Originally Posted By: Loobed
I found an interesting TC oil review here:
http://www.geistware.com/rcmodeling/articles/oil_test/index.htm
It is about 2 cycle oil in model airplane motors @ 2 stroke ratios, but it kinda confirms that Pennzoil is very good and doesn't cause too much carbon inside the chamber, but outside....
Quote:
Pennzoil TWC-3 outboard synthetic mixed 32:1. gas was 93 octane.
The engine was run for 6 hrs and nearly 3 gal of fuel was burned. Engine
temperatures fluctuated around 200 degrees F. Outside temperature was 24-26
degrees F. Engine rpm with a 24 x 10 prop was initially 6130 rpm for the
first hour, 6060 for the second hour then settled to 6000 for the remainder
of the run.
After 6 hrs of running, the carbon formation looked a lot like the Pennzoil
air-cooled. The 1/3 of the piston next to the intake port was shiny clean,
and a band of carbon equal to about 1/2 of the area of the piston ran down
the middle of the piston in line with the boost ports in the front and back.
The thickness of the carbon band was 5-10 thousands and it was black hard
carbon. The area directly in front of the exhaust port was shiny clean. The
dome inside the cylinder was without any carbon buildup. There was no carbon
formation on the ring or ring groves in the piston.
While the piston and cylinder look great, this oil mix really plugs up
exhaust systems with carbon.
At that ratio I would expect some carbon build up on the exhaust. At 500:1 I suspect there would be very little effect, if any.