ I would be inclined to fit a new spring and ball valve. You can only adjust the pressure with it fitted to your engine and the engine running. I would tighten the spring fairly tight so that you will have some oil pressure on start up. Tom. Quote Link to post Share on other sites
Ashley James Posted July 28, 2014 Report Share Posted July 28, 2014 ByPass filters are bad news and best changed for a modern full flow one. Us oldies remember 803 cc Morris Minors and A30 engines wearing out in 20,000 and endless Main bearing failures on MKVI Bentleys that also had them. For some unaccountable reason lots of American cars had them and their engines lasted well. I think the primary problem was that we couldn't cast iron to the same standard and as a result, sand goes through the bottom end destroying the bearing. R-R ran the engines on Test benches and even stripped and cleaned them and even then the mains went in 10,000, so they gave in and converted any engine they or the dealers saw to full flow. Since it's only a change of head on a Triumph, I'd do it as insurance. The worry in the early days was that if the filter was good enough to remove nothing that would damage the engine, it was also good enough to block, so diverting some of the oil feeding the cranking to a bypass filter was a good idea, or they thought it was until engines wore out as quickly as having no filter. (Ford Populars). Quote Link to post Share on other sites
BlueTR3A-5EKT Posted July 28, 2014 Report Share Posted July 28, 2014 The Full flow is a simple and wise improvement and is able to be retro fitted to all 4 cyl TR engines. The only issue you will have changing from Bypass to Full Flow is the length of the attaching bolts - longer in Full Flow. Get the whole assy with filter canister and its bolt from the later car engine (post TR2) and fit new PRV spring and ball as advised above. The filter is the same for all models and a spin on conversion is available if you so choose. Cheers Peter W Quote Link to post Share on other sites
mleadbeater Posted July 29, 2014 Report Share Posted July 29, 2014 Hi I am confused here, are we saying that the bypass valve is in operation all the time the engine runs, my understanding was that this valve ( as against the oil pressure relief valve) only opens when the filter is getting blocked, which, I think, even modern car filters have. Can someone please clarify. Cheers Mike Quote Link to post Share on other sites
BlueTR3A-5EKT Posted July 29, 2014 Report Share Posted July 29, 2014 The TR2 bypass oil filter head has no 'bypass' valve, it has a filter element bypass passage way. Only a partial amount of oil from the pump passes through the filter element before being fed to the main oil gallery - the rest goes in dirty to the bearings via the 'bypass' passage. In the later full flow filter head filters ALL the oil from the pump goes through the filter element before being fed into the main oil gallery, If the filter is blocked oil is allowed to enter the the main oil gallery unfiltered via a spring loaded bypass valve. Cheers Peter W Quote Link to post Share on other sites
Dave Satchwell Posted July 30, 2014 Report Share Posted July 30, 2014 Peter, Is there anyway of checking which you have by looking externally at the unit fitted to the car, if not is it evident when changing the oil filter, Thanks Dave Quote Link to post Share on other sites
BlueTR3A-5EKT Posted July 30, 2014 Report Share Posted July 30, 2014 Yes it can bee seen. I will dig out the reference sketch my friend Peter Taylor did and included in the Moss TR2/3/4 printed catalogue and post here if I can work out how to. Failing that check the Moss Europe PDF version of their TR2/3/4 catalogue available on line. Cheers Peter W Quote Link to post Share on other sites
mleadbeater Posted July 30, 2014 Report Share Posted July 30, 2014 Hi This is worrying, not happy with only partial filtration. Can this bypass gallery be blocked? In may days with the BMC 'A' series it was recommended to block the filter bypass valve fitted to Sprites and Midgets ( on some models there was even a warning switch and dash lamp to indicate a blocked filter). Are the filter elements the same for bypass or non-bypass filters? Cheers Mike Quote Link to post Share on other sites
stuart Posted July 30, 2014 Report Share Posted July 30, 2014 Filter elements are the same for all 4 cylinder engines. Stuart. Quote Link to post Share on other sites
mleadbeater Posted July 30, 2014 Report Share Posted July 30, 2014 thanks Stu, may I ask you for a little more advice, My Purolator filter head has an approx 1" a/f nut on top, which I assume is the filter bypass valve, as per the part no. 23 from Rimmer's catalogueunder 'Oil filter", which suggests that the unit is a full flow one, as surely there is no point having a bypass to a bypass filter. Am I correct?, Cheers Mike Quote Link to post Share on other sites
Dave Satchwell Posted July 30, 2014 Report Share Posted July 30, 2014 Thanks Pete, Looked in the Moss book and mine is bypass type, fortunately I have a full flow on a spare engine project. A job for the winter I think, All the best Dave Quote Link to post Share on other sites
Ashley James Posted July 30, 2014 Report Share Posted July 30, 2014 Thanks Pete, Looked in the Moss book and mine is bypass type, fortunately I have a full flow on a spare engine project. A job for the winter I think, All the best Dave It only takes half an hour to change as long as you don't have an oil cooler adaptor plate under it. Quote Link to post Share on other sites
Dave Satchwell Posted July 30, 2014 Report Share Posted July 30, 2014 Thanks Ash, As you say looks easy, the time will be restoring/painting the "new" one, Dave Quote Link to post Share on other sites
BlueTR3A-5EKT Posted July 30, 2014 Report Share Posted July 30, 2014 (edited) Bypass and Full flow filter heads - images courtesy of Moss Europe. Drawn by Peter Taylor. Cheers Peter W Edited August 1, 2014 by BlueTR3A-5EKT Quote Link to post Share on other sites
Bob Smith Posted August 1, 2014 Report Share Posted August 1, 2014 If any one wants to upgrade from a bypass filter to a Purolator full flow filter I have a spare New Old Stock example complete assembly 203271 (head,bowl,springs etc.) purchased in the early 70's and never needed. Quote Link to post Share on other sites
Jim Allen Posted August 2, 2014 Author Report Share Posted August 2, 2014 Bob PM sent Cheers Jim Quote Link to post Share on other sites
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