Drive belts dilemma....

Last Summer I got this great idea that I'd like to convert my York AC compressor over to a rotary style from a newer model 240.

I grabbed the Ac compressor (Diesel-Kiki?) and the PS pump with the external fluid bottle (contrast to the '84's GM style pump.

The AC compressor mounted O.K. using its bracket and shanging a couple of mounting studs. The newer PS pump went in fine.

The problem is with the AC and PS drive belts.

The '84 spec with the York Ac compressor/GM-style PS pump calls for:

PS belt 13 X 1075
AC belt 13 x 925

The '86 spec with the rotary AC compressor/newer PS pump is:

PS belt 10 x 850
Ac belt 13 x 975

(alternator belts for both models is the 10 x 920. I'm O.K. there)

What should I use?

(maybe the sizes in the middle from the '93???)

Zee, I could never get it into my head how belts were measured, so to match an old tractor's drive belts to the stuff hanging on the pegs at the farm store, I devised a couple pulleys on a 1x2 stick complete with calibrations. One of the pulleys was screwed to the stick. Reason being, it seemed no two manufacturers used the same technique to designate size. I never throw away a belt unless it is shredded beyond recognition.

Could you cut the '84 PS belt, measure it and get a sense of the 1075mm nomenclature, then wrap it around the AC end of your project, mark and measure? Same for the smaller power steering belt, but maybe you could use an old alternator belt for the measurement? Be careful of the differences between pulley measurements with a fresh belt and those with a worn belt.

Last summer someone replied to a post asking how to purchase a York compresor for a pre-85 240. the replies indicated the advice to convert from tht old, noisy York to the better DK rotary AC compressor. That's how I got into this.

I was half hoping someone who had already made this upgrade would have picked up on my inquiry and offered the solutions.

So far I got the machinery into place, but nothing of the rest of the AC system installed. the PS to AC compressor pully belt I used came from the salvaged unit, but it is so tight it deflects the PS unit noticably downward. Puzzling in itself, since it was happy just a few hours earlier when I pulled it.

Like you I'll just firgure out ome way to measure the length, then shop accordingly.

Art,
Go to www.vibha.com/veebelts.html and all will be revealed !
Colin.

Most places that sell belts can come pretty close to any measurement
you bring them. Therefore take your tape measure and run it around
the pair of pulleys, write down the measurement, add about an inch or
an inch and a half to that and that is the length you want. (Do this with
the pulleys as close together as you can get them) Use whatever width seems
right for the pulleys.
--
George Downs Bartlesville, Oklahoma

Trial and error, as Bram says. You are custom fitting stuff and fortunately, there is a wide range of belts available. When you find what you want be sure to write the size down so you have it for replacement stuff.

Good luck,

dick

use whatever fits best... In the end the objective of belt sizes is fairly simple: to get a belt that's correctly tensioned in about the middle to upper half of the adjustment range.

For the AC, it'll be obvious whether or not you can slide your old 13*925 belt over the pulley and tension it correctly. If you really need that 975 I'ld expect you would be unable to pull the 925 belt onto the pulley.

For the PS, the same goes for length - if the new pump has a different bracket or pulley that requires a longer belt, the old one won't fit. As to width, if the new pump has a pulley for a 10 mm belt I wouldn't expect it to support a 13 mm belt. Your only problem might be that the crank pulley is too wide to support a 10mm belt - at least clean that groove thoroughly, a 13mm belt will have run much higher in the groove so the lower part where a 10mm would ride will probably be caked with crud and rust. If it won't support a 10mm belt, you'll also need to get an '86 crank pulley that has the correct grooves.

If you're combining new units with the old brackets, it's a bit of a gamble what size you'll end up with. Always remember, the important thing is for the belt to be correctly tensioned, use whatever size belt will let you accomplish that objective.

Bram