Running engines at half throttle??

[NSMaple1]

With the exception of my 3200w generator, all of my splash-lubed, air-cooled, 4-cycle engines have variable throttle settings. I set them to the RPMs that match the load I am putting on them, and also take into account how fast I am wanting to or able to work. I run my splitter at full throttle to match the wood it's splitting, not how fast I can go - even at half throttle, it's usually waiting for me, rather than the other way around. Never any engine issues. Even on the many B&S powered 2" water pumps we've had over the years - run the trottle up some filling, less than half emptying. They have pumped millions of gallons over the years

Should bring this up at the go-cart rental track sometime. That would be fun watching the first-timers through the turns...

 

[Whitespider]

...I dunno how they set a genny for 50HZ (where they use that)...surely they don't slow the engine down to 3000...

That's not the got'cha you think it is... nearly all engine manufactures make "special purpose" models for such applications.
The 24 HP Kohler on my lawn tractor runs at 3300 maximum RPM... that's the specification... by design, that's where that particular engine develops maximum HP and torque... 3300 RPM is full throttle on that model... the engine is designed to run full throttle.
The Briggs on dad's old pressure washer runs at 3060 maximum RPM... that's the specification... by design, that's where that particular engine develops maximum HP and torque... 3060 RPM is full throttle on that model... the engine is designed to run full throttle.
Many engines on new push lawn mowers are designed to run at 3200 RPM... necessary to comply with blade tip speed and projectile safety laws.
3600 RPMs is the basic (actually because of the 60HZ deal)... but it ain't a law... and you can buy special purpose engines designed to run as slow as 2000 RPM maximum specification.
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[Mad Professor]

If you have older equipment it was designed to run slow rpm. A farmer I worked for would slap you up the head if you revved his tractor, tillers, garden tractors.

I can concur with this. If it bogs I use a lower gear.

I have a 1940 ford 9N, 1972 Ford 2000 gas, 1973 Ford lgt 145 (k321 motor) and 1972 troy built horse tiller (tecumseh H60). They all have original internals except the 9N, it had a valve job. None even smoke, knock or use oil. And they get worked every year, with regular oil changes, filters, and upkeep.

Chainsaws and newer stuff built overseas are a different story.

P.S. my uncle had an old chevy 6 that seldom went over 50 mph, it had over 300,000 on it when he scrapped it due to body rot.

 

[c5rulz]

Ha‼
My log splitter has an auto-throttle control; it goes to full throttle whenever the ram is moving (when the engine is on-load), and automatically goes to idle when the ram is not moving (when the engine is off-load).

S0unds like a great feature.

So, isn't your splitter then running at less than full throttle most of the time???????????

 

[NSMaple1]

Actually, come to think of it, my generator doesn't always run at full throttle either. It's an inverter genny - if it has a light load, it throttles itself back. A great fuel saving feature.

 

[Whitespider]

So, isn't your splitter then running at less than full throttle most of the time???????????

No... it runs at full throttle most of the time.
It has a hands-free auto-cycle... a nine second cycle time.
You place a round on it, throw the lever forward, and turn to grab the next round... the round has been split and the ram is on the return stroke by the time you have the next round ready. It's just a matter of dropping it on the beam and throwing the lever again... often before it even finishes the return stroke (which would be before the engine idles down). Even if it don't go that smooth it's still a 9:1 or 9:2 ratio... 9 seconds at full throttle while the ram is moving, and 1 or 2 at idle while the next round is positioned.
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[Whitespider]

Actually... I misspoke... sorry...
The length of the ram stoke is adjustable... so if you're splitting 16 inch long firewood you set the stroke length to 17 inches or so.
Meaning... the cycle time is shortened to about 5 or 6 seconds... so it would be a 6:1 or 6:2 ratio.
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[alleyyooper]

Boy glad I wear boots so I don't get all the **** spread here on my legs.
Any one hear of a machine called a snowmobile? Early ones were fan cooled and you could not run them wide open throttle on trails because it just was not safe. A little later they came out with free air machines those also were not always ran wide open even if you were racing ovals you had to slow for the corners.

There is two free air Polaris TX machines in this picture, one liquid cooled Polaris TXL and a Fan cooled Mercury, all were/are 2 strokes too. My Mercury ran heat gauges, Never varied from a 30 below day to a 30 above day, trail riding or racing it.





Oh I can hear it now ya that is in the snowy cold. So how do you explain the 2 stroke free air motor cycles ran part throttle on roads and trails? You don't even run your car or truck WFO on the roads.
I run my engines to meet the job/load required to get the job done.

Al

 

[Whitespider]

Oh I can hear it now ya that is in the snowy cold. So how do you explain the 2 stroke free air motor cycles ran part throttle on roads and trails? You don't even run your car or truck WFO on the roads.

