JENA 2.5cc Diesel progress
The first step with this engine is to fully dismantle and assess the damage and determine exactly what we'll be doing with it.
Now we'll give it a clean up and make some tooling to get on with the repairs, new compression, front end, anodizing and bearings etc.
Here's the crankcase and shaft all cleaned up and reassembled with new bearings.
A closer look at the prop driver revealed a crack in it so we will manufacture a replacement part and carry on.
Here we have the new prop driver and prop washer and bolt all finished and test assembled.
Now we make the replacement con-rod.
Now we strip, refurbish and re-polish the original cylinder head in preparation for re anodizing.
Now it's onto the piston /liner assembly which starts with relapping the original cylinder. Thankfully the cylinder is all good and is now ready to accept a new piston and contra piston.
Now we can start on the piston and contra piston and get them machined up and fitted to the cylinder liner.
Here's the piston and contra piston blanks already for final machining and lapping to fit the cylinder.
Here's the finished parts............
And here we have the cylinder assembly all together and fitted to the rest of the engine.
Next step is to reassemble the backplate and refit it to the engine.
The needle valve assembly that was fitted to the engine was both not original and unserviceable, bleeding air in through the jet due to the hole in the back plate having been drilled out oversize and the jet itself having been filed down in the flats area rendering a massive air leak between the 2 parts. We took the liberty of cleaning up the hole to a standard 4mm diameter and gently filing the flat location area back to accept one of our proprietary 4mm fuel jets. Results below.
O.K. so now the next step will be to re-anodize the original cylinder head and the replacement new prop washer. Once the anodizing is done we can reinstall the compression screw insert back into the cylinder head as this was removed before anodizing as it's steel.
Here's the engine completely finished and reassembled, awaiting the application of a prop and some fuel.
Fist pop run
Idle run, nice and solid idle, yay.