Engine: high oil pressure

[DMB-8]

My engine is a fulflo 289 and has the problem with high oil pressure that I posted before.I have done everything that was advised on the forum to no avail.
I was telling another person about this and he wondered if the partial flo oil flo cam bearings were installed and thought that would raise the oil pressure.
I wondered if anybody else thinks that could cause the problem.It will peg the oil pressure gauge at 100 lbs.at 2000 to 2500 RPM.I bought this truck with the engine already rebuilt but by an older man who has died and I can't ask him.Do the fulflo cam bearings have more holes than the partial flo.Thanks for any help that you can give me.Don Borger

[Tom Bredehoft]

I think you're thinking of the partial flow oil filter restrictor. If it's missing you will have low pressure. If it's present your car will start on a cold morning and pin the gauge, or come close. Once it's warmed up it should have 40 lbs of pressure at 40 mph in high gear. Idle pressure is meaningless, there is no load on the engine bearings at idle.

The ristrictor is a plug in the line, where the oil enters the filter with a small (.040 or so) hole in it.

[JoeHall]

If the OP is referring to the oil holes in the camshaft bearings, the answer is yes. If the bearings are installed incorrectly, their oil hole(s) are misaligned with the oil passage holes in the block. If misaligned enough to block them off, results would be excess oil pressure, and cam bearing starvation. It is very easy to get those holes out of alignment, and not uncommon, in today's machine shops.

I always double check those holes when getting a block back from the machinist, and have had to ream out a few that were all but closed off, due to misalignment by the installer.

Easy enough to check, once the camshaft is removed. Use a dentist mirror and a small nylon tie-tie.

[Flat Ernie]

Not to hijack the thread, but I have good (high) oil pressure when cold, but virtually zero when hot (idle). I understand about no load at idle, but it's very disconcerting. I had a brand X engine years ago that the machine shop left a gallery plug out of (my fault for not checking though) that exhibited the same symptoms. My mains and rod bearings were destroyed running it only a few months that way as I troubleshot and changed many components. I'd hate to have the same thing happen.

My 53 has a later 289 in it, I'm not sure of the year, but it takes a spin-on oil filter. As for 40psi @ 40mph, mine may have that in 4th gear (I have a 5spd now), or just slightly less.

What would cause hot idle to be low on a relatively fresh (well under 10K miles) engine?

[jclary]

If the OP is referring to the oil holes in the camshaft bearings, the answer is yes. If the bearings are installed incorrectly, their oil hole(s) are misaligned with the oil passage holes in the block. If misaligned enough to block them off, results would be excess oil pressure, and cam bearing starvation. It is very easy to get those holes out of alignment, and not uncommon, in today's machine shops.

I always double check those holes when getting a block back from the machinist, and have had to ream out a few that were all but closed off, due to misalignment by the installer.

Easy enough to check, once the camshaft is removed. Use a dentist mirror and a small nylon tie-tie.

Joe, correct me if I'm wrong (and I often am), but I thought that cam bearings have an oil groove(channel) machined on the outer diameter so that if they were misaligned on install, oil will still flow around the bearing and enter through the oil hole anyway. Like you, I installed mine making sure I lined the hole in the bearing with the hole in the engine before pushing them in. But the channel cut in what I call the "back" of the bearing is supposed to allow oil to enter and lubricate the cam even if the hole in the bearing isn't perfectly lined up to the hole in the block.

[63r2]

I don't know if you checked your oil pressure relief valve spring. I checked my relief valve spring length against one out of another motor and found it to be slightly longer.
Swapped it over for the shorter one and it reduced the pressure. It might not be by much but I figured every little bit would help.
pb

[JoeHall]

Joe, correct me if I'm wrong (and I often am), but I thought that cam bearings have an oil groove(channel) machined on the outer diameter so that if they were misaligned on install, oil will still flow around the bearing and enter through the oil hole anyway. Like you, I installed mine making sure I lined the hole in the bearing with the hole in the engine before pushing them in. But the channel cut in what I call the "back" of the bearing is supposed to allow oil to enter and lubricate the cam even if the hole in the bearing isn't perfectly lined up to the hole in the block.

I just went and looked at new 352 cam bearings; no groove. I usually hand carry cam bearings to the machinist, and have held several 259/289 sets in hand, but do not recall grooves. Once I get the block back from a machinist, I cannot see the outside. I focus on the inside, to make sure the oil holes line up. I cannot see how the cam could be oiled by grooves outside the bearing, but maybe inside, like some rod & main bearings.

I once had a cam bearing flake off in a GT, a sliver about 1/2" long and 1/4" wide, and oil pressure dropped immediately, most notable at idle, to about 5-10 PSI. I drove the car another 2-3 years before tear down. It did not damage anything. Pretty sure the flake was off the high side of the bearing, in a no load area. Once tore down, I saw the flake, then knew where the oil pressure had went. My point being, I believe those oil holes help regulate pressure. If blocked, they may cause it to spike, as the OP's. But maybe there are some escape grooves there, as you say, on 259/289s.

