Modified flywheel and piston??

[CharlieT]

Ok, just started to tear down a 1947 H model engine and have come across a couple of interesting things.

One is the flywheel attachment to the crank.






All the pics of cranks I've sen have a threaded end. I'm guessing that at sometime in the past, someone buggered up the threads and resorted to welding the thing on.  

Item #2....the piston.





Ok, I've slotted or drilled holes in 2-stroke pistons on the exhaust side when there was a bridged exhaust port. I've also have had pistons with a window cut into the intake side. However I've never come across a piston with slots cut thru the intake side. And yes, I mean cut thru...all the way thru the skirt.

Are my assumptions correct that these are non-standard?

[kartjockey]

That is a factory piston.  It is the thrust side of the piston and when the engine fires it offers some flex as the combustion takes place.

[Mike Sal]

Well, one thing about it, who ever welded that crank was a talented welder......your going to have to go in with a mill cutter to cut it off in order to save the flywheel I think.

Lots of old cars & motors used slotted pistons in the old days.  Offered some flex during the power stroke as well as a chance for oil to get to the cylinder wall.
Mike Sal

[pd]

Welcome CharlieT .

[CharlieT]

Well, I'll be. Had never come across a piston cut like that before. Vertical shallow grooves cut in the skirt to aid in oil retention, but never cut clean thru the skirt. I suppose with the piston thickness and the low compression, wasn't too much danger of shattering the skirt.

Thaks for the info.