WOHM 3.5cc long stroke restoration

 

First step, dismantle and check out what I've got us in for. The goal with this engine is to end up primarily with a running engine. But I want to do that keeping as much of the original parts as possible so there might be a bit of a compromise in the aesthetic department to achieve this end.

First thing to do is rebush the front housing and make and fit a new crank shaft that will also be counter balanced to reduce vibration.

Her's the crankshaft blank ready for the big end to be turned.

We also went ahead and made the replacement prop driver and spinner nut, as these were missing from the engine.

 Here we have pressed out the old brass bushing and will manufacture a new bush and refit, then onto finishing the crankshaft.

Here's the new bush made and fitted into the original front housing which was then cleaned up.

 

 Now we'll finish the crankshaft and assemble the front end.

 

Here's the whole front end test assembled......

 

Now we'll move onto the con-rod, then make a decision on whether or not to keep the original center case as it's looking, well not very good.

Here's the new conrod made, all bright and shiny and most importantly, straight and true.

 

 

Now its onto the relapping of the original cylinder liner and making and fitting a new piston and contra.

 And here are the blanks all ready for finishing and fitting to the newly lapped cylinder liner

 Here are the piston and contra piston nicely machined and fitted up to the freshly re-lapped and corrected cylinder liner.

 

Now we really need that replacement center case....................

 In the meantime, here's the new tank assembly that was missing from this engine.

 Here's the replacement center case underway.........

 Test fitting the cylinder assembly onto the replacement crankcase center section.....

 Now onto the finishing of the case.

 

 Now we move onto cleaning and reassembling the engine ready for test running.

 

Next is the cylinder and tank assembly fitted up.................

Test run................

 

Hot restart test.