180Marty wrote:Glidergeek, forgot about you having Pponk also. Also, I went back to Pponk site and see it says 265hp to 275hp--not 285. Do you know the difference between the two hp ratings or do they just vary that much.

The high comp pistons are not within the Pponk STC (although there are plenty out there running them via FA and otherwise...)

Steve shows the HP difference as a result of the choice of cylinders. Factor there is whether the cyl.s have 'venturi' type valve seats or not.I believe Steve was prudent in the claimed HP increase, it has also been shown on a dyno, that the typical Pponk O520 ends up closer to 300 hp. IMHO who builds your engine probably has more impact on how it performs (and for how long) than what STC it was built under.

As a side note, although the engine everyone thinks of when you say 'Pponk' is the O-470-50, Steve also has an STC for a 300HP O-550...

Take care, Rob

I can attest to the performance of the PPonk o470-50. You will give up nothing in performance next to a IO520. Knopp says reality is they come out of his shop a little over 300hp. They run great on 91 octane mogas. I suspect they would run fine on 87 octane, but you can't get that here without ethanol. Its a great motor, but don't know if it is STC'd for 185's. It is not, however, legal to burn anything other than 100LL. Knopp told me he finally gave up on the auto fuel STC after the feds drug the process out over several years and wanted him to run the engine with auto fuel from every state in the country to prove it would work.

As a side note, although the engine everyone thinks of when you say 'Pponk' is the O-470-50, Steve also has an STC for a 300HP O-550...

Rob, Any idea what the compression ratio of that 550 is? If high, how much of a hit would changing to 7 or 7.5 to 1 that could use auto fuel be. On the venturi valve seats----I thought everything that was pretty new had them.
Thanks Marty P.S. lots of yellow corn and beans around here from to much rain.

This is the request and response I got back from COPA about 100LL. I did find out that our local airport will be putting in it's own 2000 gallon tank for 100LL and it will be a seamless transition.

Hello Kevin,

I wondered what COPA knows about the availability of 100LL in the near future. Rumors have been going around on the internet that 100LL will not be available in Canada in a year, that the refinery is closing. For reasons unknown to me, the 100LL supplier is pulling out of our local airport here at Dryden, ON, but I have not heard if a replacement has been found. A friend from BC contacted his supplier and they said the refinery was going to be down for repair, but there was no truth to the rumors of the end of 100LL. Anyway, I am concerned both for myself as an aircraft owner and our club, that also purchases 100LL for members and the club plane at our float plane base. Our club is having the monthly meeting next week and I would like to report what COPA knows about this. Thank you for any information, hopefully you can dispel the rumors.

Respectfully yours, Steve

Steve,

Thank you for writing COPA. We are all concerned and as you know this issue has been going on for many years. I know many fuel supplier in BC are trucking 100LL from the US. There is no guarantee that 100LL will be available in the future but for now there is no immediate threat. We are following the US on this because if they pulled out for whatever reason, the rest of the world would follow.

There are several articles on AOPA's web site www.aopa.org . Just search "100LL future". A no lead alternative is in the works but the certification process is a long one.

COPA is keeping an eye on our government for signs that they may take any action to stop 100LL. So far, there is nothing on the horizon in Canada.

AVGAS Facts and Future (Shell)
http://www.shell.com/home/content/aviat ... 71515.html


Best regards,

Patrick Gilligan
Vice President, Operations
Vice-président des opérations