I know of a PA61 with a carbon fiber pipe for sale. A friend who has flown this engine/pipe combination extensively has a number of cautions. 1. It was his experience that the pipe failed after approximately 100 flights, needing to be patched. Eventually the pipe had to be replaced. This was an early carbon fiber pipe. Same as the one offered with this engine. Have people on the forum experienced similar durability problems? Did you manage to solve the issue? 2. Tuning was difficult. Head gaskets, prop switches, fuel adjustments, and so forth. I think the pipe was also modified for length. Any advice here.
Thanks.

     Earlier pipes tended to have leaks, but they seemed to be less significant on the PA61/65 than on smaller engines. If you see oil appearing where it shouldn't, pressure test the pipe in the bathtub with HOT water, mark leaks, clean with wire brush then lacquer thinner then use JB-Weld (not JB Kwik) to repair it. You can set the epoxy in a few minutes with a heat gun. I have had no problems with the last batch of Billy "diamondback" pipes and that has been over MANY years.

    Tuning is no problem and not inordinately touchy. I think the stock recommended tuning may require a bit more fiddling than the David F. setup that we all used, but either way it's not a big deal. I got it working the way I wanted and never touched the head gasket again (for the next 5 years), changed props only when I wanted to change things, and eventually only used two different props the entire time I ran it. Set the pipe and never touched it, same with the venturi. I did all my adjusting with fuel and aside from driving 2500 miles to Muncie, I never had to adjust it for the conditions from day-to-day.

    As an example, I had switched to the RO-Jett before the 2003 NATs, and had it working nicely. Then the rear bearing chipped and it ate itself up between flights at the NATs. I flew one official that way, and it ran but sounded like it was going to fly apart at any second. I had the PA as a backup, and hadn't flown it since the previous July - just put some after-run oil in it, put the engine in a ziplock bag with the pipe sticking out and attached, and put it away. I took it out, put it in the airplane at the NATs (between rounds), and tried it. Started first flip, didn't touch the needle, it ran around at 5.4 laps and 10100 RPM in a thundering 4-stroke, and was just about perfect. Never missed a beat.

  My PA61 ran great most of the time, with tremendous "power". The only complaints I ever had were related to the response of the engine in the corners. Set up stock it was drastically too aggressive for me, with far more power increase than I wanted. The usual solutions to this (lower compression or nitro) killed the "power" as fast as it killed the break. The David setup (a follow-on to Ted's 46VF system and documented in the engine setup article in SN) solved the excess break issue 95% of the time and retained the "power". More or less it was to set the engine and prop so that it would run in a 4-stroke all the time. The other 15% of the time it broke into a 2-stroke on the outside part of the square 8 and accelerated more than you would want.

   The key feature to killing the hard outside break was the spigot venturi. That had such a huge improvement that it kept me using the engine, because otherwise I would have given up. Later versions (mine was a Stage II PA, there were up to stage V, I think) were much less prone to this issue even with the stock venturi.

   Brett

   

Has anyone successfully used the PA61s with an extension manifold and a muffler, instead of a pipe? (Thank you Brett and Derek for detailing your experiences.)

I know of a PA61 with a carbon fiber pipe for sale. A friend who has flown this engine/pipe combination extensively has a number of cautions. 1. It was his experience that the pipe failed after approximately 100 flights, needing to be patched. Eventually the pipe had to be replaced. This was an early carbon fiber pipe. Same as the one offered with this engine. Have people on the forum experienced similar durability problems? Did you manage to solve the issue? 2. Tuning was difficult. Head gaskets, prop switches, fuel adjustments, and so forth. I think the pipe was also modified for length. Any advice here.
Thanks.

Hi Dennis

The engines are typically flown as suggested right out of the box, all over the World, with great success , after breakin,
They are for most very user friendly and run excellent, Needing not as much "fiddling" as most everything before them, IF you pay attention, Some, "a very very few" could not, or did not want to run them as suggested ,and there ...let admit it...are a few that cannot make a ST 46 or any other engine work well.
The pipe I have no idea what it is? who made it? when they made it? what motor range it was for? and if it was too small or damaged?
But I have over 600 to 800 flights on 2 pipes, and I have never had a pipe problem, The pipes I have made here in my shop for the past 5 years use the best highest temp resin we have ever used in pipe production, and the normally give EXCELLENT service to stunt flyers all over the world.
The stock setup runs well enough to have captured many NATs tittles and World Championships. The setup also has very good runs with excellent power. I have personally flown 2 PA engines into the US NATs top 5 , twice, with winds over 20 mph, and powered thru all of it.
many other have done the same.
The bottom line is if they want to know how to run one, and what pipe to use, what prop range and what setting, I am available to give them all of that info. as I have for many many years to anyone that asked. I find most people get off "square one" and have problems when they start setups that are far from the recommended ones.
So maybe a good idea to check out the condition of the engine, look for damage or overheating (burned up), and make sure the pipe is the right size for a PA 61

By the way the PA engines in the range from 51 to 65 have had 3 series of engines over the years, The Big 40 2 series, and the Merlin 40 and Merlin 75 1 series.

