colin3511 Posted March 13, 2019 Report Share Posted March 13, 2019 Hi, Rebuilt engine. I was able to get around 100 psi on starter motor with plugs removed. Now have the engine running but it appears to have excess pressure in the oil system. Initially it blew the spin on adaptor housing to block seal. Assumed it was bad fitment on my part. Replaced seal and now found it is leaking from there as well as the filter seal itself. I have swapped over the PRV plunger and spring but it keeps blowing oil out from the points mentioned. Has anybody else experienced this? I guess I could reduce the PRV spring force and swap the filter but I would like to understand if I have another issue first. Thoughts? Thanks, Colin Quote Link to post Share on other sites
barkerwilliams Posted March 13, 2019 Report Share Posted March 13, 2019 Colin, If the oil flow is obstructed the pressure will rise and rise it is indicating a problem somewhere. I would not reduce the PRV unless you have reason to believe it is set incorrectly. Reducing the bypass may give you a good reading but will starve bearings of the essential lubrication and cooling they need. Does the oil flow anywhere or is it totally blocked? Easiest first, does it appear on the rocker assembly? Do you have a drawing showing the route the oil takes around the engine, I believe it was in the Haynes manual, which will show places along the oil path you can check for flow. Alan Quote Link to post Share on other sites
Waldi Posted March 13, 2019 Report Share Posted March 13, 2019 Hi Colin, mine did the same. I tightened the central bolt a bit further, and this stopped the dripping at the adaptor to block square seal. The copper hollow seal ring below the head of the central bolt can take some force, but don’t overdo it. I tightened the cartridge a bit further too, now it is no longer leaking. Also: have you removed the old block- seal(s) in the grove in the block? There should be one, but mine had two. I have the relative large K&N filter installed, if you have a smaller (shorter) filter, that my bring some relief too. I was surprised by the high oil pressure after the first start-up (it was low before the overhaul at 20 lbs when hot at idle) and hope it will drop a bit over time (see the irony?) If not, I plan to install a softer spring in the prv, I do not like to have more than say 70 lbs when warm at higher revs, but expect it will lower and all clearances increase a bit and all installation graphite paste is dissolved. My concern is rupture of the oil filter. Hence a good quality filter of larger size. Waldi Quote Link to post Share on other sites
Mike C Posted March 13, 2019 Report Share Posted March 13, 2019 I had to assemble mine with Permatex Aviation#3 on the block O ring to stop it leaking. As Waldi says make sure the old seal has not been left in the block groove. If necessary tighten the oil filter the specified number of turns with a strap wrench. No way I'd adjust the oil PRV so suit the oil filter. That's the cart driving the horse. I normally get 90psi on a high idle cold, the pressure settles back to normal once the oil warms up. Note I blew an oil filter off the adapter when I first started up- the centre male threaded section did not have enough engagement with the filter. I had to heat the housing extensively and unscrew the threaded section to get adequate engagement. I was lucky I initially tested it in the garage with an eye on the oil gauge and a hand on the ignition key. You also need a filter with all the characteristics necessary to work with the adapter, after a lot of research I settled on an Australian Ryco Z37. Quote Link to post Share on other sites
stuart Posted March 14, 2019 Report Share Posted March 14, 2019 If you have an oil cooler fitted be very careful running it with over 100PSI oil pressure or you will end up with this (picture below) and a lot of oil on the garage floor! Stuart. Quote Link to post Share on other sites
colin3511 Posted March 14, 2019 Author Report Share Posted March 14, 2019 No oil cooler Stuart. I have high pressure (100 psi) or more in the filter, PRV and oil gauge pipe area. It is blowing the adaptor seal and filter seal out of their respective grooves. I need to establish if I have a blockage somewhere or is the PRV stuck closed. Having swapped the PRV piston and spring for one off an old car I hope I have ruled that out. The trouble is I can only run the engine for a few seconds before oil blows out so it will be difficult to see if oil is getting where it should and up to the rockers. I was thinking of reducing the PRV setting so at least I can run the engine for a few seconds more to see if I get the oil through. Very wary as I don't want to damage anything by lack of lubrication/cooling. Colin Quote Link to post Share on other sites
roy53 Posted March 14, 2019 Report Share Posted March 14, 2019 Hello Colin you may recall my post last year with this issue on my race car at Silverstone. Totally blew the seal out causing total lose of oil pressure. I did try another PRV from another unknown spare engine which didn't solve it .Then on Waldi's advice purchased a complete PRV from moss and problem solved. There are different spring lengths in some so beware when trying to mix and match old units. ROY Quote Link to post Share on other sites
Waldi Posted March 14, 2019 Report Share Posted March 14, 2019 To add to Roy’s post: my new prv piston was very tight in the bore of the block, so I sanded in down just a bit in diameter and then posihed it, so it moved easily without sticking. Worth checking too. Regarding reducing the prv pressure setting (by shortening the spring just a bit): Once the oil gets very hot and ckearances have increased over time, and pressure reduces, the valve will close and no oil is lost. I just don’t want to run the risk of a blow-out. Waldi Quote Link to post Share on other sites
colin3511 Posted March 14, 2019 Author Report Share Posted March 14, 2019 Thanks for all your comments. Woke up this morning dreading the thought of an engine strip down! Spoke to the excellent TRGB and it made me re-look at the PRV. They had not experienced my issue so it made me think that it must be PRV or filter related. Took the PRV out again and found a lot of crud in the bottom of the adaptor. This was limiting the movement of the poppet into the adaptor housing. Polished poppet diameter and cleaned out adaptor thoroughly. This has made a huge difference to the movement of the poppet. It was binding before. I also used another spring I had. On start up now there are no oil leaks and around 80 psi on gauge at 1200 rpm. So far, so good, so hoping that is the issue. Next thing is to double check the rockers are seeing oil to confirm all is OK. Colin Quote Link to post Share on other sites
Waldi Posted March 14, 2019 Report Share Posted March 14, 2019 The smell of succes Colin:) be carefull when driving it the first couple of hundred miles though (I will). cheers, Waldi Quote Link to post Share on other sites
colin3511 Posted March 14, 2019 Author Report Share Posted March 14, 2019 Thanks Waldi. There is quite a smell too from exhaust manifold etc., etc. Run up to temperature now and all still seems OK. Thanks, Colin Quote Link to post Share on other sites
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