Upgraded Engine Mounts

With the Southern Kit Car Club European road trip coming up it was time to give the car a check over and look for anything that might present reliability issues during the 1300+ miles.

One thing I've been keeping an eye on recently is the original Tiger engine mounts.  Other Avon owners have had issues with these failing and I suspected it was only a matter of time before mine gave me issues.  Upon closer inspection there did seem to be some metal fatigue setting in where the diagonal tubes meet horizontal plates.  I was not happy with this so decided now was the time to get on with fabricating a more robust replacement.

After jacking up the engine and resting it on some wooden joists I was able to remove the old engine mounts.  Straight away it was easy to see that in their natural rest position these had not been level with the top of the engine rubbers.  Instead they had been inclined and the tightening of the bolts had clamped them down onto the rubbers and had deformed the top of the rubbers over time.  This obviously meant that there was a constant force applied trying to tear the diagonal tubes from the horizontal plates, even before any twisting force is applied by an accelerating or decelerating engine.

With the original engine mounts fitted, the engine was not level.  So using the wood under the sump I raised the inlet side around 15mm to bring the bottom of the engine (sump) horizontal with the ground, when viewed from the front of the car.

Next I replicated the four flat plates.  This time out of 6mm steel instead of the previous 5mm.  For the diagonals I used 5mm thick 45mm box section.  This compares with the 1.5mm tube used previously.

Cutting these box sections to fit was a very difficult task.  Multiple compound angles and all work being undertaken with the engine in situ.  On the exhaust side I was having to work in between the small gaps between the exhaust headers - very difficult indeed.

In the end I got there.  Had them tack welded by Ashby Welding ready for a trial fit.  They fitted perfectly, with the horizontal plates resting on new rubbers, without any clamping and with absolutely no stress applied to the mounts or rubbers.  Back to the welders to have them fully welded up and here is the end result.  A very nice job done by the welder.

These have been painted up, fitted to the car and bungs inserted into the bolt holes to protect from water ingress.

Another long term to-do list job completed and hopefully another piece of reliability added to the car.

Front Half of Roll Cage Fitted

Brackets are supplied with the cage to mount the front half.  There are some tubes welded onto them to protect the chassis rails from being crushed as the bolts are tightened up.  Problem is these are 16mm outside diameter.  If holes were drilled big enough this would remove two thirds of the metal in each of the 25mm chassis rails!  It would be okay if they were welded in before the body was fitted.  So I decided to cut the tubes off and just drill 10mm holes, using the remaining metal of the brackets as spreader plates.

Initially the roll cage came very close to the exhaust, but after tightening up the bolts it pulled the cage far enough away from the exhaust.

The silencer needed to be removed to get the lower bolts in.  The seats and interior trim panels had to be removed to get at the upper bolts.

Steel tubes of 10mm internal diameter were needed to space the roll cage out from the upper chassis rails.

Once fitted it was clear that the front half of the cage was going to foul the mirrors.

New mounting holes were made further back and 25mm rubber grommets were inserted into the holes previously cut into the aeroscreen.

Here are some photos taken on the way to the Southern Kit Car Club 2012 Jamboree.

This was taken at the Jamboree parking.

Rear Half of Roll Cage Fitted

The previously made template was used to accurately mark out where the holes needed to be cut for the rear bracing tubes.  A hole saw and a curved file were used for this.

What I hadn't appreciated was that these bracing tubes were at a slight angle.  Meaning that the holes had to be widened to get the ends through, before the rear half of the cage could be lowered in to place.  Covers will need to be made for these.  Probably out of aluminium sheet sprayed white.

The feet were then bolted on to the bracing tubes and holes drilled in the rear of the chassis to accommodate the fixing bolts.  All in all not too bad a fit, the fabrication tolerances probably within a few millimetres.

Luckily the off-side bracing tube clears the fuel filler by about 10mm and also the filler pipe below.  Phew!  That was a close call.

After fitting I tried to get in the boot.  Oh dear, we have a problem.  Looks like the boot on the Avon Mk2 bodywork will only open to about 45 degrees with the roll cage fitted.  Never mind, access is still pretty good.

Next on to the front half of the roll cage...

Delivery of Full Race Cage

Yesterday my full race cage arrived.  This was delivered on a pallet direct from the manufacturers Caged Laser Engerineering.  It is comprised of a braced roll over bar with the main part of the cage bolting to this and the side chassis rails.

It is very substantial and quite heavy.  Much tougher than the chassis by the looks of it.  Which I suppose is reassuring and whole point of fitting the cage.  The quality is very good and it comes complete with a fixing kit.  We'll see how straightforward it is to install.

Holes need to be cut in the top of the rear tub to allow the diagonal braces to pass through.  The feet are bolted on after passing through the braces through the holes.  This helps keep the holes as small as possible.

I've made a cardboard template to establish the location of the holes.

I'll use this template to transfer the dimensions across to the top  of the rear tub.  I am praying that fuel filler is not in the way and does not need to be moved.  Once I've got the old roll over bar off, and the template offered up, I'll know for sure.

