Pre war supercharged Comet..........Zoller supercharger.

greg brillus

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VOC Member
I have been studying the pictures quite lot and trying to make sense of what they did, since little seems to be written about them........It has been kindly suggested that we use some other make/model of blower to help the project, but we will copy the original as best we can.........it may not have the exact same internals as the Zoller did, but it will still function.......Simply running an open housing would probably not work at all, because the intake length would be excessive. I'll probably start by assembling up the basic bike to a near complete stage, then make up all the other parts as we go.......It appears the right side RFM down tube was altered (straightened) to clear the blower housing with the rear suspension compressed...... The pictures also show a small manifold pressure gauge mounted on the upper right side of the fuel tank.......A tiny capillary line brazed into the main inlet pipe next to where the carby would normally be, this plumbed to a small bore flexible line up to the gauge. From details in the pictures showing the fuel tank........this looks different to the fuel tank shown in pictures Brian has sent to me.........This would lead me to believe that the bike shown in these pictures is almost certainly the one we have here.
 

A Nut

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VOC Member
Hi Greg,
I would agree that the photos are of your bike over there going by the tank. I read somewhere that Jack Williams tank sprung a leak and he had to repair it himself. Mine has been repaired and a right angled rib soldered all the way around the bottom as you can probably see in the photograph. This would seem to suggest that your bike was ridden by Jock Forbes who was the rider of the other supercharged bike. I wonder if it would be possible to "scale" the supercharger from the photograph as many years ago I spoke to Derek Chinn (I think he owns the rights to Shorrock) and he was saying about the need to match the displacement of the blower to the engine capacity.
 
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