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27th June 2021: Spring-time round-up

Some business projects kept me busy over winter and spring, but I made a start on a few small tasks on the AC. These were the front brakes, mesh guards, air-filters and water-pump. I will write them up in detail shortly, in the overhaul and restoration sections of this site.

This type of master-cylinder is a rare commodity. Girling only produced it for about 2 years and was only used by AC and Rover (up to 1949). I could not find any information on it, either in old textbooks or online. I've had to learn the hard way! The hydrastatic front brakes also give the old grey-matter a good test, as few people know anything about them.

AC's patented mesh splash-guards (fitted under each wing), are rarely found on ACs today. The above photo shows the old (aluminium) item and the new (stainless steel) version of a rear guard. It is difficult to find aluminium mesh. It's also difficult to fold stainless mesh! Fitting the front ones to the car, was a challenge, until I worked out how it was done. The brackets have to bolt to the mesh first, and then to the car. But you can't work out the fitting position unless the brackets are on the car. There's a quick release panel at the back of the wings, giving handy access to bolt the mesh in... except you can't bolt the access panel on if the mesh is fully in place! It can be done...

Someone on ebay has been selling excellent looking replicas of the labels for our air-filters. They can go on the front or back. I chose the back, so that I can repaint/re-finish the fronts later on, for a gleaming look.

Above you can see the internals of my water-pump after I made some small modifications. Some detail care and attention to the functioning of the seal, will hopefully be rewarded. Simply fitting new parts doesn't guarantee reliability. The easiest thing to check, is that the drainage hole at the front of the casing, is nice and clear, so that any leaking coolant is kept away from the bearing. If you've dismantled it, make sure that the carbon seal slides freely over its drive-pin.

14th August 2021: Re-paint hold-up.

The second half of this season, was planned for the cosmetic restoration, primarily coach painting the external bodywork. This has almost ground to a halt, while I try to get the correct colour. I initially followed advice (from various sources) to change from Tekaloid to Craftmaster (very expensive). The expensive British Standard "light olive green" that arrived, was more like sea green! No refunds. Back to Tekaloid, via my previous retailer, only to find that their supplier has changed the colour. I had purchased some 3 years ago, which perfectly matches what I believe the unfaded colour to be. I might try Avenue next, who also make Tekaloid and offer a colour-matching service. Wish me luck.

In the mean-time, I did manage to complete the spare wheel hatch with reasonable results (correct colour from old tin of paint). The numberplate was more trouble than the paint!

3rd October 2021: E10 petrol, painting progress, and getting expelled from a coach-painting group!

Each time there is a change in petrol supplied in the UK, technical confusion reigns in discussions, and so-called "help" articles. With 10% ethanol petrol arriving in the UK, one fallacy crops up frequently. That's the complaint about the lower energy content. While that might affect modern direct-injection engines, alcohol's very high latent heat of evaporation means increased volumetric efficiency. This improvement is compounded by the need for a richer mixture, off-setting this apparent increase in fuel consumption.

The above point might be even more marked with alloy heads? Confusion also reigns on the effect of alloy heads on volumetric efficiency. As alloy conducts more heat to the inlet port, this increases evaporation of the fuel droplets, thus lowering the final mixture temperature at the critical moment of the inlet valve closing. This is the only moment that the actual temperature of the mixture matters. As the great Harry Ricardo demonstrated. So, with ethanol, this benefit is multiplied. Now I need to save up for an alloy head!

What we classic owners need to do for E10 usage, is to make sure the fuel seals, gaskets, hoses and diaphrams are resistant to this latest fuel. I have made gaskets out of viton rubber for my fuel gauge sender and the glass bowl on the filter. New hoses and pump diaphrams are readily available. There is some uncertainty whether the cork seals in the carbs are at risk? I'm going to monitor mine, and if leakage occurs, I'll purchase the new jet kits from Burlen.

Many thanks to the Avenue Group (via Tool-Paint.com) for doing a perfect colour match for my paint. The photo of the bonnet above, looks nice, but in reality the surface is rippled. I need to hone my coach painting technique further. I posted the same link to Avenue at a coach painting Facebook group, and promptly got expelled and banned for "advertising"! A useful group, evidently. I'm sure I'll recover from the shame!

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Website started 29th December 2006