Front Lighting

The IVA test requires that the front indicators are no more than 400mm from the outside edges of the car.  On the Avon this would be measured in from the rear wheel arches (being the widest part of the car).  The rear arches are 1750mm in width so the indicators need to be no less than 950mm (1750 - 800) between their outside edges.  As with most sevens the indicators needed extending on stalks.

I found a plastic waste overflow pipe at B&Q which is the perfect fit to hold the motorcycle indicator units.

To create a fixing to the nose cone of the car I used a 22mm copper pipe blanking cap with a M8 bolt.  An 8mm bolt was used as this is the same as the indicator unit bolt.  The centre of the bolt was drilled out to allow the wires to pass through.  A length of rubber sleeve was used inside the bolt to prevent chafing on the edge of the hole.

As well as using glue a couple of 3.2mm rivets were used to lock the bolt in place and prevent it spinning when tightening the nut.  Finally, prior to fitting, a quick coat of black paint was used to cover the copper and rivets.

To allow more clearance on the cycle wings I've changed from the 5 3/4"  light units to the smaller 4" Dominator motorcycle units.  Being smaller they should reduce drag (a little) and boost the top speed (a little).

The wires needed extending and protective sleeving added.  The colour scheme for the wires was very bizarre.  I had to trace each one to the bulb holders to work out what was going on.  After the bullet connectors were attached I labelled each one to prevent future confusion.

Being a motorcycle light the Dominator has a flat beam pattern, with no kick-up to the left.  This is fine for the IVA test, but to help it pass the MoT the light unit is best rotated a few degrees to give the required kick-up.  To do this a second locating cut-out was filed, to the right of the original one.  This causes the whole light unit to be rotated anti-clockwise when viewed from the front of the car.

Front indicators and headlights mounted and wire in.  I'll replace the bullet connectors with soldered connections after the IVA test.  I've ordered some proper two pin connectors from Ebay for the front indicators.  This will make it easier to detach prior to removing the nose cone.

I had some black card handy in the garage so I thought I'd use it to check the beam patterns.  Here is the dipped beam.  Hot spot in the centre and kick-up to the left.  Hopefully good enough to please Mr (or Mrs) MoT tester.

And here is the full beam.

These are small light units and are mounted quite low.  As such their beam will be masked partly by the front cycle wings.  This should not be too much of an inconvenience as they will really only be used to get home around dusk.  I don't plan to be making too many long distance trips at night.

Seats and Harnesses

Intatrim Ranger seats have been installed in the car along with the Tiger provided harnesses.  I decided not to opt for colour coded piping on the seats as I think there is already enough contrast with the red harnesses and red detail line on the wheel rims.  Also, I was a bit worried that light coloured piping on the seats would quickly discolour.  That said I'll have to make sure only clean hands handle the red harnesses.

To mount each seat four M8 cap head bolts were used with nyloc nuts.  Bolting through each of the two lengthwise chassis rails and fitted with load spreading washers inside the seat and underneath the car.

Cycle Wings

After the bonnet the job I was least looking forward to was fitting the cycle wings.  It did indeed turn out to be quite involved.

First off I needed to clear the threads in the front uprights - these were rusty and also had some paint in them.  I hadn't realised when renewing the uprights that these threaded holes would be needed.  A second hand 8mm tap from a local tool shop did the job easily.

Spacer tubes need to be cut to mount the cycle wing vertical arms the correct distance from the tyres.  This is a bit of trial and error and I found it easiest to use washers to calculate the length prior to cutting the tubes.

With the stays mounted in the correct position I could start to fit the cycle wings themselves.  They don't just bolt on unfortunately.  The horizontal arms of the stays need to be bent up into the curvature of the cycle wings.  To work out how far to bend them I tried spacers of different thickness.  A couple of pencil rubbers turned out to be perfect for the job.

Then the stays were bent in the vice, ensuring that the upper part remained parallel with the tyre.  Due to the bending of the stays some of the powder coating flaked off.  Some Hammerite was applied to prevent rusting.

The cycle wings were then trial fitted using an axle stand as a height reference.  The current IVA manual states that the cycle wings must extend at least 50 degrees to the rear and 30 degrees to the front.  The rear was nearly 90 degrees so that was okay.  The front was harder to measure.  In the end the geometry of the wheel came to the rescue.  There are 12 spokes.  360 degrees divided by 12 equals 30 degrees per spoke.  With one spoke vertical I could easily determine that I had about 45 degrees coverage to the front.

A length of bicycle inner tube (700c x 23) was pulled over the horizontal arms to protect the fibreglass from the metal edges.  Holes were drilled in the cycle wings and stays and then dome head bolts used to secure them together.

19mm holes were drilled to accommodate the LED side repeaters.  I had to be careful here as it is quite close to the edge and I didn't want to split the cycle wing.  The repeaters are mounted by inserting the rubber collar into the hole and then pushing the light through, making sure the 'TOP" marking was uppermost.  Due to the curvature of the cycle wing shoulder the rubber did not want to sit fully flat with the (curved) surface.  A little persuasion from Mr Super Glue did the trick.

