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View Full Version : Yesterday's adventure - caution oil pressure



JPSmit
10-09-2010, 03:06 PM
So, some of you know that I have been having oil pressure issues where the car starts at OK pressure but then drops off as the car heats up. Various solutions had been suggested, some of which involved adding a ball bearing or a nut to the oil pressure relief spring. Yesterday I decided to try it. First thing I discovered is that you cannot put a ball bearing in the "cup" of the nut as the plunger end that slides in the spring is too long, so, I put a nut between the plunger and the spring, reassembled and started her up. She made an odd ticking noise, but, I backed out of the garage and there was oil everywhere! Immediately shut down, rolled back into garage and left it there. Went to my meeting in my Mazda, got back, and returned everything. Long story short, putting the nut on the relief valve caused such an increase in pressure that it blew out the oil pressure valve line and the gasket on the oil filter. So, I am going to suggest that this is not a solution for 1500 engines.

Billm
10-09-2010, 03:20 PM
Normally when one puts the ball bearing in they take the regular plunger out and discard it.
I seriously doubt that the ball bearing will be a significant help for you since it raises the blow-off pressure which was already fine for you (as you now know)but it really sounds like there is a bit too much gap between your journals and bearings (I am guessing "rod" bearings) and when they warm up lose your pressure there.
May be time to either change the rod bearings again (and plastigauge them) or maybe get the crank reground.
Bill

JPSmit
10-09-2010, 04:30 PM
Normally when one puts the ball bearing in they take the regular plunger out and discard it.
I seriously doubt that the ball bearing will be a significant help for you since it raises the blow-off pressure which was already fine for you (as you now know)but it really sounds like there is a bit too much gap between your journals and bearings (I am guessing "rod" bearings) and when they warm up lose your pressure there.
May be time to either change the rod bearings again (and plastigauge them) or maybe get the crank reground.
Bill

You're exactly right Bill - was just looking for te easy things first.

dklawson
10-09-2010, 07:59 PM
I have never heard of the ball bearing swap being done on the 1500 (Triumph) engine. I am familiar with doing the ball bearing swap on the A-series engines. In the A-series you remove the plunger, fit the ball, then fit a shortened Cooper-S relief spring.

The only oil pressure band-aids I'm familiar with for the 1500 are dropping the pan and slipping in new bearings. You can also install a new oil pump and lap the pump housing so there is almost no gap between the end plate and the gear/rotor. Together those can raise the oil pressure quite a bit if the crank is not worn. The external rocker feed for the Triumph engines can also cause low oil pressure. I would remove it if you have one fitted.

JPSmit
10-09-2010, 08:05 PM
thanks Doug, I don't have one, but will probably swap the pump at the same time as I do the bearings.

MCS
10-09-2010, 08:44 PM
Hey JP I sent you a PM did you get it.
sounds like your hot rod might be a little under the weather. I wish I was closer I would Zoom over and pick up a wrench.

Phil

JPSmit
10-09-2010, 08:54 PM
PM returned - thanks Phil

Guest
10-09-2010, 09:14 PM
putting the nut on the relief valve caused such an increase in pressure that it blew out the oil pressure valve line and the gasket on the oil filter. So, I am going to suggest that this is not a solution for 1500 engines.



I doubt your motor will built/hold that much pressure. Putting the nut in may have seated the plunger too deep and blocked the passage off completly. I can't see your rods and mains, or anything else for that matter; being capable of holding that much pressure. What oil valve line are you talking about?

JP, my pump checked out fine when I did my mains. A little Lucas goes a long way.

JPSmit
10-09-2010, 09:41 PM
There is an external line that can be run to feed the rockers. It an aftermarket thing. Think I'll dump Lucas in tomorrow and do the bearings again this winter.

Guest
10-09-2010, 10:30 PM
Oh, O.K, I know what you're talking about now.

JP, where does it feed from?

dklawson
10-10-2010, 07:36 AM
The external oil feeds take their supply from a T-fitting/adapter that you screw in where the oil pressure switch is. They run a braided hose up the left side of the block to the top, rear corner of the head. You'll find a 5/16" bolt there with a copper crush washer sealing crossdrills that feed the rockers. The other end of the hose attaches there. It sounds like a great idea but it robs oil pressure from the main and rod bearings. Your easily, (relatively) cheaply replaced rocker gear is over-oiled and your crank (weak spot on a 1500) runs with reduced oil supply. Not good.