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

greg brillus

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Hi there folks........Does anyone have the foggiest idea where to look for the whereabouts or info, pictures anything at all about the small Licence built Zoller supercharger's used on the 2 factory built Singles.......I know they were unsuccessful only due to time limitations (mostly from over heating from what I understand)........Anyone with possible factory drawings, sketches anything that might help in the quest to put one back together (actually possibly both bikes........you never know).........Much appreciated.........Cheers......... Greg.
 

davidd

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Greg,

I have some photos and Phil Irving's notes on the supercharged bikes. Of course, one of them, ST29, was reported to be in Victoria. I wrote about Frank Pratt in an earlier Lightning/Grey Flash review and his partner was the well-known racer, Norm Osborn. Norm is shown here racing STT29 in Australia:

Osborn, Norman (2).jpg


I believe the supercharger was removed when Norm was racing the bike. Many years ago it was said that the bike was in Victoria in pieces.

Close up photos of the supercharged engine are in the PDFs.

Zollers seemed to be the favorite of MG, so there is some general information available on MG sites:


Series A TTBlown 02-1.jpg


Series A TTBlown 01-1.jpg


David
 

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Simon Dinsdale

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I know the other supercharged bike was dismantled by the factory and the frame reused in another race bike which was eventually sold as a std TT replica. This bike is still in UK with a non supercharged TT engine.

The PDF photos David just posted are the best ones of the supercharger that I have seen.
Simon
 

A Nut

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Hi there folks........Does anyone have the foggiest idea where to look for the whereabouts or info, pictures anything at all about the small Licence built Zoller supercharger's used on the 2 factory built Singles.......I know they were unsuccessful only due to time limitations (mostly from over heating from what I understand)........Anyone with possible factory drawings, sketches anything that might help in the quest to put one back together (actually possibly both bikes........you never know).........Much appreciated.........Cheers......... Greg.
Hi Greg, I have the other TT machine, frame number D 963TTS but as Simon said it is fitted with what is described in the engine specification sheet as "TT engine". This is the same machine that is featured in David Wright's book "Vincents HRDs and the IOM ridden by Nigel Seymour Smith in the 1946,1947 &1948 Senior Manx GP. I bought the bike from Nigel many years ago and have restored it to the same specification as when Nigel rode it in the Island. I have taken it to the Island a couple of times and ridden it in the VOC closed roads sessions also a couple of goes up the test hill at Brooklands (and a bit of unofficial riding up the banking as well as a couple of runs at Prescott Hill Climb) I do have some factory photos of the bike in it's supercharged form but can't lay my hands on them at the moment. The Zoller blower was made under licence by McEvoys of Derby. Years ago I tried unsuccessfully to find a blower but they were probably specially made for the 2 machines as one photo clearly shows a HRD logo cast into the rear. It is delightful to ride but not that fast (a bit faster than my A Comet, however!) They stretched the frame a bit for the 2 supercharged bikes as they were fitted with some pretty large petrol tanks and the seat had to be moved back several inches to accommodate them but it suits me as I am 6ft tall!
Send me your email address and when I can find the photos I will send them to you.
Brtian Werrett
 

greg brillus

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It will be an ambitious project, but I will be rebuilding Franc's bike hopefully back to it's original supercharged specification........ My understanding was that Zoller seemed to cast the factory logo of sorts into the main blower casing. This seems to be the case with the ones fitted to MG's from pictures of ones I've seen. It would be very handy to have some factory spec pictures of the blower and drive housings.......We will probably make all the parts ourselves.......Rodney Brown, has kindly offered to assist here with all the castings needed........probably 3 for the blower and 2 for the drive housing. From the pictures i have studied, one item that looks a bit scary is the tiny oil pump mounted on the left side of the blower to inject a small metered amount of oil into the air intake to lube the rotor veins.......These were probably made of carbon, and would readily Gaul up the inner case wall if no lubrication was provided........Not unlike a rotary engine,ran without any lubricating oil in the fuel mix. Thanks to all for the pics, perhaps someone may have some info hiding somewhere.......It should be a fun if not challenging project, something different anyway. Making up that rather special oil tank in stainless............Hmmmm. Cheers for now.......... Greg.
 

greg brillus

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Hi there Brian, Yes Franc told me you had the other bike........It would be great to see the pictures you mentioned........I was looking at the detailed pictures David kindly posted above, and i can't tell if the drive housing/cover is in fact a casting or if it was fabricated from sheet alloy or stainless........It seems to have too many screws around it to be a simple sheet alloy cover. Mind you that seemed to be very common back in those days........lots of bolts/nuts holding everything together. My email address is feelinggreat01@bigpond.com I haven't started on this project yet, still busy with several others.......probably a job for next year give or take.......just wanted to do some homework to see what info can be found. We would probably be making 2 of everything rather than just one. I will not be buying and installing some other make or type of supercharger........I feel with the people i know that we should be able to duplicate the original as close as we can........Especially as Rodney is a series "A" fanatic and very keen to help out.
 
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