What 470 engines are eligible for ponking? Seems like I recall A & J are not, but all K and up engines are. I was also wondering about what the data plate says after an engine is Ponked. Say it was an O-470K, is the data plate restamped with "-50" after the engine model, or is a whole new data plate used with "O-470 - 50" as model?

I believe that the R motors will require a different crank for Ponking... No idea on the data plate. I'm sure someone smarter can fill us in.

Here's some info:

http://www.pponk.com/HTML%20PAGES/O470_conversion.html

I'll bet they stamp a -50 in to the data-plate, and that's why it got the -50 designation. Just a guess of course, because I have yet to Ponk mine

If I get to it first, I'll let you know Hotrod...

I have worked on two different PPonk engines... One a converted 0-470L and the other a 0-520 case... Both engines have a secondary data plate installed over the top of the original Continental data plate specifying the conversion to a 0-470-50... The top section of the Continental plate is readable for the engine case and serial number.

Brian.

I think you can do the PPONK conversion on any angle valve continental 470. We had an O-470-R(25) engine in it. The ponk required us to change the crank to a VAR crank i believe with different counterweights for the 2700 rpm redline. They then bored out the case, and put the 520 cylinders on it. The data plate on the engine is not different whatsoever. It still has the original continental data plate on it, except where it rivets to the case there is a secondary pponk data plate on it, giving the new rated power and the displacement of the engine. The main difference on the data plate is that on a 470 conversion it states 235hp and on the 520 case it states 265hp. Mine says 235 i have a buddy that had a 520 converted his says 265. The converted 470 and 520 are both 265-300 hp engines depending on what you do to them.

If you are considering the conversion, i will personally say it was worth the time it took Steve to build our engine...it was also worth every dime in my opinion! I have close to 300 hr on it since converted and it runs just as smooth as silk.

Steve Knopp is a really cool guy to deal with, and has some really cool and interesting points on "heavy case vs. light case" so much so that he reused our light case when he built mine.


Mike

Steve Knopp is a really cool guy to deal with, and has some really cool and interesting points on "heavy case vs. light case" so much so that he reused our light case when he built mine.

Do you remember any of the specifics? My 470K with Phase 1 case would definitely be "light". It has the big front main bearing that is about 3 inches fore and aft also.

182dude wrote:...If you are considering the conversion, i will personally say it was worth the time it took Steve to build our engine...it was also worth every dime in my opinion! I have close to 300 hr on it since converted and it runs just as smooth as silk....

I'm just asking out of curiosity. It seems like about half the people I know or talk to have Ponked their 180's. My K engine has 1200 hours on it so hopefully I won't be looking at an overhaul for a few years yet. At this point I'm thinking a stock 470 is enough for me, but who knows how I'll feel in the future? Steve Knopp is located at Camano Island 13W, not far from where I live, so he would definitely be on the short list for doing my overhaul when the time comes. I'm sure he could build a stock 470 to run just as smooth as one of his Super Eagles.

BTW the link posted mentions that "the cylinders are fitted with low compression pistons", but doesn't mention whether the Ponk -50 is approved for mogas?

It is not approved for moGas. For that reason I can't ever have a ponked engine...

I'm a firm believer in mogas use, that would sure take away a lot of the incentive for me.

Whats the deal with mogas not being approved on the -50? With the low compression it shouldn't be a problem...

Whats the deal with mogas not being approved on the -50? With the low compression it shouldn't be a problem...

Too much hassle jumping through the hoops of FAA buracracy. It's just a paperwork technicality.

Works fine on 87 from fredmeyer I hear. Filled up the plane last night for only 2.70 a gallon. [emoji3]

Steve said that they did the testing for Mogas, but it was going to be an additional delay to get it approved on top of the already long delay to get the basic STC completed. -Just couldn't wait any longer for the feds.

Seems a bit fishy to go so far for an STC and then quit for a bit of extra time for moGas approval. Especially if all the testing has been done already and there were no problems.
Not saying there was problems, just seems fishy. Running on moGas may not bother many of you, but being legal is important to some as well... as much as the extra power would be awesome, being legal and not wrecking my expensive engine is more important.

To answer the question about the "light case" When i talked to Steve about sourcing a heavy case for our engine build, his words to me were this:

I have a customer in Alaska with a 1972 C180 that i have done 3+ overhauls on the engine is turned up to 300 hp and he has the factory original 1972 light case 0470 R25 case still in that aircraft with absolutely no problems with the case whatsoever, if you must have a heavy case you can build it with one but it isnt a make or break decision in my opinion.

I am unfamiliar with the different Phases of light and heavy cases, our case does not have the ridges above the bolts that hold the halves together.

I have talked to people that have differing viewpoints on light vs heavy. The argument i have heard many times against the heavy case is just that...it is a heavier (weight) case with more material in the block. The argument against the light cases obviously are cracking.

Im not an engineer or aircraft mechanic, so im not going to try to be one...i have put a number of 300 hp hours on our 470 light case with no issues thus far.

Mike

As for the car gas deal on the ponk engine, steve told me over the phone that they worked on getting these engines approved to run on it. They can and will run on it, they just got tired of doing all the work for not and quit.


Mike

Thanks 182dude!!!

182dude wrote:As for the car gas deal on the ponk engine, steve told me over the phone that they worked on getting these engines approved to run on it. They can and will run on it, they just got tired of doing all the work for not and quit.


Mike

Great to know. So they would warranty it if you run on moGas? That would be the biggest kicker. If they would then perfect!