Chuck
The P&G "pump" is a transparent cylinder with a free piston in it. It
is plumbed to a spark plug hole, the intake and exhaust valves are disabled
and the engine turned over with the starter. Air going in and out of the
cylinder bumps an O ring to indicate maximum travel. Volume is directly read
by calibrations on the side of the cylinder. Several possibilities for error
exist, air temperature, piston and O-ring to wall friction in the measuring
cyl and rotational speed. Dan measures the cylinder temp and apples a
correction factor but the other two are hard to keep constant. That is why
for engines within 3% of the max or min they require direct measurement.
Hope that was helpful.
Jim in Palmdale who at any minute has to give up the computer to his
granddaughter
----- Original Message -----
From: Chuck Rothfuss <crothfuss@coastalnet.com>
To: <land-speed@autox.team.net>
Sent: Saturday, December 16, 2000 10:13 AM
Subject: Re: Rotarys
> Dave, List,
>
> I've offered to provide pieces to be measured by ECTA officials, and
have
> explained repeatedly the futility, as Dave mentioned, of trying to alter
the
> factory dimensions. (making an expensive tear-down to measure one of my
> engines unnecessary) All seems to rest with the SCTA rules commitee, as
the
> ECTA rules mirror what is established by the senior organization.
>
> I'm not familiar enough with the P&G ("pumping") equipment, that is now
> apparently available on both coasts, to understand how testing is
conducted.
> Can someone shed some light on this, and the potential use of such
equipment
> on a rotary? Since we are comparing the breathing capability of engines
> this certainly seems like a fair way to compare them.
>
> As a non-engineer I figure out most things by simply fumbling around
and
> experimenting with things til I get it right. (I call it "FUN") If I have
> to run down someone with "pumping" equipment and "pump" one of my nice
tight
> 13B's I'd be happy to do that.
>
> Chuck Rothfuss
> ECTA
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