jw4 Smokey's JW4 Formula Four Rebuild Thread

[Gary Taylor]

what a buetifull car , I love this thread  and enjoy your updates, good luck with the progress

[Mark (smokey mow)]

Once the shocks and springs were sorted, one of the other parts I'd been putting off ordering was the exhaust expansion chamber. I'd had it drawn since the summer, but I'd been holding off placing the order until I was happy that there wouldn't be any interference between it and the roll hoop.

What looks like a simple enough design proved difficult to find a manufacturer as rolling the small diameter cones from stainless steel isn't as easy as one might think. I owe thanks to John Danby Racing, who have helped me in the past with various parts and who eventually sourced a fabricator to make the expansion chamber.

I only picked it up on Friday, but it didn't take me too long to fit it to the car next job is to make a bracket to support the end of it.

[KugaWestie]

I love the look of that exhaust!

[Mark (smokey mow)]

I love the look of that exhaust!

Thanks Gary I'm really pleased with the way it turned out

[Mark (smokey mow)]

When it comes to instruments the JW4 is about as basic as it comes, the standard fitment on the 250cc cars was nothing more than an on-off switch and a 10,000 rpm tacho. 

 

With the engine being an air cooled 2-stroke and with starting by means of a good push, there is none of the complexities of instrumentation, warning lights or indeed wiring. 

 

With no need for a battery to run the engine choosing a tacho for the car was a difficult choice and with limited optons, however, in the end I settled on the Scitsu Classic Racing Tacho for the car.  It's not quite original for the period, however it is a favoured option amongst the classic bike racers and more importantly for me it is powered by it's own internal rechargeable battery. 

 

[reeves_luke89]

Just read the entire thread. Transformation is great to see, 30 minutes for me 3 years for you!

[luxseven]

Honestly, who would know the tacho is not period? Haha!

It looks very good and suits the car, and I wonder where you found it (any address?).

Coming together nicely, isn't she?

Any schedule you want to have her finished?

Cheers!

 

Jos

[Mark (smokey mow)]

Honestly, who would know the tacho is not period? Haha!

It looks very good and suits the car, and I wonder where you found it (any address?).

Coming together nicely, isn't she?

Any schedule you want to have her finished?

Cheers!

Jos

thank you Jos, finding the right parts for the car has always been the most difficult job and I must sprend 10x as long on the internet reading as i do in the garage actually working on the car. Wherever possible I've been trying to use parts from the right period, however there are a few occasions when these simply aren't available any more and I need to source something different.

The archive of information, photographs and of course the original drawings have been a massive help in piecing together this massive jigsaw and without them I'd be completely lost. Also luck and good furtune has helped me along the way.

The original plan was to have the car complete and runnning by the 15th May this year which is the 50th anniversary of the first race taking place. I'm going to miss that deadline but not by much. I still have the roll bar, fuel tank and few control linkages to complete, after which the car will be stripped back down to paint the chassis and then reassembled again with all the brake lines in place. Realistically this could be finshed by the end of the year.

Once this ones done though I then have the Carburol Special to start on. The history of that car almost deserves another thread of its own it should be an easier build as I already have most of the parts for it now.

[Mark (smokey mow)]

A little bit of progress this weekend but not too much.

 

Firstly after a 16 week wait, and 10 weeks later than it should have been, the new carb arrived for the engine.  I'd hoped to get it bolted on straight away but I've just found that I've run out of UNC bolts in the right size 

 

 

Next up, I turned some spacers on the lathe for the shock top mounts to replace the stack of washers I had been using.

 

 

 

[Mark (smokey mow)]

The final item on the list of jobs today was to look at options for the fuel tank.

 

I'd never been happy in the knowledge that the original tank was located in the nose of the car but it wasn't until today when I finally got around to modelling it onto the CAD from the old drawings did I realise quite how dangerous it's placement actually was. Surfice to say, that in the interests of safety I wont be putting mine there.

 

[Luapno]

fuel cell ? http://www.atlltd.com/C/Products/Motorsport

 

Bit on the expensive side but will not erupt in flames if you hit the tyre wall 

[Kit Car Electronics and Essex AO]

where else do you have space? On your lap?

[Mark (smokey mow)]

fuel cell ? http://www.atlltd.com/C/Products/Motorsport

 

Bit on the expensive side but will not erupt in flames if you hit the tyre wall 

 

I agree for a modern car, but not for me as I'm restricting myself to parts and technology that are in period to 1966.

where else do you have space? On your lap?

With an engine capacity 1/6th the size of my Westfield there's loads of room in the engine bay

The Mk1 type 65 Johnny Walker ran the fuel tank in the rear so thats how I plan to do mine too.

http://images.britishpathe.com/?id=55162&num=24&size=still

[Rory's Dad]

What a dear little tank - you could find one like that on an Atco motor mower!]

[Mark (smokey mow)]

What a dear little tank - you could find one like that on an Atco motor mower!]

 

Ah Brilliant, thanks Martin, I'd been trying to find a fuel tank that looks similar and I hadn't thought to look at loawnmowers I thought first off that it might have been a Kart part.

 

I'm now loking at things like this on ebay