Diablo:

Thanks for the additional input on ZDZ. I don't really agree that pipes will be standard in the US with engine sizes under 80cc or so. It is a big pain to install a pipe, and over here, pipes are expensive. It is unlikely the average non-contest modeler is going to be installing a pipe on their engines in the near future(which is the majority, by far). Also, the independent numbers I have seen posted for the ZDZ40 that do not have a tuned pipe, are 2-500 RPM less on the same prop than the one's Amelung and Top Model have posted on their sites and rcfaq.com with tuned pipes.

I hope you'll understand that I put very little stock in numbers posted by manufacturer's. Even if they are being honest about it, I can guarantee you they're posting the best numbers they've ever obtained under ideal conditions and experts tuning them. I prefer many numbers being posted by the average modeler on the street so a pattern can be derived.

Ken:

On your proposal, I think it has good merit. Whether you can get manufacturer's to take note is another matter. I too would love to see something like this. It's certainly worth a try.

Here are a couple of points of input:

-Engine mounting details
*** including recommended mounts if not included

-A standard prop should be defined for each engine size class. I would use APC as a standard so that everybody uses the same prop for RPM specs. - Not sure about the APC.
*** These are not very widely used in the larger motors.
*** Maybe for different size range motors, a different brand prop could be used - Menz's are widely used from 18" on up, so maybe that could be the standard for the larger motors.

-Engine weight in gms and oz, with muffler, carb, ignition, and standard prop, ready to fly.

*** I would rather see the weight with muffler(specified and weight given), ignition, prop nut and washer, plug and mount, if included(weight of mount if separate from motor). I do not agree with the prop, that is too variable, and I would not include the battery on an electronic ignition motor because that is also a very big variable. (carb is assumed since it is part of the bare motor)

-Engine weight in gms and oz with all optional parts not mounted.
*** Bare weight is also a useful number.

-RPM using at least the the standard prop. The fuel, air temp, and altitude should be noted.
*** I agree with this, but it would be of little value since manufacturer's are going to published optimized numbers at the very least.

-Optionally, Horsepower. The method use to determine the HP must be included. In other words, it can't just be 10% more than their competitors.
*** This would be a fairly useful number if derived from a dyno, but I know all the manufacturer's don't have one, and some are actually quoting numbers right now derived from a thrust calculator. So I don't have much hope this would be a valuable piece of info in most cases.

-A side and front view of the engine with the major dimensions shown. The overall height and width. The distance from the firewall to the back of the prop. The distance from the centerline of the prop shaft to the mounting surface.

*** This is always useful info, and should be on every site.

Great job Ken, I hope we can make something of this. I will be glad to help present it to a couple of the engine manufacturer's I have contact with. I think since the manufacturer's, or distributors in the US, as the case may be, are relatively small, and their customers are typically in touch with the people in charge, so I think there is a good chance they could be influenced to post consistent numbers like this on their Web site.

Bill