Adapting Rotary Engine to the Gearbox on Rotary Hillclimb Racing Project.
So far it has been a simple process I have just shelled out some cash to get a chassis and record information off a known complete chassis, but now the hard work is about to begin, I now have to work-out how to graft the engine and gearbox on to the rear of the Formula Ford chassis.
Rotary Hillclimb Adaptor Plate
This started with deciding on what gearbox to use, if money was no option I would have used a Hewland or Quafe Gearbox but these were well outside the budget for the project, so after some investigating I decided to use a Renault UN5 gearbox. I purchased a rebuilt Renault UN5 box from “Geoff” at Euro-Speed in Geebung on 19-1-08 this box also had a modification to the housing to support the crown-wheel for high horsepower applications, this was suggested to me by Geoff and after suffering from gearbox breakages on the previous car I thought this was a no brainer.
So I have a gearbox but how to fit it to a Mazda Rotary 13B engine? I thought to keep the conversion parts as off the shelf as I could, it seemed that if I used as much Mazda Rotary components as I can this would make replacement later (if required) easier and more cost effective.
An adaptor plate needed to be bolted to a bell housing so again the best option was to use a Mazda Rotary RX4 Bell housing and fit the Renault gearbox to it.
I purchased a slab of aluminum 100mm x 235mm x 345mm to make an adaptor plate. The photo attached shows the adaptor plate bolted to the Mazda bell housing after some 22 hours of machining on a milling machine at my workshop. Although this was doing the job this was still not the finished article.
Rotary Hillclimb Engine & Gearbox
The photo shows the engine, gearbox with the new adaptor plate bolting the whole assembly together, the engine is only a dummy one to get all the sizes etc at this point.