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Mark (smokey mow)

Smokey's JW4 Formula Four Rebuild Thread

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So what choice of finish do you have in mind for the uprights?

And just out of interest where did you get the specification of LM3 for the material, it's not one I have come across

Wouldn't fancy having to bore the center to your 4 decimal place tolerances though. ;)

Spend my life attached to solidworks these days. Amazing piece of kit.

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The castings will be enamel painted :)

I was guided toward LM31 by the foundry, I'd originally been looking at LM4 due to it's machining properties but ultimately LM31 has a much better tensile stress and good shock resistance which would be favourable in this instance.

Fear not about the machining dimensions, you may not be able to read the title block, but the general tolerance for dimensions without a higher tolerances indicated is only +/- 0.1mm.

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Ah it's LM31 not LM3. The title block is a little blurry and I mistook the 1 to be a ' )' in the material spec.

That will be why I couldn't find it ( doh! )

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crikey Mark these are pretty spectacular drawings to my clueless eye :oops:

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have to see these in the flesh when they're done :)

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Smokey,  I've followed this thread with interest and I, for one, am very impressed by your appication and research.   I cant wait to see this car in the flesh and on it's first lap round one of the classic circuits ! Great work !!!

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crikey Mark these are pretty spectacular drawings to my clueless eye :oops:

Thanks Dave :t-up: this was my day job for 9 years so hopefully I can still remember what I'm doing.

Smokey,  I've followed this thread with interest and I, for one, am very impressed by your appication and research.   I cant wait to see this car in the flesh and on it's first lap round one of the classic circuits ! Great work !!!

Thanks James, getting it back on the track is a big part of the motivation which keeps me going. I love to take it back to all the UK circuits where F4 raing took place in the 60's.

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Smokey, If `I buy some white overalls and a flat cap can I be your pit crew??  I will even bring some Craven "A"  :d

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Smokey, If `I buy some white overalls and a flat cap can I be your pit crew??  I will even bring some Craven "A"  :d

you'd be welcome :) with no kick start or on board starter I'll be needing someone to give me a push start at the sprints and hills :oops::d

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Smokey,  I have sufficient ballast at the moment to push you up the hill - and I need the exercise.  This really is a cracking project.

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I’ll be writing another update soon on the progress made over Christmas, there’s been a lot of headway in the drawings and I’m relieved to say the models are now completed at least in 3D for the fabrication of rear driveline, I now I just need to translate those into 2D to be laser cutting.

In the meantime the search has been continuing for photos and articles and I was very pleased to find this over Christmas and it finally arrived in this morning’s post. The eagle eyed amongst you will notice that it’s not an English book :oops: as I tracked this copy down in the Netherlands :cool: it's been a fun afternoon translating it into English :d :d

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Johnny Walker JW4 MkII Formula 4

A program consisting of fourteen Formula 4 races, held on the circuits including Brands Hatch, Oulton Park, Mallory Park and Snetterton, attests to the growing interest which the Formula 4 racing in England since 1966 befalls. These start-up classes of racing cars (to date it has only a few major brands) have a mandatory capacity of 250 or 850 cc.

During the first official Formula 4 showdown, which took place at Mallory Park in England, there appeared in addition to some Tecno and self-built cars, two factory JW's, ridden by Derek Minter and Kelvin Heskith, and two private cars also of the same brand. The final victory belonged to Minter, who was the sole JW racer to finish the race; one of the two private cars refused to go from the start, while the second, fitted with a Ducati motorcycle engine suffered mechanical problems and stopped halfway through the race.

On August 14, 1966 competition was fought at the small English track of Lydden Hill. This circuit proved to be ideally suited for Formula 4 races and Johnny Walker went there personally with a Villiers engine equipped JW4 for the victory. The average speed was around 95 km/h, a speed which for Lydden Hill comes near to that of a 850cc Mini, a beautiful performance so for a quarter of a liter.

The chassis of the JW4 MkII is constructed of steel tubes, which have under gone a thorough anti-corrosion treatment.

The drive is to the rear axle and via two half shafts, which run in self aligning Pollard bearings, these also serve as supporting elements for the rear brakes. At the wheels are mounted Mollart couplings, while Metalastik rubber fittings on the motor side of the axes ensure the transmission of the drive torque. Both axles are made of EN-24 steel.

Wheels are 10 x 4½"pressed steel wheels with Dunlop SP41 tires. The brake system consists of drum brakes, which are manufactured by Lockheed, type 2LS with two cylinders. The drums are made of a light alloy and equipped with a large number of cooling fins, the total brake surface area amounts to 387.12 cm2.

Both the front and the rear suspension use unequal length wishbones and Armstrong combined shock/spring elements. All steel parts feature a cadmium coating.

By means of a steering column, which is supplied in various sizes, the steering movement is transferred to a rack and pinion reduction. The diameter of the steering wheel is 279.4 mm.

The fiberglass body consists of three parts: the front, on which is mounted a Perspex windscreen and two rear-view mirrors, the engine cover and side paneling, with which both sides and the underside of the car is closed. The instrument panel is equipped with a Smith magnetic tachometer having a range of 0 to 10000 r/min and a contact switch. The factory fitted 247cc Villiers Starmaker engine gives maximum power levels of 31.2 brake horsepower developed at 7400 r/min. The four-speed gearbox is synchronized on all forward gears. From an 11½ gallon tank, housed in the front of the car, an AC fuel pump pushes the fuel to the float chamber.

Some weights and measures:

1892.3mm wheelbase, track width 1155.7mm ground clearance 76.2mm, height 812.8mm body length 2806.7mm.

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if you had access to solidworks 2014 Mark, converting profiles for laser cutting has become a 2 click process, they have really work hard on that function.

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if you had access to solidworks 2014 Mark, converting profiles for laser cutting has become a 2 click process, they have really work hard on that function.

I'd love to upgrade my existing licence but for the amount I'm using it I can't justify the lottery number quotes I'm getting to buy the latest version.

3D to 2D conversion still isn't that difficult for me though, it's just I also have to draw the assembly and machining drawings to go with them :oops:

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The drawings are the easy part surely unless your having to actually sketch the assy from scratch?

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The drawings are the easy part surely unless your having to actually sketch the assy from scratch?

It's just the quantity which is killing me. The Solidworks model presently consists of 107 individual parts and 51 assemblies, all of which need detailed 2D drawings for either turing, machining or welding :oops:

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