changing crankshaft and bearing while motr is in boat?

[lime4x4]

Just got a 86 searay that has a mercruisier 5.7 liter and it has a bearing knock.So i'm thinking it will atleast need new crank and bearings.My thinking is i might be able to do this in the boat.The boat sits about 8 feet off the ground.There is alot of room in the beilge area.So i was thinking of removing the cylinder heads and that and just rolling the motor over to gain access to the oil pan and crank and install a new crank and bearing if none of the mains spun

 

[Fishermark]

Re: changing crankshaft and bearing while motr is in boat?

At first I thought you meant with the engine in place!

But yes, if there is room in the boat, you can certainly take things off and "roll" it around. What I have done in the past is set up an engine stand right there on the deck of the boat - easier than trying to do it in the bilge.

 

[tommays]

Re: changing crankshaft and bearing while motr is in boat?

You never gonna be able to clean out the old bearing bits from the oil passages with the motor in the boat


Tommays

 

[JasonB]

Re: changing crankshaft and bearing while motr is in boat?

Last week I helped a friend change the rear main seal on his engine. We didn't have a good way to get the motor out of the boat, but did have a hoist tall enough to get the motor clear of the bilge, so we lifted it up, then put some 4x4's across the bilge and sat the motor back down on its side 90 degrees to the engine bay. Worked like a charm.

 

[bjcsc]

Re: changing crankshaft and bearing while motr is in boat?

You never gonna be able to clean out the old bearing bits from the oil passages with the motor in the boat


Tommays

That's the real issue. Won't do any good to put new bearings in an engine full of grit...

 

[Aquaman]

Re: changing crankshaft and bearing while motr is in boat?

That's the real issue. Won't do any good to put new bearings in an engine full of grit...

What grit? Any minimal bearing material lost due to wear is either in the oil filter, strainer, or ,if equipped, stuck to the magnet in the pan or drain plug.

I did a bearing change on the 440 in my Winnebago. No need to take the heads off. Drop the pan and replace the rod bearings. The mains can be done without removing the crankshaft too. Just loosen the main caps, the upper bearings can be "rolled" out and new ones "rolled" back in. But you will need to mic or plastigage the journals to make sure the crank doesn't need to be reground.

 

[lime4x4]

Re: changing crankshaft and bearing while motr is in boat?

true i was planning of flushing out the engines passages with cleaner.I have a short block i redid for a 85 truck a few years back that i never used.So i'm thinking of just finding someway of getting the old block out then installing the rebuilt block after installing a marine engine cam

 

[Coors]

Re: changing crankshaft and bearing while motr is in boat?

And brass core plugs.