Hi Brian,

I have gathered RPM numbers on both engines with equivilent props, but not on the same day at the same time, but with that said, the data that I have gathered and others with the same prop and similar altitudes, there appears to be a clear trend. It would be nice to have 20 cases for each, but it's hard to come by reliable numbers and most people either don't post them, or post them incompletely, which makes them pretty much impossible to compare.

The Taurus' all had the pitts-style muffler suppled by Taurus. The ZDZ's also had pitts-style exhaust except as noted.

Taurus 2.6:

1 - New with Zinger Pro 22X8 7100-7200 RPM - 3 sources
2 - Broken in with Mejzlik 20X10 8200 RPM - 1 source

ZDZ40:

1 - New with Zinger Pro 22X8 6600-6800 RPM - 2 sources
2 - Broken in w/ Zinger Pro 22X8 6800-7000 RPM - 2 sources
3 - Broken in with tuned can and ZP 22X8 7200 RPM - 1 source(tuned can at 6000 ft altitude)
4 - Broken in with Mejzlik 20X10 7400 RPM - 1 source(Amelung - tuned can)

(I also have numbers for the Taurus and ZDZ on several other props, but since I didn't have equivilent numbers for both on the same props, I didn't post them here)

It would be great if anyone else has numbers for either of these engines if they would post them....better yet would be numbers from back-to-back testing on the same day with the same prop and with well broken in engines as CAPtain232 is planning on doing with the Taurus TS-52 and BME 50.