SUPERTIGER G29 DIESEL REBUILD

Here's the engine as we received it from Callum

Let's get him stripped down and see what he needs.

Ok so apart from the obviously missing gasket for the backplate there is also a small groove in the top of the cylinder stub on the case where the cylinder liner seats on the crankcase which is leaking transfer compression so that'll need fixing. While the compression is not super bad it does leak down somewhat so we will carry out rebore and fit a new piston and contra, make a needle and then it should be all go.

O.K. so here we have the crankcase assembly with crankshaft, original needle jet and nut and the prop driver all cleaned and reassembled with a new prop washer.

Now we'll get the cylinder head and compression screw all sorted along with the back plate and a new rear cover gasket.

Here's the original piston assembly dismantled and the new piston and contra blanks all ready for final machining to size and fitting to the restored cylinder liner.

Next up is to lap and final fit the new piston and contra to the cylinder liner.

Here's the cylinder liner before we started, interesting to note, is the somewhat excessive relief machined into the lower portion of the cylinder. Not sure why they would have done this as the center point of pivot of the piston on the gudgeon pin falls below this point through bottom dead center which allows the  piston to become unstable I think.

 

Here's the new piston assembly all done and dusted.

Nicely restored cylinder liner with new contra piston, piston, gudgeon and rod all fitted up and playing nicely with their friends.

Having made a new cylinder gasket we have reassembled the engine, here's the progress to date.

All that's left to do now is the replica needle carrier and the backplate/mounting bolts.

Here's the replica needle and carrier all finished.

Now all that's left is to fashion something that looks like the original backplate/mounting bolts.

We decided to use existing M3 high tensile bolts and make some special nuts too spread the load better over the backplate area. 

Here he is all finished and ready for a test run.

Finally finished, now where'd that fuel bottle go.....

 

First pop test run.

Restart test.