jw4 Smokey's JW4 Formula Four Rebuild Thread

[Mark (smokey mow)]

I've had a bit of time this week so have managed to get a few more jobs completed.  Sometimes even the simplest of jobs can take an hour or more to complete and that was certainly the case with the gear knob.  I'd got one in the box of bits that suited the car quite well but it screwed on with an M8 thread and I needed 3/8 UNF for the top of the lever, so I'd need to make an adaptor.  Luckily I had an offcut of 3/8UNF studding so in the lathe I reduced the diameter at one end down to 8mm and then cut an M8 thread so one end could screw into the lever and the other into the ball.

I also bent up the seat mounts.  For metal folding I use a vice brake which is a very basic vice mounted folder that will bend upto 3mm steel with ease. I have used it on 5mm but I wouldn't reccomend that 

[Mark (smokey mow)]

The shocks also arrived from Protech yesterday.  I'm yet to finalise spring rates for this car as on the first JW4 i had to get a set custom made as they originally came fitted with 85lbs at the front and 105lbs for the rear.  This car has a heavier chassis and also a heavier larger capacity engine so I'm hoping I might be able to use standard off the shelf springs mut I need to sit down one evening and calculate the motion ratios so I can compare to the first car.

[Mark (smokey mow)]

I'm also reaching that, stage of the build where I need to start thinking about bodywork.  I've got a spare complete set of mk2 panels which I've been hoping to use.  They're a miss match of parts as the undertray is red, the upper body green and the engine cover white so they'd need to be painted. I dragged the, all out of garage loft where they've been stored for the past 3 years so I could have a closer look at them but I'm not convinced they're useable without a significant amount of work.  The lower body has been used to take a mould and has a lot of additional parts crudely grafted onto it to to extend flanges and cover holes. The upper body likewise shows signs of a heavy impact on the nose, its subsequently been filled and sanded, there's a couple of cracks and a few holes to fill.  The best part was the engine cover which is complete other than being cut in the wrong place for me to fit around a roll bar.

As I surveyed the parts the magnitude of the task to get the bodywork right dawned on me, they'd be a lot of hours of prep work and then the cost of someone to paint it to end up with a body which might still not be perfect.  As I'm fortunate to have a set of body moulds the decision has been made to commission a brand new body for the car as the actual cost of a complete new body works out to be about the same as painting the old body.

the moulds have been dragged out and ready to be trailered to the laminators of Friday.

While looking at the bodywork I thought I'd see how much cutting and shaping would be needed to fit around the extra chassis tubes that the Carburol Special has.  With the assistance of the angle grinder (it didn't have to look pretty)  I cut into the spare cockpit section I had to try it for fit.  

I think I'm going to have to loose the seat back section due to the forward stays on the roll bar but the biggest hurdle is the dash hoop, this I fear will need some creative thinking with the wind screen.  It might not actually be quite so bad as the photo but its difficult to position it exactly until I've got the lower body on.

[Nic Chase (NICO) - Shropshire & Mid-Wales AO]

This is getting exciting now!!

[Mark (smokey mow)]

43 minutes ago, Nic (NICO) - Shropshire and Mid-Wales AO said:

This is getting exciting now!!

Thanks Nic, I'm suprised myself how quick its going together but it's much easier having another car to copy this time

expect the rate of build to slow up soon though as my bank account wont be able to sustain this rate of parts buying for long 

[Mark (smokey mow)]

Update time..... Last night I ventured out into the darkest depths of Suffolk to collect the bodywork from Applied Fibreglass.  For those wondering where they are, they make all the bodywork for Andy Bates AB Performance and are based in the unit next door to Andy.

I'd asked them to refit the new bodywork in the moulds to minimise the risk of damage for the journey home so I hadn't had a chance to look at them when I got home last night, but tonight I popped the first part from the moulds and had a good look for the first time.  Hopefully the weather will be good this weekend so I can work on the main body parts.

 

[WINGNUT]

Just read this whole build thread today, absolutely unreal. Seriously talented guy top job Mark 

[Mark (smokey mow)]

There's not much to show for the last couple of weekends work as I've mainly been fettling fibreglass although yesterday was spent learning to weld.  I haven't used a welder properly since I served my engineering apprenticeship back in 1995 and although I have used one now and again for the occasional small job I've never felt confident enough to tackle anything too difficult or safety critical so I signed myself up on a one day training course will Allied Welding in Benfleet so I'd be able to do a few more of the welding jobs on the JW4.

For anyone thinking of learning I can thoroughly recommend their courses.

https://www.alliedwelding.co.uk/product-category/welding-centre/?v=79cba1185463

Back to fettling the JW4 bodywork and the first job last weekend was to release the remaining body parts from the moulds.  Its suprising how long this took with the 60+ nuts and bolts to split and then close the various parts of the moulds.

Today Was mostly spent on the lower body and thus has been on and off the car more times than I care to remember with marking and cutting for the wishbones and to clear the chassis tubes but by lunchtime I was finally happy with the fit so gave it a final sand and polish then (hopefully) fitted it for the last time. 

Light was beginning to fade by early afternoon, just enough time to make a start on the upper body but I ran out of time before I could finish it properly and I had to leave the fitting around the roll hoop for another day.

[darve]

I used to BMX on that trading estate as a wee lad

remember asking if they would help weld up a mates cracked forks.....they said no lol

bizarre how I could remember the logo ~17 years later before opening the link

[Mark (smokey mow)]

13 hours ago, darve said:

I used to BMX on that trading estate as a wee lad

remember asking if they would help weld up a mates cracked forks.....they said no lol

bizarre how I could remember the logo ~17 years later before opening the link

The roads on that trading estate are so bad it felt like I was driving around a BMX track at times.

[Mark (smokey mow)]

New year update.

With Christmas the progress has been a bit slower over the last couple of weeks whilst shopping and family gatherings have taken priority, however there's still been time for a few hours working on the car while the weather has been favourable. There's not much to show for my time though as much of it has been spent sanding, fettling and cutting to get a good fit on all the panels. I was expecting a few issues as the moulds were about 20 years old and of unknown provenience and this has created a few problems with panel fit between the upper and lower body.  It may have been that the moulds have relaxed over the years but I think possibly and more likely the old panels used to make the moulds had seen better days but either way the lower body had curled inwards whilst the upper body has spread slightly outwards.  Its just about fixed now but I'll need to add a couple of small locating pegs between the two parts to keep it all in line.

At the back the engine cover proved much more simple needing only a couple of small relief cuts to clear the base of the roll hoop, the Dzus fasteners I bought are also about 5mm too long for a tight fit so I've overed some shorter ones.

One other job I need to think about is making a fire wall to close the rather large gap between the engine bay and drivers seat.

[Mark (smokey mow)]

On the subject of the condition of the moulds, this shows an issue that wasn't overly apparent until the body had been pulled from the mould. When I dropped the moulds off with Applied Fibreglass we identified there was a few imperfections in the surface so we discussed applying a thicker gelcoat layer so these could be sanded, smoothed and polished out. The moulds having been taken from some already quite old and tatty bodywork transferred all the imperfections from these warts and all. Luckilly these all sanded out ok by progressively working through the grits and now all it needs is a final polish to finish.

[MMB]

Hi Smokey

Been a while since I checked in...looks fantastic!

Here are a few pics of the firewall I made for my JW4 when I had it. Very simple and rests on the rails and still lets the air flow from the NACA duct under the seat to the engine bay.

All the best

MMB

[MMB]

Here are a few in the car, but I have to send them in separate posts.

MMB

[MMB]

It says I am over my limit to send the last one. Let me know if you would like to see it, I can try again later.

MMB