restoration Fox Prototype

[FourFox]

I have to just change the sump on my restored early J60 so that the oil drain hole matches the hole in the hull, simple!

Take off the rear engine/fan mount and it's side plates from the block, remove the sump bolts and....it wont come off.

The sump will not clear the crankshaft and allow it to come clear of the bell-housing.

Nothing for it but to remove the flywheel (pity because it's a nice new one and sealed nicely, full of oil too). Still, I have a spare locking ring in my stores, so off we go. Remove the starter motor, bell housing and sump.

 

Whilst I've got the sump off I'll just check the distributor timing is ok with my new timing toy. It should be right as it has not been disturbed during the re-build.

There is a snag, there are no flywheel or bell housing timing marks on an early engine. Also the crankshaft pulley timing mark has lost it's pointer thingy so I don't know where TDC is. Still, a dial gauge down number 1 plug hole gives a fairly accurate guide.

 

It's not right. It's 2 teeth out. No wonder this engine was cast, and in such good condition. It would have been impossible to get the timing anywhere near right!

Off comes the oil pump and the brass timing gear from the shaft, to be fe-fitted in the correct mesh. (fortunately I have all the right tab washers in stock)

I take this opportunity to install electronic ignition instead of the old points system into the Fox distributor (different to CVRT ones). It's not easy changing the points on a Fox!

 

Take off the camshaft covers...good...I'm glad I didn't seal them on with gasket goo.

Check the camshaft timings with the plate gauges against my new timing marks..Ok.

Put power supply on to the ignition and check that number 1 plug sparks when it should (not 360 degrees out).

 

Now for a change of direction. Whilst the engine is in such a state of dis-assembly I decide to dress it as a CVRT (100B) so that it will fit on my engine test stand. It's much easier to solve any leaks or problems with the engine on the stand.

Connect up the electrics (with a slight modification for the Fox variant) (the prototype is also a little different).

Fill up the oil and coolant...quickly find a 1/4 bsp plug to stem the flow from one I've forgotten to fit in the block drain hole.

Turn over on the starter for quite some time to gain oil pressure.(It won't start yet because I have a fuel pump switch off for this procedure). Take off the oil filter and re-connect the right way round..Idiot.

 

I have a great big oil gauge so that I can observe the rate of rise and (more importantly) decay of the oil pressure when cranking and stopping. This gives a good indication of the state of all the bearings in the engine (and shows if a camshaft plug has fallen out).

 

Now switch on the fuel pump and crank again. Away first time. Adjust the throttle stop and the slow running jets for smooth running.

 

I have a good Fox silencer on the rig (which is half outside) enabling quiet running of the engine so that any un-toward mechanical noises can be identified.

 

 

I run the engine at various throttle settings until the thermostat opens.

Adjust the slow running jets again until you just get a smooth pick-up when you ram the throttle open.

Check for absence of black smoke.

Run the engine at various speeds until it starts to get really hot (there is no fan on the rig).

Check the hot starting.

Have a final check for leaks...and check the oil pressure decay when stopping.

Thats all there is to it!

 

 

Now all I have to do is re-dress the engine in Fox trim (100B), secure in the knowledge that it will perform well when installed.

 

 

Look at the clean lines of this early engine, notice the finned sump.

 

Should be installing this week.

I will keep you posted.

 

Jon

Edited February 1, 2018 by FourFox
photo restore

[ChasSomT.]

If I lived anywhere near you, I would be banned from your premises! You exceedingly fortunate chap, you!

 

Brilliant, well done, excellent post(s) please keep it up!

 

'Chas.'

[FourFox]

The Engine has now been put in the Fox.

 

 

It was more difficult than usual as there are several differences from production Foxes that I hadn't bargained for.

The gearbox is about 5mm further back, and the rear engine mounting bolts (and hence the fabric mounting spacer) are slightly different spacing, so nothing fits as it should!

 

After a little jiggling of engine angles to get the splines lined up on the gearbox...no problem.

Put in a few (new) bell-housing nuts and tighten up...hey presto...we're there! Put on the rest of the nuts and tighten home.

 

Not quite... I was about 3mm short of fitting the rear mounting bolts, a usual problem.

I don't fancy the contortionist proper way of loosening the bolts again...I just figure that it would be easier to just pull the engine rearwards a little against the (very substantial) front gerbox mountings (Ferret type).

 

Put on a 6 ton ratchet strap round the engine block and anchor with shackles to the hull towing eyes...tighten up.

And just a bit more...only need another millimetre...hell this is tight...have to use a bar on the ratchet...that's better...just one more click...CRUNCH !

 

Sod it. The stap was not properly positioned and has put too much strain on the starter motor connection box, which is now at an alarming angle.

