Cracked oil pan

Adding oil to water affect the freezing point. A crankcase full of water would mean lots of other bad things in the engine. This isn't like a frame crack, where water can collect if drain holes aren't clear, water sitting in the engine is BAD.

And ice has to expand against something to crack it. Meaning that the engine would have to be full to the brim with water.

Could you hydrolock and engine and crack the oil pan (i.e. gas from leaky floats fills the crankcase)?

 

Ice can freeze, thaw, freeze and creater a later that doesn't give. I've seen enough frozen engines with cracked blocks because of that.

It could also be something as simple as:
A guy was working on the engine, took the pan off, later dropped it and said 'I'm in trouble, I don't know what I'm doing.....' and put it back on and put the bike up for sale.


How many of us have gotten bikes that way?!!!? Could very well be you got a good snag that way.......

I have one right now that I got because it has an oil leak'. Yeah, it leaks all over the place. Why? Because the oil sensor is missing........

Dave

 

Personally, seeing as there's no marks visible inside or out & you have good compression on all 4 pots I'd be very tempted to leave the engine in the bike for now at least.

I'd pull all the plugs out, then with it on the c/stand I'd select each gear & rotate the wheel to check the gearbox is in one piece (to create a crack like that the box would either not select or be missing a ratio or 3 IMHO).

Providing all the gears selected & it turned freely/smoothly in each gear, I'd put a sump (I'm English! lol) on it, add battery, oil & petrol (again, I'm English ) and see if/what she ran like before deciding to strip it...

 

I have to agree. I wouldn't tear the engine down too far since it seems OK at this point; you're getting nice compression numbers for a 550.

A bit of possibly trivial (but possibly not) info: the USA-market 550s all had natural-finish engines. (Bottom ends, anyway.) For the oil pan to be black, it had to have been painted black, probably by the same PO.

I'm thinking he might have dropped the motor (on the cracked side) when it was out of the frame.

 

I'm very confident the pan was never off of the bike. The screws were all super, super tight in there, and never appeared to have been touched afterwards. On top of that, the pan itself was a bear to pop off of the bottom of the block.

Otherwise, I figure 130psi with need of valve adjustment is probably pretty good (I need shims, and badly). That's with the cylinders dry.

 

OK here's a weird thought that just occurred to me (and I mean weird, but you never know with p/o's...)

What if it had been laid up for a long time & the p/o decided to check the engine out as you have done, and got himself a leakdown tester. Now consider the guy has the tester, compressor & maybe a lathe too, but NO clue what he's doing when it comes to bikes... Just maybe he somehow decided that the tester screws into the oil filler & so he inflated the motor until it popped?

Highly unlikely I'd think, but just throwing it out there since you never can tell what's gone before (I recall a previous member who drilled their crankshaft for lightness, so it's definitely possible...)

 

This made me laugh because I had just read that thread again earlier today for nothing more than pure amusement!

Here it is if anyone's interested!

 

i had this years ago (30) on a honda it turned out to be to much petrol (gas) in sump (oil pan) flash point much lower, due to a leaking float valve, at the time it was hard to find because float valve was only weeping over night not poring out.

just one to look for

 

Must have been quite an explosion, denbola.

 

it was a honda c90 was not a big bang just a chuff noise and white smoke from around caseing and a line of oil road, split centre caseing, second hand engine

 

I didn't suggest the pan was OFF before; I said it wasn't black to begin with which meant it was painted (along with, I assume, the rest of the motor.)

In order to paint the underside of the motor, it was probably out of the frame.

I'm thinking it got dropped on the cracked side, and inward pressure on the side of the pan caused it to pop like that.

 

Fitz, I'm going to take it that you're right (and I can see this happening). I can also see the ice issue as well, as the PO left the bike out over winter with the valve cover OFF (of which, I have verified that no other damage has occurred, thankfully).

A few beers later & with the use of a mirror, I have determined that there is zero damage to the rest of the engine. Other than a bit of carbon, there's no other damage.

XJ project will continue on. I really wanna get this thing running (having a feeling I'm going to need a new left-hand side coil, as it does not fire) so I can tackle the brakes, install a new front tire, chain, sprockets, & get going. :wink:

 

Ok, I take back what I said, if the valve cover was off, outside, then freeze damage is definitely likely.

I have no experience rebuilding engines, but are these things really salvageable when they've been filled with water? That doesn't oxidize steel components in the engine? Like bearings and races that will wear in a hurry once you put it into service?

 

Everything is still nice, slick, & shiny inside (as in, there's still a LOT of oil, and absolutely zero signs of corrosion). Cylinder walls are absolutely perfect.

 

OK - - Suzuki outboard, 115 HP, mid '90's

Something got loose and in the crankcase at WOT and knocked a clean, little hole in the "bottom" , which is forward.

Fixed with JB-Weld without any further work.

I'm having a hard time seeing a guy drop and crack a motor, then proceed to re-install everything.

Must've had an Electric Monk ! :wink:

 

Thanks for the link, couldn't find it earlier... Wonder if he's paid off the dyno damages yet?