WOHM NUMBER 2 RADIAL ENGINE RESTORATION

 

Here is the WOHM no. 2 radial engine as received by Mr Hoepfner, needing a new crankshaft as the original shaft was bent. The engine was dismantled and inspected.

A new crankshaft blank was duly machined up and is now in the process of being indexed out in readiness for machining in the big end journals.

Below is the crankshaft progress, first step, rough out the big end journals.....

Finished crankshaft with all the big ends ground to size and polished. We left the webs as full circles as this keeps everything correctly balanced. The new shaft also has a 12mm diameter rear main bearing to take a 12x21x5 ball race. This is to give adequate support to the rear of the shaft, which originally had only a small bush, which is what lead to the original crank failing in the first place.

Next step is to clean all the case components and reassemble the entire bottom end of the engine, finally....

Now we have the prop driver, prop shaft and spinner nut all cleaned and final assembled.

Now its onto cleaning the piston/liner and cylinder assemblies ready for refitting to the engine................

Here are the 3 cylinder assemblies all cleaned and assessed for reassembly. Unfortunately the pistons are completely worn out in the gudgeon pin area with the holes being quite oval, Oh dear.

We also felt to check the rods for alignment too as the bent crank was likely to have twisted them or damaged the big end holes. The compression fit was also checked and found to be somewhat lacking so the decision was made to replace the 3 rods, relap the cylinders and fit new gudgeon pins and pistons.

 We started lapping the liners for this engine only to find that there was some serious faults in the cylinder liner finish just where the contra pistons would be fitted up and operating, OH DEAR.......

 

Resisting the urge to just throw them away and make new ones we had to ask ourselves, where does a repair stop and a new build begin? So...........

Looks like a fair bit of lapping is going to be done..................

 

 

Ok so not perfect but 100%better than when we started so good enough to run.

 We also made a start on the replacement conrods to avoid going mad lapping cylinder liners..............

Now only one more liner to do.

At last here we have all three cylinder assemblies finished with new contra pistons and pistons ready to assemble onto the rest of the engine.

 

 

Now lets get those new con-rods finished.

 

Now at last we can move onto reassembling this iconic engine.

 

Now we have the new rods, gudgeons and pistons all made and final fitted up to the engine we'll move on to rectifying a few faults in the cylinder assemblies before we start reassembly of them to the rest of the engine..............

 

Now its onto making a gasket for the inlet manifold and then we can make up the venturi and N.V.A.

 

Manifold is all sorted and fitted up so now it's onto the venturi...........

 

O.K. now all we need is a prop and some fuel, yay..............

 

Checking the quality of the restarting...............

Well that's another one saved.