[Shotimes] BB lust

[Ron Porter]

I guess I was referring to the old 2-valve Hemi versus a 2-valve wedge.

4 (or more) valve OHC engines are still superior to either of those designs.
I guess, in a certain way, that SOHC-DOHC engines could be called "hemi"
engines, but I guess that bit of marketing has been claimed by Chrysler!

Yeah, from an output-to-displacement standpoint, multi-valve engines outdo
OHV engines, and  small engines will do better than large displacement
engines. No musclecars were running around with 2-4 liter Cosworth engines,
though (probably not fair to bring up the Cosworth Vega at this point!!).

Ron Porter

-----Original Message-----
From: shotimes-admin@autox.team.net
[mailto:shotimes-admin@autox.team.net]On Behalf Of jfmcrr@sbcglobal.net
Sent: Thursday, November 28, 2002 11:35 AM
To: shotimes@autox.team.net
Subject: [Shotimes] BB lust


>I really don't believe that any wedge-type head is better than a
>central-plug "hemi" or other symmetrical combustion chamber. Just way too
>many compromises. Super high octane fuel, as well as 40+ degree timing
>advance were things that wedge heads needed, as well as stuff like indexed
>spark plugs.


         Let's see...   how much overlap can you get out of a hemi
motor?  Can you get good compression and a fast burn combustion chamber
combination out of a motor without a domed piston?  The hemi is a fabulous
motor for nitro,  4:1 static compression and huge boosts.  With a flat
piston, it has THE minimum surface area combustion chamber for running hand
grenade motors.  But when you have to rely on atmospheric pressure to
charge the cylinder,  you need 4 or five valves,  intake tuning, exhaust
tuning,  squish areas,  compact combustion chambers,  high
compression,  and valve overlap.  Hemi's can manage two out of seven.  The
Keith Duckworth designed Cosworth motors of the 60's relegated hemi's to
history as high output to displacement N/A motors.



                                                 Joe Facer
                                                 AFM 237
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