Formula Junior..Volopini replica

I have a rule, one project at a time! but there is a clause subsection 1 that I can plan and acquire parts for the next build...SO.

The plan is to build a visual replica of an early 60`s Volopini formula Junior....cause I can. They are a really nice looking little car that should be a lot of fun. My friend has a genuine original one that i will model it on with a few mechanical concessions to today`s availability of parts. Originally the cars were designed around standard production components readily available to keep the cost down. Do a search of Formula Junior as its good reading.
Some of these cars were live axel, some were front wheel drive, some had independent suspension all round, there were literally hundreds of manufacturers with all sorts of ideas.
The original Volopini was Fiat based and I will run a 4K Toyota 4 speed, MX5 front and rear suspension components including Vis LSD.
The diff. centre is offset to allow the driver to sit lower in the chassis and you can see from my mock of of the rear, that its going to be a squeeze.
The chassis will be a tube frame with a larger bottom rail as per the origional. I will keep updating as I collect more bits but no steel to be cut until Mclaren number 3 is out the door.
It should be fun.
 

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Rear axel set up.
I have set up the various components roughly as they will be in the car, the off set means outside to diff center drivers side is 900mm and the other side is 580mm. Basically you sit low in front of the axel and beside the diff head.
I will try and use the standard suspension arms otherwise it may need a custom upper arm fabricated.
Cheers
Russell
 

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Gee it`s almost a year since I last shared my plans on building Formula Junior replica, well the time has not been wasted with work still being completed in my McLaren project. That`s 80% thru the certification process now and should be driving within the next month. Its also Anzac Day tomorrow so that also means our wedding anniversary...27 years and yes as some of you will know the last 5 years has been a different journey that we continue to work thru...it`s become the new normal!, So there has been plenty of road trips and bucket list things to work thru with more to come.
As for the FJ, I have spent my spare time sorting out all manner of issues before I start cutting steel. No matter if I build the car with all original parts and 50 year old steel, it will never be allowed to run with the `real` cars. The problem that creates is that the roll protection now has to be to today`s standards and that means a front and rear roll bar, which also means that the drivers head must sit clear beneath their line. What the car will be able to do though, is run in Formula Libre plus all manner of club events where the car must be scrutineered. I have already started collecting steel and built a new solid build table, and sourced a local company to roll some of the chassis sections rather than build a tube roller. My friend who has the origination Volopini has been very helpful in allowing access to measure or get my head around dimension, like the fact that the cockpit sides are parallel, so some rolled aly sheet will make good molds for the mid section. I will still have to make molds for the nose and tail, and yes I am itching to get started.
Cheers
Russell
 

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Well a little more progress, I have taken a very short break from the McLaren, still doing all the little bits that just keep occurring as we work thru on road compliance.....
I have built a new build table so that I can set out components and have a good think so as to be ready for construction. To that end, I have set up the rear sub frame and cut off the diff mounts to enable me to off-set the diff. I cut off one arm of the diff housing and will fabricate a new rubber mount and re position the other. The drive axels are at a reasonable angle and will be a simple job to shorten and lengthen. The MX5 diff set up involves an Aluminium ladder `brace` that goes forward in the car to control diff rotation, it looks like I will have to fabricate a custom version as it interferes with keeping the diff towards the RH side of the car. The rear sub frame will be used to locate the suspension as its only 20mm wider than the origional car and will be easy to hide...certainly a large labour / fabrication saving. I can now spend spare time looking for road blocks before I start construction. Its amaizing how many bits I have left over that will suit this car, that seat mould is from my first McLaren and I have enough nuts and bolts to build many more.
This build along with my present car sadly have to fit in with our journey ( Carol`s ) who is currently in hospital, so no pressure but it sure helps to have something else to think about.
Cheers
 

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More progress.
Finally made some decisions regarding shifting the diff over, managed to utilize the chopped of standard mount. The mounting of the torque arm on the diff was a little bit of a challenge and we ended up working towards a plated join as it`s impossible to get the standard mount into the subframe due to the diff having been moved over 150mm from the centre line. I will not plate it until I have more structure in place. I have also made plastic pipe dummy chassis rails so the the bender can make me a pair. I have also fabricated the flat spring mount on the subframe and ordered the appropriate spring.
Failing all that it`s back to the McLaren.
Russell
 

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VOLOPINI FJ Replica
Now some serious progress as the McLaren is all but finished, It even has a VIN number now.
I had the chassis rails bent last week and spent a few days just looking and thinking!!. I have also completed the off set of the differential and made the mounting plate to accept the torque arm, this will either be the original Aluminium arm cut down or a fabricated tube one. As you can see in the first photo, I have laid down the base rails and attached them to the sub frame along with the cockpit floor structure. The upper side chassis rails will be approx 300mm above the bottom rail with diagonal bracing. Because this car is being built to modern schedule A rules it will have to run both front and rear roll bars so structure will need to be developed for the loads that could be applied . The rear suspension coil springs have been changed for a leaf spring to create a more period look and the front suspension is currently standard MX5 but I may replace the bottom wishbone with a custom made one as its `ugly`. Small shocks will fit in the standard position. This is a `fun` build so their is only one rule...enjoy the build.
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Well a good couple of days full effort and the chassis is on the rotisserie to catch up all the hard to get welds. I have also made the inlet / exhaust manifold whilst the engine was in the chassis before it gets freshened / cleaned. Next task is to set up the steering shaft down to the rack and then back onto the front suspension which will have inboard shocks as its not possible to fit the shocks thru the MX5 upper wishbone in an acceptable manner. The rack is a rear steer LH drive from an American Austin? mounted in a left hand front steer position (had to think about that one) that Leon kindly gave me. In between things I have been stripping down the Toyota 4K and the bore is standard and will just need a light hone with new rings, the clutch is also in great condition so will go straight back in. I have yet to drop the sump and check the bearings but feel the should be fine.
This build has always been about fun so I am trying to not build it to quickly! Fuel tank metal work is due in a few days so will need to do some perfect welding. The back end of the car is almost just an assembly job now by using the MX5 sub frame, the entire chassis as you see it weighs 55kg with the roll hoops yet to be added.
Cheers
 
