Diesel Engine Maximum RPM

[jinman]

For those of you with diesel engines in the 90 to 110 HP range, I'm wondering what the maximum no-load RPMs of your engines might be.

It's a rainy day and I'm entertaining myself by reading some engine specifications for my LB75.B w/95 HP turbocharged 4-cyl IVECO engine. I was surprised to see that the Maximum "no-load" speed was 2380-2480 RPM. I don't think I've ever revved the engine over 2400 RPM, but I surely could easily do that when transporting a load of dirt in the FEL. There is no marking on the face of the tachometer to tell me to limit RPM.

I admit I'm a bit lazy and don't often shift out of 2nd gear for loading the bucket or transport because I'm going up a grade and 2nd gear works out well. When I really need to dig, I'll shift to 1st. For long hauls, I'll shift to 3rd. But, for short hauls of 200' or less, I just put the transmission in 2nd and leave it there. I often rev-up to 2200 or slightly more. The full load RPM with the torque converter stalling is 2200 RPM. Most of the time in 1st or 2nd gear, my wheels spin before the torque converter stalls.

When I dig with the backhoe, 1600-1700 RPM seems sufficient to give me plenty of power. I'm just curious if other diesels in the same range as mine have similar RPM maximums or higher/lower? I know I get the best fuel consumption by keeping RPM below 2000 where the turbocharger boost is lower. What do you see on your machines?

 

[scott_vt]

Good Evening Jim,
After reading your post the first thing that came to mind was the purchase of a rev limiter, if that engine revs that easily...

It might be good insurance JMO...

 

[jinman]

Scotty, I don't think there is any danger now that I know the limits, but I was surprised the the maximum RPM was not above 2500. I'll keep an eye on myself and see that I don't go too high. I'm pretty easy on tractor generally.

 

[Dirthog]

Put your foot in it and don't worry about the injection pump is governed and will only go so high also the tachs in the dash are not the most accurate we always use a seperate one when setting pump or checking preformance on machines.

 

[jinman]

Thanks for the info Dirthog.:thumbsup:

 

[jonyyuma]

Just wondering if the maximun RPM isn't still controlled by the centrifical force of weights inside the inj. pump?Yes, we used a Spin tach on the end of the shaft to set, before we had the rpm light gun?

 

[Bob Rooks]

Just wondering if the maximun RPM isn't still controlled by the centrifical force of weights inside the inj. pump?

Nope. Inside the governor, which is attached to the fuel injection pump.
The governor still can be overridden by say, going down a hill in too low of a gear. Bad ju ju.