[DMB-8]

The engine # that I am having the problems with is P100909 I can't seem to find a # this high can anybody tell me when this engine was built.I found the cam bearings are all the same from 51 to 64 so It can't be the wrong bearings so it must be a bad installation not lining up the holes.I guess I am going to have to pull the engine and tear it apart.Thank You,Don

[Skybolt]

The engine # that I am having the problems with is P100909 I can't seem to find a # this high can anybody tell me when this engine was built.I found the cam bearings are all the same from 51 to 64 so It can't be the wrong bearings so it must be a bad installation not lining up the holes.I guess I am going to have to pull the engine and tear it apart.Thank You,Don

If you just want to check the bearing alignment you could do a partial teardown. ie. just like a camshaft swap. You would need to remove the radiator and maybe some of the grille, depending on what car the engine is in. Then remove the valve covers, the rocker gear and pushrods. Remove intake manifold. Remove the valley cover and take out the lifters, remember to note what order and side. Remove distributor. Remove the water pump etc... Remove the timing cover and proceed to remove the camshaft. Once out it will take a bit of work to inspect the bearing clocking but it can be done. It is a bit of work but you will not have to remove the engine or crack it open that much. If found to be fine then you have maybe saved some time. If wrong then you are halfway to replacing them.

Just and idea as I have done a cam swap this way before.

Len

P.S. I have skipped some details but you should be able to get the gist of the procedure.

[Skip Lackie]

That engine number would be a very late 1963 289.

[DMB-8]

We tore the engine down took the intake off pulled all the lifters and took the camshaft ou`t and checked the cam bearings.Everything was alright.We then pulled the relief valve out again and I could see the relief hole for the oil into the crank gear cover.I could see something still in there.It turned out to be another piston,when the guy rebuilt the motor he neglected to take the old piston out and installed a second one,but only one spring,After reinstalling everything the oil pressure is right on now.Never figured there would be another piston in there when we removed and installed new piston and spring.Thanks for all the help that the forum gave me.Maybe this will help somebody else so they do not have to tear engine down like we did.Thank You.Don Borger

[jclary]

We tore the engine down took the intake off pulled all the lifters and took the camshaft ou`t and checked the cam bearings.Everything was alright.We then pulled the relief valve out again and I could see the relief hole for the oil into the crank gear cover.I could see something still in there.It turned out to be another piston,when the guy rebuilt the motor he neglected to take the old piston out and installed a second one,but only one spring,After reinstalling everything the oil pressure is right on now.Never figured there would be another piston in there when we removed and installed new piston and spring.Thanks for all the help that the forum gave me.Maybe this will help somebody else so they do not have to tear engine down like we did.Thank You.Don Borger

Apparently, none of the rest of us thought about two pistons either. (Including me.) Thanks for returning to explain. You have done us all a favor.

[JoeHall]

Well ain't that a kick in the teeth. Who'd a thunk it even possible to stuff a second piston in the hole. In the military, designers have tried for decades to make equipment, "Marine proof" and "Soldier proof" to no avail. Similarly, looks like Studebaker did not do a very good job in making stuff, "idiot proof".

[DEEPNHOCK]

Learn something new every day...
I did not think the cavity deep enough for two pistons.
Also would thing the spring would coil bind if two pistons were in there.
Did he cut the spring to get the cap/bolt on?

We tore the engine down took the intake off pulled all the lifters and took the camshaft ou`t and checked the cam bearings.Everything was alright.We then pulled the relief valve out again and I could see the relief hole for the oil into the crank gear cover.I could see something still in there.It turned out to be another piston,when the guy rebuilt the motor he neglected to take the old piston out and installed a second one,but only one spring,After reinstalling everything the oil pressure is right on now.Never figured there would be another piston in there when we removed and installed new piston and spring.Thanks for all the help that the forum gave me.Maybe this will help somebody else so they do not have to tear engine down like we did.Thank You.Don Borger

[TWChamp]

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Joe, correct me if I'm wrong (and I often am), but I thought that cam bearings have an oil groove(channel) machined on the outer diameter so that if they were misaligned on install, oil will still flow around the bearing and enter through the oil hole anyway. Like you, I installed mine making sure I lined the hole in the bearing with the hole in the engine before pushing them in. But the channel cut in what I call the "back" of the bearing is supposed to allow oil to enter and lubricate the cam even if the hole in the bearing isn't perfectly lined up to the hole in the block.

I've never had to take any of my Studebaker engines apart, but other engines I've worked on have had the full circle groove in the block where the cam bearings are installed (bearing saddles). I always place the bearing oil hole up, since the valve springs push the cam down. With the bearing hole up it get a good oil flow which is wedged into the bearing surface by the rotating cam. If the hole was at the bottom, it could be blocked by the cam being pushed down with a lot of valve spring pressure.