I read with keen interest your recent article covering the Jowett Jupiter (Motor Sport, February 1989) but I feel some points of detail need to be mentioned. Firstly that the chassis only was designed at ERA (production cars). Whilst it is true that the Jowett Jupiter has an enthusiastic following within the Jowett Car Club (which caters for all Jowett models), it is also true that a 100% dedication exists for the Jupiter within the Jupiter Owners’ Auto Club. This club was established in 1962 as it was considered that the then Southern Jowett Car Club was not meeting the needs of Jupiter owners.
I found the pictures first-class; one or two shots were even new to me. I also observed a rare showing of a Mk 1A or SC-type chassis.
1. I don’t remember that the distributor was ever driven from the camshaft, but via a skew-gear driving both it and the oil pump from crank.
2. Firing order is 1-4-2-3.
3. Approximately six chassis were produced at ERA’s, all of which were modified back at Jowett’s with some North Country logic. All production chassis were then made at the Idle works, as was the complete car.
4. Yes, a Zenith carburettor was used, but one per bank (flat four).
5. All production Jupiters had aluminium bodywork, save the bulkhead.
6. The caption for the top picture on page 157 should read Marcel Becquart.
7. The lower right picture on page 158 is HAK 268, currently being readied for further service.
8. The R1 as shown on page 157, is also being meticulously restored.
I must draw the attention of Motor Sport readers to what is considered the definitive work on the Jupiter: The Jowett Jupiter — The Car That Leaped to Fame by club registrar Edmund Nankivell, published by Batsford.
Although it is out of print now, you are advised to obtain a copy.
Steve Keil, Jupiter Owners Auto Club, Woodford Green, Essex