I have a rather old mechanical oil pressure gauge in my dash. When I started my new engine I ran it off and on for several days while making adjustments (turns out I had a bad carb). Oil pressure on an external mechanical gauge stayed at 60-80 until warmed up then dropped to around 30lbs. Not bad. Today I connected the gauge in the dash and went for a drive. I immediately noticed the oil pressure reading very low 5-0lbs when stopped. Revving the engine in neutral would bring it up a bit but not over 20. Engine is quiet and running well. Thats why I was wondering if those mechanical gauges ever go bad. I'll hook the other gauge up at the dash tomorrow and see what it reads. I figure using the same line as the current dash gauge should tell me if its in the line. Anyway, it starts and runs and shifts and all that stuff. Just have to seal up a couple exhaust flange leaks and sort out the gauges! MoonShadow Lives! 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

Congrats Chuck on rolling again, I know that its been a long project. I never had one quit reading, but I have had cheap ones spring a leak.

Glen Henderson



Freedom is not Free

Letohatchee, AL

When I connect a mechanical oil pressure gauge, I always turn the engine over to get the oil flowing through the line before connecting to the gauge. Could you have air trapped thereby giving you a false reading?

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

never thought of that..? trapped air, never seen fitting instuctions mention doing it, well there you go, i'll look into ..



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

Trapped air can be a good thing: It can help "cusion" oil pump pulsations which will tend to fatigue the inners of the pressure guage.  The air will not change the guage's ability to read oil pressure, as the air is compressed to that same pressure and will "telegraph" the correct oil pressure into the guage.

Regards,   JLB

55 Ford Crown Victoria Steel Top

Pressure is pressure whether transmitted by oil or air. You may have a bad gague. Can you plumb it into an air pressure source and cycle it with a second gague to verify it?

My plan today is to add a T at the block and install a second mechanical gauge and see what the difference is. Will post results later. 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

Ok it rained all day so make that my plan for tomorrow. 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

If the gauge checks out look at the bypass on the pump.  Might be stuck open.  Does the pressure still read high when cold?

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

Yesterday when I started the engine cold it had about 40lbs. After warming up it was hovering around the 0. The other gauge, before I removed it, was reading 60-80 cold and 20-30 hot idle. The difference is about 20lbs lower. Thats why I'm leaning towards a gauge or line problem. The oil pump is a brand new gearotor type.

Its raining again today so I'll have to wait until later to hook up both gauges. I have more  tinkering to do anyway. I have to move the wires one spot on the distributor to get more accurate timing. Its at 12deg but is also against the head bolt. Both of my 600 Holleys need rebuilt to work and I still have a pesky exhaust leak at both tailpipe flanges. I'm going to try double gaskets on them.

Its so hard to believe that with a 28x26 garage I still have to work outside! I think I need to get rid of more stuff. 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