Friday, 19 February 2010

Refurbishing the chassis

Chassis ready for shotblasting

Once I was satisfied the engine and gearbox fitted ok, the body shell and the running gear were removed to leave a bare chassis. The outriggers and side rails had already been replaced 20 years before, but there were now a couple of areas at the rear of the chassis which had to be cut out and repaired. Two sets of rails were also needed to bolt the seats through, as originally they were only bolted through the fibreglass floorpans with large penny washers to spread the load! Then of course there were the seat belt mounting points to fabricate and weld, which were not present when the car was built.

Once all the welding was complete, it was ready for shotblasting.

I chose not to have the chassis powder-coated at the same time, as it was very expensive and any modifications to the chassis at a later date would require grinding off the (expensive) powder coating and touching up with paint. That would defeat the purpose of having the powder coating in the first place. In addition, the original chassis was silver not black, so I decided to go with a painted silver finish.

The chassis was back within 48 hours and then it was all hands to the pump. It was crucial to get the chassis coated with a rust prevention layer as quickly as possible before the damp started to oxidise the finish. I chose to use a rust prevention system called POR15, which is comprised of two different products:

POR15 Metal Ready, which is a liquid rust converter and etcher
POR15 Silver Rust Prevention Paint

One coat of the Metal Ready was brushed on, left to do its job for a while and then washed off with water.

The shotblasted chassis after washing off the Metal Ready etcher. Note both sides of the chassis now have seat mounting rails welded between the centre and rear outriggers

This produced a slightly alarming sight; rust streaks, but actually this is the way the system is designed to work. The Silver Rust Prevention Paint that follows works better on a slightly rusty surface.

The chassis primed with Silver Rust Prevention Paint. Starting to look a bit sexy now!

Unfortunately though, the prevention paint is not UV-resistant so I had to add a coat of the product Sterling Silver (made by the same manufacturer) to stabilise the finish against sunlight.

The chassis painted with Sterling Silver to make it UV-resistant

So that was the chassis complete. Now I could move on to the suspension and running gear.

Friday, 12 February 2010

The rebuild begins...trial engine fit.

The first part of the rebuild was straightforward: assemble the engine and check that it sat on the engine mounts properly.

The engine minus cylinder head

One should never assume anything is straightforward.

The original engine was a 948cc from a Standard Ten, but this had long since disappeared so I chose to use an engine from a 1300 Triumph Spitfire. Outwardly, it looks very similar to the Standard Ten engine, which is important to me as I want to maintain as much of the original appearance in the engine bay, plus it gives far more performance for modern day motoring.

However, it wasn't going to be a simple job to just drop the engine in. The front plate had the wrong engine mounts, so I had to change the plate for one from a Standard Ten. I had done this swap several times before on an 1147cc Triumph Spitfire engine and there was never a problem. This time was different. Unexpectedly the crankshaft starting fouling on the front plate so I had to grind out the crankshaft hole to make it larger. Also, the engine back plate and gearbox bell housing had to be cut and shaped on either side to clear the chassis rails.

The cylinder head was then removed to check the bores and valves, which were fine, and I took the opportunity to give it a quick decoke to remove the carbon deposits from the pistons and valves. The cylinder head was put back with a new gasket (first picture above), and the head was torqued down to 45lb/ft using the correct sequence for tightening the nuts. I left the valve clearance adjustment until the engine was placed permanently in the car at a later date.

Then I turned my attention to the mounts on the chassis, which I had put in 20 years before with the intention of racing the car with a Ford engine. Now the intention was to keep the car as original as possible and use it only for classic runs and club events, so I fabricated a mounting to take the Triumph engine.

The existing Ford mounts

The new mounts to take the Standard Ten. At this point the old mounts are still in place

I was hoping to keep the old Ford mounts in case I ever wanted to fit a Ford engine in the future, but it became clear that they were going to foul the exhaust and starter motor so disappointingly I had to cut them off.

Test fitting the engine to discover the Ford mounts must be removed. Note my wife's hand guiding the gear box onto its mounts. And she bakes decent cakes too.

The engine was fitted with a new clutch assembly plus new clutch release arm pivot bushes, which had worn badly on one side.

To join the engine and gearbox to the rear axle I turned my attention to the prop shaft. I had two old prop shafts knocking around, one which had the flange to fit the 1300 gearbox and the other which had the flange to fit the Standard Ten axle. These were taken to a prop shaft specialist who checked the universal joints and pronounced them fit for scrap.

So, much to my irritation a new prop shaft had to be fabricated (at great expense!) but they did an excellent job so I don't really begrudge them. Much.

At this point the engine was removed and work began in earnest on the chassis.