Discussion
http://www.pistonheads.com/sales/835241.htm
Looks like my old car has had two more owners since it left me , only sold her last year .. looks very nice !
Looks like my old car has had two more owners since it left me , only sold her last year .. looks very nice !
That's a very nice car, but what's this about bigger valves? When I took the tops of my humble 350i (also for sale on PH) the valve heads couldn't physically be made any bigger or they wouldn't fit in the combustion chambers. Did the 390 have a totally different head? Regards, Sadmark
Most probably hearsay or the heads were reworked later. 390SEs generally ran standard valve sizes albeit with some major porting work and a higher lift cam. 275bhp is utter nonsense as the airflow meter was the standard 3.5L version and was incapable of flowing enough air for that sort of power. In addition the injectors were standard 3.5L and again, can't flow enough fuel for 275bhp. And so on... 
grahamw48 said:
Does the hotwire 400SE have a bigger AFM/other changes to 390SE ?
Not a huge %age bigger I don't think. There was an excellent article on here some years back (Joolz, maybe?) that went into the why and how of airflow meters, something to do with air stalling etc. that conflicts with what the flapper is trying to do. The hotwire is a constant venturi that doesn't suffer from the same problems. From my very hazy memory, and the Riggwelter isn't helping... 
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