Farmall Cub

A member of the list (I forgot who) asked me to post temperature readings for my cub since I started to run the blenedd synthetic oil in it. My test cub is a 48 that was overhauled 17 years ago and is a working tractor. It is beginning to get a little blow by and to use a little oil. Also the oil pressure when hot was beginning to get fairly low. It was about 18 pounds at full throttle and 3 pounds at idle. While this is pretty low, the old timers accepted wisdom was if you had any oil pressure when hot at idle was ok. I installed Castrol Syntec Blended 20w50. The hot oil pressure now is 25 at full throttle and 9 at idle. Blow by is almost non existant.

I worked it for about 45 minutes mowing at full throttle in 2nd. Air temperature was 90 degrees.

Coolant in top of radiator was 200
bottom casting temp was 121
bottom pipe going to engine was 135
rear of oil filter housing was 167
side of oil pan was 174
side of touch control was 128

This was my second set of readings. I had taken some earlier before I realized there was trash in the radiator. Those readings were approximately 10 degrees higher across the board except for the top of the radiator. It was approximately 200 both times.

John,

What did you measure those temperature with

Infrared thermometer from Radio Shack (22-325)
Got it on sale about 2 years ago for $30

Does your IR pyrometer have adjustable emissivity or is it fixed

Since I'm not familiar with what you are referring to, and there are no instructions for any adjustments, I assume it is fixed.

John,

Some IR pyrometers have an adjustment for emissivity. Emissivity correction is needed to get accurate measurements when using an IR pyro on different surfaces and color. A flat black surface will indicate a different temp than a bright shiney surface at the same temp.

All this doesn't mean a flip for what you're doing, the temps taken are just a reference. Sure shows that the cooling system on these old Cubs works well.

Sorry I was just bored

Donny M wrote:Does your IR pyrometer have adjustable emissivity or is it fixed

I heered once that the bestus way to get rid of that adjustable emissivity was to feed it some chocolate candy medicine. Fergot the name of it but I recall it being called Ex-sumpin.

I R pyrometer are great for finding blockage, or a injector skipping diesel engine.

Donny M wrote:John,

Some IR pyrometers have an adjustment for emissivity. Emissivity correction is needed to get accurate measurements when using an IR pyro on different surfaces and color. A flat black surface will indicate a different temp than a bright shiney surface at the same temp.

I assumed that's what you meant, but wasn't sure. The instructions tell you that if it is a reflective surface such as a shiny radiator cap to put a piece of masking tape on it and give it a little time to reach the same temperature, then read the tape.

Hi all:wink:
As for oil pressure when we were building race engines for th 67 bug one of the big race builders parts bucks said you need 10psi per 1000 rpm's any more and you were just wasting horsepower. And way too much pressure would foam the oil and wash out bearings.

On the plus side just got done cutting a 2 acre pasture. Amasing how much more power there is with new idler pullys those old worn out bearings just suck up power.

John *.?-!*cub,

Thanks for information on castrol I have allis C (sorry not cub) with same problem of low oil pressure put 20-w50 gained 3-4 lbs running hot while cutting grass.

Marc