This weekend, the Space City Pantera Chapter sponsored a dyno day for it's 
members and eight Panteras ran on the Dyno.

With the aid of a wideband sensor and dyno operators who allowed us to tune 
the cars on the dyno, we were able to explore several variables in a 
controlled environment.

An article outlining the event in greater detail will appear in Profiles, 
but, I was encouraged by the attendees to share three learning's with the 
Forum.

1) Total timing advance.  Myth - Cleveland's like 32 - 34 degrees total 
advance.  We tested open chamber Cleveland heads and Aluminum A3 heads from 
32 to 40 degrees total advance.  We did not test the closed chamber as the 
total timing test for these heads was performed at a previous dyno run.

All the head configurations tested made more HP and TQ at 38BTDC.  All made 
less at 32,34,& 36.  These results were consistent with the closed chamber 
test that also performed better with 38 and more advance.

Myth - Busted. All engines tested made more power at 38 degrees advance.

2) Myth - The Dogbone Air cleaner ( known as B & M, Air Tec, etc) is 
constrictive on carbs with a choke horn because the air cleaner sits low 
over the carb.

This test was performed at the request of Gray Gregory whose 377 stroker 
topped with a dogbone air cleaner made an impressive 347 HP at 6400 RPM. 
His carb has a choke horn, no spacer between the air cleaner and the carb, 
and a single air filter on each side.  I submit that this is a serious 
challenge as we are talking about a larger than stock engine running at higher 
than average RPMs.

The result, a one horsepower difference (loss) at 6400 with the dogbone 
verses no air cleaner at all.  You read that correctly - 1 horsepower at 
6400 RPM on a 377 stroker.

Myth - Busted! It proved not to be an impediment to airflow on the primary 
side of the carb.

3) Myth - Coating Ceramic headers significantly reduces engine bay 
temperatures.

We tested the temperature of every cars' headers with a pyrometer 
immediately after shutdown of full throttle testing.

Ceramic Coated headers averaged about 460 degrees and painted headers 
averaged over 800 degrees!

Myth - verified as true

This was a great event.  Everyone learned a great deal about tuning and 
benefited from the information provided by the wide band A/F meter.  More 
cars were too lean verses rich and the owners were able to rejet on the spot 
to improve their A/F ratios and performance results.

JT