The Stovebolt Site Forums The Shop Area Engine Shop Oil Pressure gauge (newly rebuilt 216)

So I was running my newly rebuilt 216 on my garage built engine stand, I hooked up an ammeter, voltmeter temperature gauge and an oil pressure gauge. All the gauges worked except the oil pressure. I have good oil to the rockers, but the gage doesn't move, I cracked the line to bleed out the air in the line, switched gauges, and still no movement. I disconnected the line going into the oil filter and hooked it to the gauge, still nothing, but oil would come out the fitting on the canister like it was being pushed out from the bottom of the canister and out the intake. I have the input to the canister connected to the port from the oil galley.This is the rearmost port. I am wondering if the tee fitting may be wrong or the size of the oil lines. I am using 1/4 " steel brake lines to hook this up and standard brass fittings from Home Depot to connect to the canister. Generally just hooking it up like I have for years.

What have I got wrong?

216's aren't famous for lots of oil pressure, but it everything is assembled properly and the pump is good. you should see 15-20 pounds of oil pressure at idle on a cold start. Sometimes the pressure will drop considerably once the engine warms up. Have you tried running the pressure gauge directly to the oil gallery without the filter connected? Try removing the distributor and spinning the oil pump clockwise with a 1/2" drill motor, using a cut-off blade from a large straight bladed screwdriver. There should be a noticeable torque load on the drill, and the oil pressure on the gauge should rise. Are you using an original-style oil filter such as a Fram or an AC? Later type spin-on filters need a restrictor incorporated into the circuit somewhere to prevent a major loss of oil pressure to the engine.

Oil flow from the valve train should indicate that the lower end of the engine is getting at least 15 PSI of oil pressure- - - -that's the point where the oil distributor down by the driver's side oil pan rail opens up and starts oil flowing to the rocker arms.
Jerry

Yes, connected directly to the galley and then to the gauge. Good oil flow to the rocker shaft. When doing this, oil poured out the open end of the canister

Here is a clip of the oil to the rockers www.youtube.com/watch?v=8KbrN3gr4cY

Of course it did- - - - -the inlet to the canister is near the middle, and the canister fills all the way to the top while the engine is running. Gravity is going to let it drain until the oil level in the canister reaches the inlet fitting. If this is a newly-built engine that's been assembled properly, you've either got a bad oil pump or there's a major pressure leak somewhere. I'd start by checking the relief valve in the pump to see if it's jammed in the open position. It's time to at least drop the oil pan and look for obvious problems, or turn the pump without running the engine and try to figure out where the oil is going. The engine is probably salvageable now- - - - -if you keep running it with low/no oil pressure, it won't survive very long.
Jerry

Nice video

Did not see the oil connection to gauge?

Let's see the gauge. 30lb or 100lb? or ??????? What W oil are you using?
I am not a 216 guy, but in all looks a little on the dry side to me. A rebuilt motor is pretty tight.

I couldn't see any oil pressure on my 216 with the 80psi short sweep gauge that was in it, so I bought a SW 0-30psi full sweep fuel pressure gauge. Works great with an easy to read 15-20psi cold, and 5-7psi hot.

Ditto on using a 0-30 PSI gauge. Even if it pegs out on a cold start, it won't stay there long. Being able to monitor the low reading is much more important than avoiding maxing out the gauge on a cold start.
Jerry

Yes, if you happen to be using a large-max reading gauge with a short sweep, 10 lb will barely register. If you are using a 30lb then it's 1/3 the sweep. Was just wondering about that. Hot Rod Jerry can tell you about:
1. Viscosity vs pressure
2. New rebuilt motor fits vs pressure
3. Pressure after break in
4. He has already said don't expect much pressure. These motors are called low pressure
5. Does he think the video shows normal flow or on the dry side?

MikeE: Do you know what pressure you had, on that same gauge, before rebuild?
Are there babbitt bearings? Who did them? Did they have the "knowhow"?

I'm not seeing enough oil flow to the rocker arms, although it's probably going to increase at cruise RPM. The engine also sounds too noisy, like somebody is using some sort of water-thin oil like 5W-30 or similar instead of something with enough physical thickness to provide a cushion between the moving parts. These old engines just weren't built with the sort of tight tolerances that make ridiculously thin lubricants necessary. What was considered to be "normal" oil clearance in a brand new engine 50 years ago would be considered to be "worn out" on one that rolls off an assembly line today. In my decidedly biased opinion, anything thinner than 15W-40 oil is too thin! Those thin, high-flow oils will prevent proper oil pressure from building up to anywhere near "normal" on an old stovebolt, and the engine will sound like it's beating itself to pieces (because it is!)!
Jerry

