Engine Houres/Turbo RPM'S

[Boatcarpenter]

Two questions.
1. What is the relationship of multifuel RPM'S to engine hours?
2. What is the relationship of multifuel RPM'S to turbo RPM'S?
Anybody know or can point me in the right direction?
Thanks,
BC

 

[AaronW]

Pretty sure that I read somewhere that the hour meter was calibrated to run accurate at 2000 ERPM.

 

[jwaller]

as to your second question there is no direct relationship.

turbo rpm is more directly related to fueling in our case. there is a day and night difference between 2000rpms and light throttle and 2000rpms and wide open up a hill under full load and boost.

 

[Boatcarpenter]

AaronW- Thanks, that sounds reasonable.
jwaller- I've got to think about that. Seems that only so much exhaust can can be produced at 2000 RPM no matter what the load is. You are filling and emptying the cylinders the same amount of times. A little more air in as boost increases, and more fuel as you accelerate to keep up speed, and a lot higher temps. I suppose that all adds up to more expansion of the hot exhaust gases as they exit the engine on the exhaust stroke producing more flow through the turbo thus increasing its' RPM'S?
Will have to do some research on that.
Thanks,
BC

 

[Towerguy1]

Its true that the cylinders are the same volume but think of it this way......

Without fuel the cylinder basicly compresses air from atmosphereic pressure, The volume of the cylinder.

Now add some fuel, The fuel when compressed detonates and expands more than the volume of the cylinder produceing power.

Now climb the hill.. More fuel used at an equal RPM bigger boom more volume to press the cylinder down = more exhaust turbo spools up to produce more boost = more volume compressed into the cylinder for bigger boom

And what does this mean.... cats don't taste like lobster

 

[Boatcarpenter]

I think that is how I am going to think about the turbo part of your post Mike.
And now I have to go see if I can catch one of my neighbors cats.............................
BC

 

[CUCVFAN]

You've got a whistler. Don't you hear it spool up as you push the pedal down?? When driving on a level road in 4th or 5th, press the accelerator down and listen to the turbo change sounds. Hardly any RPM increase = lots of turbo speed increase. If you had a turbo boost gauge, you'd see it move every time you depressed the throttle.

The turbo is sized for the engine and is non-waste-gated (and it's a diesel - no throttle plate), so it isn't as dramatic as it could be on a gas engine, but it's speed is related to the amount of fuel being burned not so much engine speed. My GLHS Omni will go from vacuum to 15psi in a heartbeat under load with no significant RPM change. That takes a dramatic increase in turbo speed.

 

[IHASFIP]

Another example is to have a boost gauge and rev the motor up to say 2000 rpm and look at the amount of boost you are making. Then get out on the road going up hill at 2k rpm and see the difference.

D