warming up in the garage and fumes question

[deezler]

...With my diesel tractors, is it better for the engine to run at reduced throttle for light work that doesn't need the RPM's? I'm not talking about dogging the engine at near-idle, but for light work that doesn't require the RPM, is it better to run the engine at say 1,500-2,000 RPM vs the full throttle 3,000 RPM?

I know some people who just run the engine at full throttle all the time, regardless of what they're doing.

I guess I would say it depends. In general, in terms of engine health.... it doesn't really matter. There is no downside to running harder at lower RPMs, they are made for it. Sounds like you got a few good answers before I came back here to see this. On modern DPF tractors, running at higher engine speed might lessen the regen cycle frequency, but again it depends on how you are using the machine.

Almost all our diesel tractor engines make more/most power at the top end of the RPM range on your tach. So if you need that much power or ground speed, you have no choice but to rev up. But if you have sufficient power at lower engine speeds for what you are trying to do, you might as well save some revs and fuel.

I look forward to buying my next tractor and getting a Kioti linked pedal, to automatically rev the engine up and drive more like a car, and not having to constantly adjust the throttle lever based on what I'm trying to do.

 

[LouNY]

I'll disagree that the tractors are making thier power at the top end,
the HP peak is usually at pto speed and the torque peak is considerably lower.
My tractor the engine HP peak is around 2400 engine rpm which is the engine rpm for the pto to be at 540,
the torque peak is at 1750 engine rpm which is also the engine speed for the economy mode on the pto.
I do considerable road travel and i can definitely feel the engine as it pulls down in rpm on hills,
on a steep grade it will start to fall off in rpm rapidly down to around 1850 rpm and then settle in and pull hard till it
pulls down to about 1700 rpm at that point if i don't down shift she will fall flat on her face quickly.

 

[Deepdrop]

Hopefully this forum allows links. Is this the type of flexible tubing that people were suggesting? Would 15 feet of this cause enough back pressure to be an issue for the engine?

Amazon.com: Walker (43) 1-3/4" Diameter - 25' Long Galvanized Flex Tube: Automotive

 

[deezler]

I'll disagree that the tractors are making thier power at the top end,
the HP peak is usually at pto speed and the torque peak is considerably lower.

All depends on exactly what motor you have and how the manufacturer tuned it for your application. But this would be considered a very typical power curve for a CUT (Kubota) :

A quick google image search can find you many more power curve plots. Of course while power generally rises with RPM on our little diesels, how it feels and is gets to the ground in a useable way is another story. Hydro trans behavoir is a whole curve ball on top of the engine output. One thing to remember is that if you back off the rpms a bit, you are also slowing down and thus less power is required to maintain speed under your present load. So it could "feel" more powerful.

I like running at lower rpm whenever possible, to save some fuel but also just to keep the dang noise down. My Mitsubishi 3-cyl screams above ~2400 rpm.

 

[deezler]

Hopefully this forum allows links. Is this the type of flexible tubing that people were suggesting? Would 15 feet of this cause enough back pressure to be an issue for the engine?

Amazon.com: Walker (43) 1-3/4" Diameter - 25' Long Galvanized Flex Tube: Automotive

That could work. You shouldn't be adding any detrimental amount of back pressure with tubing like that, BUT, I would kinda question how fully effective it would really be. Unless you have a very tight fit on your tractor exhaust tip, plenty of fumes are going to escape into the garage still. It'll probably get kinda sooty and nasty after repeated uses. And then you have to handle it while kinda hot to get it off and in a safe place before driving the tractor out?

Seriously though, it doesn't hurt anything to just drive the tractor outside right away.

 

[BrkMstr]

Hopefully this forum allows links. Is this the type of flexible tubing that people were suggesting? Would 15 feet of this cause enough back pressure to be an issue for the engine?

Amazon.com: Walker (43) 1-3/4" Diameter - 25' Long Galvanized Flex Tube: Automotive

I've never used Galvanized, I've used rubber exhaust hose, from the 1 ½ up to 8", I had a large coach, diesel pusher - big cat engine, I could not start it and move it quickly as it had air suspension and when the slides were out it needed to have the suspension leveled then pulled in, so it took time - an engine that size fills a 40 by 60 garage with fumes quickly the exhaust hose took care of it, I used a small one when working on the diesel generator on the coach - they work flawlessly - simple to roll up and maintain - they do not melt / overheat they are made for it - they have been used in service bays for many years - don't use them often now - but at fifteen or twenty below I'm more comfortable starting in the garage and letting it run a couple of minutes before moving it outside, there is no leaking into the garage it flows out the hose - I'll also use the hose if I'm tuning an engine etc., you can get them on the web or at your local auto-parts store, obviously; do a little research in length - ten - fifteen feet no issue longer, dependent on engine, I may install a in-line blower - you can get exit ports for doors as well as Y's for two hose connections (dual exhaust), they work......

 

[JethroB]

Deezler and John0829, among others. Thanks for posting your credentials along with your advice.

 

[BleedingOrange]

I would find it a royal PITA to have to hook up a piece of exhaust hose every time I wanted to start my tractor and let it warm up in the garage. I start it gently lift my blower a couple of inches off of the ground, and move it outside the garage, and let it warm up. I guess everyone needs to do whatever makes them feel they are doing it right, but sometimes I have to wonder if we overthink stuff way too much.

 

[cdaigle430]

so far so good, start it up in the garage for a little above idle (about 5 minutes) then pull it out of the garage and raise the rpm for about 15 minutes-no issues.

Its why I prefer to run my walk behind snowblower-no warm up time needed no matter how cold.

 

[3Ts]

About that kerosene heater used indoors, or for that matter any combustion indoors that does not have outside air coming in - In addition to the CO and CO2 problems there is also an oxygen depletion problem. The combustion burns up the oxygen in the room. If you do this you should have an oxygen monitor as well.