Lifting my Engine

[bcboomer]

My 1986 O'Day 40 needs new motor mounts.
The mechanical work is familiar but I've never lifted a motor in a sailboat.

The first thing I learned is that the prop shaft needs to be disconnected!
I found this out by putting a scissor jack under the front of the engine, spreading the load with heavy plywood, and jacking it up a very little. Water gushed out from underneath the jack and for 2 or 3 heartbeats I thought I'd pushed the jack through the bottom of the boat. Then my brain started to function and I remembered that I am replacing the mounts because the engine shifts so far forward when in reverse that the PSS seal sprays water in surprising amounts

However it has planted a large seed of doubt about jacking the engine this way. Has anyone out there have any experience lifting a similar engine (Westerbeke W46) in a similarly designed boat (2 parallel deep fiberglass beams with access holes cut out for bolt access and a sump underneath?

Neil

[AfterHoursNLCT]

I don't know about lifting your engine, but I do know your PSS
seals should never be spraying water inside the boat. You need to check your bellows for tears...LL

[olepedersen]

undo shaft slide it back check for leaks measure each old motormount for height from
engine bed check for leaks unlock upper nuts on old mounts remove mounts one at the time, replacing them with the new one pre adjusted to the same height as the old one
Realign propshaft with feelergauges when aligned lock it all down .That should do it.
Ole

[bcboomer]

Afterhours

The bellows is not leaking under normal use but the mounts allow the engine to move a lot. Only in reverse and especially under a heavy load water comes past the seal. The bellows is adjusted really tight so I assume a DPO adjusted it real tight instead of replacing the mounts.

Ole
I understand the mount replacement procedure but my concern is: how safe is it to jack the motor up with a scissors jack sitting in the sump?
Is this the conventional method or do I need to fabricate some kind of bridge between the mounting beams and pull it up?

Neil

[zeehag]

my repair guy lifted my engine and re aligned it solo. he didnt use my hydraulic jack, i dont know what he used as i was shopping for dinner when he did it. he also repaired my 4 motor mounts and solidified things and secured stuff so nothing moves around or vibrates anymore.
he did this at anchor.

when the engine was set into its rightful place, there was no longer any leakage from packing gland...finally!!!!

[psneeld]

If you are doing motor mounts you may be able to just do one at a time...the motor will balance on the other 3.

If not, I lifted my 3208 cats and trannies that were around 2500 pounds by spanning the engine compartment with 4x6's . I then used threaded galvanized welded eye bolts with links to the lifting rings on the motor. I could use one finger to turn the wrench whch turned the nut and gently pulled the motors up off the mounts. Grease the threaded rod/eyebolts and it's easy!!!

[Target9000]

Originally Posted by bcboomer

I understand the mount replacement procedure but my concern is: how safe is it to jack the motor up with a scissors jack sitting in the sump?
Is this the conventional method or do I need to fabricate some kind of bridge between the mounting beams and pull it up?

Neil

I wouldn't try jacking a motor up by the sump unless you are really sure of a few things...

1) The actual pan in the boat can support the whole weight. If you're putting it right on the hull it isn't a problem but in our boat there is an actual pan under the motor that isn't very thick.

2) The oil pan on your motor is a single piece and can support the weight. You don't want to mess up a gasket or dent up something.

3) You have the jack setup so that it cannot move when it takes the full load. Keep in mind you're on a boat and as unlikely as it may be... Suppose someone throws a wake your way while you're doing it?

On our motor I have some attachment points above the motor that I can use to attach a block a tackle to the motor's lifting eye. You might look to see if you have room/ability to do that.

[olepedersen]

You are getting good advice,let us know how it goes. Ole

[John A]

My Perkins 4-108 was replaced with a Yanmar while at anchor in Simpson Bay, St Maarten.
A steel bar was placed across the top of the companionway and the engine placed on the cabin floor using a chain come-along (type of block and tackle), a boat with a hydraulic hoist came alongside and took the Perkins and left the Yanmar.

A boat next to me hoisted his engine out my tying two halyards to the end of his boom and used a block and tackle for the same results..

[GILow]

Originally Posted by AfterHoursNLCT

I don't know about lifting your engine, but I do know your PSS
seals should never be spraying water inside the boat. You need to check your bellows for tears...LL

I've just replaced our PSS seal, and I would say this sounds a little like the bellows have gone a bit hard. Our size is compressed a whole inch when installed, and I would say it would hold water for at least three quarters of that movement. Therefore, if a little movement causes the seal to leak, it implies there is very little force on the carbon ring due to very little remaining force in the bellows.

Matt

[GILow]

One more thought, I would never jack an engine up by the sump. If the sump bends, you are almost certain to introduce leaks around the sump pan seal.

I'd do one mount at a time, or find a method of suspending the engine from the lifting points, most engines have designed lifting points to avoid damage caused by lifting from cast components, such as the pump (yep, I've seen a pump housing sheared off this way) or even the manifolds can be too weak.

Matt

[bcboomer]

Thanks for all the suggestions.
Lifting with screws by the eyes would be the best but I don't have room and sight lines for timbers or the budget for a custom steel frame.
The oil pan on the Westerbeke W46 looks pretty solid and I'm only putting part of the load on it.
I'll leave some bolts in the aft mounts while I do the front ones so it can't get away on me.
The sump on the O'Day 40 appears to be 10mm thick fibreglass and the bottom sounds like it is part of the hull. I think that it will take the load if I spread it with a piece of 3/4 plywood, but I'd be a whole lot happier if another O'Day 40 or 39 owner could tell me he has done it this way.
Failing new information to the contrary, I'll jack it up in the morning.

[donradcliffe]

The sump will take the load if you spread it out, but the sump gasket will be compressed and probably leak when you unload it. Think about levers and halyards.

[GILow]

Originally Posted by bcboomer

I remembered that I am replacing the mounts because the engine shifts so far forward when in reverse that the PSS seal sprays water in surprising amounts

OK, now I thought about this some more, I am confused.

If the engine moves FORWARD when in reverse, then it must be a very different setup of engine and forces compared to my boat. On mine, the prop shaft thrust is taken by the engine, so if the mounts failed (if I HAD engine mounts, but I don't, the engine is hard mounted) the engine should move BACKWARDS in reverse.

Is your setup different? Some kind of "V" drive? But even then, the shaft seal should only leak in forward gear.

Matt

[Phoenician]

You should check out the following link which includes great, step by step instructions on how to replace motor mounts


Replacing Motor Mounts & The Obstacles Photo Gallery by Compass Marine at pbase.com