jw4 Smokey's JW4 Formula Four Rebuild Thread

[stephenh]

I take my hat off to you, Mark. I'd never have the patience (let alone the skill!) to do this, but it is great that someone can to keep these old cars alive. Or in this case, more a case of bringing it back to life.    

[Mark (smokey mow)]

good skills smokey wan :-)        This is an epic rebuild

  

I take my hat off to you, Mark. I'd never have the patience (let alone the skill!) to do this, but it is great that someone can to keep these old cars alive. Or in this case, more a case of bringing it back to life.    

Thanks guys if I'm honest, when I bought the car at the start of this year I would never have imagined quite how involved the research would become, but the more I read the more I want to make sure that the restoration is as true to original as I can make it.

[Norman Verona]

Mark, do you know how many other original cars there are and, if so, is there enough to start a race series. (Or have I missed this info)

[Mark (smokey mow)]

Hi Norman, that’s not such as silly question, but in honesty at the moment I can only guess at the number of surviving original JW4’s or other F4’s.

 

The September 1966 sales literature mentions that Johnny Walker were at that time producing 2-3 cars per week “but preparing to lay down for a very large batch of up to 200 cars during the winter months to meet home and export markets.”  However this figure is confused somewhat by Johnny Walkers own 2012 autobiography which accounts that “in total we built some 50 cars which were sent all over the world”.  I would imagine therefore that they never achieved their full manufacturing potential and the large export order never came off.

 

Of the cars produced I am aware of only 5 other JW4’s that are or may be close to their original 1960’s spec. Most I think I have spoken of on this thread before before but those I know of are:

 

1/ Bob Dustan’s car which was in Washington State, but was sold to a Thierry Linard in Belgium

 

 

2/ On the 28th September 2008 at Prescott (car 181) a 500cc Norton engine JW4/2 was sprinted by Nina Morgan.  On the basis of the engine choice I would assume this one to be quire original, although I can’t find any photos of it from the event. Our own John Loudon was also sprinting in his Westfield at that event.  Nina also appeared in the car at Llys y Fran in July 2008 (car 77) which coincidentally was also a round of the WSCC Speed Series 20 Westfield’s were entered that day. results link

 

3/ Last known in 1988 is Ken Edwards JW4/2 in Gloucestershire

 

 

4/ Again nearly 30 years ago there was Mr Clifford’s 750cc Triumph engined car in Lancaster

 

 

5/ finally there is Michael Ford’s JW4/3 which was last known in 1999.

[Mark (smokey mow)]

There were also plenty of other manufacturers in F4 as well as Johnny Walker (or Formula K as it was known on some continents) representing all the original classes of 250cc 650cc and 875cc and then later on the 1000cc catagory.

Tark Estonia (Tallinna Autode Remondi Katehas) 83 of the Estonia 15’s with Jupiter 350 engines were built between 1967-70 and 136 of the 15M from (1970-74)

http://s282.photobucket.com/user/Markkuusk/library/Formula%20Estonia#/user/Markkuusk/library/Formula%20Estonia?sort=3&page=1&_suid=138633347021706122629656630423

Tecno from Italy was one of the first of the F4 manufacturers and their Ducati engined 4K was the main competition for the JW4’s in the British 250cc classes.

http://www.wheelsofitaly.com/bluespice/index.php?title=Tecno

Vixen VB1/ VB4 were raced in good numbers in both the 650cc and 875cc Classes by drivers such as Davrian’s Pat Longhurst and 3 times BTCC Champion Bernard Unett.

http://www.turrinowirewheels.com/news/vixen/

http://anarchadia.blogspot.co.uk/2010/06/vintage-thing-no64-vixen-imp-formula-4.html#!/2010/06/vintage-thing-no64-vixen-imp-formula-4.html

Evad 4 exhibited at the 1967 Motorsports show together with Johnny Walker

http://www.imps4ever.info/specials/evad-4/evad-folder.html

LeGrand Cheetah from California used a 700cc BMW motorcycle engine

http://www.conceptcarz.com/vehicle/z16684/LeGrand-Cheetah-MKI.aspx

Ginetta G17 only a handful were made (4-6 approx) and ran the 1 litre imp engine

There was also various one-offs and specials

Noel Clutterbucks Formula 4 Special

http://forums.autosport.com/topic/155087-motorbike-powered-race-cars-in-australia-1950-1980/

Voigt Renquik Special which was a highly modified JW4 developed for sprints and Hill climbing in the 1970’s

The following other cars and drivers are also known to have competed in British F4 races between 1966-67

Colt F4 (875cc) – Laurie Billing

Davbon (875cc) – Bob Jarvis

Blaycar (250cc) – G. Blaynee (entered by Keith Blaynee)

Speedcraft (650cc) – Derek Forrester & Roger Keele

Mantis(650cc) – M.J. Crowther

Briham F4/2 (650cc) – P.Orr (entered by Briham Racing)

FR4 (650cc) – Douglas Niven (entered by W.Rochfort)

[Norman Verona]

I guess it'll be best to finish the rebuild and then get it on a s many motorsport forums as possible. Of course you could contact Classic & Sports Cars to see if they want to run an article, they may be interested if you do the words and photo's - it's free editorial (as long as it's up to their standards)

 

Thanks for the info, looking forward to the next chapter.

