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Smokey's JW4 Formula Four Rebuild Thread


Mark (smokey mow)

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Mark (smokey mow)

After an overnight stop at the Premier Inn, I was welcomed once again by Brian Lowe and Vanessa Pickup.

There's no hiding from Jos and Dom that there's now a second JW4 in my garage :oops::d I don't have any history for this chassis other than the visual clues which it offers to it's past. Notably the nose structure has been altered to form a crash structure around the pedal box. Both this and also the side tubes of the chassis have been drilled in a manner that suggests at some time the chassis has been skinned in aluminium panelling possibly much like this JW4 of A Bailey photographed at Prescott in 1968 and the JW4 chassis'd Voigt-Renwick Special which through it's success in hill climbing takes some credit as the inspiration behind the modern trend in bike engined single seaters.

The engine for my latest JW4 is somewhat modest and goes back to the roots of formula IV, this car will be built as a class 1 car with a 250cc Villiers Starmaker Engine. The Villiers Engine was one of the first to feature in a JW4 so it's quite appropriate that this car will be rebuilt to include one. Wheels are taken care of with a set of JA Pearce Magna Mk1's.

In the van was also loaded 2 sets of bodywork, the first is very usable for the new car whist the second shows a lot of damage but would be useful for mocking up purposes.

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Sitting alongside the bodywork though is the main items that interested me which is a complete set of JW4 body moulds. Ironically I have some letters on my history file that suggest these moulds may have originally been taken from my bodywork :d

There's a few other smaller items as well such as engine spares, seats, a screen and some more uprights but that for now pretty much concludes a very successful shopping trip.

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Final picture for the day before I zipped the car back in its Carcoon .  

Or is it… About a year ago I posted on this thread that I was hoping to have my car completed and running in time for the 50th Anniversary of that first race, and I’m sure many of you may now be wond

Only a small update as I've been back on the DIY for the last couple of weeks.   There's not much left to do now but one of the jobs was to fit the chain.  This was on the list to do a few w

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One of my favourite threads this, I might just read it all again and watch it unfold.

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Mark (smokey mow)

One of my favourite threads this, I might just read it all again and watch it unfold.

Thanks Dom :t-up::)
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KugaWestie

Another successful trip oooop norf Mark

 

When do you start production  :d

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luxseven

Hi Mark,

 

Your hidden agenda may be to start a JW4-race-series all on your own, isn't it  ;)

Cheers.

 

Jos

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Mark (smokey mow)

Your hidden agenda may be to start a JW4-race-series all on your own, isn't it  ;)

 

When do you start production  :d

No plans for that just yet :d for now I just want to get my two JW4's finished and racing again. After that if I can help to keep other cars running then or help to provide any spares then that would be great.
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Mark (smokey mow)

For tonights update I thought I'd look back at one of the other manufacturers that participated in Formula IV, Briham.

Briham was established by brothers Peter and Brian Hampsheir. The pair are more famously known these days for their involvement with Elden racing cars with which they received some notable successes in Formula Ford.

The Briham F4 car was first shown to the public at the 1967 Olympia Racing Car Show, an event which was also supported by both Johnny Walker and Evad. the write up for their stand in the show guide reads as follows:

Briham.gif

Up until recently the Briham has been something of a unicorn car to me. both fabled and mythical, I had seen it listed on results sheets from races and on the 16th July 1967 P.Orr drove an F4/2 Briham in the Formula IV race at Brands Hatch, however finding images on one had proved elusive.

Almost as much an unknown to me was the material Mallite used in the construction of the Full Race Chassis. Mallite as it turns out (thanks to Wikipedia) is a laminate composite with a balsa wood core skinned both sides with duralumin which is an age hardened aluminium alloy.

The very first McLaren prototype the 1966 M2A used Mallite extensively in it's construction although it's more common application at that time was in the construction of flooring an partitions in aircraft.

After learning that a Briham had survived I was eager to see the car during my latest visit to help complete my history and research.

Pulling off the covers I suspect this is the first time in years that the car has seen the light of day, but through the dirt and cobwebs there were many features of the car that were familiar to myself with both the front and rear suspension uprights being the same as my own car and also the Vixen F4 I had seen earlier this year at Race Retro.

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The noticeable difference with the Briaham is the inboard suspension and the position of the rear shocks inboard offers very little piston movement relative to that of the wheel.

Like the Vixen and JW4 the Briham has no rear diff, but rather than using a single inboard drum or disc there are two drums mounted conventionally outboard in the wheels.

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With the rear bodywork removed the Mallite and fibreglass composite chassis was obviously visible and there was surprising little spare room in the engine bay around it's 650cc Triumph engine. This was a problem which beset the car and lead to issues with overheating in races due to the lack of airflow around the engine.

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Up the front and like the other F4 cars there is very little crash structure forward of the steering rack and your feet and the pedals are really exposed at the front.

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Peering down the footwell the inboard shock absorbers are evident hidden behind a pair of curved aluminium guards which offer very little leg room I later found out.

