Lightening a piston using common tools

getback wrote:
  WOW I am sure that cant be gotten anymore, never seed that before.   

He has 297 of them according to the quantity dropdown list. If that's his SKU49cyspi product.

I'd like to compare the performance of one of those on a Tee Dee against his Old style SPI Tee Dee P/C with the full size piston. I wonder if the heavier piston achieves more torque due to inertia, meaning less slowing in high gee maneuvers.
Rusty

I have a crankchaft that broke while  fling because of a bolt too short to fix the propeller With an rc plane I landed but the engine is running full blast I remember the amazing crazy sound Me the internal components of my engine survived except the crank We can see the mark left by the rotation of the conecting rod on the tank valve Area no valve damage I use this part even if it is damaged on out side  its a black widow fuel tank one wit circlip

davidll1984 wrote:I have a crankchaft that broke while  fling because of a bolt too short to fix the propeller With an rc plane I landed but the engine is running full blast I remember the amazing crazy sound Me the internal components of my engine survived except the crank We can see the mark left by the rotation of the conecting rod on the tank valve Area no valve damage I use this part even if it is damaged on out side  its a black widow fuel tank one wit circlip

Yeah, that's what we call a "shaft run". Hearing the little things run at their extreme limit with no load is a scary thing. I had a Gilbert do it. Never heard one of those go anywhere near that fast before, and it survived.

Had the same  experience with a TeeDee020 that threw off a 3 bladed drone prop that had its hub split..obviously IC engines generate repetitive dynamic load peaks that props designed for smoothly running electric motors will not endure for long.

The poor thing whined at a very high pitch before I reached to the forced landing site of the RC plane with no prop, but it survived the unloaded- and uncooled- run without any notable damage and continues its service in the nose of my Roaring 20 balsa RC plane..

most of the time when this happens the crankshaft goes back into the crankcase But a perfectly tuned engine can survive By survive I mean piston cylinder crankcase.The outer part of the valve should retain the motor connecting rod on the crankshaft pin Results the connecting rod can continue to rotate freely in the path inside the crankcase I used to do this modification with several of my bee engines Often I find the spec too much space between the outside of the valve and the crank pin To check remove the cylinder press the connecting rod check that the connecting rod fits well on the perimeter of the valve and can turn freely without catching Outside the path inside the crankcase The seat of the path retaining clip valve will eventually be too worn out will interfere with the connecting rod The plastic model wears out quickly but remains a good option can be changed more often to prevent a sudden damage