[Mark (smokey mow)]

Final update before christmas

The lead I've been following about the 1967 Olympia Motorsport's Show is proving to be quite fruitful. What initially begun as a picture in a children's book took me further to some text in the show guide and now I've managed to obtain (all the way from Belgium) a couple of original press photos from the show.

Considering the prints are now 46 years old they're still in remarkable condition and the quality and crispness of the images is superb. The detail photo of the rear suspension wears the stamp of the photographers Larkin Bros Ltd of High Holborn and the words "Formula 4 Class 2 650 Norton Engine.

The second photo has a stamp on the from the "Central Photographic Unit" of the now defunct "Fort Dunlop" tyre factory in Birmingham.

[alexander72]

regulation totty in the driving seat there Mark 

[Doug Dastardly]

Drivers were certainly prettier in '67

[luxseven]

No silencer! Must have made a lovely noise!

Cheers and Merry Christmas.

 

Jos

[Mark (smokey mow)]

The last few days I've been messing about trying to complete a few of the drawings so I can begin getting some parts made, first up is the rear uprights. I've lost count of the number of times I've drawn and then redrawn them again till i eventually settled on a design I was happy with. I've looked at all options from modifying something existing, fabrication from sheet steel and eventually casting.

Casting has always been my preferred option since that's how the cars original uprights were made, but the difficulty to date has been that of coming up with a shape which minimises tooling and machining operations so as to keep the costs lower. Ultimately the design I'm settling on only requires a 2piece mould for casting (split vertically down it's centre line) and machining is limited to the centre bore for the bearings and a facing cut to the rose joint mounting bosses.

The shape is slightly meatier than the JW4's original uprights, but this is mainly because I'm planning on casting in Aluminium rather than Magnesium like the originals.

For peace of mind and also as a checking exercise, I carried out a very quick stress analysis on the upright. Solidworks which I'm using for the 3D design work comes packaged with a very basic FEA application.

Predicting loading on suspension components without the benefit of physical test data is not an accurate science so I had to make a bit of a liberal guess at some of the loadings involved. Principally my modelling looked at the potential torsional loads on the upright and the affects of a wheel striking a kerb or fixed object.

The first image below indicates the areas which have a factor of safety of less than 2. It's difficult to see in the picture but there is a small red area showing in the fillet blend between the main body and the lower legs. This was easily resolved by increasing the fillet radius, but in reality I would expect to see an improvement were the modelling carried out with bearings fitted in the castings.

The second model shows the overall distribution of stresses, red for the highest stresses and blue for the the lowest stressed regions. Again the highest stresses being centred around area where the bearings are housed and the casting is at is thinnest.

Overall I'm quite happy with the results so the next stage now is to progress the design and model to include both shrinkage machining and shrinkage allowances (1.3% in the case of LM31 Aluminium).

Once the 3D model is completed it's then on to producing the two dimensional machining drawings needed to enable meet to finalise some quotes for them to be made

To date here's probably about 30hours work gone into the 3D drawings of the uprights (not including all the earlier designs I discounted) and then another 15 hours for the following 2D drawing much of which has been spent working on machining tolerances for the bearings. There's still a few more hours left to go on them before I'm ready to send the drawings off for the patten making, casting and finally the machining.

[XTR2Turbo]

Top stuff.  Will there be a chance to sell them also once the patterns are made.  I'm figuring that a small run won't cost much more than a one off

[TIG Brother]

Now this is my idea of a rebuild thread. - good work Mark!!

Have been reading this in the background since you started the thread.

Just please tell me you are not going to chrome everything?

What edition of solidworks are you using? just 15 hours on a 2D drawing seems a little in the AutoCAD days.

The choice of going cast on the uprights I think it's a great idea. As you say keeps the car more in the style of the original era.

Looking forward to seeing how things pan out with this.

[Mark (smokey mow)]

Top stuff.  Will there be a chance to sell them also once the patterns are made.  I'm figuring that a small run won't cost much more than a one off

the patten and machining will be the two highest costs, in the scope of things the casting process is actually the cheapest. I'm aiming to get a couple of extras cast to hold as spares but not machined.

TBH I'm not sure how much of a market they'd be for them, but if someone wants a pair then the opportunity will be there for others should they want some made in the future.

[Mark (smokey mow)]

Now this is my idea of a rebuild thread. - good work Mark!!

Have been reading this in the background since you started the thread.

Just please tell me you are not going to chrome everything?

What edition of solidworks are you using? just 15 hours on a 2D drawing seems a little in the AutoCAD days.

The choice of going cast on the uprights I think it's a great idea. As you say keeps the car more in the style of the original era.

Looking forward to seeing how things pan out with this.

Thanks mate

I promise to keep the amount of chrome to an absolute minimum F4 was after all a low cost racing formula, the only parts which were orignally chromed being the wishbones. The rest of the steel parts were either cadmium plated or enamel painted.

I'm running solidworks 2004 it's the last copy I had bought for me before I left Engineering, but for what I'm using it for its perfectly adequate. I doubt I'd be able to do what I'm doing on a 2D CAD package, I initially started on 2D with HP ME10 before moving onto Solidworks and then Pro E/Mechanica for FEA work.