Hey Tom and all: I think you hit the nail on the head, but you didn't
say so. It's not just solexes or su's it's all the engine parts,
it's a system and all the factors come into play not just the carbs.
The intake, heads, ports valves, cam etc. all need to work together as
one is not much good without the others. Bill 66&67spls in NM
----- Original Message -----
From: "Thomas Walter" <ra0618@email.sps.mot.com>
To: "road" <datsun-roadsters@autox.team.net>
Sent: Friday, September 22, 2000 8:48 PM
Subject: Re: Solex's vs. SU's ..again and again and again...
> > 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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