Oil cooler blockage a possibility? 1935 50-series

[Pete Phillips]

Working on a gorgeous little 56-S coupe from 1935. Does not seem to be oiling properly in the oil filter cannister nor in the top of the engine. Gauge shows little to no oil pressure. Engine has been rebuilt recently and sounds okay when run. Am wondering if the oil passages through the external oil temperature regulator (the little box on side of engine that supposedly cools the oil by running engine coolant over it like a small radiator) could be blocked? Has anyone with a '31-'35 straight engine ever experienced that? Is it prone to happening on these engines? Or is the oil pump just losing its prime?

Pete Phillips, BCA #7338

Leonard, Tx.

[Guest buicker]

Working on a gorgeous little 56-S coupe from 1935. Does not seem to be oiling properly in the oil filter cannister nor in the top of the engine. Gauge shows little to no oil pressure. Engine has been rebuilt recently and sounds okay when run. Am wondering if the oil passages through the external oil temperature regulator (the little box on side of engine that supposedly cools the oil by running engine coolant over it like a small radiator) could be blocked? Has anyone with a '31-'35 straight engine ever experienced that? Is it prone to happening on these engines? Or is the oil pump just losing its prime?

Pete Phillips, BCA #7338

Leonard, Tx.

What is the pressure when first start it up,

[Mark Shaw]

Pete,

I suspect the small orafice in the tube leading to the rocker assy may be plugged. That tube also is just an interference fit where it goes into the top of the head. That joint could also be loose and leaking pressure. You might try removing the top end of the tube and cranking the engine to see if you get flow and pressure. If you don't find the problem, I suggest you make a jumper tube to bypass the oil cooler and re-test to eliminate that component. Do this last because the oil cooler usually just leaks coolant and does not block oil flow. Most I have seen (including mine) have the cooler bypassed.

[Pete Phillips]

The car doesn't show any oil pressure when running. I pulled the oil pan and the oil pump today, and it seems that the plunger or piston or whatever you call it in the oil pump is getting stuck or gummed up and not dropping down as it should to let oil in or out. I cleaned out the gum, made new gaskets for the oil pump, and am going to try to reinstall and run the engine with that. Checked the step-down orifice at the back of the rocker assembly, and it was not blocked.

Pete Phillips

[Pete Phillips]

Still no oil pressure. I can spin the oil pump with a drill and it puts out all sorts of oil. But nothing is getting to the top of the engine, not even to the tubes coming into or out of the cylinder head. There is a plug in side of engine just below oil pump, and nothing comes out of it when opened. I think the oil filter plumbing is not correctly hooked up. One tube on bottom of filter housing runs up to upper rear of engine (and nothing comes out). The other tube runs from near top of filter housing to bottom of filter housing. I suspect this is wrong. Will try to attach photos. I am at my wit's end with this oiling problem. Does anyone have a photo of a similar engine that they could post, so I can compare exterior oil lines? 1935 50-series.

Notice the plug in lower side of engine in the second photo, just above the coolant hose in the photo. Seems to me that should have an oil tube attached, but nothing comes out of it when I remove the plug.

Pete Phillips, BCA #7338

[Pete Phillips]

Took the oil cooler apart, and it was indeed blocked--intentionally! Someone blocked off both incoming and outgoing oil tubes from the oil pump to the oil cooler. This photo is out of focus, but that is solid brass or bronze across the end of the feeder tube--solid! Been brazed in there! The oil had no place to go! No by-pass across the oil cooler. Both tubes are the same--blocked at one end and open at the other.

Pete Phillips, BCA #7338