David Hill

My Feedback: (2)

Hi Guys,
I saw the post about a 422 in a Q-500. I have a question about using a 428 Nelson in a 422 Quarter 40. If you were to use an APC Q-500 prop on the engine, how would the plane fly? I always wondered why they would not let this combination race. It would be a great way for some of us to try 422 without buying another motor AND at least with the air valve you can pull the power back a bit if it is getting ahead of you.

Thanks,
David

Larry F

Hi Dave,
Before I moved east from Iowa last year we did just what you were talking about and it worked great. I had a Dago Red that I put a 428 Nelson in with an APC 8.8 x 8.75 and the air valve. The plane was very fast. We had no radar gun but with stop watches we worked it out to about 180 in straight and level flight. I am sure with some playing with the right prop, you could improve on that.
Where do you plan on flying/racing? Maybe ask them if you could try it in a race.

Larry

David Hill

My Feedback: (2)

Hi Larry,
The closest place would be Bowie MD I would guess. They do some 422 racing down there. I went to watch the JR Cup race down there, but it rained all day Saturday and I could not stay to watch on Sunday. I guess I would have to find out who to ask there if I could do it.

Does anyone else think this is a good idea or am I wasting my time?? I just figured with more torque and less drag this might be a good combination.

David

Lewis S.

My Feedback: (229)

Hi David,
See if you can get a hold or Rick Moreland. One of the nicest guys you will ever meet. I bet if you ask him, they will let you fly, BUT it is up to him. Don't have his email handy, but if you go to the WWW.NEPRO.ORG site and look for the link to PGRC you should find his contact info. Also it might be listed in the race schedules we have posted up there.

Tell him Lewis says hello : )

daven

My Feedback: (1)

We did exactly what you suggested about 4 years ago. It helped ease the transition of not having to buy a new engine right away.

The Q500 motor worked great on the Q40s, and I guess I wish the 422 rules would have been written that way in the beginning to help limit the amount of different "expensive" motors that we need. It also takes the wood prop factor out of the equation because the APC quickee props worked great.

If you use the barrel carb on the quickee motor, you will have open up the engine compartment with a dremel to make room for the throttle linkage.

DHG

My Feedback: (7)

David,

Whoever told you it was "illegal" to run a carb in 422 (QM40) is flat WRONG. The rule says it can be a carb OR a venturi. And it can be modified, too. I've been using modified carbs for two seasons now and I prefer them to the shutoff for several reasons, including the ability to test-fly at reduced speed and the fact that when you throttle back to land, the engine dies out rich and cool instead of starving lean.

Now, as to whether to use a 428 (Quickie) engine, with the lower timing and a bigger prop -- that works fine although you do give up a little speed. The only thing you would need special permission for, if you wanted to enter a QM40 contest with that setup, is the Quickie prop. The rules in QM40 require either a wood prop (which can be modified) or an APC 7.4 x 8 chopped carbon fiber prop (which cannot be modified). The APC 7.4 x 8 isn't the most efficient prop for a Quickie engine, but it would probably work ... otherwise you'd need to ask first if you could use a gray APC Quickie prop such as an 8.8 x 8.75, or just find a wood 9 x 8 or thereabouts and clean it up.

Best part is, when you get the airplane trimmed out and get used to it, the high-timed 422 engine will bolt right in. The crankcases are identical. Go for it!!

Duane

Ed Smith

Basically, at the moment, 422 is the premier racing event in the AMA rule book. If the rules were allowed to be changed to cater to the many suggestions that come up we would no longer have a consistent racing event.

You need to convince the racing fraternity to have a 422 entry level event where you could race your suggested setup.

Good luck with that!

Larry F,
I think your 180mph is a bit optimistic. You would need the engine to turn your 8.8 x 8.75p prop at 23,000 to get that speed. If you have a legal 428 Nelson that can do that I will buy it for any price!

Ed S

bl10

Back in the days of “Slow em down” Fred B put a Q500 engine in one of his Q40’s to determine the effect. While we didn’t really try to optimize it the results were surprising. He brought the plane to a Basin race for testing. I launched for him and could feel less (not more) thrust while sitting on the line. The first lap was about 1.5 seconds slower than a good Q40 and each following lap was at least a .75 seconds slow. As it worked out the plane was slower, by quite a bit, than his Vortex Q500 with the same engine. We didn’t experiment much with props but it definitely was much slower than a Q40 and somewhat slower than a Q500. Only thing we could figure was combination of less horsepower and the increased wing loading of the Q40 airframe killed it in the turns. (As I recall its speed was about the same as a Q500)


Barry

luv to race

My Feedback: (1)

I'll out bid Ed for the 180mph quickee motor!