 

Nothing else for it, remove the starter (not easy with the engine now in place).

Take about an hour repairing the starter with a new teminal box (found several in the starter-bitza-box).

 

Slacken the bell housing nuts (should have done this first time).

Repeat the positioning process, without the starter this time!

Nicely lined-up...bolts are a bit tight...Some chump has wound in M8 bolts instead of the correct ones.

Make very short 5/16 unc tap and remedy the situation..finding the correct bolts in the meantime.

That will teach me to clean out all the threads properly before fitting the engine.

 

Progress has since included re-fitting the starter motor.

Fitting the oil cleaner assy (having fitted it with a new filter and filled it full of oil).

Connecting up all the electric connections and the oil pipes.

Replacing the carburettor. (it had to be removed to fit the engine under the swim screen beam, prototype only)

 

More progress tomorrow, hopefully.

 

Jon

Edited February 1, 2018 by FourFox
photo restore

[FourFox]

The engine-bay is getting a bit 'busy' now with all the services connected. I had difficulty in extracting my lead-light plug through the tangle of pipes and cables!

 

 

Fans and alternator have been checked and cleaned and new toothed belts fitted.

Notice that the aluminium fans are quite a bit different to the standard steel Fox ones.

 

 

Should have the radiators sorted today, and then a start on the dashboard wiring!

 

Keep you posted.

 

Jon

Edited February 1, 2018 by FourFox
photo restore

[robin craig]

Jon,

 

A couple of points.

 

As you well know the bevel box for the fan volutes is a sealed housing with seals on the shafts to the fans themselves. Why wouldn't you take the fill plug and replace it with another fastener of the same thread and drill it and tap it and make a vent line like I did on the one over here. I used brake line and an in line filter for a fuel line to stop any fluid escaping.

 

I ran the line horizontally to the right and then turned it up a ways. Sorry I cant find a picture of it.

 

Since you are not going to be swimming your beast, then the need for that bevel box to be sealed is negated. I most honestly believe that the fan bevel box is a poorly designed unit in as much as level checks and top ups are not possible without taking the rear of the vehicle apart.

 

By putting a breather on the bevel box then you relieve the internal pressure that builds and therefore hopefully have a longer lasting restoration.

 

The other thing that puzzles me about the pictures, is that you seem to have left the engine bay unpainted. Any reason?

 

regards

 

Robin

Edited March 2, 2012 by robin craig

[FourFox]

Hi Robin

 

The engine bay (and the rest of the inside of the vehicle) has been left in the original aluminium metal finish. It was never painted on the prototype. The same with my prototype Scorpion.

 

I agree with your comments on the fan bevel gearbox. I have had many attempts to seal these without success. The problem seems to be worse on NOS fan units (like yours). This is probably because on older worn gearboxes, all the oil up to the the seal has already been ejected due to air expanding in the gearbox.

 

Incidently, if you were swimming the Fox, and there was a water level insde the hull up to the fan gearbox, I think your problem might not be the water entering the gearbox!

 

Have you noticed that the prototpe fan gearbox is a different design to your later one?

The adaptation to the filler plug (that you can just make out on the phpto) carries a thermal sensor to measure the temperature of the gearbox during testing at MVRE.

There are at least 20 such sensors remaining in all sorts of locations on this vehicle. You can see one on the coolant pipe to the header tank, and some others on the oil cooler.

You can also see pressure measuring points on the oil filter unions. The are now blanked off, but some of the brass gauges for pressure measurements remain in place in the hull.

 

Radiators are now fitted. Will post some photos next week.

I have to do quite a lot of work on the electrics as amost everything is not functioning.

 

Jon

Edited March 3, 2012 by FourFox

[robin craig]

Jon,

 

Quite a while ago I was passed these pictures to post on this forum by Alan Turner (think I got the name right) of the RAWHS. They are posted elsewhere on this forum and this seems to be an appropriate place to post them again.

 

I did notice differences at that time to ours and yours confirms that. There are so many differences, like how the generator receives its forced air for cooling etc etc.

 

So will you be putting a breather on the bevel box then?

 

R

[FourFox]

Thanks Robin. Those photos are really useful.

 

In the background of the first photo you can see the Fox hull showing the bilge pump outlet pipe. I don't have one on mine so that is most informative. I can now make one of the correct shape. The bilge pump is in the same place as a production Fox but it is mounted horizontally.

 

The second photo shows the oil cooler with only one radiator feed, not 2, like on a later one. Again it confirns that mine is correct and not just a bodge-up with a CVRT cooler.

 

 

I have the correct alternator ventilation feed adapter shown in the photo (instead of the later bi-furcated one). I will be fitting it when I can find the correct jointing hose. (I know I have on in my stores somewhere.)

