Any guesses on how much water is needed to run a Ford Lehman 120 for 24-45 minutes on the hard.

[albinalaska]

Appreciate any input or insight on the following matter:

We're at the point where we need to focus in on starting up our engines while on the hard. We have twin Ford Lehman 120's and as I'm making preparations I'm wondering if I can access any real-life experiences from anyone who has run their engines on the hard beyond winterizing for a few minutes. The engines have been turned over relatively regularly over the past few years but have not been started since we hauled out in 2022. So, it's beyond time.

I have access to a portable truck-bed tank that I can get down to the yard next to the boat that holds around 430 gallons of water. My initial plan is to have the large tank next to the boat and transfer water via a transfer pump to a smaller reservoir we can place in our cabin right above the engines. The smaller reservoir would be plumbed appropriately to the intakes of one engine at a time and in essence would ensure the water supply remains constant without having to worry about working the pump too hard or figuring in the length of hose or lift of hose from the larger tank outside the boat.

I'm looking for any areas of concern I haven't perhaps considered or other factors to take into account. I am also wondering if there are any opinions on how far a 430-gallon tank might get me? If this information isn't available, I am happy to report back when this finally goes down. It's winter here so the water will be cold but will unlikely be "ocean cold", so I'll need to keep an eye on the temps. Anything else?

I'm open to considering any variation of my "beautiful drawing" plan. I get the sense that drawing water directly from the large tank up and over the side of the boat and down into the engine room will run the raw water pump beyond its designed capabilities - but by all means if anyone else has an opinion on the matter this would certainly save me some labor.
As always, thank you for any input!

Kyle

 

[MVCalypso]

Unfortunately, I don't know the raw water consumption rate for the FL 120 - but I had an idea.... Perhaps you can place the tank at the transom and arrange the exhaust flow to go back into the tank to make a (mostly closed) system. That would let you get close to as much run time as needed (subject to water loss in the tank to engine, back to tank loop).

 

[albinalaska]

great thought- really appreciate it

 

[Jeff F]

It takes a long time for the engine to get up to operating temp with no load.

How long do you want to run them? You could pull the impellers and run them dry for quite a while.

ETA: Oops, just saw the title. You might get 15-20 minutes dry. Watch engine coolant temp and monitor exhaust system temp with a heat gun.

 

[hollywood8118]

The best solution I ever saw was a guy needed to do the same thing placed a small aluminum boat on sawhorses, put a bunch of water in it placed it right under the exhaust outlet then ran a hose directly to the raw water pump. He dipped the end under water in the aluminum boat, primed the hose then fired up the boat. He trickled a hose into the aluminum boat to make up for the little that splashed out and the loss from the water injector at the shaft(s). The water filled aluminum hull displaced heat and he did this for quite some time. Most boat yards don't seem to like boats started and just dumping all that water on the ground. Also saw the same thing done to run AC once.
Thought it was pure farmer type engineering!.
Hollywood

 

[DennisB1]

I run my Cat 3208 375s with a garden hose connection about 4 gal/min at idle rpm no load. That flow lubes the raw water impeller and provides some cooling at idle rpm you could run for hours. If your exhaust is raw water cooled you should run water thru the exhaust. If you run for say 15 minutes you could as suggested earlier remove the rubber impellers. That still could be a problem for the seals in the raw water pump without water due to the rubber shaft seals .You could the RW pump flooded which would be easy without the impellers installed.

 

[SteveK]

Good ideas so far. My thought is that a garden hose suppy is not enough water flow or GPH. A fire hose is too much. I see the ideas presented coupled with enough supply for any RPMS planned as the solution.
So what is the GPH for raw water at say a max planned RPM.

 

[Nick F]

Garden hose will be plenty for a motor with no load. Remove the impeller. Connect hose to raw water pump inlet. Don't start the flow until the engine is running and stop flow immediately on stopping the engine. Check that there is water coming out of the exhaust.

 

[mvweebles]

Your diagram showing the reservoir above the engine puts the exhaust elbow below waterline. The engine is at risk of hydrolock if water is allowed to flow without engine running. Better would be to have the reservoir below the exhaust elbow - a 5-gal bucket in the engine room that you manually fill as the engine drains the bucket.

