jw4 Smokey's JW4 Formula Four Rebuild Thread

[Mark (smokey mow)]

The last parts for the axle  were finally ready for me to collect from the fabricators this week so finally I could complete the assembly of all the parts.

The delay was due to the difficulty in machining some of the parts.  The axle itself is made from 3 parts, the end of which is a cut down front axle from a Classic mini.  The mini axle needed to be turned down so it could be located within a corresponding recess in a ground steel shaft that would ultimately run on a pair of kart bearings, but we hadn't factored that the mini axle would be hardened steel.  Three lathes of ever increasing sizes later and we could barely make a dent in it so eventually the decision was made to send it away to be ground to the appropriate profile. 

The brake drum flange is likewise made in a similar way by turning down the mini drive flange.

After a trial assembly I found the drum wasn't quite sitting as close to the backplate as it should do as it was bottoming out on the spline so it was onto the mill to take a few mm off the face.  I've not owned the mill for long having picked it up a few months ago in the bargain area of my local machine mart so I wasn't too sure how well it would cope with the job in hand, but as it turned out everything went fine.

That photo reminds me that I must get tidy the work bench some time soon.

[Alan Cutler (Adge) - Dorset AO]

Following this with ever increasing respect for your engineering skills. Great to see more progress.

Don't forget, if you tidy your bench, you'll never find anything again, if you're anything likes me!

[Mark (smokey mow)]

2 hours ago, AdgeC said:

Following this with ever increasing respect for your engineering skills. Great to see more progress.

Don't forget, if you tidy your bench, you'll never find anything again, if you're anything likes me!

Thanks, I can't take too much credit for much of the engineering as other than drawing it and then bolting it all together At the end I have to rely on other people and businesses to do much of the welding or machining.  I'd love to have a better equipped workshop but I just don't have the space for all the tools I'd need.

[Mark (smokey mow)]

Next up was a job I hadn't planned to do but after a chance meeting and a discussion at the Maldon car shown earlier in the year I decided that I'd get one of the seats covered. Back in the 1960's the original race seats were covered in a padded black vinyl which offered a degree of comfort but I'd originally planned to use the plain black shells for my rebuild rather than having them covered. The bare shells offer a bit more room for the larger driver and also being a race car would mean they're easier to dry after any wet weather. I'd already intended to get the steering wheel recovered as the vinyl was worn through and torn in a couple of places, but since I had a spare seat shell I though it'd give them that to try too.

 

The company who did the wheel and seat for me is County Coachtrimmers near Maldon and I have to say what a cracking job they've made of it.  The wheel looks like new now, but More so I'm very impressed with how the finished seat has turned out.  I gave them one of the old seats as a patten to work to for the stitching and they've matched the original beautifully.  

[jeff oakley]

I have read this thread and like others I am very impressed. Your attention to detail and getting things right is up there with the best.

Building anything is hard to do so from drawings and a set of basic bits is in another league. Wish I lived near to come and have a closer look at your work

[Mark (smokey mow)]

On 9 September 2018 at 18:24, jeff oakley said:

I have read this thread and like others I am very impressed. Your attention to detail and getting things right is up there with the best.

Building anything is hard to do so from drawings and a set of basic bits is in another league. Wish I lived near to come and have a closer look at your work

Thank you Jeff, you or anyone else would always be more than welcome if ever in the area.

[Mark (smokey mow)]

There was only time for a few small jobs this weekend but that was enough to prime and paint all the parts and then complete the final assembly.

This is everything that makes up the rear axle.

 

And then fully assembled  

[Mark (smokey mow)]

No photos to show (only a drawing) but knowing I was going to be having a day off work today I thought I'd take the opportunity to get the chassis for the Carburol Special booked in at the fabricators for the missing body mounts and a few other ancillary brackets to be welded on.  These I'd all had laser cut during my last order and were folded up so an easy job to weld into place.

 

With all this completed by luchtime it was loaded back into the trailer for it's next journey which was to the powdercoaters  

Due to the surface rust I've gone for the full pre-treatment of shot blasting, zinc priming and then powdercoating so it'll be a couple of week wait now before I get to see the finished result.

Then the final assembly will begin

[Mark (smokey mow)]

Whilst the chassis has been away at the powder coaters it's given me a chance to get on with a couple of other small jobs.  First off I thought I'd better clear the workbench! Two days of tidying later and I could finally see the surface again. 

Now I could use the bench again I was able to make a start on assembling the engine. The castings were given a good clean up to remove all the oil and grime whilst the covers were cleaned up and polished.  To save a few £££ and since I had a bit of free time I thought I'd have a go at trying this for myself.  begining with a 400grit paper and working up through to 2000 grit followed by a final polish with the bench grider the results were pretty good but it took ages and a lot of sweat.

[Mark (smokey mow)]

Finally whilst I'm typing updates today I collected the chassis back from Powdercoating.

I'd not been able to establish the exact colour Johnny Walker used for his cars, other than knowing it was a shade of grey. In the end I settled for RAL7040 which these days is more commonly known as "window grey" but also happens to be the same colour that Cooper, Lotus, Van Diemen and Jedi have used for paint their chassis. 

[Kit Car Electronics]

26 minutes ago, Mark (smokey mow) said:

Finally whilst I'm typing updates today I collected the chassis back from Powdercoating.

I'd not been able to establish the exact colour Johnny Walker used for his cars, other than knowing it was a shade of grey. In the end I settled for RAL7040 which these days is more commonly known as "window grey" but also happens to be the same colour that Cooper, Lotus, Van Diemen and Jedi have used for paint their chassis. 

same colour as my cement weather boards - let me know if you need any to clad it

[Dave Eastwood (Gadgetman) - Club Chairman]

Always amazes me just how tiny the chassis looks!

[Mark (smokey mow)]

10 hours ago, Dave Eastwood (Gadgetman) - Club Secretary said:

Always amazes me just how tiny the chassis looks!

It's pretty snug Dave, if I was to put on much more weight I probably won't fit!

[robhume]

Mark, the JW is looking really good and looking at your chassis drawing reminded me how little protection

there is for feet.

It particularly brought back memories of being towed up Lanark High street with the bodywork off,  trying to get the Bonneville engine

to start and seeing my feet sticking out front, eventually ending up being escorted back home by the local plod, who I have to say were very good.

Are you trying for Crystal Palace next year?

[Mark (smokey mow)]

7 hours ago, robhume said:

Mark, the JW is looking really good and looking at your chassis drawing reminded me how little protection

there is for feet.

It particularly brought back memories of being towed up Lanark High street with the bodywork off,  trying to get the Bonneville engine

to start and seeing my feet sticking out front, eventually ending up being escorted back home by the local plod, who I have to say were very good.

Are you trying for Crystal Palace next year?

Hi Rob, you're right that the feet forward position is not great! One of those things that was ok at the time but now with a bit more knowledge and an eye on safety the design could somewhat be improved.  Remember the JW4 originally also carried the fuel tank in the nose in front of your feet! At least with such a small amount of power, if i were to crash I wont be going that fast.

All that said, the Carburol Special does have a few extra tubes in the nose and pedal box area, which I'll also be sheeting in aluminium so that will offer so additional and much needed protection. You can see the additional nose tubes in the picture below.

I've been looking at Crystal Palace as I missed it last year but being relalistic with this car my entry will more likely be as an exhibitor rather than as a competitor.