Not to worry, I can now reveal...
39Axxxxx - 3.5 SD1 Factory recon 9.35:1 cr 1982-87.
So, fine for unleaded and probably around the 160bhp ish mark on SU's
Bloody hell, how on earth did you find that lot out?
Well thats great news anyway,so he can just fill it up with optimax and get back all those missing ponys? No need to play with the timing or anything? If its putting out 160 ill eat my hat. Its got side exit exhaust iirc, maybe not quite breathing as it was designed?
Ps whats are SU's?
SU carbs.....
Unless its injection, which I would be surprised
Carbs fairly sure, but no adjustments required? Just fill it up and away you go? No reason why the builder would say use 4 star knowing it will take unleaded?
Wonder if he may have fiddled with it to get it in that chasis?
Not much he could fiddle with that would affect its ability to run on unleaded!
Right, home from work now, thank god. Sorry, i should have made myself more clear, bloody machine was playing up and i could not concentrate on the important stuff like cars.
I had a 600 race/track bike(bare with me) and took it for set up on a Dyno with a carb kit and a panel filter to take full advantage of the full Muzzy race system, a basic stage 1 tune. They said to run it on 4 star/lrp for the octane rating or failing that shell optimax then Super and last on the list was unleaded, for the
Octane rating.(never fully understood why, they just said bigger bangs,so that was good enough) So, bearing in mind there may not be a Standard air box on the rover v8, probably a k and n on a twin choke or similar purely to fit under the double sided bonnet(hinge down the centre job iirc) and the exhaust is def. more free flowing, i suspect it may have had to have been tuned to run with those inlet and outlet parts and there for the tuner may( or may not, dont know) have said to the builder it will run better on 4 star. Then the builder may have said to Dad to run it on 4 star and Dad, as sounds likely, not knowing the motor, presumed due to the age, that it would 'only' run on 4 star.I would be suprised if the builder did not know it would run on unleaded. So, having established it is possible to run on unleaded (or has the ability as you rightly say) the question remains,for me at least, should we? Without knowing the state of tune of the engine? Given the probs getting 4star/lrp i wonder if optimax or similar would be more suited? Will speak to Dad and see what he has with the documentation, a bloody great folder of stuff apparently. This could take a while.
My knowledge does not cover what difference the fuels will make to the engine tune. I suspect on an unleaded capable engine, only an unnoticeable drop of a few bhp when going from 4star to unleaded? So thats really where i was coming from, probably a bit too belt and brases? Cheers.