Something Fred and I did one day in California. Was, shortly after I won my first quickee Nats in 2000. Fred and I were practicing and I took that same airplane with me. He had me put that quickee in a dive from an altitude of "out of sight".... fly it right down towards us and he put the radar gun on it.. and all it did was 177 or 178... It just got to a certain point and started running over the prop.

Totally agree with Barry. That would be one way to slow down Q40 ??!!?? put a quickee motor in it. And some big tall landing gear to clear the prop.

RB

daven

My Feedback: (1)

The gear was fine, the quickee props cleared the ground.

David Hill

My Feedback: (2)

Hi Guys,
Thanks for all of the input here. Maybe I will try the air valve on the engine if I can fit it in. Really a shame for us 422 beginners that we just can't bolt in our 428 engines and use the current APC props. If they want to encourage more people to fly this would be a great thing.
I thought many times about joining the NMPRA again, I belonged some 15 years ago, but I can see things have not really changed all that much. It seems like those with the big dollars are still controlling what happens as far as rules go and the heck with the part time sport racers. If they really wanted more guys to come in, this idea I mentioned would be a no brainer. I really like this forum, you guys say what is on your mind AND some GREAT POINTERS!!!!


David

bl10

David:
You can bolt your 428 engine directly into a q40 so long as you use the standard backplate. The cases and dimensions for both engines are the same. The air valve 428 intake will probably require a bit of grinding on the nose of the plane. This is not a “No Brainer”. As I stated before a Q40 airframe with a 428 engine is actually slower than a Q500 airframe with the same engine. So why would anyone want to fly a plane that is slower than a Q500, more expensive than a Q500 and generally a pain in the butt to take off and land as compared to a Q500.


Barry

daven

My Feedback: (1)

Quoted from bl10

"So why would anyone want to fly a plane that is slower than a Q500, more expensive than a Q500 and generally a pain in the butt to take off and land as compared to a Q500".

Because they look cool

Although I agree with everything you said. LOL

dcran

Dave, I can say without a doubt that if you brought your q-40 with a quickie engine and prop to one of our races in TX, you would be allowed to compete. I think all you need to do is approach your VP and/or contest directors. You will probably get the same response.

I personally feel you have some misconceptions with NMPRA. There is no clear cut answer as to what rules would make every racer happy, and bring the masses of modelers over to pylon racing. If there was, we would be using that protocol. I have been involved with the rules process, and it entails a commitee of several racers who discuss issues and democratically vote accordingly. I don't think it has anything to do with there wallet size..

Ed Smith

Let me recap this to make sure I have it right.

Put a 428 engine in a Q40 which will fly slower than the event he is already flying to prepare himself for an event that is much faster.

Hmmmmm....

Ed S

daven

My Feedback: (1)

I don't think speed is the issue for people learn how to fly a Q40. The toughest part is getting use to take offs and landings.

bl10

Dennis:
You are correct, if someone wanted to run a Q500 prop he or she could do so if the prop meant the Q40 prop rule where you have two choices, APC 7.4 x 8 molded carbon or wood. He could not run any other molded prop. In order to permit any other prop we would have to know in advance and apply for an exception on our sanction and advertise the event as having said exception. The exception would invalidate any record set at the race. If we did let he or she compete without the sanction exception we would be risking our insurance coverage by knowingly allowing an illegal / unsafe plane to fly (the prop is not only a performance item but heavily embroiled in safety issues as well). As most of us know the difference between the 422 and 428 engine that determines prop size is the sleeve. I think a new sleeve and piston is about 80$. So if you’re going to spend the money for Q40 airframe why not put in a competitive engine?

Barry

DHG

My Feedback: (7)

Barry,

I agree. Although the original concept of QM40 (use your Quickie engine on a semi-scale airplane) didn't pan out as advertised, we're still not that far off. By changing the piston/sleeve set, David could get a fully legal QM40 engine out of the Quickie engine he already owns. And he could change back easily, too. Yes, that's more work than just unscrewing 4 mounting bolts, but it's still not too bad ... certainly better than having to cough up $350 for another engine just to try out the event.

He could even go a step further by getting an extra carb and flaring the opening so it looks & runs like the QM40 venturi. That would fully equalize the performance while avoiding the feeling of having a "tiger by the tail," which you get from having only a fuel shutoff instead of a throttle. I suspect this may be a bigger factor than airspeed in keeping new people away.

