At what RPM do you get maximum oil pressure. I want to do an oil pressure test on my 312.

Thanks


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

No kind of spec on this?  I want to see if the pump is putting out too much pressure

How about max pressure - what should it be?


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

my 292 shows 55psi at1600rpm hot with 5-30 oil, at idel25psi. cold at 1500 70psi. engine has lots of miles with no oil leaks(pan was off with repairs to oil pickup tube,pump is gear type. the guage is mechanical

Paul.  I've seen the FoMoCo oil pump pressure and r.p.m. information somewhere.  I'll be darned if I can remember where let alone put my hands on it where I've looked.  I checked my Ford Repair Manuals and found nothing.  My vintage Motors Manual indicates 50 p.s.i. for the y-blocks, BUT gives no indication of engine speed.

In the back of my head, I'm vaguely remembering 50 psi at 50 mph vehicle in final drive.  I'm also remembering seeing higher readings when I was using single weight engine oil and the oil was less viscous when cold.

As Cliff indicated, oil pressure reading is lower at engine idle in an engine at normal operating temperature.

Back in the day, increased tension oil pump pressure relief valve springs were marketed or shims to use with the existing oil pressure relief valve spring to increase the oil pump's output pressure.  I remember reading somewhere a caution about increasing the relief valve spring pressure too much, causing 'washing' (eroding} of the engine bearings.

Sorry to have been unable to come-up with concrete info. for you.     


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

I got carried away way back in the day and over shimmed the relief spring. Promptly blew the gasket out of the spin on filter. Took some shims out and was fine. Got the pressure up a bit and the engine lived for a while longer until my then wife put a rod through the side of the block. Still have the rod hanging above my work bench.

From the General Specifications section in the 1957 Ford Car Service Manual,
 

 
Before I converted my racing Y in the altered roadster to a dry sump oil system, I would see in excess of 95 psi cold at 2000 rpms using a shimmed spring gerotor pump.  Hot oil would put it at in the 35 psi range at the same 2000 rpms.  Besides general bearing clearances within the engine, the viscosity and temperature of the oil are major players when it comes to oil pressure attributes.

Lorena, Texas (South of Waco)

Thank  you all.  I am worried about too much oil pressure than too little as I can't keep a rear main seal from leaking.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

The other thing with too much oil pressure is that you can actually wipe the bearings and end up with damage.

Paul.  I don't see a relationship between your engine's oil pressure and the rear seal leaking.  Yes, the rear main bearing is pressurized, but on the '56 there's an oil slinger on the crank between the rear main and the rear seal area.

Some time ago I wrote about an acquaintance who had three (3) new neoprene rear seals installed before resorting to a BEST Brand rope seal.  The engine was a 312 complete rebuild with rear seals 2, 3, (neoprene) and 4 (rope type) installed by a retired Ford mechanic who knows y-blocks.  The first neoprene rear seal was done by the machine shop.

What is your history on this rear seal problem?


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

No Shortcuts:
History

I bought the Tbird in 2006.  It was a running car.  I got only very small amount of drips.  Did not have to touch engine except for maintenance items.  OIl consumption was very little.  Block was later replacement block, B9A if I remember correctly.  Car originally was a Fordo, now has a C-4.

Drove the car to Oregon from NJ and back in 2008., used only two or,three quarts of oil for whole trip.  Old seal was still in the car.

In 2010 I decided to do a full restoration.  While it was being worked on, I decided to replace the rear main seal and the oil pump while cleaning up the engine.  Used a "rubber" seal, offset the ends and used silicone sealant in all the places that I read about here. Finished the resto in 2012. Used an aftermarket (aluminum) seal retainer which didn't fit correctly and I had to grind it some to clear the main cap..  It seemed to work ok and made another trip to the west coast in 2013.  About half way here it started to drip oil.  At the end of the trip it was using quite a bit.  That winter (2013/2014) replaced the seal with  another rubber/neophrene seal recommended by Ted (Best Gasket) and carefully matched the retainer to the crank.  Both times we looked at the plug at the back for leakage and it seemed to be okay.  Used silicone sealer in all the usual places.

The car started to leak again during  a trip to Springfield , MO in 2014 and got worse in a trip to Pittsburg, PA in 2015 so in 2015/16 decided to replace it with the new Best gasket rope seal.  Bought a OEM retainer and used that.  It started to leak almost right away.  Crank was removed the last two times that the seal was replaced.to make sure everything went in ok.

I'm at wits end.  I can still use the car locally but can't imagine using it at high speeds for out of state trips (want to go to Tennessee in 2017).  Not sure what to do.  I recently bought a mechanical oil pressure gauge and check pressure.  Cold, it's 60 idle, 75 at 2000.  Hot, its 30-35 at idle, 60 at 2000/2500

The same guy that helped me did another rope seal (Best)on another 56 312 and he has no problems with it (recently returned from another trip to the west coast).

When the crank was taken out, bearing and crank surfaces looked good and bearings were not replaced. Crank end play was checked and was in spec.

Because you can't see up there, not sure just what is leaking - side seals, crank seal, maybe even the cam plug.

Any suggestions?  I should have listened to the old saying, leave good enough alone.  I have an extra 312 (57 block) and am seriously thinking of having that rebuilt (short block) to solve the problem.  This engine runs really good and I get good gas mileage and hate to replace it but the oil problem is driving me nuts.

Thanks




54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