YMJ wrote:
By-the-way, going back to the modern castings debate.....it appears everybody is at it, even pre-War racing Astons nowadays use block and heads still warm from the foundry. And you can't tell me that money was no object in that period - nobody had a pot to piss in....even the toffs - the castings made today will be infinitely finer products than the originasl in every respect.
your pretty wrong with all of this, the pre-war cars are using new castings mainly because the 80 year old originals are just worn out from either use or damage. there is little or no performance advantage at all.
the biggest issues that they have are castings that are choked up with rock hard calcium deposits from water and cracks that have started either from heat cycles or frost damage.
'in period' there was probably more money floating about for racing then, as it was the persevere of the very wealthy, people like Tim Birkin, Dorothy Padgett etc literally spent millions of pounds paying for, and racing top end 1930's race cars, some of the fancy homologation specials that where created and built where amazing cars - Riley Sprites for example looked like a standard Riley but where virtually all magnesium castings (bar the block and head), they even ran magnesium clutch baskets....building special cars like this brought the whole company to its knees and bankruptcy.
ive got a book at home that details the factory preparation of the 'W.O' era racing Bentleys. the work that went into them was mind boggling - the book is full of very clear, detailed, black and white photos of the cars in bits - like the success of the minis in the 1960's its easy to see how and why they won just about everything.
I also doubt that the modern castings are that much better than those made by the 'high-end' manufacturers in period, Rolls Royce, for example where well known for their ability to produce complicated, thin walled quality castings, but of course they also had a rigorous testing procedure and any that didn't make the grade (as much as 20%) where simply scrapped off....
certainly the repro RR heads and blocks that are available now don't offer any performance advantage bar the fact that your winding the clock back to when the car was new, I suspect that the people making them enjoy a smaller scrappage rate by using modern casting & machining processes (which we do with the Arden head), but, in the main , they are simply trying to produce an economic product that allows the car to be used.
a few years ago me and my dad went to have a look at a derby Bentley that had its engine in bits, the owner had sent the car to a restoration shop to have the engine rebuilt, the garage had stripped it and blown his entire budget having the cracked head welded up and part machined. he had then run out of money and go the car back, the head was epically rubbish, it looked awful - when my dad asked the guy 'why didn't you just buy a new head' the guy just looked blankly at us and said 'what?, you can buy new heads.....'
a new head was (about) £5000, he had spent £2500 (from memory) having his part repaired.....
a very interesting subject!!!