Duane

HighPlains

My Feedback: (1)

The original concept of Q40 WAS to use the same engine, but unfortunately (or fortunately depending upon your point of view) the designers of the event didn’t create an airframe with enough drag. More drag would have required a larger diameter propeller to pull it around. A lighten Formula One airframe would have been about the right size if the goal was to use the same engine, though the prop would have been around 8 to 8 ¼” diameter. BTW, I think that most modern Quickies could run well with that same size.

Formula One aircraft were demanding to land with a wing loading of 25.6 oz/sqft.
Q40 is quite a bit easier at 23 oz/sqft.
Quickies are lighter than most trainers at 16.1 oz/sqft, so the landing speed can be slo-o-w.

There was a serious look at slowing these things down about 4 years ago. You would get more agreement promoting child abuse. RC Pylon racing is the ONLY racing speed event that won’t do this, even if it kills our events. Control line speed does it all the time by increasing the size of the control wire to increase the drag. Speeds today are about the same as speeds 20 years ago, even though the engines are so much better.. NASCAR and Drag racing have done the same thing. Didn’t they run around 220 MPH at Daytona back in the early 70’s? Now they have dialed it back to around 190 MPH. Drag racing is more like us, they placed a 3.25:1 rear end ratio on Top Fuel to attempt to hold the top speed to only 300 MPH at the traps. Last I heard, they were up to about 330MPH. Technology marches on! Oh yea, they lost a driver just this past week.

So for safety, we now have course workers off the course. The down side? Well now you DON’T have to fly around pylon 1. Might as well be flying from the side line, as that makes it much easier when your not worried about slicing. Not as difficult, also not as much fun in meeting the challenge.

It used to be that you could not pick up a model magazine without seeing articles and advertisements on some aspect of pylon racing. Not any more. People love racing (just not pylon), high speed airplanes (just not pylon), and our numbers are very low. Why?

Tony Pacini

It's not so much that they didn't specify an airframe with enough drag; they didn't close the loophole by specifiying a minimum prop diameter......

Ed Smith

This whole discussion is somewhat academic but I have nothing else to do right now.

Duane,

I am not so sure that will work. The top of the exhaust outlet in the Q40 case is relieved to clear the higher exhaust port of the Q40 sleeve. If the 428 case is ground away to clear the Q40 sleeve exhaust port then that engine is now illegal.

However, do the new 428 cases come with that area relieved?

Ed S

P.S. I really do think we are searching for something to say here.

js3

My Feedback: (3)

Ed,

I can't speak for the Nelson motors, but the Jett's Q500 case is relieved in the area of which you speak; it will accept a Q40 sleeve.

John Z Williams Jr

Ed, you can slide a qm liner in a 428 case and it will work if you take up the exaust port... Is that illegal? its not a performance enhancing change so I would not worry about it, but others may, what you can do is buy a qm case for 65.00 and it will work for both applications, that is what I do now, that way I can build either a qm or quickee motor and I can change them back and forth in about 7 minutes!!!!!!!!

DHG

My Feedback: (7)

Ed,

I stand corrected. I'm so used to buying the QM40 cases that I forgot about that small difference.

When I want a Q500 engine, I always order a QM40 case with the milder-timed Q500 sleeve installed. That way I'm fully legal and competitive in Q500, but also have the option to swap out the piston & sleeve later for QM40 if I want to. There's no performance penalty for using a Q500 sleeve in the QM40 case; the extra space and the little "lip" at the edge of the sleeve above the exhaust port don't seem to affect the way it runs.

David, sorry for the confusion. If it's any consolation, I actually ran a season of QM40 locally, using a backup engine that I'd built late one night & inadvertently used a Q500 case. My rpms were down a little, but I figured it was due to the altitude and/or dirt scratches in the piston. (We get those, here on the moon.) I trimmed my props down to regain the missing rpm and never even noticed until much later, when I took the engine apart to change bearings. The setup was still much better than if I'd used a Q500 sleeve and big Q500 propeller. So my advice is, go ahead & do it anyway, even if all you have is a Q500 case. If you find that you enjoy QM40 enough to continue with it, you can buy yourself a full-on setup for Christmas.

Duane

p.s. Ed, you'll notice I didn't try to blame the rum ...

js3

My Feedback: (3)

JZ,

I would most certainly call that a performance enhancing change to the motor; you're grinding away metal in the exhaust port to allow the use of a higher-timed sleeve. See Duane's post above. He states the performance of the Q40 sleeve in the Q500 case was down a few RPMs and he had to compensate by trimming the prop. So if you relieve the port to accept the higher sleeve, you'll be enhancing the performance.

Not that that matters at all. If you grind the exhaust port, your motor is no longer stock and IS illegal.