Regards
Randy

Thanks for your information Randy. As you know carbon fiber pipes are made by different individuals. This appears to be an older pipe not made by you. My friend who bought the engine was not sure of the origin of the pipe. It was sold as a package by someone who did not know much about what they were selling. Brett's experiences are consistent with the experiences of a club member. Older pipes have been known to spring leaks. I did not personally know of an individual who ran a PA61 without a carbon fiber pipe, which is why I asked the question. Great to know about Allen's experience. I can now ask him about how he set the PA61 up. Or you. I have no problem doing that.

I have seen many PAs run extremely well. The ones used in our club show their quality in many ways. Very durable. Excellent stunt runs when set up correctly. The quality of the engines are obvious even when flipping them over. I have also seen a few that have not run all that well. User error, failure to follow your direction. So be it. I have great respect for the PA engines. Which is why I am considering purchasing one. I have not purchased one until now because, frankly, I did not think the quality of my flying or building warranted the investment

On the other hand it takes me out, how folks who have been perfecting these engines for 30 or 40 years overlook how hard it is to get the many variables that need to be right right, when making any model airplane engine work well. Those of us who are coming up in this hobby hit all kinds of issues. (Like myself at the tender age of 66!) Even with comparatively simple set ups. Bad vibes, faulty tanks, poor prop selection, problematic mufflers and pipes. Frankly, without folks around to mentor, I don't know how anyone gets an engine to work as well as it can. Also, I have been at contests where folks competing at the highest level did not appear to have an optimum engine package. At least to my lying eyes. It happens. Always useful to pick up information. Especially when it's easily available on this forum. It's a great resource. Thank you Randy, Brett, Derek, and James, for schooling me. Three top 5 flyers. Nats winners and potential Nats winners. Including the designer and manufacturer of PAs. Far as I'm concerned, I am availing myself of a valuable asset by asking questions. Thanks to Robert, of course, as well.

Is Banjock involved in this somehow?  Is this Suzy Q's engine?  If so I think thats a Windy pipe.

Kent Tysor had a bunch of Windy pipes where the resin had been cooked right out of the hot section, however it took considerably more flights than 100 to do that.

Yeah. It was an early Windy pipe on Suzy-Q. The pipe with the PA61 looks like the same one. I'll say what we think it is, since you blew the cover, I was trying to be discreet. Engine appears to be brand new in the box. My Honda Civic, however, is not the same vintage as Mike Palko's Honda Civic. He totes his Electric soylent Green Mustang around in his car, but the rear shocks in my vintage Civic intrude just a bit more into the trunk. Dunno if I can fit a 60 size ship in the tight hole. (Why do I think that last sentence is funny.) Which means putting my 1980 Malibu station wagon on the road for some serious miles. Am I that bold and courageous. Among other things it's a hot rod with a suspension stiff enough to loosen my elderly teeth. No air conditioning. I used to think it fun and funny driving around in 90 degree heat drinking ice water from a gallon jug. The sea of sweat running down my back, sort of cooling me down. Doing the 300 plus miles to Brodak or for the matter or the 630 plus miles to Muncie in the old Chevy... Am I still man enough. Am I. Gotta be kidding. The gas bill for premium, rates another, you gotta be kidding.

Brett, out of curiosity do you remember what the plug life was with your PA?

   With SIG fuel, anywhere from 20 to 50 flights. With Powermaster, indefinite. They never blew, it was just a matter of taters.

    Brett

Also, I have been at contests where folks competing at the highest level did not appear to have an optimum engine package. At least to my lying eyes. It happens.

      Oh, that's not any lie!  Most of them, including people routinely finishing in the top 10 at the NATs, are not optimum and are probably making it harder on the pilot than it needs to be. The beauty of the PA and other large piped engines running low pitch is that it can be FAR off the ideal run and still permit you to get in decent patterns. The basic performance of the engine is so far beyond what you need to get through the flights that it doesn't need to be optimum. That's why almost any setup is far superior to almost all 4-2 break systems we used to run like the ST46 and 60. As long as the engine keeps running, it will make it through the pattern, even if you miss the needle a bit or it's set up wrong. It's FAR, FAR, easier to get an acceptable run with these super-high-quality engines. And, it's not going to change unless something external changes, very much unlike most ST46/60s.

   Another incredible advantage is that they are all the same. If you set your engine up the way David sets his up, you are very likely to get a run very similar to his. Same with Randy's setup. So you can know 90% of what you need to know by merely reading the instructions.

