1952 Bentley MkVI Big Bore - Freestone and Webb
by Chris White - Part 1

The style of the car is beautiful, as you would expect from Freestone and Webb, but the finishes are completely shot. The interior leatherwork is all beyond refurbishment; if you lean on it, it splits. The headlining has suffered from water damage and quite a few generations of moths and the carpets have been home to something noisome from the animal kingdom that I can't identify by the smell alone. Suffice to say that the garage needs a good airing before you venture in to work to on the car!

The body work is fairly sound with a few repairs needed around the spat mounts, the running board, and one front wing that was damaged in transit. However, the paintwork is dire and almost certainly unsalvageable. It looks as if has only been painted once since its original paintwork, but badly. I am not an expert in painting cars so I don't know for sure what has happened to the paintwork. Actually, that is not strictly true; I know what has happened (it has crazed, split and shrunk all over the car), I just don't know why. I suspect poor preparation of the paintwork when it was resprayed so the new paint has not bonded properly to the original Alternatively it could be a reaction between the paints if they were incompatible. I shall have to get some advice as it will make the difference between rubbing down or completely stripping the car to bare metal.

The upside is that the engine and gearbox are absolutely mint; there not a spec of dirt anywhere around the bell housing, top of the gearbox and starter motor, which is a good indication that the units have been out of the car cleaned and probably refurnished (given that it is very unlikely that someone would remove the engine and gearbox just to clean them). All the hoses and clamps were new and the engine had been repainted and the nickel-work replated.

The car was in the process of being restored when the previous owner died; his wife just shut the garage door and left the car - that was eleven years ago! I seemed to be in possession of a car that had had all the engineering work done but required the cosmetics sorting out i.e. the body shell and the interior. This was borne out by the fact that it only failed its MoT on a loose ball joint! The greater worry was that the car boiled up as soon as the engine was under any load or exceeded 25mph! This was a big problem and I spent weeks looking for the solution.

I started checking the obvious things like a stuck thermostat. It had some alien 'stat in it that was also broken. I replaced it with the correct, and hugely expensive, part. We struck up the car which promptly boiled again. Next, I flushed out the block (from the rear tap) which, after a small amount or rusty water, ran clean. I flushed the radiator and again found very little contamination. The radiator also had a sticker on it from the company that had refurbished it, so I expected a clean bill of health. I even took out the heater tap connection on the water pump to make sure that the impeller was turning (slacken the fan belt, poke a screwdriver into the hole and turn the fan gently). You can feel the impeller blades turning if it is firmly fixed to the shaft - they have been known to come loose. All was as it should be.

I removed the access plates from the block to check for silt even though the water ran clear when flushed. Bentley 6's are known for silting up from the rear and the stuff sets like concrete, so no amount of flushing will clear it. Needless to say, the block was pristine inside which further substantiated that this engine had been rebuilt.

If it was the case that the engine had been fully rebuilt then, we reasoned that, possibly the bores were a bit tight. The solution to this is to connect a hose to the rear drain tap and take off the rad cap. Hey presto loads of cooling which allows you to run the engine at a fast tick over for a couple of hours to break in the bores (don't use synthetic oil for this or your engine will never break in properly). Two hours later we connected it all up properly and hey-presto, it boiled again.

I began to suspect that the engines' apparent fine fettle was purely cosmetic as nothing seemed to stop the car boiling. Up till now I had avoided dismantling any major components, but I decided that the water pump would have to come off to see what was going on. I couldn't get significant volumes of water to come out of the top hose when running the engine even with the thermostat removed.

When I finally got the pump off (remove the fan blades from the pulley first and you will manage without taking the radiator out) the passage from the impeller chamber to the engine block was completely blocked (see picture IMG 2055). A small amount went into the block but careful work with a dentists pick removed it without any dropping further inside. The stuff in the water pump assembly was like solid salt crystals compacted into the passage and had to be dug out with a stout screwdriver. I then media blasted it all and repainted it ready for reassembly.

Having removed all the crud and back flushed the engine again. By this time the neighbours were used to seeing a river flowing from my drive and no longer rang Yorkshire water to report a burst main! I reassembled the engine and started the car. She purred away happily holding a steady 75degrees which she maintains under all conditions ,so I seemed to have finally solved the problem.

It is strange that the only corrosion should occur here in an otherwise perfect engine and my hypothesis is as follows:- The bottom hose is of the concertina type with a steel spring coiled inside it to prevent it collapsing at any bends. The top hose is like an elbow and is normal straight section pipe. However, the previous owner had used a bottom hose on the top as well. Under normal circumstances the car would have been run and would have had plenty of anti-freeze/inhibitor in it all circulating on a regular basis; but, this car had stood for at least 10years with just water in it. The consequence was that the spring had corroded away (bits of it were found on top of the thermostat) and most of the residue had dropped through into the water pump. This had caused electrolytic corrosion in the alloy spacer piece between the water pump and the block. Presumably this had been the most vulnerable piece of aluminium in the vicinity. In the course of 10 years the crystallizing aluminium salts had completely blocked the water passage only leaving the 1/4 inch bypass hole that goes to the front cylinder.

I am now 99% certain that this engine and gearbox has been totally rebuilt and that the problem was caused by the unusual circumstances surrounding this cars' rebuild. If you are putting a car away for a considerable length of time, the lesson to be learnt here is - either store the car with a dry engine or make sure you have plenty of inhibitor in the water system.

I have just bought a TIG welder and I shall shortly embark on the restoration of the body work. I have a pile of scrap aluminium to practice on first in the hope that I can avoid blowing holes in the body.

I shall keep you all informed of progress.