Checking a non-running engine

[psyguy]

hi guys

i am looking into getting an 1100 (8v) engine to put in place of my 850

the 1100 engine has an unknown history and isnt running at present (it is in a frame but the cams are off, shims missing, stator cover missing, carb parts missing, etc)

the engine suffered a hit from the front left hand side to the point that the rear engine mounts bent - the stator cover is missing and there are a few broken fins on that side


the engine turns over and shifts through all the gears up and down

i turned the engine by hand to run the exposed rotor against a straight edge - to check for any run-out (as that's where the engine was hit) - i could detect only a minimal runout (like 0,5mm or less)


i am thinking of taking the engine appart to inspect everything inside and rebuild the engine


do you see any problems with this?

can you think of any problem that i might not be able to see when the engine is appart but would become obvious only when the engine is put back together and tested?

any help appreciated

.

ps. these engines are not available down here as spares so, unless i can salvage this particular one, Bruno is going to stay an 850

[almarconi]

the engine suffered a hit from the front left hand side to the point that the rear engine mounts bent

If it was hit hard enough to bend steel motor mounts I wonder what it did to the alloy block? Unless you can get the engine for almost nothin you would probably be better off finding a complete engine in better condition. Until you tear it apart and have it checked for wear and cracks, you really don't know what you are buying.

[psyguy]

oh, forgot to say... getting "another" engine isn't really an option (due to my location) so it's either this one or none

but thanks for pointing out about possible cracks in alu, never thought of that

[almarconi]

How much do they want for the engine?

Do you have access to a machine shop/machinist who could check out the engine?

I have never rebuilt a motorcycle engine but have rebuilt a car engine. Typically you need to have the block cleaned and checked for cracks before any work is even started on it. No sense wasting time/money on machine work and the block is not sound.

[psyguy]

engine i can get cheaply

i have rebuilt a gs before and have access to good machine shops

would that be only a visual inspection for the alu block, or something else?

[OhioEric]

...call Bert Munroe...

[Old Colt]

How much of the 1100 top end will swap onto the 850 Cases?
I have only researched this with the small engines so I do not know the bigger ones.

[bwringer]

The 1100 top end wouldn't work on the 850 lowers. It's the whole engine or nothing.

I'd say grab it way-cheap, then disassemble and have the cases MagnaFluxed to check for cracks. The most likely location for the cracks would be where the engine mounts are. (There are other processes besides MagnaFlux to check aluminum engine bits for cracks -- a good shop will know what to do.)

The good news is that most case cracks can be repaired. Again, you'll want a good shop with experience in these things.

[Nessism]

Magnaflux is for ferrous metals so you can't use it on aluminum. Some sort of dye penatrant would be appropriate though.

I'd just eyeball the engine and if it looks good, take it. Cracks around the mounts can be repaired by welding if necessary.

Regarding installing the engine in an 850, I have no personal experience but from what I've read, you need a matching drive shaft - something about the flange being different.

Good luck.

[drhach]

I would be reluctant to buy it under any condition, however, if you're in a position where this is your only choice....In addition to what's been said, I might hook up a battery and try to get a sense of the cylinder condition by doing a basic compression test. Maybe at a minimum take the head off and see how things look in there. I suppose if you have access to a machine shop, things like bore condition are not really as much of an issue as alignment of critical components.

[tone]

if this engine really is your only option for an 1100 i'd drop the sump off & have a good poke around in there for any bits of ally, bearing material or evidence of liquid gasket, this should give you a fair idea of its pre-accident condition

if the moror mounts are cracked or bent its almost certain that the crankcases will have some stress fractures even if you cant see them, mounting bolts will probably be bent too which makes removal interesting

Why is the top end off, i'd want to know the story there

having said all that if its dirt cheap it could be a good scorce of spares for another engine if not rebuildable itself

[jmanz6]

This a little pet peev of mine. Magnaflux is a company, NOT a process. The correct name is magnetic particle inspection. It is only usefull on ferrous metal so AL is out. What you would need is a Dye Penetrant inspection, or Ultrasound inspection. Either a visible penetrant or a flourescent penetrant will find the cracks if there are any. You don't even need to be a trained inspector to do it usually. My company sells the kits to do it on a small scale and we sell to small shops/individuals all the time. You should be able to find someone in your neck of the world to get a kit from. Magnaflux does sell penetrant kits BTW.

Now that the rant is over, I would be worried about the engine being damaged from the impact. If it were hit just right it could be fine, but it could also be stressed in bad places. I would suspect the engine mount area is full of cracks if the motor mount brackets were bent. I would also be concerned with the integrity of the bottom case. AL is shifted easily and it could be just out of alignment. Since you did check with a straight edge for runout you might get lucky. I would offer next to nothing since it may only beo worth the scrap value in the end.

[bwringer]

Thanks for the corrections and clarifications regarding the branding and uses of the various crack inspection processes... I'll try not to screw THAT up again!



Now if you'll excuse me, I'm going to go xerox some papers on our Canon copier, and then get a few Puffs kleenexes to wipe up a spilled RC coke in my co-worker's Lexus jeep.

[psyguy]

thanks guys

my main concern is that i dont put the money and effort into inspecting and rebuilding this thing, but then disover something wrong with it only afterwards

do you recon there may be any issues that may be invisible to the process of inspection and measurement of the internals?

would it be better to get the engine running first and get into the tear-down only after that?

[bwringer]

If you can rotate the engine by hand or with the starter and shift through the gears smoothly, that will tell you a lot. Since the cams are out, you'll either need to reinstall them temporarily or find a way to feed the cam chain smoothly.

If you can get the cams back in, I'd definitely do a compression check before proceeding much further. That will also tell you a lot about the engine. First rotate it slowly by hand with the plugs out and listen for any knocking or untoward noises.