C.A.R. Posted January 6, 2011 Posted January 6, 2011 This is what can happen & what the fix is when the O.P. Relief Valve fails = dead engine. PMac will explain the rest shortly... Quote
Zeddophile Posted January 6, 2011 Posted January 6, 2011 Obviously the thought is that its better to have too much oil pressure than none at all? Didn't have a failure in your weapon did you Lurch? Quote
peter mc Posted January 6, 2011 Posted January 6, 2011 not nice to find this in the oil filter and all the bearings have failed . i was not a fan of replacing the p r v with a plug before as i have not had one fail in 10 years of playing with L28 s . I have allways replaced the valve with new one when building new engines, so this was not nice to find .so i will be taping all engines from now on, with 3/8npt pipe plug Quote
C.A.R. Posted January 6, 2011 Author Posted January 6, 2011 It's an L28 race engine that belongs to a 240Z owner here in Vic. He's a member on here too, but is lurking atm... Quote
peter mc Posted January 6, 2011 Posted January 6, 2011 it a customer from my shop with a mad 240z :'( Quote
. Posted January 6, 2011 Posted January 6, 2011 I don't get it. I would have thought the failure of the valve would only impact the proportion of oil being sent through the filter??? It seems like you are saying it causes engine failure due to lost oil pressure? Where does the pressure go? Quote
peter mc Posted January 6, 2011 Posted January 6, 2011 it hapend mid race at the island and it went from 70 psi to 25psi and at 7000rpm all bearings died the reason for no oil presser the BB from the valve has worked its way in to the oil passage and closed it of Quote
DatPilot Posted January 19, 2011 Posted January 19, 2011 FUUUUUUUUUU....... Saw an L28 the other day (in some tokyo autosalon pics) that had an belt driven external oil pump that mounted to a custom bracket where the oil filter goes, alot of work done too, but it was a race engine and turbro'ed and all blingy with $2000 of speedflow fittings etc.... Quote
1600dave Posted January 19, 2011 Posted January 19, 2011 Anybody have any thoughts on the pros / cons of tapping and inserting a tapered plug as shown versus using a welsh plug in the existing hole ? Quote
luvemfast Posted January 19, 2011 Posted January 19, 2011 I have one of Neil Cartlidge's old blocks and it has a welsh plug Dave Quote
1600dave Posted January 19, 2011 Posted January 19, 2011 Yep, I used a welsh plug in the engine I built for the FOSC event at Bathurst last Easter - just curious about other people's opinions (and whether I should have used a tapered plug). I used tapered plugs everywhere else in the engine, but used a welsh plug for the oil pressure relief. Quote
peter mc Posted January 19, 2011 Posted January 19, 2011 the reason i taped the hole was ,i had a plug come out on a 2j but lots of people use this that method each to there own Quote
Wayne G Posted January 19, 2011 Posted January 19, 2011 At the risk of being flamed, is that the oil filter bypass valve? Meant to open when the filter blocks maintaining some oil pressure to the engine? Quote
Riceburner Posted January 19, 2011 Posted January 19, 2011 I'm still running the BB and spring in my new motor, what work needs to be done for the welsh plug? My bottom end is already assembled and a grub screw would mean stripping down and starting all over again :'( Quote
peter mc Posted January 19, 2011 Posted January 19, 2011 it is meant to save the motor when the filter is blocked but they can fail and when they do its not good. most road cars will not have a problem . race cars with remote filter and oil coolers have built in reliefs to bypass the oil .when the valve fails the oil pressure drops not completely but its not good at revs in a race to have 40 psi at 6500rpm ps will you be at the engine day gareth will explane it there Quote
DAZDA Posted January 20, 2011 Posted January 20, 2011 ... the BB from the valve has worked its way in to the oil passage and closed it of Do you mean the oil feed from the oil pump? Or the oil passage from the filter to the main engine oil gallery? Quote
Riceburner Posted February 24, 2011 Posted February 24, 2011 Reviving an old thread.... What do I need to do to replace this relief valve with a welsh plug? What size is it and where can I get this welsh plug from? Quote
RB30X Posted February 24, 2011 Posted February 24, 2011 I've been wondering where yOu get small ones like that too for a secret project I'm working on. Quote
Moderators Zedman240® Posted February 24, 2011 Moderators Posted February 24, 2011 Might be better to tap and thread then install a screw in plug rather than a press in plug. Quote
peter mc Posted February 24, 2011 Posted February 24, 2011 That's for sure, much safer! But this must be done in the first parts of the build stage so you can get all the metal out. Quote
Riceburner Posted February 25, 2011 Posted February 25, 2011 too late to tap a thread as the bottom end is all together. So it's fit a plug depending on work required or stick with the stock relief valve. I'm not fussed either way but may as well do it if it's easy to do. Quote
260Coupe Posted February 25, 2011 Posted February 25, 2011 too late to tap a thread as the bottom end is all together. So it's fit a plug depending on work required or stick with the stock relief valve. I'm not fussed either way but may as well do it if it's easy to do. I've seen Z shop built engines with a 5c piece jammed in the relief hole...............seemed to work just fine Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.