Lifting a LF120

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Dixie Life

Senior Member
Joined
Feb 4, 2011
Messages
213
Location
USA
Vessel Name
Aku Uka
Vessel Make
43’ DeFever
I need to replace the engine mounts on my LF 120. At the same time I'm planning on reparing some bad stringer wood under the front right mount. My question is, without going to a yard to have the work done, can I place some timbers on the wheel house floor above the engine room hatch openings and lift the engine with a small hoist? I don't want to damage my floor. I'm concerned about how much weight it will hold. Has anyone ever done it this way?:blush:
 
When we had the engine mounts changed on our two FL120s the diesel shop lifted the engines using a tool called a PortaPower and wood blocks and braces they'd developed over the years for this specific application.

However members of the GB owners forum have lifted engines, specifically single engines, using chain hoists hung from a wood frame erected in the main cabin over the engine space This can be more difficult or impossible to do with a twin because in boats like ours only half of each engine is accessible to a lifting device through the main cabin floor. Hence our shop's use of the PortaPower under the engines. But since you have a single suspending your engine from above should work very well.
 
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I used 4x6's across the main cabin (to where it was supported by verticals) with 12"x 1/2" eye bolts and chain/shackles to lift my 3208 Cats when I replaced the isolation mounts.

Spray the treads with silicone and I raised them no problem with one finger and a normal box end wrench

Drill through the 4x6's and put the nut on top with a fender washer...the rest was easy because the cats had well balanced lifting eyes.

A Lehman should be a snap.
 
I've used the methods described by Marin and psneeld for years in non marine environments and they work well.

Rigging is part art and part science. Weight distribution is key. If you doubt the integrity of your floor with the 4 x 6 lumber, place 1" thick plywood between them and the floor to help distribute the weight over a larger area.
 
I used a timber, all thread, washers, nuts and a big wrench. Also shored the forward deck beam a bit.
The perkins weigh in at around 1,200 lbs. from what I remember. The starboard engine here had to be supported because I was rebuilding the transmission as well. I replaced the front motor mounts on the Port engine by blocking off the stringers and leveraging with a 4' piece of 2x4, one corner at a time, then re-aligned the whole thing.
 

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I am not familiar with your Litton 41 but if your floor timbers are similar to Poster #5's photos; then the load will be no problem. I was fortunate to borrow a portable steel double A-frame engine hoist with a 5 T chain hoist. The loading was not an issue on our MT44. We used a sheet of 1/2" ply under the motor IOT preserve the flooring and that probably also distributed the load a bit. As ridiculous as it will sound, I based my initial assumption of strength based on dock party. When it rained, at least 18-20 people piled into the salon and continued the party. There was no problem with the extra ton or so. False empiricism? Probably.
 
...... and continued the party. There was no problem with the extra ton or so. False empiricism? Probably.

Actually I was thinking the same. The engine is a big load but with the support spread over a wide area its a lower PSI load than a couple of fat guests. There used to be a moderately fat woman ate lunch at the same restaurant we ate at every Friday noon. You could actually feel her walk by and know who it was. But nobody would think twice about inviting her about either.
 
You may be able to change the mounts without rigging by adjusting 3 mount studs high which may take the pressure off the 4th. Unbolt the mounting bracket from the engine, remove & replace the mount, and bolt the bracket back on. Undo the prop coupling first.
The forward left mount bracket may support the alternator so you would need to loosen the belt and readjust it.
Removing the forward right mount bracket with the others adjusted high may leave room to do your stringer repair.
15/16" open-end or Bonney wrench if they are the common mounts.
 
I have HEARD of a person or two in the past using a big round fender to lift it from below. While I question the ability of THAT piece of hardware to do the job, a lifting bag that has some thickness could maybe support it enough to swap out the mounts. Perhaps a combination of a lift bag to take some of the weight and the eye bolt that Scott described would work if you are worried about the salon sole's ability to hold up.

Just a theory, though.
 
OK, this may be a dumb question. If I use two 1/2" eyebolts (one front, one rear) to lift the engine & tranny high enough to repair the stringer, will the threads on the eyebolts hold all the weight. I don't know the tranny weight but the engine weight is 1100lbs. I'd like to leave the tranny connected to save on down time.
 
Fabbing up a steel lifting frame would be a piece of cake for any welder. Build it in three pieces to be assembled over the engine and a simple chainfall after that. then you're only applying weight on the areas designed to take a load like that.
 
OK, this may be a dumb question. If I use two 1/2" eyebolts (one front, one rear) to lift the engine & tranny high enough to repair the stringer, will the threads on the eyebolts hold all the weight. I don't know the tranny weight but the engine weight is 1100lbs. I'd like to leave the tranny connected to save on down time.

Should be plenty...here's the "generic" working load for a hot dipped galvanzed bolt

1/2 " 13 threads...... load limit - 2200 lbs
Load limits are based on a safety factor of 5 to 1.

http://www.boltdepot.com/fastener-information/Eye-Bolts/Forged-Eye-Bolt-Working-Load-Limits.aspx

I used 2 bolts to pickup a Cat 3208 and tranny...if memory serves me...that's around 2500 lbs for the config I had.

Just make sure you get the ones with a forged eye...the kind I got were from a place that sold dock hardware.
 
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I have HEARD of a person or two in the past using a big round fender to lift it from below. While I question the ability of THAT piece of hardware to do the job, a lifting bag that has some thickness could maybe support it enough to swap out the mounts. Perhaps a combination of a lift bag to take some of the weight and the eye bolt that Scott described would work if you are worried about the salon sole's ability to hold up.

Just a theory, though.

I don't think I would lift an engine with a bag under the oil pan. I don't think it would take the weight.
 
I don't think I would lift an engine with a bag under the oil pan. I don't think it would take the weight.

Really? I have set all sorts of engines on their pans. I do see that it would become a pretty dynamic lift with forces of the engine weight going every which-a-way. Especially on a round fender or lift bag. However, I will only add that it doesn't need to take ALL the weight, just enough to divide the load with the salon floor.
 
I don't think I would lift an engine with a bag under the oil pan. I don't think it would take the weight.

When I was a kid, I made that mistake. I sat a Ford 360 engine onto the pan while removing motor mounts. I bent the pan bad enough it started hitting the crankshaft on every rotation. This lead to a hole wearing through, and ultimately cost him the motor. I learned many lessons the hard way.
 
Some oil pans are pretty wimpy but plenty of gas engines sit just fine on them if you do it right.

Don't think I would do it with many diesels..just not worth the chance unless I saw one sitting that way or it was recommended by someone I trusted dearly.

Doesn't matter.... the OP knows he can lift it easy enough several ways with lifting rings and as light as a FL120 is...the surrounding decks can support it no problem as long as it spans then supports near some deck support verticals.
 
Fair enough.
 
I'm just speaking from hard-earned experience. We had to pull the motor after our mistake, the same would cost thousands in a boat. I would not place 1,100-1,500 pounds on the tins. The risk has pretty expensive consequences.
 
When I was a kid, I made that mistake. I sat a Ford 360 engine onto the pan while removing motor mounts. I bent the pan bad enough it started hitting the crankshaft on every rotation. This lead to a hole wearing through, and ultimately cost him the motor. I learned many lessons the hard way.

That's what I'm talking about, damage to the pan from the weight. Not damage to the air bag. It just doesn't seem like a good idea to me. It might not damage the pan, but it might. Then what?
 

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