Running engines at half throttle??

[Whitespider]

Well that is all fine and good. . . but what about the increased noise and fuel consumption? I always idle my engines for the environment and children.

Idling an engine off-load is not a problem... my whole post was about running it on-load... and I addressed fuel consumption.
*

 

[WoodTick007]

Idling an engine off-load is not a problem... my whole post was about running it on-load... and I addressed fuel consumption.
*

What about the ozone and the environment and the oceans and the children? Hmmm? Hmmmm, Mr Spider?

 

[abbott295]

That's when you need to be sure you have bias-ply tires on it.

 

[greenskeeper]

No BS...

Running a small, air-cooled, non-pressure lubed, 4-cycle engine at anything short of full throttle is detrimental to its health... and because of the governor setup, it will often actually use more fuel, not less. Small, splash-lubed, air-cooled, 4-cycle engines are designed to run at full throttle... that's when lubrication and cooling air flow is optimized. When running at ½ throttle, horsepower and torque is drastically reduced, causing it to lose a greater percentage of RPMs when load is applied... which causes the governor to fully open the throttle sooner and for a longer period for recovery... which means more fuel and more heat while at the same time receiving less lubrication and cooling air flow.

Small, splash-lubed, air-cooled, 4-cycle engines should always be run a full throttle (approximately 3400-3600 RPMs depending on model) whenever any load is applied... no matter how small the load. Anything less than full throttle is causing unnecessary wear and damage... and likely even using more fuel. (Keep in mind that "full throttle" is not "wide open" with the governor setup on a 4-cycle.)

No BS... seriously... no BS...
*

I should send my log splitter engine out for a scientific study then. Going on 16 years running almost entirely at 1/3 throttle for hours on end. Every application is different.

 

[brenndatomu]

4-cycle engines should always be run a full throttle (approximately 3400-3600 RPMs depending on model) whenever any load is applied... no matter how small the load

Naw, ain't buyin it. I been running my small engines at 1/2 - 3/4 throttle (mostly) for ~30 years (+) now, ain't blowed one up yet. I try not to run the bag off any of my equipment and it seems that things last much longer for me than the average Joe. And my log splitter uses much less fuel run 1/2 -2/3 throttle that than if I go full bore. It gets thirsty at 3600 RPM.
I'm not saying that engines should always be run at something less than full throttle, just that they can be if you use some common sense and kinda match speed to load. Sometimes WFO is called for, like 20" bar buried in a 24" log...

 

[Whitespider]

What about the ozone and the environment and the oceans and the children? Hmmm? Hmmmm, Mr Spider?

The topic was small engines... not environmentalism.

How many times do I have to say it?? Running a small, splash-lubed, air-cooled, 4-cycle engine at less than full throttle (under load) will often cause it to use more fuel, not less. It also causes the governor to fully open the throttle for a greater percentage of the time.

Now, use your head for a second... if it's using more fuel overall and/or fully opening the throttle more of the time... wouldn't that mean more emissions?? If your goal is to reduce emissions, then the best way to do that would be to run the engine at a speed (RPM) that produces the optimum ratio of power to fuel consumption... which is full throttle. If you believe running a small, splash-lubed, air-cooled, 4-cycle engine at less than full throttle (under load) is better for the environment... you're delusional.
A small, splash-lubed, air-cooled, 4-cycle engine runs at peak efficiency at full throttle (3400-3600 RPM)... peak efficiency is the key to reducing emissions, not engine speed. You're not using your head...

And just so you know... I don't buy into the environmental extremism.
I believe in common sense... not extremism...
I'm not adjusting how I use a small engine because of some ridiculous notion it saves the environment, but I will keep the engine properly tuned so it runs a peak efficiency... which is good for me, good for the engine, and good for the environment.

I should send my log splitter engine out for a scientific study then. Going on 16 years running almost entirely at 1/3 throttle for hours on end. Every application is different.

No... the application of load on a small, splash-lubed, air-cooled, 4-cycle engine is the application of load... not different applications.
The work being done may be a different application of the load... but the effect the load has on the the engine is still the same.

