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Pressure Relief Spring & red line oil

shorn

Jedi Knight
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I thought I needed to replace the oil pump on my BJ8. Hot engine idle was under 20 psi and running around 2500-3000 rpm was under 40 psi. I use 20-50 oil. But the $2 pressure relief spring replacement boosted the idle pressure to almost 30 psi and the 2500-3000 rpm pressure to about 50 psi. Guess I can live with that for a while. Also changed the transmission oil from 30 wt oil to red line MT 90. Of course, it was a lot more than a couple of bucks, but I believe the car shifts significantly better.
 
That's great, because I was getting ready to order an oil pump for the same reason. So, where is this magic spring?

Walter
 
Walter, The spring is part of the oil pressure relief valve which is located on the engine block behind a large nut just behind and below the oil filter. However, to check and see if you suffer the same problem ,just put a small washer in the valve cup ahead of the spring and button it back up. start the engine and see if oil pressure comes up.You may need a couple of washers. Let us Know how you get on.-FWIW---Keoke
 
When I replaced the spring, the pressure relief valve itself did not come out with the old spring, but stayed inside the chamber. Is there a way to get it out easily? Since my oil pressure increased with the new spring, there may be no need to examine the valve, but I would like to know for future reference.
 
Hi Shorn, have you got one of those small telescoping pencil type magnets it will fetch it for you.-FWIW---Keoke
 
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When I replaced the spring, the pressure relief valve itself did not come out with the old spring, but stayed inside the chamber. Is there a way to get it out easily?

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The relief valve is a cup shaped plunger with the open end toward the outside. It sometimes gets varnished up & sticks. This can even be the cause of erratic oil pressure.

I have had good luck removing it by wedging a wooden stick into the open end & slowly working it back & forth & twisting as it gradually comes all of the way out. Something like half of an old fashioned wooden clothspin should make a good handle. Something that will wedge into the plunger with a very slight taper. Some carb cleaner might help to get it out.

When you get it out, make sure that it is clean, put it back in, & rotate it against it's seat to possibly get a better plunger to seat seal.
D
 
So after just one day of higher oil pressure with the new spring, it dropped back down some on a 50 mile ride today. I took the NEW spring out and compared it to the spring I removed the day before. The new spring WAS about 1/4 of an inch longer than the old one that I removed. I assummed the old spring just became compressed over the years. But today the new spring had actually compressed somewhat in just one day. Perhaps, they just aren't as good a grade. Anyway, I used Dave Russell's idea and shimmed it a little, and the pressure came back up to yesterday's level. Oh, the magnet pulled the relief valve right out, so I was able to clean that as well.
 
The magnet "trick" worked like a champ for me the other day. Ordered a new spring/valve from Healey Surgeons and installed it. Pressure went up but did drop some when the engine was fully heated up. Will monitor as I drive it some more.
 
[ QUOTE ]
But today the new spring had actually compressed somewhat in just one day. Perhaps, they just aren't as good a grade. Anyway, I used Dave Russell's idea and shimmed it a little, and the pressure came back up to yesterday's level. Oh, the magnet pulled the relief valve right out, so I was able to clean that as well.

[/ QUOTE ]
A lot of springs are poor quality. A good properly tempered coil spring will maintain it's design length for a long time. A poor spring will take a set the first few times that it is compressed. An easy check is to measure the spring length, compress it in a vice until all of the coils are just lightly touching (coil bind) or nearly touching & let it set for a couple of hours. Remove the spring & measure it's length again. If there is significant shortening, the spring is low quality & will not maintain it's design tension. Throw it aside & look for a better spring. Any spring will fatigue a bit over time & loose some of it's tension, but it should take years, not one compression, to lose tension. If the spring has gotten shorter, taken a set, once it has taken a set it will usually remain at it's new shorter length for quite a while. Sometimes something can be adjusted to compensate for the loss of length, such as a shim, & it will last quite a while at its new set length. Some triumphs & such have adjustable spring stops to adjust for loss of spring tension to adjust oil pressure. Same idea for putting spacers under sagged coil springs.
D
 
HI Dave, I havent seen them lately but there are adjustable replacement caps for the Healey pressure relief valves.These adjustable caps allow you to comphensate for weak springs, actually you can make one but it takes a lathe to do it-FWIW---Keoke
 
Hi Keoke,
Never heard of such a thing, much less seen one. I would suspect that the factory chose not to do it because of cost or to keep folks from fiddling with it. It's an irresistable temptation for many to turn the screw a bit & I think Healeys don't particularly appreciate super high oil pressure. I don't have that much experience with Triumphs, but, folks setting the pressure at 80, as sometimes happens, puts a lot of strain on the pump drive, can flood the oil rings, & make more leaks. Do you think that super high pressure helps, or is it more of a cult thing? I have always heard that 10 psi per thousand rpm is adequate. Maybe it's a case of "more is always better"? I found the required spring spacer length in two tries. I have a lathe & a mill. Less time & effort than making or running down an adjustable one & one less thing to fiddle with. An interesting idea though.

shorn,
I had the same experience with Redline MT 90 in my transmission.
D
 
Dave;
Moss carried them for a while I do not know if they still do or not. But I think you are right about keeping folks from fiddling with them.----Keoke
 
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