F 12 farmall question

bumblebee · Jun 25, 2015

Does anyone know how to determine if the valve springs are the strength they should be. I was hoping that there was a way to check them without removing them from the engine. There are two lengths of springs listed for the F 12. Mine is a 1934 model
so does anyone know the length it should have? Thanks for your advice.

Steve@Advance · Jun 25, 2015

Curious as to where this is going...Is there a reason to believe they are wrong or bad? A running problem?

Nothing scientific, just pry down on them, feel for a difference, look for a broken coil. Unless one feels drastically different, odds are they are ok, or good enough for the low RPM the old motors turn. If there is a valve failing to close, and the spring appears good, it's probably a bent or rusty valve stem.

T.R.K. · Jun 26, 2015

Well, actually there is a specificaton for those valve springs, if only we knew how to look it up now. And had the equipment to test them.

For the Small Block Chevy back in its day and depending on which spring on which head it was measured as a certain pressure at a certain length. I remember checking the valve springs on an engine I built in the Auto Mechanics shop at the technical college.

The tester used a beam type torque wrench for leverage and there was a chart that converted the pounds of pressure exerted by the spring at the specified length of spring.

For you, I don't know of any way to test the springs on the tractor. I have heard of forcing a wedge or spacer under a questionable spring to see if it helped the valve function on that particular cylinder.

I recall one of the last tractor engines I built, with all the springs on a table side by side you could see 4 or so that weren't as tall as the others. I replaced them.

F 12 farmall question

bumblebee

Well-known Member

Steve@Advance

Well-known Member

T.R.K.

Well-known Member

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