39 replies to this topic

[Ethel]

Air getting in will allow the oil to drain back down the pick-up pipe, like taking your finger off the end of a pipette. Still a mystery where the air got in though,

[mini13]

I think the issue was a sticky relief valve not fully returning.

[stevede]

Hi and thanks fro the replies both.

 

A small and hopefully, final update. I thought I would add this in case anyone else has a similar issue.

 

I took the car out for a run, initially happy with the new pressure. After around 15 mins, with the oil nice and warm, the pressure had dropped off to about 50psi when running. Wasn't too happy as I thought the drop was a bit excessive given the run time since new bearings.

 

The weird thing was, when I stopped at a junction, it went back up to 75psi at idle!

 

Set off again and dropped to 50 and stayed constant.

 

More web searching and the opinion on the bearing relief valve varied, so I put the standard one back in and I have 75 at start up. 70 - 75 running dropping to 50 at idle even after a short run on the motorway. I've ordered a new valve as the one I have has a couple of marks, but I think I may now have cured the problem.

 

I did find a note on Calvers web site which showed a similar issue with the problem traced to a screwed in oil plug. I'm not at the stage yet where I want to pull and strip the clutch case to check. (I have the standard gallery plugs) But one to note as it's the only plausible explanation I have seen relating to the some problem I had.

 

http://www.calverst....lugs(bungs).htm

 

 

Regards

 

Steve

Edited by stevede, 11 September 2013 - 08:23 PM.

[carbon]

Steve,

 

Good to hear you have sorted the problem, just a quick word of caution about using the ball bearing relief valve in cold winter weather.

 

I was running one of these for about a year until one very cold morning the high pressure blew out one of the oil gallery plugs (was showing well over 100 psi on the gauge, with 15/50 oil). I think the problem is that the spring has less travel with the ball instead of the plunger, and can get coil-bound before the relief port is fully uncovered.

[stevede]

Steve,

 

Good to hear you have sorted the problem, just a quick word of caution about using the ball bearing relief valve in cold winter weather.

 

I was running one of these for about a year until one very cold morning the high pressure blew out one of the oil gallery plugs (was showing well over 100 psi on the gauge, with 15/50 oil). I think the problem is that the spring has less travel with the ball instead of the plunger, and can get coil-bound before the relief port is fully uncovered.

 

Hi Carbon, many thanks for your reply.

 

I have taken the ball out as it was giving strange readings. I received the new std plunger today so will fit over the weekend.

 

Regards

 

Steve

[mini13]

Yes the balls can have this effect,

 

its due to them doing somthing akin to the "malteeser trick"

 

 

see how it bobbles about.... I belive this causes the eratic pressure.

 

I have had good experience with adding a cup and pin arangment to keep the ball ans spring aligned, similar to what avonbar used to offer

 

http://www.avrclassi...duct/?pid=47904

 

easier just to use the std part though, and maybe slim it down slightly.

[jagman.2003]

Useful thread. I'm rebuilding a block & am very interested in all the options & precautions to take.

[welshdan]

The oil pressure in my turbo motor takes a good while to build. Pobably several seconds. I put it down to the thick oil in there, pressures are perfect otherwise

[stevede]

Have run the engine for around 150 miles now. From cold, the oil light is on for perhaps 2 seconds and after that goes out immediately if the engine is stopped & re started. I haven't done the first oil change as yet so still running thick 20/50.

 

Whilst running, and even after a short motor way run and some rush hour start stop, the pressure has remained constant at 50psi idle rising to 70 plus above 2500rpm.

[minimuk]

sounds good to me....