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youtube.com/5Tractorguy
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Discussion Starter #1
I had a quick question about model "L" pto and engine speed, wondering if any one had answers.
What is the ratio, engine speed to pto speed, (just the pto shaft alone without any attachments bolted to the tractor). What is the pto speed from the engine speed, half, 1/3, 3/4?

:thanku:
 

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It's on the 2nd or 3rd page in the service manuals from the '50s and '60s. It doesn't actually give a ratio, but it gives a table of engine/ground/pto speeds. You can calculate the ratio if needed.
 

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youtube.com/5Tractorguy
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Discussion Starter #3
Thanks John! I had looked at that chart before I posted the question, looking over the ground and engine speed. For some reason I didn't see the PTO RPM to the right side. Darn! :fing20:
Now I can figure it out.....
 

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youtube.com/5Tractorguy
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Discussion Starter #4
Well here's what I came up with... asked the question, mind as well answer it. From using the chart in the service manual-

HIGH RANGE
Engine speed-1364- PTO Speed-682- Ratio-2:1- or PTO is half the speed of the engine.

LOW RANGE
Engine Speed-946- PTO Speed-341- Ratio-2:3/8

The Hi Range was easy to figure out, half of 1364 is 682. 2:1

Low Range (rounding decimals), I took 946 engine RPM/2=473 473/2=236 236/2=118 118+236=354 -close to 341 PTO speed.

On a ruler... 946=1" 473=1/2" 236=1/4" 118=1/8". 1/8+1/4=3/8 or 118+236=354

Odd way of figuring it out, but I think it's fairly close.

The reason to why I asked this question is because I have another tractor project in mind. It still has a lot of thought to go through to see if it will work, but if all goes well, you all should be seeing it sometime this winter/spring.
 

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No problem. I've spent a while studying those manuals haha. And, I get to do all sorts of crazy calculations in some of my courses.

Low range should be 2.774:1 engine to PTO. 947/346 = 2.774.

I wanted to run a driveshaft off the front of the PTO for a FWA pulling tractor (1/4 scale club at my school) but I wasn't sure if the clutches would hold up. We ended up going with a CVT for next year's tractor. Weight is another big concern since we're limited to 850 pounds, I believe. I'll be curious to see what your project is :fing32:
 

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youtube.com/5Tractorguy
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Discussion Starter #6
Low range should be 2.774:1 engine to PTO. 947/346 = 2.774.

I'll be curious to see what your project is :fing32:
That's what I had for a decimal too. But for what I'm attempting to build, I needed a fraction, so I figure that 2:3/8 is about as close as I'm going to get before it get's too complicated. Trying to keep it simple, or at least so I can understand it.

It'll be a goodun'. I just hope I have all the stuff/parts to do it...
 

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Gravely Model L Guy
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i have not even started on my "project" yet :banghead3
 

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I have G.A.S.
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My PTO driven, 200 amp, DC welder needs 6000 rpm minimum. I have no problem getting 10,000 RPM. The welder doesn't care what the RPM is, as long as it's above 6000. No difference in the welds between 6000 & 10,000. An L struggles under the load, my PRO 16 has no issues at all.



 

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Old Iron Connoisseur
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My PTO driven, 200 amp, DC welder needs 6000 rpm minimum. I have no problem getting 10,000 RPM. The welder doesn't care what the RPM is, as long as it's above 6000. No difference in the welds between 6000 & 10,000. An L struggles under the load, my PRO 16 has no issues at all.



More pictures please or a link to a thread I may have missed on this attachment!
 
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