Project - Snail

Can I ask a potentially stupid question?

To what extent are internal parts from 2 identical, yet worn engines interchangable? It's not really a reflection on your situation Plowsie - as people are mentioning valves and pistons (can see the pics).

Do some engine parts wear in unision which make them unique to being fitted together i.e crank and crankcases? I'm just interested

I bloody hope so Luke

Unfortunately, my spare engine seems to have slightly bigger bores and pistons and that has put a damper on things

I bloody hope so Luke

Unfortunately, my spare engine seems to have slightly bigger bores and pistons and that has put a damper on things

[yorkie_chris]

Originally Posted by lukemillar

Can I ask a potentially stupid question?

To what extent are internal parts from 2 identical, yet worn engines interchangable? It's not really a reflection on your situation Plowsie - as people are mentioning valves and pistons (can see the pics).

Do some engine parts wear in unision which make them unique to being fitted together i.e crank and crankcases? I'm just interested

Rings are a one-time thing. Once a set have bedded in together that's it, you can't really stick them in another cylinder and expect good results. The piston maybe but the rings wear in place and need this to seal.

Some gears will wear together, but chances are you will get away with this. Things like dog teeth I would imagine are not critical(so long as both OK), but I would keep each gear together. Stuff like oil and water pump, power requirement is small enough to use either, the gears don't get a massive amount of strain like drivetrain does.

Crank and crankcases, well what type of bearings are you looking at? Plain bearings will be fine, as in good conditions (running) the bearing surfaces never actually touch. However there may be several different sizes available to get the clearance right. If it's a roller bearing crank like on the aircooled dinosaurs and smokers then it's just drop in. They're parts ****** that will take anything

There's also the crank endfloat shims to consider, these aren't so much a wear item but 2 sets of cases and cranks won't be the same to within 2 thou or however near it needs to be. So you'll need to adjust that. (probably)

Valves, I wouldn't mix and match valves in guides. If it's come out, put it back in same way.
Same with buckets. Rockers. Collets. Springs. Seats. Retainers.
Seals are a wear item so replace them as matter of course if you've had them out.
Also be careful, if you are removing valves DON'T rag them out. There will be a burr on top of valve where collets sit, take this off with a fine whetstone or you will rip the seals and possibly knacker the guide.

[yorkie_chris]

Originally Posted by plowsie

I bloody hope so Luke

Unfortunately, my spare engine seems to have slightly bigger bores and pistons and that has put a damper on things

Use the barrel off the spare engine too?

I've lost track of what's f##ked and what isn't lol.

Originally Posted by yorkie_chris

Use the barrel off the spare engine too?

I've lost track of what's f##ked and what isn't lol.

Right spare engine, seems to have bigger pistons cos they dont fit in the main engine. And the main engine pistons seem to be too small for the spare engines, as in there is a slight bit of clearance down the sides that doesn't look too enticing, I think I may be best to go and get some sort of digical measuring device to be accurate.

Upon looking at the spare, a slightly less battered piston but still classed as fecked. Somebody liked their engine fecking.

[yorkie_chris]

See this is why you should have bought some old gixxer ... they are such parts bin specials you can fit nearly anything from nearly any other model!

So is that the head off the spare or the one in the bike?

The head is the main, is it okay to interchange that with the spare engines head? Seen a wiseco kit earlier, my that does.look fit.

[yorkie_chris]

Yeah if it will fit (the 2 engines are for the same model right?). If you're using a big bore you'll need the matching head gasket.