High Idle Mode

[Pete]

While I can list many positives about an LRC, one of those would not be ample engine torque when docking at idle. It would be nice to have a "high idle" mode on the main engines that with the flip of a switch, maybe two switches, elevated the idle to maybe 800 or 900 RPM. So, it struck me that going back many years when I used charter buses and Trailsways, that these buses had such an option. All I know is when the bus stopped for loading and unloading, more often than not the driver would reach back to his left, flip a switch and presto the engine went into high idle mode. When it was time to move the bus, the high idle would be turned off. Was told it was to supply ample AC or heat while the bus was not moving. I am aware that such a feature is available on modern day diesels and as best I can determine these are done with software, thus of no help to me.

I suspect back then this was a feature on the governor, but does anyone know for sure how it was done in the old mechanical DD days, and if the option would be adaptable to a 453 variable speed governor that I have?

Thanks

Pete

 

[Glory]

An air controlled cylinder. is what was use to increase the RPM.

This would be a possibility, if you have an air compressor on board. An alternative might be a DC,
in your engine voltage, solenoid to advance the RPM.

Or the old fashion way, move the lever.

JM

 

[Boatsb]

I'm with the moving the lever option. The last thing you need it to complicate the process with non standard apparatus.

 

[SKYCHENEY]

Can your gears handle shifting from F to R and back at high idle? It seems like upgrading to single lever controls would be a better option.

 

[Glory]

I didn't think the plan was to leave the RPM elevated. And I hope not.

Another thought, the LRC concept doesn't normally mean " hurry up", for that matter most boats don't mean hurry up compared
to a car.

JM

 

[davidwigler]

I have learned to use power when docking. Without thrusters it is necessary in current or wind conditions.

 

[JLR]

This came as a standard feature on my 1292 DDEC's.

 

[MikeP]

I'm not understanding why such a thing is useful on a boat since the throttle lever(s) can just be moved to whatever RPM you want and it (they) will stay there. On a road vehicle, sure, it makes sense since the accelerator is spring loaded to return to idle so there is no way to "hold" a fast idle except by pressing the pedal.

 

[Pete]

Thanks for the responses. Just to clarify some points, the high idle I envision is only used on those windy days, and high current situations. Today I use the throttles manually, but this is very imprecise when you decide you need the help. The precision of preset is attractive to me. Actually, my dream would be a setup that drops the rpm (defuels) as you go through neutral and is only active when the gear is engaged. This would avoid the high rpm shifting wear and tear on the gear.

Pete

 

[Boatsb]

Thanks for the responses. Just to clarify some points, the high idle I envision is only used on those windy days, and high current situations. Today I use the throttles manually, but this is very imprecise when you decide you need the help. The precision of preset is attractive to me. Actually, my dream would be a setup that drops the rpm (defuels) as you go through neutral and is only active when the gear is engaged. This would avoid the high rpm shifting wear and tear on the gear.

Pete

That's single lever controls.

Their great for just that reason.

 

[rsmith]

Going to blow up your transmissions

 

[kelpy]

My 16-92 DDECs have a low idle button that comes in handy when docking. It can be programed from the controls.
As for non DDEC engines, just bump the throttle lever up a bit but don't get carried away.

 

[jim rosenthal]

Or you could put some kind of mark on the throttle lever housing to indicate where to set the lever for a higher idle.

I think the wear and tear on your marine gears is going to go up, though.

 

[Dan Mapes]

I wonder if the owner's manual says something about not shifting above idle or max reverse rpm?

 

[capttonyf]

I'm confused, big power boats have a low idle so that the boat doesn't jump around as much in tight docking situations or idle speed zones. But a high idle? That's what throttles are for, why put your transmissions through that. If you need more power, AFTER you put it in gear give it a little throttle, then back it off again BEFORE shifting back out of or into gear and throttle back up again after you've made your next gear selection. Granted your working 4 levers instead of 2 but that's really how it needs to be done. If your not comfortable with using all 4 levers, set them up a way that your most comfortable and go practice. I wouldn't look to spend money and reinvent the wheel, I would practice maneuvering/docking the boat. There are throttle within inches to a foot or two away. Use those as your high idle IF you need them.

Tony.

 

[Boatsb]

My engines idle low at about 550. I like that as it cuts down on that jump in and out of gear. On the lrc it should respond a bit slower than a convertible but I'd use the throttles as needed and not set a high idle.

 

[Tinman]

My Cats have High/650 rpm and Low/550 rpm idle settings. Use the low idle docking and the throttles if needed. Also have single lever controls which are a big plus. If using high idle when leaving the slip make sure all lines are untied or you could break a piling. LOL