What is the reason for running on the hard? Was it running properly when it was stored in 2022? Has engine work been done since that needs to be tested? If the only reason is concern that the engine hasn't been run in a while, I wouldn't worry too much. 3-years sitting isn't that long. I've seen diesels fire right up after 10+ years of sitting. Barring any other factors, id launch and go from there.

Peter

 

[Serene]

Page #9 of the Ford Lehman Operator's Manual, states 35.3 GPM @ 2,400 RPM.

 

[Serene]

Page #9 of the Ford Lehman Operator's Manual, states 35.3 GPM @ 2,400 RPM.

Reading the manual again, it isn't explicit if this is coolant or raw water flow, so may be coolant.

 

[SIBERNUT]

When i bought Phelps, it had been sitting on the hard for over 10 yrs w no problem. I guess i dont see the problem here. If it didn't freeze in 2 yrs, why pick now to mess w it? Forced launch or something?

 

[kchace]

When I winterized my FL135s using the 5 gallon bucket method an engine at 6-800 rpm’s would empty the full 5 gallon bucket in less than 30 seconds.

Ken

 

[alormaria]

I believe the hose in a 3 gallon bucket would be enough to keep ahead of the Ford at idle. I basically do this every year.
I don't get why the concern for Lehmans that have only been sitting for 2 years. My boat sat for 4 years and the engine started right up and has ran great (for a Lehman).
Every boatyard is different but where I am now the contract mechanics run the i/o and inboards for seemingly hours on the hard. The water just finds its way back into the river like the rains. This year I think it helped.

 

[albinalaska]

Your diagram showing the reservoir above the engine puts the exhaust elbow below waterline. The engine is at risk of hydrolock if water is allowed to flow without engine running. Better would be to have the reservoir below the exhaust elbow - a 5-gal bucket in the engine room that you manually fill as the engine drains the bucket.

What is the reason for running on the hard? Was it running properly when it was stored in 2022? Has engine work been done since that needs to be tested? If the only reason is concern that the engine hasn't been run in a while, I wouldn't worry too much. 3-years sitting isn't that long. I've seen diesels fire right up after 10+ years of sitting. Barring any other factors, id launch and go from there.

Peter

The reason for running on the hard is that (after checking my math) it's actually been 4 years since we've started them up. We are doing a total rewire but also replacing the water lift mufflers, racor replacement, fuel lines etc. and generally, I just don't want to wait till we're dipped in by the slings to find out she doesn't turn over.

 

[albinalaska]

When i bought Phelps, it had been sitting on the hard for over 10 yrs w no problem. I guess i dont see the problem here. If it didn't freeze in 2 yrs, why pick now to mess w it? Forced launch or something?

Thanks for the response - any response, even confusion is helpful. 10 years gives me a good perspective. I'm just concerned about the engines seizing etc. and I've just not been down this particular rabbit hole before where the work has required the boat to be on the hard for so long. We still have a long way to go but I'd just had to rebuild and refit our boat just to have a no start. I have resources telling me the engines will seize; the fuel is bad... etc. etc... so I can't help but feel like I should be more aggressive with starting them up just to ensure they work. If I'm perhaps overreacting... that's great news.

 

[albinalaska]

I believe the hose in a 3 gallon bucket would be enough to keep ahead of the Ford at idle. I basically do this every year.
I don't get why the concern for Lehmans that have only been sitting for 2 years. My boat sat for 4 years and the engine started right up and has ran great (for a Lehman).
Every boatyard is different but where I am now the contract mechanics run the i/o and inboards for seemingly hours on the hard. The water just finds its way back into the river like the rains. This year I think it helped.

I appreciate that perspective and thanks for the response. As I crunched the numbers its actually been going on 4 years. I just get paranoid we're not being prudent in preventative issues that may arise while we're busy focusing on other systems on the vessel.

 

[Nick F]

Don't overthink this !

The engine will take a long time to heat up at idle/no-load and you will monitor this with the temperature gage.