Finally, the wiring for the side repeaters was extended to reach the inside of the car.  This was cabled tied to the cycle wings stays and under the cycle wings cable tie mounts were attached using Grip Fill.  Before fitting the side repeaters I tested them on the car battery.  They are reassuringly bright.  One oddity is that the black lead is not negative, but positive!  White is negative.

In the end I am quite pleased with result, but the cycle wings are quite a lot of effort from start to finish.

Coolant Expansion Tank

The standard Tiger expansion tank bracket has a flat piece of metal, sort of like a foot, which I believe originally would be bolted through the chassis rail at the front of the battery tray.  Like a number of people I wanted to mount the tank further back (uses spare space in front of the scuttle and allows more access room around the back of the engine).  The lower foot was cut off and the horizontal piece of metal was used to bolt the bracket to the battery tray.  However, this has no fore/aft strength, i.e. if somebody leaned on the expansion tank it would bend the battery tray aluminium.  To get around this I cut a couple of 'legs' from 20mm wide steel strip.

When mounting the bracket I bolted down through the bracket, then the battery tray and finally the legs (one on each side).  The end result is pretty sturdy.

Engine coolant plumbing complete.

Joining the Engine and Gearbox

New clutch release bearing fitted to the clutch fork.  Lubrication applied as instructed in the clutch kit.

Engine and gearbox fitted together.  New cap head bolts, thread locked and torqued up to the correct amount.

With the Tiger ERA sump fitted the gearbox mounting holes in the lower crank case are no longer present.  Only the upper five bolt holes can be used.  Two dowels are still available to ensure gearbox alignment.  Next job is to crane the engine into the rolling chassis and make good the engine mounts.

Flywheel and Clutch

To add the new ring gear to the Tiger lightened flywheel the former was put in a hot oven and the latter in the freezer.  Once fitted the ring gear was held in place with weights until both had returned to room temperature.

Comparing old (Focus) and new lightened (Pinto) flywheels.  On the scales the Focus weighs in at 9.8kg and the Pinto at 5.8kg.  Hopefully this will give a good performance boost in terms of acceleration, along with a more responsive throttle response.

The flywheel bolts were shortened so that the same amount of thread (15mm) showed through the rear of the flywheel as in the original Focus installation (the lightened Pinto flywheel is thinner - no prizes there).  All good so far.  However, the edges of the bolts clash with the tapered edge of the flywheel.  Also the socket fouls on the flywheel.

Plan B was to use another, original length, set of flywheel bolts and use washers as spacers.  Two washers were needed for each bolt to compensate for the thickness of metal removed from the flywheel.  The washers nearest the flywheel needed filing down (from 5mm to 3mm) on one edge.  Okay, the edge was not there until I filed it!

Flywheel bolts installed with thread lock.  Each was marked to show that it had been torqued up to the correct value.  In the centre is the spigot bearing fitted.  Pushed in just flush with the outer edge.  It would've gone in further, but here it should provide maximum support for the gearbox input shaft.

Fitting the clutch using an old borrowed gearbox input shaft as a centring tool (Thanks Pete).  This made it very easy to get the perfect alignment of the clutch plate.

Steering column (upper and lower)

Two 12mm holes were drilled in the upper steering column mounting brackets. These were drilled towards the top to allow maximum leg room for the driver. The steering column is adjustable so it will be possible to lower it if required.


Sturdy 12mm socket head bolts were used to securely mount the upper steering column. Initially the grey plastic bush at the lower end of the upper steering column was chafing on the chassis mounted cylindrical bracket (tube). To minimise this I used a file to smooth the edge of the tube - removing a hard lip of powder coat and slightly radiusing the edge. Finally a smear of grease was added to the inside of the tube prior to assembly.


The lower steering column simply bolted in three places: to the triangular tube at the bottom of the upper steering column, the steering rack, and in the middle the rose joint bolts to one of the side chassis tubes. This rose joint mounting was left loose as it may need to be removed to install the engine. When it is ready for final assembly a thread lock solution will be used.

Floor mounted pedals mounted

I am fitting the Tiger floor mounted brake and clutch pedals. First to do is the brake. The brake master cylinder had been mounted previously so, after inserting the pushrod, it was relatively easy to establish where the floor bracket for the pedal would go and hence where the holes needed to be drilled. The pushrod seemed a little long, so in order to maximse leg room in the cockpit I decided to shorten it. In the end I only removed about 5mm. This was to ensure that the pedal still had it's full travel, i.e. the master cylinder bottomed out and the back of the pedal did not foul the bulkhead. Also as the pedal swings the pushrod does not move in a perfectly horizontal plane. It arcs slightly and as such the pushrod cannot be too short or it fouls on the slides of the master cylinder plunger.

The clutch pedal was mounted next. Before drilling the holes this was lined up with the hole in the bulkhead where the clutch cable passes through.



The chassis now needs to be turned over so that larger holes can be drilled in the aluminium floor to allow the nuts to be added to the pedal mounting bolts. Finallly the lock nut can be added to the brake pushrod connector and the stop can be fastened under the rearmost bolt on the brake pedal bracket. This prevent the pedal falling towards the driver and the pushrod falling out of the master cylinder. Not what you want whilst driving!