Bentley S1 Restoration

Refurbishment of my Bentley S1 B527EK




I bought my 1957 Bentley S1 in June 2009. A friend told me about the car and that it was for sale. I drove out to see her one Sunday morning and found the graceful old girl resting amongst various other classics in a peaceful garden setting. After having a good look at her and a brief test drive I was satisfied that she is an honest example and well worth refurbishment. A deal was done and the adventure began.


Not knowing much about her recent service history I decided not to drive her home so I hired a flat-bed truck. She arrived safe and sound, ready for the refurbishment to commence. We always name our cars, and after much discussion we decided to name her Sarah.


I decided to start with the engine and service items to see if I can at least get her running again. The first thing I did was to remove the oil bath air filter which once removed allows good access to the ignition components. The oil bath was cleaned, painted and set aside.


Next I started on the cooling system, and encountered my first problem. The thermostat housing cover is very corroded and rusted solid in place. I applied lots of penetrating oil but that did not seem to help. More drastic measures were required, so it had to be cut away from the housing and replaced.


The water pump was removed and sent away for refurbishment.


All drive belts were replaced.


The various gaskets for the cooling system were traced and cut from suitable gasket paper.


The rocker cover and carburettor components removed for restoration.


Preparing the rocker cover and carburettor components for painting...	...and the completed product.




Even the dining room table was host to various Bentley parts during the restoration when cold winter nights rendered the workshop inhabitable.


The distributor was modernized by replacing the old twin points system with purpose-made electronic ignition from Jolley Engineering in the UK.	Once installed the electronic ignition is so well hidden the engine looks stock standard.


Electronic ignition tip: The electronic ignition is supplied with a higher power coil, which demands a good, clean 12 V power source to operate properly. The wiring on our cars is 50 or more years old, and on both my Bentley’s I had rough running with the electronic ignition until I provided a clean 12 V power source to the new coil. To do this simply follow the coil power wire to the fuse box and replace it, as illustrated above.


The radiator was removed and completely refurbished by a radiator specialist.	The gearbox oil was changed, and it was encouraging to find clean fresh oil in there which suggests good prior maintenance.


On Sunday 13 December 2009 I had assembled enough of the engine to take the car for it's first test drive around the block. The purpose of this test drive was to do an assessment on the brakes. After months of standing she soon fired up and I gently eased her out onto the road. With no bonnet, a temporary air filter consisting of a cloth tied over the inlet pipe and a noisy rusted exhaust it must have been quite a spectacle to onlookers, but she performed impeccably, and the brakes appeared to be in good order!


The air silencer was painted and new rubber straps were fitted. The rubber straps were cut from the rubber they put under carpets. It worked perfectly!	The refurbished air filter and silencer fitted back on the car.

At this point it was time for a tune-up, which revealed another problem. Leaking exhaust valves! This left me with no choice...it was off with her head!

With the help of my good friend (and classic car expert) Hamish we managed to remove the head in one afternoon.


The problem was soon revealed...three burned valves! I is incredible that the car still ran as well as it did!	Once the manifold was removed we cleaned everything up and plugged the oil holes to prevent stuff from falling into the engine while we work on the valves.


A mirror was propped on an old blanket and the exhaust valves were removed by feel and looking at the mirror view only. This was unknown territory for me, and I felt a huge sense of achievement once all the valves were out, especially without losing any of the smaller bits that could fall away and disappear forever!	The cylinder head was placed in a vice and all the inlet valves were removed. Once that was done the head was cleaned and special attention was paid to the water channels.


The inlet valves were numbered so that they could be replaced into the same position. Note the holes clearly visible in two of the exhaust valves.	Once the head was cleaned the inlet valves were lapped in.


Lapping in the valves is a long tedious process, but well worth the effort.


All the components were laid out neatly and the inlet valves installed with modern valve stem seals.


The starter motor looked like it could do with some attention so while I had access to it I decided to remove it and give it a good service.


The next step was to blast all the muck out of the cooling channels so all the other holes had to be plugged using wine corks, dowels and old underwear.


The water tap at the rear of the engine was completely blocked, but it cleaned up really well.


The next three weeks! was spent lapping in the exhaust valves, and then finally the valves were fitted along with new valve springs.


Adjusting the valves is very tricky because the only way to see inside the side of the engine is with the use of a mirror, so your brain and hands have to work in reverse!


One of the exhaust manifold bolts broke off flush with the block, so Hamish skillfully welded a blob of weld onto the broken bolt so that we could get a grip on it. We heated up the area above the bolt and applied penetrating oil, and still it took two days to retrieve the broken bolt from the block!


The exhaust manifold was fitted using new gaskets and nicely cleaned up nuts. It all looked very smart indeed.


The new head gasket was positioned using some spare bolts as a guide, and finally the head went back on!

	At this point we did a leakage test to make sure that everything is OK and the results were very good! So far so good!
Torquing down the head.


The rocker arms were worn where they touch the valves which would make adjusting the clearances almost impossible, so the rocker shaft assembly was completely dismantled.	Rather than electric grinding the rocker ends I chose to do it by hand on an oil stone which produced a lovely polished end result with remarkably little effort.


In this picture you can clearly see how the rocker end wears out where it rubs against the valve stem. This makes accurate adjusting of the valve clearances almost impossible.	Gentle grinding by hand on the oil stone results in a perfect polished surface maintaining the curved profile.


While you are at it also check that all the oil ways are clear.	The rocker shaft assembly installed and valve clearances accurately adjusted.


While we still had good access to the carburettors it was decided to refurbish them.


The student and the Master celebrating success when she fired right up and ran like a Swiss clock! Working under Hamish's mentorship was one of the most enjoyable and rewarding experiences I have had in all my years of classic car ownership.



With most of the major mechanical problems solved it was time to tackle the bodywork. The car was disassembled and sent away for painting.


While the car was away for painting I had the opportunity to refurbish some of the components while they were off the car.


The upper surfaces of the door wood were in poor condition, so it was sanded down, re colored and painted with many coats of polyurethane interior gloss before final sanding and polishing. The end result was not bad for a first attempt!


About three months later the car was back home sporting a fresh coat of paint, and the reassembly commenced.




To be continued...