Jupiter restorations.

[Srenner]

I have used Jaguar, Ford and custom valves. James Miller has used Subaru valves. Stay with the smaller stem diameter (5/16" or perhaps 7mm) as too large a stem hampers the gas flow and look for valves that are relatively flat across the head as this will aid flow. A good shop can trim length and the head easily, as well as cut a groove for the keepers.

If you decide to get some valves made, a very small increase in the head size is a good thing ff you have enough meat on your NEW hardened valve seats. Bad idea to skip installing these.

Iskenderian 5005 valve springs will fit the original Jowett retainers. These are a dual spring with more seated and nose pressure than than the Jowett spec. I have run the dual Isky, just the outer spring and the Isky outer with the Jowett inner and have not had problems in any of those configurations. At one point, I decided the full Isky was too much open pressure for the RPM that the motor saw and have run just the outer spring on the race car. YOUR RESULTS MAY VARY!

The outer spring in the 5005 set used to be available, but I can't recall the part number.

I have been using Chevy bronze silicon guides machined to fit and put valve stem seals on the intakes.

[David Kemp]

Thanks for your help. Those isky springs seem to have double the pressure of Jowetts!
I think I will try just the outer spring. Do you know what Pontiac they were meant to fit?
Here Isky sells a set of 8, if I knew what engine I can probably just buy 4.
Would running a 1.5 inch intake valve be too much?

[PJGD]

In the past, I have had sets of Jowett valves made for the Club by G&S Valves in Godalming: http://www.gsvalves.co.uk/index.html

Philip

[David Kemp]

Thanks, I have contacted them. They were quick to reply saying" they supply to JCS"

on another matter valve springs appear to be pontiac 389.

[Srenner]

I seem to think they were a VW Beetle part for hot-rodded motors. Doesn't really matter, I have them on almost every motor I have built since 1990. But NEVER with the original Jowett valves. Jowett valves are not particularly strong. James Miller lost the heads on valves several times and the ones on a Sparrow motor in Jupiter 62 also suffered failure. I don't think I have used Jowett valves since my first motor build in 1989.

[David Kemp]

I have acquired a series three timing cover . however the cam stop is not adjustable, as I thought series three were.
Is this some last factory attempt to control cam float? or someones fix from bygone eras?

[Keith Clements]

I met the garage mechanic that got a payment from Jowetts for suggesting this modification.

[David Kemp]

I have cleaned up my wiper motor, and used the boot polish to brighten the plastic.
This works well on old plastic & extremely well on Bakelite.

[David Kemp]

the mechanism for the door strap is rather intricate & very corroded, does any one know of another car that shared the mechanism? I doubt Jowett alone made this part.
Also the back tail lights are Lucas st461-1 , from what I can find out are shared by Rolls Royce , Bently & AC, des any one know of another less bespoke manufacture that used them & a source (other than wrecking another jowett).

[David Kemp]

Folks a made a liner puller with my new toy a vintage lathe.
After pulling the liners can anyone tell me if the mess on the liner is the latter O ring type or someones
attempt to increase the liner lift. It appears to be made of rotten card board or leather . with copper shims.
Also the seat in block they sit on looks cruddy, is this normal before clean up?

[Keith Clements]

The original seal was a fibre ring with copper shims. Latterly the fibre gasket was replaced with a solid annealed copper ring with copper shims. This helped reduce liner sinkage.

[David Kemp]

I have all the liners out, & noticed this stud hole.
It appears to have a gap made by machining.
Is this within Jowett tolerance? Or has someone cleaned up in the past & gone a bit too far?
Should I try to weld it up?

[Keith Clements]

That is not correct. it might be just corrosion.

[Keith Clements]

That is not correct. it might be just corrosion.

[David Kemp]

A bit of an update, my local auto electrician has rebuilt the starter motor. he did his apprenticeship in 1970, when lucas parts were common. He loves their simplicity & availability of parts. total cost $110.00.
This is new bearings, brush's, spring, good used drive pinion , armature skim & all wiring tested & rebound.
I doubt I could buy the parts for that.
One weird thing in all his years he can't recall ever doing a lucas starter of this type with reverse rotation.
Jowetts must be the only car, or is there another Marque?