J-(Chicago)

Friend of mine brought over an olds 350 engine. He's not sure if it was a runner or not. Bought it at a swap meet. I Put my oil pressure gauge into it and primed it with my drill. 90 psi cold pressure.

Thought my gauge may have been wrong, put a different one on. Same thing. It isn't leaking past the oil filter gasket though, and seems to be holding fine.

He said he put a new oil pump in it. Stock replacement. not the high volume unit.
I pulled the valve covers off, and the rockers are getting oil. albeit, not very much.
Odd that a stock replacement pump would make that kind of pressure.

coppercutlass

Would blockage create higher oil psi. ? When I prelubed my current running 355. I took me honestly like 10 minutes to get oil to the top half. During that time I was seeing oil pressure over 60 psi around 70 but once it fired up it sat right where it needed which I found weird but I didn't make much of it since the psi never changed after.

MDchanic

Blockage would not make the pressure higher unless the blockage was at the relief valve.

What weight oil is in this thing?

- Eric

J-(Chicago)

I'm going to start with the oil and filter. The oil seems really thick like straight 30 or 20-50.

Oil could also be thickened by soot or rust. Viscosity could be too high resulting in poor flow.
Don't put chainsaw bar oil or "motor honey" in the crankcase.
Filter could have blockage, and/or a shoddy By-pass valve.

Deposits in oil gallery system could cause increased back pressure as well i would imagine. Or could just be the pump seat is a tough cookie.

J-(Chicago)

Update: 5w30 and new k+n oil filter. Gauge still pegs above 80 with my electric drill. Both gallery plugs are oiling. I pulled the water pump bolt in front of the gallery squirter, and oil will come out of the hole. Flashlight down the distributor hole shows the distributor squirter oiling a nice steady shot onto where the gear would be. Oil filter adapter checked out fine.

I'm guessing the pump is not bypassing soon enough.

J-(Chicago)

What do you think? Run it on the engine test stand and see if I can blow the filter off or not? The motor was only 200 bucks.

My neighbor used to have an old 80's escort that would go to around 100psi when cold, but would drop to 40 once warmed up.

MDchanic

You may find that the bypass valve unsticks once it warms up. I'd probably do it, though if it's on a stand, it's just as easy to pull the pump and look at it.

- Eric

J-(Chicago)

Wise words. Doesn't sound as fun though. I'll ask him what he wants to do tomorrow.

ThePackRat

When I was like 5-6 years old (1976/7) my father took me along while he looked at & drove a white & saddle 64 Riviera.

He ended up buying it.

It soon became obvious that the car did not take kindly to oil filters ... & would violently launch them at will.



One day out of the clear blue sky I say to him :

What happened to those gold stripes that were on the side of the roof ?.

Him - what gold stripes ?.

Me - there were gold stripes on here before you bought it ... I remember them from the test drive.

Him - I don't remember there being any stripes on here.

Me - there was - I am sure of it.

Him - hmmmmm ?.

Within the next couple of days he went back to the local realtor that sold him the car ...

And sitting there in the lot is another white & saddle 64 Riviera with gold stripes on the side of the roof.

As it turned out .....

Dad got the ole' "switcharoo" pulled on him.

The striped Rivi was indeed the one we took the test drive in & was the one being advertised for sale.

He ended up taking pix of the 2nd Rivi that clearly showed the stripes & successfully took the guy to court.

Whether he got the money back for what he paid for the car or whether it was the estimated costs to yank the motor to go in & make things right I can't recall ... but he won.

Not bad detective work for a lil' clueless kid at the time I guess.

Should have had my hand out the day that case was settled.

J-(Chicago)

NICE work, detective. From then til now with the Rallye.

ThePackRat

That would be the other packrat.

J-(Chicago)

Haha. My mistake. Apologies.

J-(Chicago)

I checked out a pump I have here in the basement, and anything under 3/8 of an inch shim shouldn't block the bypass. I put a K&N high pressure filter on it and ran it. Eric, you were correct, once I warmed it up pressure went down to 30 psi at idle and almost 85 at 4000 throttle. Seems it was just a little gummed up from sitting.

Smitty275

If the engine isn't running the lifters aren't moving and thus only a few of them will pass very much oil. Since the crank isn't turning you have no oil wedges being formed which causes oil to actually flow through and around the bearings. Also many of the feed holes to the rods are flat out blocked. That's why you have such high oil pressure with a drill motor and yet it can be normal once its fired up. All you doing when you prime with a drill motor is verifying that the oil pump works, the filter is on, and that there is oil everywhere up to the oil pressure sensor. It is not a way to gauge the condition of the engine.