Engine Oil Pressure Problem!

Lee ODell

When I bought my 52 Hudson Hornet there was a rebuilt 308 engine thrown in on the deal. There was someone wanting to buy the 54 engine out of my 52 for his 54 Hudson. Since I had this spare rebuilt engine I said OK. At the same time I had the 232 head replaced with a 308 head. I didn't want to have to buy 92 gasoline. While driving home after picking up the car with rebuilt engine installed the oil pressure gage was only showing 25psi. The old 54 engine had 50psi. This was just before the International Meet. The next time I started the engine the oil pressure topped to max. 15psi. I shut it down imediately. No trip to the San Metao International meet in the Hudson was very disappointing. I was already leary about driving it with only 25psi oil pressure to the meet 400 miles away. I was beginning to feel the engine swap was a big mistake and changing engines just before the meet.

I called the Hudson hot line Walt Mordenti for help and advice when we got back home from San Metao.

Now two people with a hearing problem trying to communicate on the telephone can be challenging and I suppose hurmorous for someone listing.

What did you say Walt? My hearing aid battery is beeping, Lee, I can't hear you. But we got it sorted out.

I had already added 3 washer to the oil pressure valve to see if spring was weak. Walt suggested the spring may be weak or broken. The pressure came up to 25psi immediately dropped to 20psi then up a couple pounds. Not good. Shut off engine.

First question Walt asked me. What year is the engine and is the timing chain slapper mounted on the timing cover or bolted to the block. Now the last thing I want to do is start tearing the engine apart after it has been installed in a car. The casting number is a 55 308 block with earlier crank no flywheel spacer. Nothing to do but remove the radiator, damper and timing cover to answer the last part of Walts question. Walt said there is a difference between 51-54 and 55-56 engines at the front of the block. The 55-56 engines have an extra hole to mount the timing chain slapper. The earlier engines don't have the bolt hole because the slapper is attached to the timing chain cover on 51-54 engines.

With the timing chain cover removed we found the slapper was attached to the cover and there was a empty bolt hole behind the cam gear on drivers side of block. The rebuilder had not installed a bolt in the hole. Walt said to instal a 5/16 bolt, 18 thread, 1/2in long bolt, (NO LONGER) and a lock washer and try to get it in behind the cam gear if you can without removing the gear and remove the 3 washers from the oil pressure valve. I sure didn't want to remove the cam gear to install a bolt/lock washer and chance opening another can of worms messing up cam timing. Thank goodness for my mechanic son Ricks help putting the bolt in, because with my hand tremmors there was no way I could get that bolt started. Rick, also shaved a little off end of bolt and off head of bolt to get it under cam gear. He put the cover and damper back on and I started the engine. Instant 40psi, yah ho.

Thank you Walt for sound advice and instructions to solve my engines oiling problem long distance. You made my day a happy one.

Thank you Rick for helping work on my car and the use of your shop to eliminate oiling problem.

Thank you Dany for swaping engines for me.

Lee O'Dell

Kdancy

Good info to add to my tech notes! Thanks for posting-

SuperDave

There is a small "dime size" plug in the front of the engine that is part of the oil supply for the cam. If it is removed during block cleaning and not replaced it will have the same result. (Don't ask me how I know that.)
If you suspect a leak such as this.. You can plumb an air line into the oil system and put pressure on the system. use a stethoscope to detect the "HISSSS". If the valve side covers are removed, you might even see an oil mist.

Chris Smith

When I bought my 54 I discovered it had the same low oil pressure issue. After surfing the web for possible causes, I read about the missing bolt under the timing chain. Sure enough, there was no slapper or bolts in the block. That 54 slapper/oil drain trough that is mounted to the block is appearantly a hard part to find.

Lee ODell

I edited my post error. Correction: 5/16 bolt, 1/2 long, 18 thread.
Lee O'Dell

dougson

Do people use an electronic sender for oil pressure or a mechanical/tube type. Any real difference?

GrimGreaser

I was just wondering which timing setup to use on my 56 motor... I had kinda forgot which setup came off which motor since I have both laying around the shop. Hadn't payed much attention when taking them apart, other than the different setups. Good stuff to know.

Richie

Dougson, two of my Hudsons have the mechanical gages with copper tubing, not the plastic tubing. I will soon convert the third Hudson over to the mechanical gage. My personal opinion is the light is OK but by the time it comes on, say on the highway it probably too late. I like knowing what the oil pressure is in lbs. I watch my gages(oil & temp) pretty closely. I guess the light or gage is just personal preference. Richie.

[Deleted User]

Lee, glad we keep talking and solved the problem. Glad Rick could help you install that 5/16 x1/2 inch x 18 thread with out removing the timing gear. I've done a few and just loosened the 3 bolts on the gear which just gave enough room to slip the bolt in. Walt.

Geoff

Can I have your collective wisdom on another oil pressure problem? My Jet shows a momentary drop in oil pressure when cornering left, or going uphill, if the oil level drops 1/2" below the full mark. Sits pretty well on the 40 lb mark when cruising, but the oil light will flash when going round a left hand corner, and drops to around 15lb on the gauge. Goes back up when going straight. Have tried bending the limit arm on the oil pick-up so it sits further down, disconnecting the oil filter and blocking off. Still does it. Got me beat. Fix is to keep the oil level slightly over full, but that doesn't help establish a cause.

[Deleted User]

Did you remove the screen and clean it good? Are you sure the pick up moves free, up and down.? Did you use the correct (O) ring on the pan to block pick up? The O rings they sell today will not seal good, contact Doug Wilrick for the correct one. It is square not round. Walt.

Geoff

Not sure on the O-ring, but will sure check it out next time I have the sump off. Thanks for the tip. Screen is clean, and pick up flops up and down fine.

[Deleted User]

As far as the oil light as opposed to gauge neither one is likely to be noticed in time on most cars if underway on the road. I have only had it happen to me once ,made a tight turn and oil light came on. How I noticed it I dont know as it was a bright sunny day. 73 Chrysler engine ,lifters were clicking by the time I got off the road and stopped.
I like the newer idea of a relay working of the oil switch that kills the fuel pump or ignition. Stops the car if you notice the light or not,
Roger

hornet53

Wouldn't a relay in the ignition circuit based on the oils pressure make it impossible to start?

[Deleted User]

They do , or if you did one your self you put in a by-pass button for starting. My old Catapillar forklift has such a circuit from the factory (1965)
Roger