Keep in mind, a log splitter engine is under load for a tiny amount of time over a 16 year period when compared to, say, a lawn tractor maintaining 3, 4 or 5 acres of grass. Heck, for that matter, total run time is typically a lot less... a whole lot less. My log splitter is over 35 years old now... but I've been through several grass cutting machine engines during that time.

Just because your engine ain't broken don't mean you ain't running it in a way that causes unnecessary wear and damage... which is all I said. I didn't say it would break in 16 years... or 10... or 5... or 50. Small, splash-lubed, air-cooled, 4-cycle engine engines wear out mostly because of run time under load... but there is a way to reduce the effects of run time under load... it's called full throttle (clean oil also helps a lot).
*

 

[Whitespider]

Naw, ain't buyin it. I been running my small engines at 1/2 - 3/4 throttle (mostly) for ~30 years (+) now, ain't blowed one up yet.

Than don't buy it (shrug)... but see the above post, just because you ain't "blowed one up" don't mean sour owl squat
Heck, I wasn't even talking about blowing up... a brand spankin' new engine can "blow up" for many reasons.
Also, keep in mind, small "pressure lubed" engines (they have oil filters on them) are not what I'm talking about... that's a different animal.
*

 

[Sawyer Rob]

What it boils down to is, how much load is on the motor...

Sure, if it's "heavily" loaded for the hp, that's not good, but it it's making "enough" hp at "part throttle", running it that way absolutely saves fuel, it also makes "less" heat and is no problem for that motor at all!

Now, I'm NOT talking about chainsaws here...

SR

 

[Whitespider]

..."part throttle", running it that way absolutely saves fuel, it also makes "less" heat...

You're not looking at the complete picture.
Heat is generated more by the fuel burned than friction... and heat is regulated by the cooling air flow.

When load is applied to a small, splash-lubed, air-cooled, 4-cycle engine the RPMs drop... which causes the governor to to open the throttle to wide open position. It don't matter where you set the throttle control (it's actually a governor control)... it's the governor that controls the actual throttle... and when RPMs drop under load, the throttle goes wide open no matter where you've set that throttle control. When the engine is running at less than the full throttle (setting) the engine loses a greater percentage of RPMs when load is applied... which causes the actual throttle (controlled by the governor) to go wide open sooner, and stay that way longer to recover RPMs (because HP and torque are reduced).

There ain't no magic to remove the physics... when the governor causes wide open throttle under load it means more fuel... which means more heat... while, at the same time, the lower RPMs (because of your throttle setting) are moving less cooling air past the engine, and less lubrication is being delivered (splashed) to the friction parts. A small, splash-lubed, air-cooled, 4-cycle engine does not run cooler at "part throttle" under load... it will actually run hotter. In truth... the fastest, most efficient way to cool a small, splash-lubed, air-cooled, 4-cycle engine is to run it at full throttle off-load because cooling air flow and lubrication is optimized.

However, a log splitter engine is not under continuous load like, for example, a grass cutting machine... so the effect ain't as great, but it's still there.
*

 

[JeffHK454]

There's no debating that splash-lubed engines are designed to be run at full throttle..it takes a certain RPM to sling the oil where it needs to be. I run mine at full throttle because it's where the hydraulic pump makes its full flow rating and I get the most work out of my splitter.

My objective is to get the splitting done so I can go fishing or offroading..fun to me isn't listing to a splitter putt along all day at 1/3 throttle to save $3 worth a gas.

 

[brenndatomu]

Heck, I wasn't even talking about blowing up...

OP was...

guy was replacing a garden tiller engine a elderly lady had because it overheated.. he said she would never run it full throttle and it burned its self up..

and when RPMs drop under load, the throttle goes wide open no matter where you've set that throttle control.

Exactly...don't matter if the throttle is WFO or 1/2. But when set at 1/2, it is shooting at 1800(ish) RPM and that means less fuel intake strokes...so less fuel used. Then once the load is removed (log splitter) my 1/2 throttle engine needs less fuel to supply its 1800 RPM (while it is waiting on me to load the next log) than yours screaming away at 3600 the whole time

 

[brenndatomu]

There's no debating that splash-lubed engines are designed to be run at full throttle..it takes a certain RPM to sling the oil where it needs to be

If that were true then no small engine would have a throttle...just set at 3600 permanently, like some of the cheap push mowers are now.
I have never seen any small engine manual that says "never use the throttle in any position other than full, because it gon blow up if you do"

 

[brenndatomu]

I run mine at full throttle because it's where the hydraulic pump makes its full flow rating and I get the most work out of my splitter.

