> The key to power ain't the carbs, it's in the head to let the engine breath
> better as was related to me by a well respected Cosworth/foreign race engine
> builder. Too bad he's so damn expensive though.
>
Mike,
This is true, but over looks a simple matter of the "swirl" of the combustion
chamber.
You can get two cylinder heads side by side, with head "A" flowing much more
then head "B". Yet the paradox is that head "B" produces more HP at all rpm
but the very top end.
Difference is the port directing the incoming mixture. The more swirl and
turbulence within the combustion chamber, the better the burning and more
power is produced.
I got to spend a couple days in a "Engine Fundamentals" class a few weeks
back. Basically a graduate level course by University of Michigan crammed
into two days. One interesting video was of some quartz cylinder engines
with high speed video. I was fairly impressed, and shocked, to see puddles
of unburned fuel sitting on the cylinder head! Yes, during combustion the
puddle just sat there! Amazing.
Also to watch the spark ignition was quite shocking... the flame would never
blow in the same direction! Identical conditions, yet the turbulence flow was
always in the different direction. In some cycles you could see an incomplete
combustion, yet in the next a full burn of too rich of a mixture.
I have to admit some old myth's die hard. I had for ages believed that premium
fuel burned slower. Not so, all the grades burned the same. Premium just had
the additives to prevent knock, so you can run a higher spark advance (which
creates a higher pressure, hence better performance). Of course you need higher
compression to take advantage of the advanced spark to gain the higher
combustion
pressure.
Still had a great time in the class. Yes, work paid for me to "attend". One of
the
few times I would have gladly paid out of pocket!
Cheers,
Tom Walter
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