Engine case swap - How hard

[oobyscoot]

Further to my post about my broken engine mount, I have decided to swap the casings with the other engine, How big a job is this? Whould I get it dont in a weekend?

Anyone else done this who can offer some tips ?

[sledge]

Do you know exactly what is involved in changing the cases?

[oobyscoot]

Do you know exactly what is involved in changing the cases?

Nope.

No stranger to the working of the internal combustion engine, but mostly work on car engines and derv engines. Could rebuild you a landrover tdi lump in 2 days, but this is my first forray into bike engines.

[Big Rich]

It is a pretty big job. Between pulling the 2 apart, keeping everything organized, measuring everything for the "good" engine (no point in assembling a soon-to-be paper weight), etc, etc. Unless you have somebody right there with you that knows there stuff and all the parts go together just right, it could take a lot longer than a weekend.

Where is the front motor mount on the 500? If you can just swap the bottom halves it may be a lot easier. Maybe even find a good TIG welder to repair it?

Fact of the matter is, your bike is down until it gets a motor. So either find a third or go for the cases.

[oobyscoot]

Cheers for that Big Rich.

I was intending to just pick up all the bits from the running motor and put them all in the other crankcase.

There realy isn't anything worth keeping from the insides of the original motor, (it threw a conrod at 135,000 miles).  

Also Not too fussed about having the bike off the road, i got 2 others (working), was just after knowing what to expect with the Job.

[werase643]

in one day.....doubt it
consider complete engine rebuild
going to need brgs for the crank into the new cases at a min
plasti-gage to get the right ones and wait a week-10 for new ones

or just slap it together and hope

[oobyscoot]

going to need brgs for the crank into the new cases at a min

or just slap it together and hope

Ah, does that mean I cant use the top crankcase from one engine and the bottom of the other ?

The original engine has a crack in the bottom case, the new(er) engine has the mount missing from the top.

The alternative I guess, is to grind it all off, make it look like it was never there and hope the MOT man dont realise.......

[The Buddha]

going to need brgs for the crank into the new cases at a min

or just slap it together and hope

Ah, does that mean I cant use the top crankcase from one engine and the bottom of the other ?

The original engine has a crack in the bottom case, the new(er) engine has the mount missing from the top.

The alternative I guess, is to grind it all off, make it look like it was never there and hope the MOT man dont realise.......

No way you can slap the top from 1 and bottom from the other. Dont need all 4 mounts, 3 is plenty.
Cool.
Buddha.

[oobyscoot]

Anyone know if a missing mount is an MOT fail?

I may just grind it off the engine and make it look like it never was there, and cut the lugs off the frame and paint it up so no one will ever know.......

....particularly if the Buddha thinks 3 is enough.....

[The Buddha]

I guess I should ask more Q's, but the bottom 2 mounts are very important, I'd say the top 2 are less important especially the top front one. In your case let me ask you ... you are one mount bolt short, how has it been working for you.
Cool.
Buddha.

[mister]

This might seem unnecessary at this stage, but I am curious WHY you were trying to remove the engine with only 22k on it when there was nothing wrong with it? Was the bike no good and to save on re-registering another bike you figured it'd be easier to to swap the engines?

Care to show us a photo of this Cracked mount so we can better see the damage?

Michael

[ben2go]

Case swap is a big job and requires some motorcycle spec tools.It'd be better to swap in another engine.What happen to your engine case?

[sledge]

Upper and lower cases are machined in the factory as a pair, like cam-caps are. If you start swapping and changing them there is no guarantee that everything will line up correctly. Even if you swap the cases as a matched pair the original crank and balance shaft bearing housings may be in a different tolerance band from the original cases. Upshot being the bearings may require replacing to give the correct running clearances......its all a far from straight froward exercise.

I am assuming its the forward mount directly bellow the cylinders that has broken on the basis I have seen it several times. Its usually as a result of an accident impact or because the steel bolt corrodes into the alloy case and the case gives before the bolt will come out....not much you can do with it other than glue the broken piece back on touch it up with some paint and hope no one notices. You wouldnt be the first to do it  

Nothing in the MOT regs about broken mounts but they do state "all major components must be secure"........so its all open to personal interpretation and is going to depend on how the tester views the situation. If he sees the damaged fixing as a compromise to the security of the engine/frame he will fail it......if he doesnt he wont 

I would take it to the nearest MOT station and ask their advice before stumping up the cash just to be given a fail.

[oobyscoot]

Buddha  -- It seems fine wihout the top mount, been up and down the motorway at 95+ mph and some twisty A roads and all seems well.

Mister  -- The donor bike was bought only for parts, my only thought was to get "Ruby" back on the road, at whatever cost in terms of cash or effort. After 135 K miles, i got quite attached to her.

Sledge -- Yes thats the one, But surely vibrations will just break up any glue that goes on there........

[The Buddha]

That front mount - yea weld it ... in fact to make it extra clean, get a aluminum pipe with a 10mm ID, grind off the engine case to where the surface is clean and relatively straight, cut the pipe into what could be called a 3/4 pipe I guess ... then slap it on, put the bolt in place, press it on tight and tack the ends. Then keep the bolt in place but keep slowly rotating or moving it, or use a random steel rod, and just keep moving it so it doesn't get tacked to the aluminum, and just weld away, surface fit imperfections are all fine cos the weld will fill it, its better to have some imperfections to fill. Easy, ... then spray high temp paint on it and no one will know.
That part of the engine case has a ton of meat there, you can easily weld it up and never hurt anything. Easy. Oh have to do it with the engine in the frame but you would need to take off the exhaust and maybe the front wheel. Getting the bike up higher as well as laying it over may be needed to get the underside, but well, put some tires down and lay it over.
Cool.
Buddha.