Apples and oranges cannot be compared...
We ain't talkin' about 2-cycle snowmobile engines...
We ain't talkin' about large, multi-cylinder, pressure-lubed, liquid-cooled automotive engines...
We're talkin' about small (typically single cylinder and less than 15 HP), splash-lubed, air-cooled, 4-cycle engines.
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[Sawyer Rob]

We're talkin' about small (typically single cylinder and less than 15 HP), splash-lubed, air-cooled, 4-cycle engines.

Then we are talking about the thousands and thousands of 4 cycle "inverter" gen set motors, mine is splash lubed and I can't remember the last time it revved to WOT!

Mostly it just sits there running for hours on end just above an idle to half throttle...

Hasn't hurt it one bit and it uses a lot less gas with lighter loads on it.

It's been doing this every time I use it, for all the years I've owned it...

SR

 

[ckr74]

I run my engines to meet the job/load required to get the job done.

Exactly. I've been around small engines for a long and even had my own repair service. Small engines will run a long time if taken care of. I do agree that 2 strokes need to be run wide open under any type of load.

 

[c5rulz]

Apples and oranges cannot be compared...
We ain't talkin' about 2-cycle snowmobile engines...
We ain't talkin' about large, multi-cylinder, pressure-lubed, liquid-cooled automotive engines...
We're talkin' about small (typically single cylinder and less than 15 HP), splash-lubed, air-cooled, 4-cycle engines.
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Granted apples to oranges.

But the fan cooled snowmobile engine should be much more sensitive to engine RPM in regards to cooling.

FWIW, I took a lazer temp indicator and got around 160 degrees on the crankcase of my splitter after an extended run at 3/4 throttle.

 

[GVS]

Ha‼
My log splitter has an auto-throttle control; it goes to full throttle whenever the ram is moving (when the engine is on-load), and automatically goes to idle when the ram is not moving (when the engine is off-load).


Many new engines are set up exactly that way... see the quote below.
The (user) throttle control was never intended to be used as anything except a way to go from full-throttle to idle, and back again. The sliding cable/lever design was just the simplest, easiest, and least expensive way to accomplish that... and incorporate the on/off and choke controls into the same control lever on many. Read nearly any owner/user manual and it will tell you to always run your small, splash-lubed, air-cooled, 4-cycle engine at full throttle when on-load (most pressure-lubed as well).


There's one-hell-of-a-lot of truth in that... although the EPA has also pushed for it because of the efficiency aspect (which effects emissions... take note WoodTick007).
I have four pieces of (relatively newer) equipment set up that way now ... my generator, my push mower, my snow thrower, and my pressure washer. They have an on/off control switch, a separate choke or primer control, but no throttle control whatsoever... 3600 RPMs or nothing. I really miss the ability to idle them down off-load (generator ain't a big deal)... but as you said, people think they're smarter than they really are, and now we all have to live with being protected from ourselves because of it.
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The only reason the builders went to small engines without operator controlled throttle is (1) less cost to the builder and (2) get the engines to wear out sooner thus selling more engines.I just love starting my snowblower on a sub zero day and having it go right to max goverend RPM and staying there until it's shut off .Not good!My emergency generator goes right up against the govener also to maintain 60 cycle but at least on that engine I can hold the linkage back to keep RPM down until it warms up a bit and it's thrown some oil around in the engine.All the rest of my small engines are run at half to 3/4 maybe 7/8 ,seldom at full.Of course the saws are pined if the chain is in wood.I've never had one blowup or overheat 55+ years .Efficiency is probably higher at full throttle but so is wear since wear is directly related to piston travel.In other words in 1 min.time the piston travels further at 3600 RPM then it does at 3000 RPM.It's been written that all 2 strokes should be run at W/O throttle .Not so .I sure won't run my snowmobile W/O for very long!

 

[ckr74]

.Efficiency is probably higher at full throttle but so is wear since wear is directly related to piston travel.

A piston is only going to go up and down so many times.

 

[svk]

This is starting to get interesting.

 

[NSMaple1]

Huh, forgot about the snowblower.

Wide open with the chute buried in fresh snow, but part throttle when walking it back to home base or cleaning up some spillage. Or placing the snow just where you want it in a tight space not far away.

 

[brenndatomu]

Boy glad I wear boots so I don't get all the **** spread here on my legs.

This is starting to get interesting.

I've had mah boots on since page 1...

 

[svk]

I've had mah boots on since page 1...

There are so many side discussions now I don't even remember what the OP was LOL.

 

[NSMaple1]

You mean everybody doesn't have their boots on all the time around this place?

 

[svk]

You can tell it's spring break up season with the amount of cabin fever in this place over the last few weeks!