What you do need to worry about are 2 things - not running the impeller dry and not overheating the exhaust system.

Remove the impeller and put a small flow of water into the exhaust. You can check the temperature of the first part of the exhaust system (by hand or with an infrared thermometer).

 

[SIBERNUT]

When i started that engine on Phelps, i tapped into the oil gallery where the pressure gauge sender goes. Gave it some pressure w fresh oil & a pump for a half hr

 

[kapnd]

Without putting any load on the motor, there’s no reason to run it for more than a few minutes, and I wouldn’t recommend revving it up without a loaded warmup.
A garden hose poked into the open strainer should suffice .
If it ran well when it was put to bed, and was fresh water flushed or winterized, my bet is it’ll start right up and purr!

 

[Deckape]

Put your hose into the open strainer with thru hull valve closed . Idling ,you should be able to keep strainer full .

 

[Caballero II]

Good ideas so far. My thought is that a garden hose suppy is not enough water flow or GPH. A fire hose is too much. I see the ideas presented coupled with enough supply for any RPMS planned as the solution.
So what is the GPH for raw water at say a max planned RPM.

In my experience, full hose flow from a domestic tap is too much for a Ford Lehman 120. When I fresh water flush, I shut the flow down to approximately 50% flow. That seems to mimic normal salt water impellor driven flow pretty adequately.

 

[ronobrien]

Appreciate any input or insight on the following matter:

We're at the point where we need to focus in on starting up our engines while on the hard. We have twin Ford Lehman 120's and as I'm making preparations I'm wondering if I can access any real-life experiences from anyone who has run their engines on the hard beyond winterizing for a few minutes. The engines have been turned over relatively regularly over the past few years but have not been started since we hauled out in 2022. So, it's beyond time.

I have access to a portable truck-bed tank that I can get down to the yard next to the boat that holds around 430 gallons of water. My initial plan is to have the large tank next to the boat and transfer water via a transfer pump to a smaller reservoir we can place in our cabin right above the engines. The smaller reservoir would be plumbed appropriately to the intakes of one engine at a time and in essence would ensure the water supply remains constant without having to worry about working the pump too hard or figuring in the length of hose or lift of hose from the larger tank outside the boat.

I'm looking for any areas of concern I haven't perhaps considered or other factors to take into account. I am also wondering if there are any opinions on how far a 430-gallon tank might get me? If this information isn't available, I am happy to report back when this finally goes down. It's winter here so the water will be cold but will unlikely be "ocean cold", so I'll need to keep an eye on the temps. Anything else?

I'm open to considering any variation of my "beautiful drawing" plan. I get the sense that drawing water directly from the large tank up and over the side of the boat and down into the engine room will run the raw water pump beyond its designed capabilities - but by all means if anyone else has an opinion on the matter this would certainly save me some labor.
As always, thank you for any input!

Kyle

Mine sat for 3 years before starting with only a few occasions to roll them over by hand. Diesels like to work, so running them with no load for any length of time will have negligible to zero benefit and could be detrimental. Working them raises cylinder pressures (temperature rise is a side effect). Raising cylinder pressures seats the rings to the cylinder walls and running at no load for extended periods can glaze the cylinder walls and preclude any further seating of the rings (permanent damage). The best way to run a diesel is to start it and idle for a few minutes, run it at 50% load (underway) until normal op temp is achieved and then run as needed/desired. They should also be run under full load (underway, full RPM) for 5-10 minutes during every outing of any length (a day). If you are concerned with running it for a time on land to exercise it, it really does no good other than to cycle the valve springs which can be done periodically by hand. (Rotate the crank 90 degrees every few months) This is what I have learned in my many years as a diesel tech. Hope this helps. Good luck.

 

[Nepidae]

For the safety of the engine I wouldn't think of funning it dry.

With some ingenuity you mighy be able to make somethiing to attach to the top of the strainer that you could then attach a hose to to get a constant feed.

OR

This (Flush Buddy Inboard Motor Flusher | West Marine) could work.

Made for just what you want to do.

Good luck.