Asking US$5,000 obo.
Formula Four is a class for cars powered by 750 cc motorcycle engines (850 cc for 2-valve engines) -- like an early version of F1000. The Xpit was designed in Ontario in 1972 by Eric Siegrist, and this example was built by Eric Siegrist and Stu Lamont, probably around 1974. It's powered by a first-generation Honda CB750 SOHC.
The Chassis
The car is currently being run as raced in the mid 70s, without wings. However, it has been raced in a more modern configuration, with a GSXR-750 engine and wings. The wings are included.
The Powertrain
While essentially stock in configuration, the CB750 engine has numerous upgrades that improve reliability and, to a lesser extent, performance.
- Balanced crankshaft
- Forged Carrillo connecting rods
- Reinforced rocker cover (rocker tower braces) as used on factory Honda race engines
- Modified float bowl sumps (for operation under lateral G)
In addition, the deal includes the following components that could be assembled into a much more powerful (but still F-Four legal) engine.
- Hilborn mechanical fuel injection system (with pump)
- 836 cc kit (larger-bore cylinder barrel and matching pistons)
- Ported cylinder head with enlarged valves
Because of the large number of CB750s made, engine and transmission components are readily available from Honda dealers or online sources such as Bike Bandit and Vintage CB750. Compared to most, this is a very easy vintage car to keep track-ready.
Miscellaneous Components
A large number of spares and related components are included.
- Front and rear wings (not currently being used, but fully functional)
- Side cooling inlets
- Rear lower A-arms
- Rear uprights
- Many Honda components (cylinder heads, starter motors, clutch components, transmission bearings, etc.)
- Drive sprockets of various sizes
- A second set of rims, with rain tires mounted
In addition, critical chassis dimensions and most custom components have been modeled in 3D CAD, facilitating their re-fabrication should that be required.