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As you climb behind the wheel it is quite a challenge to thread your body through the narrow tub and I found it virtually impossible to fit both feet at once through the narrow gap between the front shocks. Sitting behind the wheel the driving position is very reclined, you lay virtually on your back with arms outstretched to the steering wheel. The gear shift sitting just to the right of the wheel.

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There's no getting away from quite how tight the cockpit is though and even with my 10stone frame I found it uncomfortable. The chassis construction has somewhat compromised the driving position (something I haven't noticed in the JW4) as your knees are pressed hard up against the underside of the Mallite bulkhead whilst at the same time your calves are squeezed inward by the suspension.

Brian Lowe intends to rebuild this car himself to bring it back to it's former glory and I wish him well. The project is complete but the years haven't been kind to the chassis and it will take some work to clean up the rust and recommission the engine.

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What a fantastic read Mark, this has kept me engrossed for the last couple of hours and I'm really looking forward to see the progress. Very impressed with your attention to detail and originality for the JW4. Great work!

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Mark (smokey mow)

Mucking about in the garage earlier working on one of the other cars it was difficult for my attention not to be drawn occasionally to the chassis hanging from the ceiling. Eventually I had to give into temptation and started to remove a couple of the rusted up rivet clamps that were temporarily holding the aluminium panels in place.

The chassis is definitely that of a JW4 and the light steel bracing tubes are still present among the heavier alterations, but it's these differences and obvious modifications to it that would suggest that it's later history has been different to most JW4's

Up front extra tubes have been added that widen the nose slightly and form a box that would have enclosed the pedal box. The tubes bear the witness marks and holes that show this area and the sides would have been panelled.

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In the centre of the car the tube that carries the wishbone mounting has been doubled in width and a more recent addition includes a hoop in front of the steering wheel formed from roll cage tubing.

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At the rear a substantial frame fills the base of the engine bay where normally this would be empty of any tubes.

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My previous searches for a chassis number in the usual places at the rear had been unsuccessful but in better light I spotted a subtle weld bead on one of the top chassis tubes that was not evident in the same spot on the opposite side suggesting this may be a chassis plate ??? There was still no suggestion of a number on it so it was time to break out the wire brush to clean away some rust to get a better look :oops:

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So what was the Carburol Special? Well I recall Brian having referred to the car as such when I first saw it back in March although I must confess to having forgotten it amongst everything else.

Google, comes to the rescue here offering a program and results from Harewood Hillclimb on 20th April 1975 where John Shapley was entered by Carburol Products in a car powered by a 1015cc Kawasaki engine. The same car and driver then later appears on the 1st August 1976 Harewood results sheets with a best time on that day of 45.36s to complete the hill.

Luckily the Harewood website also offers us a glimpse of what this Frankenstein car looked like back in 1975.

http://harewoodhillhistory.co.uk/blog/wp-content/flagallery/1975-july-british-hillclimb-championship-copyright-steve-wikinson/john-shapley-caburol-kawasaki-harewood-bhc-75.jpg

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Mark (smokey mow)

Finally some build progress :)

Well after several months of reading, researching and gathering it had to happen at some point and at last there's been some progress with the build.

It's nice when the day finally arrives that brings shiny new parts and nothing comes much shinier than a new set of wheels.

Back in the day the JW4 was available with a small number of wheel options; as standard steel wheels were supplied but optionally either Cosmic RW10 or the JA Pearce Magna were offered. When I bought my JW4 it also came with set of magnesium Cosmic wheels but these have been causing me a few problems so I began looking at other options.

Minilite's and Revolutions were an obvious choice, as were the Dunlop D1 but none of these to me were really within keeping with the styling of the car and nor were they original fitment on the JW4. It was then that I by chance discovered that JA Pearce had been reincorporated again in 2012 after the companies original dissolution back in 1973 and were remanufacturing the Magna wheel in very limited numbers. Perfect timing for me ! :)

For those that are interested the following links offer some history of the JA Pearce Magna wheels and also the extensive process in casting and manufacturing them.

http://japearceengineering.com/products/magna-wheels/

http://japearceengineering.com/general/reinventing-the-wheel/

At the weekend I finally got to see my new wheels for the first time and this is one of my own wheels :cool: I'm very happy right now :cool: next job is to order some tyres for them :)

JAPMagnaWheel.jpg

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Nic (NICO) - Shropshire and Mid-Wales AO

Very nice Mark. Good to see your devotion to originality. There is a fair amount of work involved in making the wheels.

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luxseven

Wow, great craftsmanship. Any indication of the price-tag?

Will you opt for the magnesium or steel?

Cheers.

 

Jos

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Excellent updates and story so far - that Briham certainly looks interesting with a combination of "modern" inboard suspension yet fitted with outboard drum brakes at the rear !! (and as for that narrow slot you put your legs through ........ :cry: ). I guess we didn't worry so much in those days...

 

Those JA Pearce wheels are certainly iconic of the era - I can't remember exactly when I lost saw a set - may have been on an early Marcos? It's good that they have enough orders to be back in business.

 

 

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alexander72

Absolutely top class Mark - a joy to read - thanks mate 

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