Another good days effort with the motor back in the frame,(will freshen up later) brake and clutch pedals fitted and the basic plan on the front rocker suspension sussed out. Waiting for some square section steel to arrive to get that underway. Better slow down or else it will be finished to soon. Got to love those suckers......
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Here is a question for all and sundry, it`s right up JacMac`s resume .
I have moved my differential across to allow a lowered drive position `beside` the drive shaft in old school Formula Junior tradition.
The difference in axel lengths is 260mm.
I need to cut the axels so that when the two sets are swapped and welded / sleeved, the overall length will be close on correct.
Next stop to ask is my highly educated grandson.
Cheers for any assistance.
Russell
 
Solved that one easy old school, just laid the two axels side by side and move one until the total overall length was correct and marked the cut! axel part A then attaches to axel part B...hey presto... both axel`s are the correct length.

More progress now with the front end set up, all the steering is now fabricated, the Mx5 rod ends were drilled and tapped put to I/2 inch unf to fit the c/moli tube and welded up super strong. The shocks are in board and can be actioned by two different profile fulcrums depending on how the weight sits. The radiator is all mounted but out of the car while playing around the front. The drive shaft will be sorted and the torque arm is fabricated and mounted. The clutch and brake pedals are all go (and wo) and the roll bars are fabricated waiting final fitment along with the fuel tank. Pretty soon it will be time for the body work.
 

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Well we managed to get Carol back across to Aussie to visit the grand kids, a bit tiring but done.
So now some time back in the shed. Had two very successful days where I adapted the Mazda drive shaft to the Toyota shaft, it would have been easy if they were both the same dia. as a special sleeve 100mm needed to be turned at approx 2.5mm wall thickness. This sleeved the dia gap and was then tig`ed up nice and straight.
Then it was onto cutting the axel`s so that we accounted for moving the diff over some 165mm. After much thought and measurement, I took the plunge and cut them both at the anticipated marks. I then stripped the short axel completely to avoid any damage to the boots and stripped the diff ends off. Much thought on how to hold the axels produced the jig that clamped the axel`s whilst I tig`d the core / centre of the axel. Once the axe`ls were tig`d I then put them in the lathe to check and adjust in the press where needed. Over all they are very straight, I have run the long axel up in the lathe at 1450 rpm and it was fine. Then it was just a case of reassembling the axels, new grease and boots on. The big moment came when the axel`s were fitted into the car...and they fitted yahoo. The rest of the car chassis is all but done and I am just going around making sure that all sundry brackets etc are in place before any paint. Then its onto the body mould. Meanwhile the Toyota 4k is getting a once over with a hone, new rings and bearings along with a suitable cam....should be good for at least 90hp?
 

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One step forward, 3 steps back. After much discussion with the paint expert / salesman, I bought some of a new Aussie brand of super hard chassis paint. Big mistake, as even though it flowed on and looked really glossy when brushed on, the devil was in the detail later because any area that you had touched up or brushed out a run, turned into a disaster as it cured turning into frothy bubbles resembling honey comb. This stuff goes rock hard in less than 24 hours so when I looked at my handy work next morning I was gutted. I then drove up and had a discussion with said sales person who despite admitting the instructions were wrong and he had also experienced the same problems, was not interested in any assistance. After more than 10 hours stripping this stuff off, we will be talking further. I now plan on sending the chassis out for sand blasting and powder coating which will be better result. Meanwhile, the motor has been stripped fully and will be delivered to the engine reco guys next week. And there is a myriad of small bits to paint.
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Randy V

Admin
Lifetime Supporter
Russell, your chassis paint looks like it may be formulated the same as POR15. It goes on thin but gets rock hard. Problem is that it gets poisoned easily by water and high humidity which breaks the paint down and leaves billions of little bubbles like what you have.
Also, I believe you need to either have a layer of rust or etch the bare steel with acid. There’s an acid that you can spray on and it leaves a coating that you can paint over. It was called Metal-Ready from my recollection....
Darned shame that you have to get it all off there in order to re-coat...
 

Terry Oxandale

Skinny Man
Supporter
Randy, I was going to same the same thing. Looks exactly like POR15 with the same characteristics. I've found POR15 looks and holds up better on lightly oxidized steel, rather than clean steel.
 
Guys i read a few days ago on a Professional car painting group on Facebook Auto Body and Painting , never use any etch coating on steel if you are top coating with an epoxy, you end up with Russel's problem the two dont play well together.
 
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