My 312 came with the external oil lines to the rocker shafts already installed. The oil pressure switch is on the end of a tube that extends a few inches out from the block. Threaded into this tube at 90* is a valve with the oil line heading up to the rockers, so that the flow to the rockers could be shut off or reduced with the valve.



The oil pressure light is on at idle speed, and while there are plenty of potential reasons why oil pressure might actually be low, it seems to me that having the switch located on a line that leads to two relatively large openings (the oil overflow tubes at the ends of the shafts, not to mention all the rocker oil holes) might give a false low reading. Currently the valve to the rockers is wide open and there is a good stream of oil that flows out of the overflows.



I'm thinking the flow to the rockers could be reduced which should elevate the pressure reading at the switch. But how much flow is enough?

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

How much is enough? I don't know, but first you need to find out if there is an overall low pressure problem. So, with the valve covers off, does there appear to be reasonable oil flow at the rockers? If they are generally wet with oil, & it's flowing, close that valve completely for a minute or two & see if the oil light goes off at idle. Then report back...

Paul

Ok, I'll check that in the next day or two and report back!

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

I think the best place to test oil pressure is on the driver side of the block towards the front where the original oil pressure sender screwed in. Its just behind the block breather. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Moonshadow, my 55 292 came (to me) with the oil pressure sender located just rear of the oil filter, right above the oil pump. Is this the wrong location? If it doesn't matter a whole lot I will leave it there because i have already cut the sender wires to fit that location.



Mark

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

So: I removed the valve covers and was surprised to find that there was not a steady flow out of the overflows as I had previously observed. I installed a new oil pressure switch just a few days ago and had noticed that around the same time there seemed to be more valvetrain noise than usual. Anyway, I closed the external oiler valve and observed no change: the oil light would come on, flicker off, flicker, come on steady, etc. Then I reopened the valve and lo and behold, there is oil coming out the overflows again and the oil pressure light is off for good. Also the valvetrain was a bit quieter.



I believe there was some sort of debris in the passage restricting flow to the rockers and the pressure switch alike. Whether that debris was petroleum-based and dissolved or has simply moved on to the rocker shaft, my plan is to remove and thoroughly clean the rocker shafts to ensure the oil is going to every hole it should up there.

1954 Crestline Victoria 312 4-bbl, 3-speed overdrive

I'm definately not an expert on the Y but I don't recall seeing any oil senders in the back. All I've seen were in the front. I'm sure someone will prove me wrong. It probably makes little difference. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Looking through the "Mercury Repair and Adjustment Manual - 1954" and the "Ford Y-Block" book, all photos and diagrams that I found show the oil sending unit to the rear (right) of the oil filter. That's where it is on my '57 312. However I do have a question. On the left side of the engine there are three other small plugs. One is between the fuel pump and the breather pipe, one is just below the block drain petcock, one is about 3" left of the oil filter, and the fourth is to the right of the oil filter (sending unit goes here). My question is - are all of these oil channels and can any one of them be used for an oil sending unit? The oil gauge on my '54 Merc works OK, but I may want to put a second oil pressure gauge just for safety's sake and I am wondering if I could use one of the other ports.

When Injustice Becomes Law, Resistance Becomes Duty

The oil galley runs in a straight line from rear to front. So any screw in plugs on that line are into the oil passage. I think the front is as far away from the pump as you can get so you would be reading the oil pressure at that point. I really don't know if it makes any difference. My 57 (back in 59) had the sending unit towards the front. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

I've had my sender at the very front since I can remember and the indicated pressure has always been lower than I expected but still reasonable. I've wondered if placing it closer to the filter will make a difference but haven't tried it.

The hole at the very front corresponds with the front main so it makes sense that some pressure will have been lost by then because of the passages to the other 4 mains.


Lawrenceville, GA