Redline?

[California]

I tried to explain that in a recent PTO horsepower thread. People just don't get it.

I saw a Ford chart like this but simpler, long ago. It has always stuck in my mind as illustrating how HP (just the mathematical product of torque x rpm) eventually falls off at high rpm because torque is falling faster than rpm is rising.

Note the (*) explanation at the bottom.

Thinking of the hp/torque relationship another way, torque is twisting force while hp adds the concept of how fast that torque is being applied.

Ok, school's out.

 

[Tinhack]

I wish my 1925 Model T engine had curves like that. It barely squeezes out 20hp on a good day. :laughing:

 

[California]

I wish my 1925 Model T engine had curves like that. It barely squeezes out 20hp on a good day. :laughing:

I saw the T chart while looking for the one I posted. Here it is! (1922).

 

[Tinhack]

Yeah, I believe I have that one. Never seen one do 50mph though. I think you'd leave parts behind.

 

[California]

Yeah, I believe I have that one. Never seen one do 50mph though. I think you'd leave parts behind.

Interesting that they chickened out at 1900 rpm. :laughing:

 

[Tinhack]

LOL. Ford claimed they took some test engines to 3000rpm. But that was in a lab. Without that 75lb. flywheel, no doubt.

 

[Tchamp]

Ditto.

I tried to explain that in a recent PTO horsepower thread. People just don't get it.

That was going to be my next question. what rpm is peak hp at .

 

[California]

What rpm is peak hp at .

Looks like Yanmar wants you to run 2400 rpm for maximum available hp.

My 'impressions' in post #6 were a little off. Here's the info in YM240 [YM2000] Operation Manual, probably the closest English-language manual for your slightly smaller YM1500. Again, this is general information just to get you started and hopefully the YM1500-specific data will appear.


I posted this in an old thread discussing fast idle etc that you might want to read. Several of the best importer/dealers participated:
https://www.tractorbynet.com/forums/yanmar/87955-20-series-owners-manual-errata.html#post981950

 

[bmaverick]

LOL. Ford claimed they took some test engines to 3000rpm. But that was in a lab. Without that 75lb. flywheel, no doubt.

My YM2610 is 2,800rpms rated. Adding the 200rpms that the tach has, the tractor still can reach it with no trouble. I too adjusted the set screw on the throttle linkage not to exceed the 3,000rpm limit. I seldom even get the machine over 2,600rpm anyway.

You'll like your YM1500. Using the multi-speed PTO will in turn help keep those high RPMs a tad lower and still hit 500 to 540 PTO speed.
In the manual it states the YM1500 has a 3-speed PTO. 639, 828, 1097. You'll run the engine RPMs lower to hit 540 for each of the selections.
Our machines are real fuel sippers.

 

[California]

... I seldom even get the machine over 2,600rpm anyway. ... You'll like your YM1500.

I seldom run anywhere near maximum rpm on either tractor. The 3-cylinder YM186D occasionally, momentarily, when I'm trying to do something that I probably shouldn't.

The YM240 two-cylinder is much cruder. It sounds like its going to grenade over 1900 rpm, its painful to listen to, although these run for years at maximum in fishing boat, refrigeration, generator applications without harm. Hearing protection mandatory! With the same torque available anywhere from 1800 to 2400 rpm I very seldom push it to 2400.