   The rest of this is general, not specific to any engine

     Despite all that, there is still some advantage to getting the last 10% right, as well. If someone else gets it perfect, and you don't, you have to work harder to get even. Most people never get the last 10%, and many don't even realize how far off they are (since you can get through the pattern reliably even with it WAY off). Those who can recognize (or are WILLING to recognize it) don't know what to do about it. Usually they try stuff at random (things that aren't really variables or likely causes of problems like the pipe length and compression) and sometimes it helps and sometimes it makes it worse. Most of the issues that David and I have worked on for the past 10 years or so are things that most people don't even consider- fuel delivery and carburetion. The rest of the system is already the way it needs to be and the big stuff has long been figured out.

      Don't overlook the "willing" to work out problems aspect. Many people simply won't consider many potentially useful changes because of borderline-religious aspects of various rules floating around, many of which are wrong.

    Brett

   With SIG fuel, anywhere from 20 to 50 flights. With Powermaster, indefinite. They never blew, it was just a matter of taters.

    Brett

Ok, that is in family to what I see.  12 to 40 flights on Sig.


I only ran all Powermaster in the DS 60.  There I would get 225 flights between changes.

Ok, that is in family to what I see.  12 to 40 flights on Sig.


I only ran all Powermaster in the DS 60.  There I would get 225 flights between changes.

   Different individual engines have different tolerance for SIG. I borrowed Bill Fitzgerald's 61 as a test for the 1999 NATs and was about ready to switch back to the 40VF to get more power. Then I checked the plug and almost the entire element was covered with tater. Put a new plug in and WOW, that's a lot of power. But it would tater up the new plug in 10 flights and it became very weak again. That was close to a plug a day at the NATs. I ended up just scraping them with an exacto knife for practice flights, then put a new one in for Top 20 day.   My later engine (that Derek now has) was much less prone to this and I would get 50 flights, easily.

 Now that VP Powermaster has the full 10 or 15%, there's not much reason to run SIG any more.

     Brett

          ...Despite all that, there is still some advantage to getting the last 10% right, as well. If someone else gets it perfect, and you don't, you have to work harder to get even. Most people never get the last 10%, and many don't even realize how far off they are (since you can get through the pattern reliably even with it WAY off). Those who can recognize (or are WILLING to recognize it) don't know what to do about it. ....

That last 10% is *EVERYTHING*


getting to it is another matter, though, as you point out.

Soon. Certainly will not build a plane for it this season. It has been a busy year for me. I'll be picking up my station wagon later this week. Hard to believe a Quadrajet can deteriorate all the ways this one did. Maybe it had something to do with age. That Quad coming off a 76 Olds V8. Worked fine until six months ago. At least I can get a 60 sized plane to the field in the wagon. What are you flying this season? Same as last year?

You're right Randy! Except good mileage on the station wagon is 19 on premium, if I do this and that with the gas fillups to fool myself into feeling  better.

You should ditch the Quadra-bog and get a Holley 750 vacuum secondaries carb.  Than that car will fly!

The 750 vacuum secondary is a nice carb for sure. But if you really want to kill your mileage then get the 750 with manual secondaries (double pumper). Use a light return spring and you can actually feel the secondairs in your foot. Just stay out of them around town, but when you need to bust a punk from time to time and light mashing of the pedal and its all over but the crying.

, and I am still looking for more of that last 10%....

Me too.....

The plastic parts in the Quadrajet were lunched. I didn't even know there were plastic parts in there. A friend said it's the ethanol in the gas. What do you do about that.

Well, you could write a letter to Obama about the ethanol in the gas....   

There are rebuild kits sold for the Quadra bog that have parts (especially the accelerator pump) that resist damage from ethanol laced gas.  That will be the cheapest way.

Well, you could write a letter to Obama about the ethanol in the gas....   

Yes, please do so.  Ethanol gas sucks! 

so does your fuel mileage with ethanol  fuels !!

Randy

Fortunately I live close to a big lake and the fishermen like to run real gas in their boats. I buy good gas every time I am on that side of town.


Derek

Dennis, maybe the solution is to give up on the wagon and get an e power car.  After all, Howard Rush manages to transport an Impact in some little peanut car (Prius or something?)

Lost myself another point. 

My PA61 has "RAN 04 303" engraved on it. Can anyone tell me what vintage this motor is? My understanding is that it is a Randy rebuild. Motor is unused, as far as I can tell. Got it from a source I trust completely.

Say Mike, isn't that the one you were going to sell me so you could buy the latest and greatest electric set-up?

You bet, field in great shape. Should be a good contest. Bring shade (and the 61).   

Thanks for the feedback, everyone. Car is running. No doubt I'll buy a PA.