Running on One Engine.....-gctid376701

[Guest]

So about every month or so, a newby comes in and asks about fuel consumption. A lot of the responses say that they usually run on "one" engine.

I never tried this and there are plenty of times that i think this would work out good for me!

The only problem is that i dont know what tranny i have, so im scared not knowing whether to put the non-running engine in Neutral or in Forward or Reverse gear!

My baby is a 1985 4550 with 220 Hinos, which may not help much but, can someone help me?

[Guest]

Doug AKA as DCMB or COF has numerous replies on this. He has a 38' MY and has done it for years. Maybe he will chime in. You should find out what trannies you have but I wouldn't try it until you have heard from others on the BOC who have done it on 45s with your power plants and trannies. Knowing the manufacturer and type of tranny you have and a call to the mfg technical departments will offer a lot of advice, by all means do this.

Richard

[Guest]

Hey Doug, my bad I mistyped your initials, correct to DMCB but I still like COF!

Richard

[Guest]

Richard Tulip wrote:
Doug AKA as DCMB or COF has numerous replies on this. He has a 38' MY and has done it for years. Maybe he will chime in. You should find out what trannies you have but I wouldn't try it until you have heard from others on the BOC who have done it on 45s with your power plants and trannies. Knowing the manufacturer and type of tranny you have and a call to the mfg technical departments will offer a lot of advice, by all means do this.

Richard

It was actually Doug who encouraged me to post this thread. He said he locks his with a pipe wrench so it doesnt spin and puts the transmission in neutral.

He didnt feel comfortable enough telling me what to do, since i didnt know which tranny i had, which i understand.

hopefully others with a 4550 will know or give me a tip on how to tell.

wish there was a big red sticker that says "acme 5000 super tranny"

[Guest]

Richard Tulip wrote:
Doug AKA as DCMB or COF has numerous replies on this. He has a 38' MY and has done it for years. Maybe he will chime in. You should find out what trannies you have but I wouldn't try it until you have heard from others on the BOC who have done it on 45s with your power plants and trannies. Knowing the manufacturer and type of tranny you have and a call to the mfg technical departments will offer a lot of advice, by all means do this.

Richard

It was actually Doug who encouraged me to post this thread. He said he locks his with a pipe wrench so it doesnt spin and puts the transmission in neutral.

He didnt feel comfortable enough telling me what to do, since i didnt know which tranny i had, which i understand.

hopefully others with a 4550 will know or give me a tip on how to tell.

wish there was a big red sticker that says "acme 5000 super tranny"

[Guest]

Sloppy2,

I searched the sticky: MY database and "Hino 6-393 EH 700 + EH 700 TI Engine Manual. The manual shows diagrams of several transmissions which might give you a hint of what your tranny is but if you can't find numbers on the tranny case it might not help. I would think others that have/had your model could chime in and help ID it so thechnical support could be contacted.

Hope this helps

Richard

[dmcb]

Sloppy2 wrote:
It was actually Doug who encouraged me to post this thread. He said he locks his with a pipe wrench so it doesnt spin and puts the transmission in neutral.

He didnt feel comfortable enough telling me what to do, since i didnt know which tranny i had, which i understand.

hopefully others with a 4550 will know or give me a tip on how to tell.

wish there was a big red sticker that says "acme 5000 super tranny"

You misunderstood. I DO NOT do anything to mine and I can run that way without damage. I said I did not know about your tranny so I couldn't advise. I do know some transmissions cannot safely do that but I don't know which ones.

No problem Richard.

Doug

[SomeSailor]

On mine (46' trawler... full displacement), people are saying it should not be allowed to rotate without the engine running. Most in the know with big heavy trawlers say that they run more efficiently with twins than a single. I'll have to prove that out for myself though.

If you're willing to slow down (I have no choice now) then Doug's long range cruising routine is very cool. It's amazing he can do a whole summer on the numbers he mentions. Plus he can always pick up and run on plane if need be.

[yachtman]

Running on one engine with the transmission locked is highly.inefficient and pushes the running engine harder than necessary. The stopped propellor works like a brake just as well as when turning under power it moves the boat.

The only way to run on a single is to free wheel it. On my 3988 my starboard transmission was damaged and locked up. I had to return to port on one engine. I could only do about 5kts and i was pushing it hard the other tranny felt really hot.

