Carburettors

[Keith Andrews]

you can tig repair and re tap..
Best guys to see about tigging stuff like this are aircraft certed welders at the local aerodrome....and a bottle of chivas.
They will take one look at the thead say what it is and ask if u want them to re threadt.

[Forumadmin]

Spent the day transferring bits to the replacement carb body, rearranging the petrol pipe so it did not foul the choke actuator now on the wrong side, designing a bracket to hold the choke cable that had been used instead of the rods for the Dellortos, drilling the body to head bolt holes as they are not standard on a Jowett, and setting up throttle linkage. If you have a close look at a Jowett carb you will see the holes have been filled with weld and holes redrilled and the choke actuator on the offside has been braised on. Were these Jowett mods or done by Zenith? The choke braket came with one of the spare Zeniths and with some redrilling and bending did the job.

Anyhow car started first time on the button but continued to run fast until three throttle return springs were fitted. Hopefully , the car is now mobile!

[george garside]

many years ago I had a Jupiter (E2SA568) that was fitted with a pair of downdraft SU carbs (fitted by previous owner not me!) They worked very well, providing smooth flat spot free progression from about 25mph to a speedo 90 in top and giving around 36 mpg on long runs running at around a speedo 75/85mphmph on motorways and wherever else posible.

There were however 2 snags that I never fully sorted.

1. the choke arm (jet lowering arm) on the dynamo side was unable to be used as it fouled the dynamo - no problem starting on t'other carb in summer but a complete bugger in winter solved only by a sqirt of ' quick start stuff) down the relative air intake.

2. when jet adjusted to give best economical high speed running tickover was poor an;d various different needles failed to rectifyu this but I am sure it would have eventually been sorted.

I have never come accross another Jup with downdraft SU's - are th;ere any about - or indeedJavelins so endowed..

george

[Forumadmin]

I did have a pair of SUs that were fitted to a Jav engine I acquired. They just did not look right! They had a large balance tube holding them together.