 

The fan bevel box seems to retain sufficient oil for satisfactory operation. It only leaks a bit when the unit is tipped on it's back for some time. If I have a more serious leak it will be an easy matter to remove the temperature tranducer and fit an open pipe like you have on yours.

 

I have been contemplating connecting up all the remaining sensors to some modern recording device. It would make a good show demonstration, and sure be a good diagnostic tool. Still, this decision will have to wait until the rest of the restoration is much further progressed.

 

Jon

[robin craig]

Jon,

 

I presume you didnt realise about these pictures being here already, hence why I reposted those two.

 

You should have a look at the rest of the pictures Alan posted some via me which are here

 

http://hmvf.co.uk/forumvb/showthread.php?16863-CVRW-Fox-RAWHS-Pictures&highlight=RAWHS

 

I think you will find them more than invaluable.

 

Regards

 

Robin

[Marmite!!]

Jon,

 

I presume you didnt realise about these pictures being here already, hence why I reposted those two.

 

You should have a look at the rest of the pictures Alan posted some via me which are here

 

http://hmvf.co.uk/forumvb/showthread.php?16863-CVRW-Fox-RAWHS-Pictures&highlight=RAWHS

 

I think you will find them more than invaluable.

 

Regards

 

Robin

Some more from Alan here http://hmvf.co.uk/forumvb/showthread.php?15456-Fox-CVR%28W%29-Gallery

[FourFox]

Yes...great photos.

 

The last one is a previously unseen photo of my Fox 00SP87.

There is also a picture of it from above.

I would like to borrow the originals to copy for my archives if anyone knows where they are.

 

Jon

[Marmite!!]

Yes...great photos.

 

The last one is a previously unseen photo of my Fox 00SP87.

There is also a picture of it from above.

I would like to borrow the originals to copy for my archives if anyone knows where they are.

 

Jon

 

Alan who posted the photos is sadly no longer with us.

[FourFox]

The engine is now installed and most of the vital electics are sorted. The temperature gauge works fine (after connecting the dash board earthing strap) and the fuel gauge shows 3/4 of a tank. I had to dip the tank to verrify this!

The oil warning light now works (changed the bulb) and most of the dash lights were also blown!

 

The ignition switched on (and the fuel pump re-connected)...Tick...tick ...tick etc. Must be an air leak in the fuel system...Tick....tick...tick etc. Hang on! that begins to smell of petrol...It's dripping from the outside exhaust joint!

 

Take out the plugs... number 2 and 4 cylinders are full of petrol....the carburettor float valve has stuck open and poured about 1/2 a gallon of petrol into the engine. It worked fine on the test bench, honest.

 

Pump out the petrol from the cylinders, drain and re-fill the oil with nice new oil (again). Pour the petrol from the exhast pipe...it's a good job it didn't fire-up!

 

Put in a new float valve.

 

Whilst fitting the 'boomerang bar' I noticed that somone had cut it in half. I find out why when re-fitting it. On the prototype, the header tank return pipe runs throgh this bar and it is impossible to fit it after the fan pack is installed (unless you cut it in half). In my store of bits I find a complete prototype bar (amazing as they only built 15 of these) and decide to pull the fans again and re-fit it all properly.

 

This all took 2 days as the alignment of the fan drive is very difficult on this early system. I like to get it to 0.1 mm concentricity to avoid over stressing the coupling. The early tombstone supports have only 3 mounting bolts per side and no positive location. Every time you remove the bolts to shim it, it moves, and you get a varying measurement.

 

Here is a photo of the cut 'boomerang bar', a whole one and a production Fox one (with the radiators hinged forward).

 

 

The 'new' bar still had to be coaxed into place with a hide hammer! Still, at least all the bolts (16 of them) lined up, eventually.

 

Engine fired-up first time and runs very smoothly.

 

I have re-fitted the painted wheels so that (when the weather improves) I can run the Fox outside and steam clean the suspension units before painting in the correct DBG.

 

In the meantime I have prepared (and now painted) the complete rear aspect of the Fox so that it will remain mobile when the exhaust is re-fitted.

 

The messy job of removing all the old paint can then be done outside!

 

 

The new exhaust guard and exhaust pipe have now also been finished ready for re-fitting when the DBG is dry.

 

More progress next week!

 

Jon

Edited February 1, 2018 by FourFox
photo restore

[FourFox]

Finally got around to moving things around in the shed so that I can get the beast outside and make use of that great spring weather.

 

As you can see I have nearly finished painting the rear aspect and re-fitted the exhaust and it's new guard. The badly beaten out right hand rear bin will have a union flag marker (stuck on a thin aluminium sheet) to disguise the bumps. Its apparent that the gloss DBG shows up evey ding and scratch!

