Ricardo W, My .02:
1) By orienting the spark plug _away_ from the intake valve, the ground electrode may help shield the center electrode from wetting. Probably marginal, and not related to combustion efficiency per se, except in the sense of blowing out the candle, but this may be beneficial, for instance, cold starting an engine that suffers from puddling. 2) Using a plug such as the ultra-fine tipped iridiums would probably be of considerably greater benefit than orienting old fatties. 3) True "flow development" always produces good results on old crap heads from the 50's-70's. (Or perhaps you mean focusing only on CFM in isolation and I'm misunderstanding?) 4) All other things being equal, higher octane fuel does allow higher compression, which increases BMEP and power. (Or perhaps you meant just using a slower burn rate "higher octane" fuel without increasing the ratio?) -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
