Thank you for posting your findings; it's a very generous way to run a business. I've been waiting for better/more minds to chime in, but before the bread turns stale I'd have several things I'd like to know. ( I'll probably leave it to one question per post so you don't have to sort through too-much-novice-at-once. ) With the alterations you've made to ASBO 44 do you think the stock ignition timing is good enough for running beyond what was the rev limit?
Thank you for your interest in this. The best way I can answer that is to say this machine performed well in excess of my expectations and I certainly didn't feel the need to question the ignition timing, advance curve, or any other related areas. There are a couple of other 'Asbo' 535 GT machines which are very similar and also run performance cams timed to my specs, but this is the only one currently running with a head I modified slightly too, as well as my usual modifications and performance cams timed to my specs. Another machine is up to this spec with the head mods, but last I heard of it was still running standard cams, with the inlet retarded and I would expect that to probably go as well as this machine if / when fitted with performance cams timed to my specs.
I think there has been a lot of 'over thinking' where the tuning of these machines is concerned and most of what is required to make these machines fly is already present and correct and just in need of some modifications, such as combustion chamber tidying around the valves, shortening the barrels as required and a little porting work. Bolt on stuff which I would consider 'must have' items would include decent valves and springs, performance cams, carburettor conversion and a decent exhaust system.
I have no idea what Asbo 44 could do in terms of top speed, but I am sure it could get into three figures with no trouble and there are no flat spots, although the engine likes to be at north of 3,000 rpm in the higher gears and really wakes up at around 4,000 rpm, pulling strongly to 7,000 rpm, according to what I saw on the rev counter. All the other Asbo GT's have been able to reach 6,000 - 6,500 rpm with no problems, which is also well above standard.
B.W.