What have I got - help with ID

[Bob_Matthews]

Bill

I think the chances of the rod going through the cases is virtually zero or 0.0001%. I'm going to start it in my workshop and rev it a little for no more than a few minutes or shut it down immediately if I hear any untoward noises.

Now if I was going to take out out on the road, thrash the nuts off it on full chat at max revs on an steep uphill incline then there's maybe a chance of that happening - but I'm not and I do have a lifetime of mechanical empathy

[themoudie]

Morning Alex,

May be the "rod through the case" was a bit excessive but as a man with "mechanical empathy" you'll understand that my having seen Ducati single motors "grenade" themselves, admittedly during warm up or after some healthy "exercise", I am wary of unknown quantities. Have fun with the rebuild.

Good health, Bill

[Bob_Matthews]

A little update.

I didn't get the engine running as the 6v coil was duff and only gave a weak and intermittent spark - so the engine is now stripped.
The big end feels good with only a small amount of side play. I took out the 3 radial sludge plugs and removed about 1/4" of rock solid debris from each, I also removed the welch plugs from the crank pin and cleaned that too. The crank was then immersed in a bucket of diesel for a week and then blown through with compressed air.

As I stripped the motor I measured the stroke and estimated it be about 66mm, barrel off and measured the piston at 70mm.
So this makes the engine a 250cc, right? Despite what the cam cover and log book tells me!

Does this mean that I now don't have an Elite, or has someone swapped the top end or the whole engine?
I also found a letter 'S' stamped on the head but not sure if this has any relevance.
The inlet port measures 27mm with a 30mm throat and a 32mm valve.
The exhaust valve is 30mm with a 27mm throat.
Oh, and found 3 base gaskets under the barrel, so I guess I'm going to have check the piston clearances.

All thoughts appreciated.

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[Jon Pegler]

You are correct in thinking your motor is of 250cc capacity.
The crankcases are from an Elite as I stated before, but the crank is from a 250 De Luxe or a 24 Horas.
The head is a Spanish Elite head with the S stamp on it, although the valve sizes are usually 37mm inlet and 35 exhaust with that head.
The Spanish Elite cylinder barrel had quite a thick liner and a 67mm bore which was capable of being bored out to 70mm as your barrel is now, so it may be an original 200 barrel or a De Luxe 250 barrel.
I have a 5-speed Mototrans Elite that has had a similar crank/cylinder modification and it works fine.

Jon

[ranton_rambler]

Valves are same size as my Italian 175TS.
Ian