One thing I have learned on RCU is not to believe or shall I say place confidence in any manufactures numbers nor any individuals numbers, and not to expect any particular performance numbers on any engine. There are only a handful, no not even a handful of individual out there that can, have, and will take the time and put forth the effort to compare performance on an engine under controlled conditions. Even then, as Dick will tell you there are variables that effect performance.

I have two ZDZ-80s one ZDZ-100 two Brisons, and a couple of Zenos. Love them all, I can get OVER 1000rpm difference on either ZDZ-80 by switching the manufacturer of the same size prop and exhaust systems. Like Dick, I have one ZDZ-80 that I promise you will out pull 99% of all 100s. It is all in accordance with the Prop manufacturer, Prop wood species, pitch,(and I will promise you if you get down to the nitty-gritty and measure two wood props from the same manufacturer they will not be the same, length, pitch, thickness; sanding, sealing, cutting,quality control, that particular day), exhaust, fuel, and fuel, mix.

If you like the engine, it's reliable, it performance meets your needs, Its a good engine.