There is some argument for full throttle here. On some hydraulics you just need the RPM to make things work well.
But on my splitter, it only makes ~1 second difference between 1/2-2/3 throttle VS full, and that it if I do a FULL stroke (out and back) which doesn't happen much. So thats less than 1 second per stroke lost, meh, who cares, I'm rarely in that big of a hurry. I prefer the less noise 1/2 throttle setting...but that's just me, each to their own. And 'bout the only time I run my mower full tilt is if it starts raining and I'm almost done...then ZOOM! (all 8MPH of ZOOM )

 

[JeffHK454]

If that were true then no small engine would have a throttle...just set at 3600 permanently, like some of the cheap push mowers are now.
I have never seen any small engine manual that says "never use the throttle in any position other than full, because it gon blow up if you do"

Who in this thread is saying it's gonna "blow up" ?

I'm saying that the people that design and build these types of engines recommend for peak performance and longevity that they be run at full throttle. This thread is a perfect example of why manufacturers have started taking throttles off equipment ..to keep people who think they're smarter than they really are from running equipment at part throttle , hurting effiency and durability.

My crappy old SpeeCo is slow enough at WFO ..1/3 throttle I'd still be splitting 2014's wood..

 

[Whitespider]

Then once the load is removed (log splitter) my 1/2 throttle engine needs less fuel to supply its 1800 RPM (while it is waiting on me to load the next log) than yours screaming away at 3600 the whole time

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).

If that were true then no small engine would have a throttle...just set at 3600 permanently...

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).

This tread is a perfect example of why manufacturers have started taking throttles off equipment ..to keep people who think they're smarter than they really are from running equipment at part throttle , hurting effiency and durability.

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.
*

 

[greenskeeper]

unless you are lugging the engine, any throttle setting is ok to get the job done. If my splitter has a 6hp engine at 3600rpm or whatever and I can split wood at 1/3 throttle or say 2hp without lugging then there is no harm being done, less noise, less wear, less fuel consumed.

 

[brenndatomu]

least expensive

Now thats why some of these newer engines have no speed control, that and there is no reason for speed control on a genny for example, since 3600 is needed to set 60 HZ. Speaking of HZ, I dunno how they set a genny for 50HZ (where they use that)...surely they don't slow the engine down to 3000...
Not to mention that 3600 RPM all its life will wear it out faster...so its win/win for the mfgrs to set throttle for WFO all the time

 

[Joesell]

I can see why you might run a Supersplit at 3/4 throttle to help with the gear mesh.

However, I dont understand why you would run a hydro splitter at anything less the WFO. The hydro pump is set to run at max output at 3600rpm. Running it slower doesn't change the psi, it only changes the speed of the ram.

Splitting wood is a chore, not something I do for fun. Why would I want to stand there and watch the ram move any slower then it has to. Not only that, but people spend crazy amounts of money to shave a few seconds off the cycle time.

I guess adding seconds is free. Some people can't resist a freebie.

 

[JeffHK454]

I can see why you might run a Supersplit at 3/4 throttle to help with the gear mesh.

However, I dont understand why you would run a hydro splitter at anything less the WFO. The hydro pump is set to run at max output at 3600rpm. Running it slower doesn't change the psi, it only changes the speed of the ram.

Splitting wood is a chore, not something I do for fun. Why would I want to stand there and watch the ram move any slower then it has to. Not only that, but people spend crazy amounts of money to shave a few seconds off the cycle time.

I guess adding seconds is free. Some people can't resist a freebie.

Exactly !

 

[Sawyer Rob]

I don't run my splitter wide open, it goes fast enough without it, I'm old and getting slower, I don't need to go any faster! lol

Also, there's LESS noise, it uses less fuel too, but then again, I'm not running an under powered splitter either, or one with a splash oil system...

AT LEAST that's been MY experience...

SR