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Smokey's JW4 Formula Four Rebuild Thread

Mark (smokey mow)

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Good work Mark.  As the dark nights are soon upon us I'll be looking forward to reading updates

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Thanks for the kind words everyone, and also for pestering me over the last few months to get this written :)

Over the next few days/weeks i'll try to bring you all up to speed with where it is at the moment. Much like my narrow was this is very much a winter project for me and something to tinker with during the colder months so there's not much progress to report as of yet. However once the Westfield is sorned for the winter I'm expecting that to change :d

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looking forwards to seeing updates Mark (just dont let it become a Cleggy Spyder Rebuild :blush::d )

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looking forwards to seeing updates Mark (just dont let it become a Cleggy Spyder Rebuild :blush::d )

At least you still have the Spyder Clark, so there's still hope for it yet :)
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With the garage cleared, tidied and the narrow project delivered to it's new owner, finally i could make a start on inspecting exactly what I'd bought. First up the was the front suspension.


The first real challenge was dismantling everything. 40years of grime and rust doesn't make it easy to remove the nuts and bolts, but for some liberal coating with WD40 eventually the battle was won. It was surprising to see the tyres bore a manufacturing year of 1968 but were somewhat perished and a few decades past their best! My local garage were good enough to not only remove them but also dispose of for free for me so I could then get a better look at the wheels.


With the tyres gone and after a quick blow over with the pressure washer it was refreshing to see the wheels looking remarkably good and no visible signs of any damage. The wheels are 10" Cosmic RW10's and magnesium.

After a bit of discussion earlier in the year I'm still yet to get them x-rayed but it will be done before I even contemplate putting tyres back on them.



Next onto the suspension and it's fair to say that the dampers are all scrap. They're Armstrong AT7 units from classic motorcycles and no longer in production but there is at least plenty of alternatives available that I can now use, I notice that several of the classic racers seem to favour the Hagon units so that's something I'm presently looking at and helpfully they're based the other side of Essex. Usefully the Speed Series sprint at Castle Combe earlier this year also gave me the opportunity to get the springs tested to establish their rate so I can get replacements.



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The wishbones whilst covered in surface rust should rub down and clean up ok eventually to allow them to be re-used although one side is much worse than the other suggesting it's been sat for a while with one corner in the bushes. I'm also a bit perplexed at the moment by the selection of rod ends and have my suspicions that at some time the arms may have been re-tapped with a different thread. The parts list suggests that everything should be UNF, which is true for most of what I have, except the track rod ends at the hub are BSP for the lower and Metric for the upper?!

With the steering rack off the car, I also too the chance to strip and clean it ready to eventually go back on again but I was confused to see what at fist appeared to be a clamp around the preload nut.


Cleaning back the dirt and unscrewing it soon revealed some horrors that lay beneath it.



Getting a replacement casting would be out of the question so the only chance would be to attempt a repair. There's only one person locally who I could think of with the skills to repair such damage to Aluminium so after swapping a few emails with Martin at MJS fabrication it was dropped off to him for repair.

The plan was agreed to mill off the boss, then make a replacement which could be welded into it's place. This was also complicated by the fact that all this would have to be done with the rack gear still in place as the Uj's on the end of the rack have been welded on after it's assembly and so preventing any chance of the gears removal.


The results exceeded my expectations.




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top work there by Martin - wouldn't expect anything else :t-up:

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Top craftsmanship, like that weld!




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Wow, excellent work there, and a great thread to while away the winter hours. Thanks Mark!

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So for this evenings update it's the front uprights and brakes.

Braking comes courtesy of The Riley Elf paired with minifin Aluminium drums. your eyes don't deceive you and indeed those are drum brakes on the front axle!!


On the surface they all looked in pretty good condition and indeed on removing the drums, there was barely any indication of wear on the shoes or linings. I didn't take many photos of this stage, but there was only a small amount of surface rust on the backplates and the cylinders needed rebuilding. After all these years it was nice to see the wheel bearings were faultless and still packed with grease so that's one less thing to have to worry about.


Having stripped everything down, the first job was to refurbish the steering arms. The rust on these was only superficial and they cleaned up fairly easily with just a wire brush.


Painting these gave me a chance to try out the powder-coating kit I bought at Stoneleigh last year which has been cluttering up my kitchen floor for the past year. I had to improvise for the spray booth.



After 20 minutes baking with a hot air gun the final result came out well.


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On to the drums, and having shopped around on the internet for parts it actually worked out cheeper to buy complete new brakes rather than the parts needed to refresh mine. £60 for a pair seems pretty reasonable compared to the price of brakes for the Wesfield :d

The uprights were checked, cleaned and repainted then bolted to the new drums.


All bolts lock wired, to ensure nothing comes undone.


Before and after.



And finally new brake pipes fitted to link the cylinders


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