I have several gauges, none less than 75 LBS. And all from my pile of parts. I will track down a low pressure one and see what I get. This is on my test stand and I used what I could find. No idea what pressure it had before, using 10w - 30, and just re plumbed the lines to the filter and the gauge using 3/16 steel lines. These connect to the plastic line going into the gauge

Be sure your oil pressure gauge line is on the "upstream" side of the line to the filter, the one that's attached to the gallery in the side of the block that's about 4 inches above the oil pan rail. It will be slightly above and ahead of the coolant drain petcock . The oil port down low just above the oil pan rail is the "output" line for the filter, and it carries the reduced pressure downstream of the oil distributor on the way to the rocker arms on a spray-oiler engine. If you attach the pressure gauge line to that port, you'll get virtually no reading.
Jerry

That is how I have it.

Hi Mike
I just joined... and don't want to step on any toes... but I've been running Chev 6's doing the for jobs they were designed for, for a lot of years. And I've driven them flat out and fully loaded with splash oiled 2 tons and pressure oiled 3 tons. In all those years I've never worn one out to the point of needing an overhaul.

Having said that... the old splash oilers were designed to use Nothing Heavier than SAE 20 at the hot end until ambient temperatures were over 90 degrees... and we never did. Anything heavier than 10w-30 is way to heavy to spray out of the oil nozzles and hit the rod dippers the way it is supposed to.

Tolerances in the old splash oilers were actually Tighter than the pressure jobs. Rods for example run as close as .0005", and should never be more than .0015" clearance. Check the factory specs if you don't believe me.

Now as to your oil pressure problem... with cold oil, even with something like a 5w-20, you should be seeing something around at least 20 pounds at start up, and about 14 pounds warmed up and around 2000 rpm.

If you don't, and you have oil at the top end as your video suggests, then the first place I'd look is at the metering valve on the left side of the block. Due to the design, splash oilers Will Not develop oil pressure unless the metering valve is working. In fact, the sole purpose of the metering valve was to develop pressure to show on the gauge, and pressurize the mains and cam bearings 1935 and after, and metered pressure to the rocker arm shaft 1940 and later. All main and cam bearings were pressurized by 1932, and the rods oiled by pressure stream 1935 and after, with the top end oiled with metered pressure by 1940.

The supply to the rods runs under essentially 0 pressure flow from the down stream side of the metering valve and has no bearing on the pressure registered on the gauge at all.

Check for a bad spring or the valve stuck open. Also check for the right gaskets on the right sides of the valve. The inner and outer gasket are not the same.

And the metering valve is the easiest thing to get at too!

Interestingly, the 1929 engine ran 0 pressure to any part of the engine. The metering valve did nothing but develop enough pressure to show on the gauge so the driver knew the pump was working.
Good luck! Hope you find the problem!
Ole

I'd strongly recommend checking the relief valve in the base of the oil pump, then.
Jerry

Is it possible you left the oil distributor valve out.
Read this Chevrolet article.

I am sure I have it in there.

Does anyone but me bother to test an oil pump for volume and pressure before they install it? Probably not! All it takes is a bucket of oil, a couple of braided high pressure hoses, a few fittings, and a pressure gauge, plus a 1/2" drill motor.
Jerry

OK, here is what I am doing. I have ordered a 1-30 lbs. gauge, and found a nos distributor valve on e-bay. Both due in this week. Also, I did not replace the mains or cam bearings on this engine. All the clearances were .0020 on the mains and rods. On the video, no valve adjustment has been done since the initial start up, so that may explain some of the noise and the exhaust is a sketchy set up right now. I am going out to check the spring on the valve and insure it is free and working .

I'm working on a couple of possible solutions to the chronic "low oil pressure" problems of spray-oiler engines. With a little creative plumbing, it looks like the Melling M-45 oil pump intended for the full pressure 235's and 261's can be adapted to the 216's and spray-oiler 235's. The gears in those pumps are taller, and they will move a higher volume of oil. The reason oil pressure gets low, especially in an engine with a lot of miles on it, is the fact that lube oil leaks out of a bearing with extra clearance faster than the pump can replenish it. The gears on the 216 pump are so short that once the main bearings and cam bearings get worn somewhat, the pump just can't keep up with the demand for oil, so the pressure drops.

Another approach would be to adapt the engine for a newer, higher volume pump. I'm working on an adapter that will mount a Melling M-55 pump for a small block V8 to a stovebolt engine. The M-55 has even taller gears than the M-45, but it also would need some machining on the pump housing to fit the adapter properly. I did some research last night and it looks like a pump for a 230/250/292 6 cylinder would be easier to adapt to the earlier sixes. Any of the above pumps should be able to supply 20+ PSI oil to a 216- - - - -AT HOT IDLE! Stay tuned for more developments!
Jerry