So i would have to say locking up a prop to run on one engine would be a no go.

Edit:I i am not saying you sbould free wheel your prop im just saying the only way to run on a single engine is to free wheel it. You still need to find out if you can turn yours safely with out running it.

[dmcb]

SomeSailor wrote:
On mine (46' trawler... full displacement), people are saying it should not be allowed to rotate without the engine running. Most in the know with big heavy trawlers say that they run more efficiently with twins than a single. I'll have to prove that out for myself though.

If you're willing to slow down (I have no choice now) then Doug's long range cruising routine is very cool. It's amazing he can do a whole summer on the numbers he mentions. Plus he can always pick up and run on plane if need be.

Originally I was looking at single engine trawlers. Mainships and Albins were at the top of the list.

I feel I have the best of both worlds now because I have trawler economy and also the ability to pick up and go as you say.

Doug

[Guest]

yachtman wrote:
Running on one engine with the transmission locked is highly.inefficient and pushes the running engine harder than necessary. The stopped propellor works like a brake just as well as when turning under power it moves the boat.

The only way to run on a single is to free wheel it.

Agreed - I had about five hours last year running single on my 38 and this works - not sure how much advantage fuel wise versus twins at same speed - probably not a lot

[smitty477]

From memory only on that year Bayliner you could have a Hurth HBW 450 or a twin disc MG502.

In either case it would be noted on the top of the case on a stamped al plate around the vent and shifter quadrant area.

Perhaps take a pciture of the plate or the entire transmission for better look or help with the ID.

I will check when home tonight and confirm this information.

FWIW - Running with a locked propeller at slower speeds is slighly more efficient then when it is left to freewheel.

Hope this helps

[dmcb]

yachtman wrote:
Running on one engine with the transmission locked is highly.inefficient and pushes the running engine harder than necessary. The stopped propellor works like a brake just as well as when turning under power it moves the boat.

The only way to run on a single is to free wheel it. On my 3988 my starboard transmission was damaged and locked up. I had to return to port on one engine. I could only do about 5kts and i was pushing it hard the other tranny felt really hot.

So i would have to say locking up a prop to run on one engine would be a no go.

I think the key here is pushing it hard.

You will find there is a point where pushing it farther does little or nothing.

At that point you will damage your engine because you are lugging it.

You can almost feel it when you have reached that point. Careful adjusting the throttle will product little if any gain. Back off then to avoid damage.

All hulls will push easy. Even larger yachts can get get good mileage if you keep UNDER hull speed. Sometimes another 100 rpms will greatly increase the fuel usage and its all downhill from there.

Carefully study any boat tests that give mpg in their tests and you will see this.

I think you are right about locking the prop but I also think some experimenting might prove if you don't try to go even to hull speed it might not be as drastic a problem.

When I bought my 38 from Ohio to Northern Michigan, I ran both engines but kept the speed about 8 mph as I recall. I got 3 mpg doing that. So slowing down one one engine gets about 25% better than that.

Going that slow on both engines might get better but here is the other problem doing it.

You want some load on a diesel. Running on one engine at 1100 or 1200 rpms seems to do this. It is always at the proper temp but more important when I run up the rpms I only get a few seconds of black smoke and it clears right up.

To my thinking that tells me I am not doing damage to my engines by running to slow.

Don't take that as anything more than my thinking on this subject however.

I have come to really like this slow speed and have no desire to run on plane. It is quiet. I can see ahead to avoid problems with ease. It makes a very enjoyable ride even for a long day. My equipment is being easily used and I get good economy.

Its a boat ride. The longer the better. Why rush it?

Doug

[smitty477]

http://www.bayliner32xx.com/downloads/HBW360A-HBW450A.pdf

Please see section 3.5 - freewheeling.

"Sometimes another 100 rpms will greatly increase the fuel usage and its all downhill from there"

Best advice you will ever get from someone who not only knows the facts but practices them.

"I think you are right about locking the prop but I also think some experimenting might prove if you don't try to go even to hull speed it might not be as drastic a problem"

Locking a prop will make little difference but there is a slight advantage to locking a prop in effciency.

Hope this helps

[dmcb]

To keep this from being lost in this thread, as I understand some transmissions should not be free wheeled. I don't want that to be lost in this discussion as it could cause serious damage.

The question posted in the OP is still unanswered.

Doug