We , being mainly my brother, with me supplying argumetative comments at various points , and a few parts.
And finding the originals to copy on ebay.
Basically all side valve SS1/2s had RAGs , all OVH cars had SUs i.e SS Jaguars.
For production reasons we ha to make 4 pairs,e.g investment casting the float bowl tps had a minimum of eight in a tree. These were basically moulded from the originals . a Pattern maker made the main body section and a pattern for the clamp on the top. WE had somee xcellent foudries here. but there was till a lot of complicated machining . making the needlles and jets was very specialised. One particularr item , a small ball joint from memory on the link between the carbs had a weird thread . I think Brass but 48 TPI. No taps or dies available, so I said we could pick to two best and have them investment cast and th e threads will come out. Doug said, But they;ll shrink. But, both male and female will shrink at the same rate and so still work together. But it may confuse someone in 100 years if they measure and try to calculate what thread it is.
It will be interesting to find out more about the "bronze"head. A simple test with a magnet would be a star
Id be worried about nyloc nuts on head studs. They need to be hard [ as d the washers] andby definition if the material has been able to be pressed over the nylon [ or fibre] then it can’t be hard. and I think might affect the tension reading.
“C. E. Truett’s was probably amongst the most highly developed. Chassis number 18105, Truett’s 1937 car was originally driven in standard form until it was returned to the factory for various modifications. These included a special engine with a bronze-coated head (thought in those days to assist heat dispersal), stepped pistons giving a compression ratio of 10:1, polished Dural rods, and magneto ignition. The chassis was lightened by drilling too, the car obviously being modelled on 18008.”
Interesting that the 'bronze ‘head picture had screw in core plugs [ or at least the one can see.I have seen these on earlier 2 1/2 SS engines but can’ t remember them on 3 1/2’s but could be wrong.Or it could indicate a non- standard head.
The bronze colored head on #39064 will hold a magnet, which supports the “bronze coated” premise. And I agree with Ed, the nyloc nuts used for retaining the head are suspect. However, for what it’s worth, I’ve driven it 500 miles with no issues this past summer. Partly to determine what I need to fix in the restoration, and partly because Lori and I decided it’s fun to drive. We wound up showing 39064 at four local shows and British meets since there is such a desire for unrestored cars with “patina”! And the previous owner in Europe drove it quite often on rallies and tours. When I strip the engine down, I’ll report on the bronze question. Dave
