Newbie here, the 312 in my T-bird has very little oil pressure at hot idle. I installed an oil pressure gauge so I'm not guessing. At cold start getting high pressure around 60lbs. As it warms and is driven the oil pressure drops and at hot idle it scares me.There's little or no pressure showing on the gauge. The motor even sounds "squeekie" at hot idle. If I race the motor it moves up to about 30. Any suggestions? BTW, a new Melling Oil pump was installed awhile ago.



1957 Thunderbird 312 Fordomatic

#1 Is this something new or an on going problem?
#2 What oil are you using ?
#3 Where is the sender for the oil pressue, at the pump, or in front of the engine.?
#4 With the rocker cover off, are you getting oil to the rockes at idle ?

If the engine is high mileage, then general bearing wear is at the top of the list for the low oil pressure.  On a different train of thought, you can try tightening the flange nut at the oil pump for the inlet oil tube though as a subtle air leak at that point can affect the oil pressure greatly.

A few years back, I dealt with a freshly built 312 that also had similar oil pressure symptoms and for the short term, a high volume oil pump was installed which alleviated the low oil pressure problems at a hot idle.  That initially fixed the low oil pressure problem and added 15-20 psi of pressure to what had been there before.  In the meantime a new engine was built for the car and once that low oil pressure 312 was removed and disassembled about a year later, it was found that the crankshaft had been over-ground during the rebuild.  This created too much clearance on both the main and the rod bearings.  Re-grinding the crankshaft to the next undersize fixed that problem.

Lorena, Texas (South of Waco)

Mine does the same, as soon as its hot it falls away, shes getting on a bit and worn. I just go with thicker oil, still goes perfectly well..



"Came too close to dying to stop living now!"

Ted, you mention high volume oil pump, is one available for a 312 and where?

1957 Thunderbird 312 Fordomatic

To the best of my knowledge, there are no high-volume oil pumps for the Y available.  For that matter, even new production stock volume gerotor pumps have not been available for several years now.

To make a high volume pump for the Y, I use the 25% longer gerotor rotors from a 289/302 SBF hi-volume oil pump along with a custom machined recessed cover that compensates for the longer rotor assembly.  This combination requires the longer oil pump drive shaft from a 302/332 LYB truck engine to get that correct match up in length between the oil pump and distributor.  A full write up on what is involved in making one of these pumps is in issue #84 of the Y-Block Magazine starting on page #12.

If there is a difficulty in getting a copy of YBM #84, let me know and I’ll see if I can dig up a copy of the article.  I’ve been through a couple of computers since then so it may be gone in the original digital format.  That particular article was originally published back in 2008 and actually written some time before that.

Lorena, Texas (South of Waco)

I’ve posted the high volume oil pump article that was published in a previous issue of The Y-Block Magazine to my own web site.  Here’s the link.

http://www.eatonbalancing.com/blog/2014/09/19/hi-volume-oil-pump-for-the-y/ 

Lorena, Texas (South of Waco)

low oil presure,as a last resort if you are geting lots of oil to rockers  pinch off both return tubes, and follow the preveous advice. if this all does nothing, go to thebank and rebuild. befor you have a catistrofic  failure,especially with a 312.