excessive oil pressure

[barrmust]

I have a 1957 289 and it has to much oil pressure. It has 370 psi on my test guage. I have confirmed it is over 100 psi with another guage. the oil relief valve and spring have maybe 200 miles on them since new. the whole engine has only 200 miles since it was completly rebuilt. I have taken the relief valve out and it is free and not stuck. I even put it in backwards and no change. Any one have any ideas? I dont remember it having to much pressure after it was rebuilt and now it does. It has blown the o ring out of the filter housing and split the rubber line to the oil guage. The engine starts right up and is not noisy when running. Could the spring be defective? I notice the spring is slightly bent when it is out of the block. It also sits at the edge of the hole in the block when it is not compressed by the bolt. Any and all help or ideas would be great.

Russ

[MARSHALLR]

Did you check to see that there is nothing else(such as an extra plunger)in the bore? This is grasping at straws,but I did find one in my 289.Good luck, Marshall

[jackb]

I can't see the oil pump generating that kind of pressure.....BTW-where are you taking your readings from ?

[barrmust]

I am pretty sure that there is not another plunger in the bore.

I am taking the reading at the oil port on the right head at the back. I have disconected the oil pressure guage (it is stuck on 80 now) from the head and and connected the guage to it. I am using a pressure guage I use for trans work so it reads to 400 psi. As far as I know it is fairly accurate.I went out and purchased another guage that reads to 100 psi to verify my readings and as soon as the engine fires it spins the neadle around till it hits the 0 psi stop. So I have confirmed it is at least over 100psi. As i said it has blown the rubber line to the guage and pushed out the gasket on the oil filter canister (it is a partial flow set up).

So in what direction should the open end on the relief valve face? Towards the bolt or the block?

[MARSHALLR]

I can't remember which way it goes.I will look in the shop manual tomorrow. MARSHALL

[Tom Bredehoft]

Relief valve, the spring goes in one end, toward the outside, the .040 or .060 hole goes toward the crank.

[img=left]http://www.alink.com/personal/tbredehoft/Avatar1.jpg[/img=left]
Tom Bredehoft
'53 Commander Coupe (since 1959)
'55 President (6H Y6) State Sedan
....On the road, again....
'05 Legacy Ltd Wagon
All Indiana built cars

[Flashback]

Did you do the rebuild? Was this a problem immediately
after starting? Do you know what new parts were replaced?
Need to backtrack a little.

Tex in Alabama

[rkapteyn]

I WOULD SAY THAT THE PASSAGE BACK TO THE TIMING GEAR HOUSING IS PLUGGED.
BOB K.

[barrmust]

I did the rebuild. Everything was replaced. The engine had spun a rod bearing and broken a rod in half at the crank end. So crank, all rods , pistons ect were replaced. The block was tankes, .030 over, heads rebuilt, ect.

The problem stemed from a previous owner leaving out the the thick washer behind the crank timing gear. The engine had almost .100 thrust clearence. They also used a mismatched set of used rods when the put in a .010 and .030 crank in the engine. So it ended up in the engine going BOOM.

I am pretty sure that the engine had good oil pressure when first put together. the oil pressure would drop to 40-50 after getting hot. All the tolerences were on the tighter side on the bearings and thrust.

So exactly what route does the passage to the timing cover does take? Is it just a straight hole, or does it make some turns? Any idea how big the passage is? Can I push something down the hole to check for a blockage? I will try to check it out this evening.

Thanks for all the help so far.

Russ

[Chicken Hawk]

Just read of your problem. You mention that the spring is at the edge of the hole in the block when not compressed by the bolt.

The spring should be well inside the block and not at the outer edge. The spring should be about 1 5/8" long and have 14 coils.

If your spring is correct then I suspect something is inside the hole besides the plunger or else the plunger is stuck.

I suggest you get a BIG rag and hold by the hole (to keep oil from going everywhere) and have someone start the engine for about five seconds. This should blow anything out that might be there.

If the plunger comes out and nothing else, then use a stiff brush and try to clean the passage out and might use some laquer thinner or acetone or use a drill that will just fit in the hole to try and clean out any hardened sludge, etc., that might be holding the plunger from going all the way in.

Good luck.

Ted

quote:. . . It also sits at the edge of the hole in the block when it is not compressed by the bolt. Any and all help or ideas would be great.

Russ