BIG BOY PEPPERELL 23 T/R DIESEL

This project was brought into being as an addon to our Pepperell 23 team race diesel replica engine project, and is the concept prototype for a limited production run of a 24cc version of those production replica's.

As with all our machined from solid concept engines it will start from here.........

A block of 4" square x 6" long 6061 T6 ally

End of the first machining operation carried out on the lathe looks like this....

Second machining operation completed, also on the lathe, leaves us here....

Custom built engines require a vast amount of additional purpose made tooling to be manufactured, which consumes a huge amount of time, which contributes to the often high final price.

Photo below shows us ready to go to the milling machine for the first milling operation.

Here's the milling operations completed.

 

Off the mandrill and partly fettled and ready to mount up on our special tooling to machine in the entire cylinder portion of the crankcase.

Next up is to make the special tolling required to machine the cylinder outside and inside.

Here's the next machining step finished ready for the final crankcase profiling operation.

And here's the finished case all ready to receive the rest of the engine parts.

Here's the completed backplate case ready for the drum valve and bearings.

Here's the venturi intake hole all machined into the back plate and ready for the ventui itself to be made and assembled onto it.

 

Next up is the crankshaft..............

First stage......

End of the first machining operation.

Now we will need the fixture made for machining the big end journal.

Now lets get everything cleaned up and assemble the crankshaft to the crankcase.

Now we'll focus on the front end, collet, prop driver and spinner nut.

And all nicely assembled together.

Now it's onto the drum valve and end cap.

Here we have all the backplate assembly parts all finished and ready for assembling.

And final assembled.

Test fitted onto the rest of the engine and they all play nicely together, YAY.

Now we start on the cylinder and piston assembly along with the con rod.