 

Note also the restored original number plate, which was found underneath the civillian plate.

 

 

The 2 weeks hard slog of removing the rest of the paint has started!

I must make some time to remove all the tools and loose bits from the insides so that I can give it a few laps of the block and check for leaks before re-fitting the insides.

 

Jon

Edited February 1, 2018 by FourFox
photo restore

[stevenivers]

Beautiful work mate :shocked:

[challenger]

hello there, I have recently found a VHS that I have for some time. On it is a sales blurb, about 10 minutes long about Fox. It shows it firing, driving around the gun being removed and the engine and transmission being taken out. The vehicles shown are 00SP86, 47MS22, 08FD74 and 09FD90. I am at present wrestling to get it transferred to disk but am having problems with picture quality and sound. But I will persevere. The film was produced by United Motion Pictures and is in colour. Anyone seen this before? PS it also shows quite a bit of the vehicle swimming.

[FourFox]

That sounds great archive material. I can't wait to see it!

 

When you have succeeded in your digitization could you send me a copy?

 

Ta

 

Jon

[challenger]

Certainly.

[david1212]

hello there, I have recently found a VHS that I have for some time. On it is a sales blurb, about 10 minutes long about Fox. It shows it firing, driving around the gun being removed and the engine and transmission being taken out. The vehicles shown are 00SP86, 47MS22, 08FD74 and 09FD90. I am at present wrestling to get it transferred to disk but am having problems with picture quality and sound. But I will persevere. The film was produced by United Motion Pictures and is in colour. Anyone seen this before? PS it also shows quite a bit of the vehicle swimming.

 

If you are still struggling I have both a Philips(badged JVC) and a Panasonic SVHS VCR both with TimeBaseCorrection hooked up to my DVD recorder plus an older Panasonic HS-950 I can try too.

[FourFox]

Rear quater re-painting is now under way.

 

Most of the remaining paint has now been removed. The complete assembly and under-body has been de-greased prior to masking and painting.

Note the bolt-on tie down points on the lower hull. The production ones were all welded.

 

 

Masking is in place and a coat of primer (with a little bit of green added) has been applied.

 

 

And the resulting DBG top coat.

 

 

I know.....there are a few runs...but it's more important to get a good coverage where you won't notice too much.

Only 3 more corners to go.

 

About half of the superstructure has alredy been stripped.

More progress next week.

 

Jon

[FourFox]

The restoration seems to be going backwards!

 

 

After removing the swim screen I dsicovered that the 3 parts of the screen tinwork are in very poor condition and is not really restorable. I have been meaning to CAD draw this type of screen for some time as the one I have for my prototype Scorpion is of a later type...so I might as well make 2 sets of similar hardware.

 

It takes an age to get all the holes on the drawing in the correct place, as many had been drilled in situ on the prototypes.

So I decided to draw up the tinwork for the wings as well...at least all the holes should then line up as I shall be making all 4 mating sets of components. (and won't it look smart with all new tinwork!)

 

Whilst I was at it, I then decided to draw-up the tinwork for the production Fox, as that will be the next on the list to restore and some of the panels are a bit eaten away!

It makes good economy to cut as much as possible on the Laser at the same time. Also the CNC bending will not cost much more for two sets, as most of the time involved is in the setting of the tooling. Incidentally, the production tinwork is quite different to the prototype so 2 complete sets of drawings had to be done. Also left and right hand front wings (fenders) are of different design on the prototype. I don't know why, perhaps the driver's door used to foul the hump in the right hand wing if you opened it in a hurry (not a problem on the Mk4 Ferret which is a similar design, as the door opens downwards)

 

Laser cutting of all the bits is scheduled for tomorrow. There are over 80 individual pieces of 1.5 mm zinc coated steel, utilising 9 sheets of 8 x 4 metal (with an overall usage of about 80% of the metal).

 

I will keep you posted on progress.

 

You can see on the photo that I have filled in quite a few holes in the hull that were on the sides above the swim screen line (now over-painted green). More seriously, there were 6 holes each side revealed 'under the waterline' when I removed the floatation bins. These holes were used to bolt on quite large ballast weights to bring the vehicle up to design weight whilst under test at MVEE. Obviously they did not want to use real ammunition, personnel and weaponry with all the crew kit whislt driving round the test track for 3000 miles.

I must say that I had not realised that there would have been weights affixed between the floatation bins and the hull.

 

I don't think we shall be swimming the Fox in deep water! It would have been quite a short trip if I had not revealed all the holes!

 

Jon

Edited May 20, 2012 by FourFox

[ferrettkitt]

Excellent work love this thread!