The general consenus from the 426, aka Q-500 Intermmediate thread seems to be that we should promote 424 heavily at the local level.

However, every time a newcomer shows up here, we seem to have to tell them to check and see what 424 variant rules are being run in their area. This is not a good thing, as has been pointed out many times before.

The two areas of variance are the engine restrictions and the airframe restrictions.

The most common engine allowed is the Thunder Tiger Pro 40. This engine is not a high quality engine, and from the information I have, APRA allows the bearings to be changed because the stock bearings are marginal, or at least were marginal in the past. NEPRO and now SEMPRA only allow the TT Pro 40 in 424.

Marketing of pylon racing has been brought up as an issue, too. What sense does it make to lock O.S. out of the game? Many, many sport flyers love the O.S. engines because they can take them out of the box, put them on the plane, run a tank of fuel through them, and go flying. The O.S. quality allows for this. The lower end engines require cleaning, etc, before being ready to run. MDS is also being locked out of the game. O.S. is the Great Planes/Hobbico in-house and premium line and MDS is Horizon Hobby's primary line. From a marketing perspective, allowing only the TT Pro 40 is a major problem.

The airframe restrictions some(many?) groups are using also limit marketing potential. It is easier to mass produce a decent bolt on V-tail in composite materials than with wood. I've heard the argument that as soon as a low cost composite Q-500 airframe is available, the wood wing / wood tail restrictions may/will be lifted. Is this true? Should it be true?

I would like to hear from the people who put the restrictions on engines and airframes, and why they deviated from the rule book. Once these issues are on the table perhaps, more will understand why they are there. I personally don't understand the engine restrictions. I don't have the rules infront of me but I thought there were RPM restrictions written into the rules????
Airplanes, I kind of agree with, all we hear about is how expensive it is to participate.

The main purpose to unify the rules would be to run 424 at a national level (ie. at the NATS). Which in my personal opinion it should be run. Even if it was for 1 day (lets see if we can get that can of worms started again). Another reason would be ease of transition from one geographical location to another.

Dan

Dan,

The airframe and engine passage in the 424 rules is included below.

16.3.1. Airframe.The airframe specifications
for this event are identical to those for Quickie 500
(Event No. 428).

16.3.2. Powerplant
a. Engine.

1) Maximum displacement:0.403 cubic inch.

2) Configuration:Stock, commercially available,
front-intake, side-exhaust.

3) Intake:A single carburetor, as supplied by
the manufacturer of the engine being used,
with a maximum inner diameter of 0.325 inch.
The carburetor shall be fully functional and
shall be stock, except for longevity-enhancing
modifications as follows:

(a) Adjustment screws and idle needle valves
may be held in place with commercially
available thread locker, epoxy, or other adhesives
and safetied with rubber bands, wire, or
plastic ties.

(b) Barrel retaining screws or pins may be
replaced with commercially available screws
or pins of harder material and may be held in
place with commercially available adhesives.
Barrels may be deburred for smoother movement
and may be safetied with rubber bands,
wire, or plastic ties.

(c) Throttle arms may be modified or
replaced.

4) Exhaust system:The engine shall be
equipped with an expansion chamber muffler or
zero-boost muffler as provided by the manufacturer
of the engine being used, and having a single
exhaust outlet with a maximum outlet area
of 0.0621 square inches (equivalent to the area
of a round hole measuring 9/32 inch in diameter).
The distance from the center of the piston
to the centerline of the muffler shall not exceed
2-3/4 inches. The overall length of the muffler
shall not exceed 7-1/4 inches, measured from
the front of the header to the back of the exhaust
outlet. The outside diameter shall not exceed
1-3/4 inches. No modifications to the muffler
are permitted except that the muffler may be
tapped for a pressure fitting to supply pressure
to the fuel system. Tuned mufflers and tuned
pipes are prohibited.

5) Fuel feed:Other than muffler pressure, no
fuel system pressurization is permitted.

6) Power output:Sport Quickie is intended as
an entry-level event for pilots who are new to
racing. As such, it is not a suitable event for the
use of engines that come with tuned mufflers or
otherwise are capable of turning a stock 9 x 6
APC propeller at over 16,500 rpm on the
ground. If engines more powerful than this are
to be used at a contest, the contest should be
sanctioned as Quickie 500 (Event No. 428), not
Sport Quickie.

Dan:

I will weigh in on the whys and wherefores of APRA as opposed to 424 as well as any other rules deviations used.

1st off my credentials: We run at least 10 races a year between Whittier, the Basin and PHX. All races except the PHX Winterfest run three classes: 422, 428 and 424-APRA (the Winterfest runs 428 and 424-APRA. I CD four of these events and am deeply involved with race management of all except PHX. (PHX also puts on monthly APRA races but does not use the 9 lap rule)

Rule deviations are as follows:

422: APC 8 x 7.4 carbon fiber filled molded props permitted:
Rational: We believe use of this prop promotes 422 racing by eliminating a huge variable and added expense.

428: No deviations.

APRA-424: Deviations from the 424 rules are as follows.

1. No composite wings or tails.
Rational:
a.Cost. A competitive Q500 composite airframe cost is prohibitive for an entry-level class. The Vortex, arguably the best quickie around, runs from $400.00 to $650.00 depending on level of completion.
b.Performance. A composite airframe is perceived as being faster. If it is or not I can't say but I don't believe there were any wood and foam quickies in the top 10 at the Nats.
2. Permissible engine list.
Rational: Two samples of all engines permitted are tested both in the air and on the ground using a reference 9 x 6 APC prop. Only those which give no huge advantage are permitted.
3. No RPM limit.
a. The current predominate engine the TT PRO 40 will exceed the 16500 RPM limit specified in the 424 Rules using the mandated APC 9 x 6 prop.
b.It has been our experience in racing classes where RPM is limited it in necessary to check the winner of each heat. This takes 2 to 3 minutes additional each heat which severely impacts the number of rounds we can get in. We see as much as a 1000 RPM difference from the morning to afternoon with the highest RPM during the heat of the day.
4. APC 9 x 6 prop. (Sometimes supplied at the race)
Rational: Levels the playing field. Same size prop as permitted engines are tested with.
5. Engines must be stock except for bearings, bolts, back plate mount (if used) and head gaskets.
Rational: Some sport engine bearings will not hold up under racing conditions. Intended to be the same as 428 engine rules.
6. Novice pilots are permitted to fly 9 laps instead of 10 until he or she meets break out criteria.
Rational: Levels the playing field and encourages new pilots. The break out on the long course is 1:45. A good pilot can beat this in 10 laps but it’s a struggle for most. We consider this a entry-level event and want to give the novice a chance. We generally have a 9 lapper in the top three but almost never have a 9 lapper winning overall. We also award both 9 and 10 lap fast time plaques.


These rules work for us. Our average number of entrants, split between three classes, is between 40 and 50 with 428 being heaviest followed by APRA then 422. APRA turn out has been on the up swing. A couple of years ago when several APRA contestants were flying composite airframes entries had fallen to about half of what they were and are again.


Hope this helps


Barry

That just about covers it Barry, good job. I would like to add a couple of things. The rule about bearings, gaskets, bolts, etc, being allowed, is not a new rule, or one that has to do with APRA only. It has always been that way, even in the AMA rule book. Page 112 in th current AMA rule book, says this is allowed, and is considered stock. No new news here.....OS, MVVS, Rossi, Webra, etc, were disallowed IN APRA, only because of "SPEED & COST". Yes the TT's are less quality, but also "SLOWER & CHEAPER". The last Thunder Tiger Pro 40 I bought a couple of months ago cost me $65. A lot cheaper than the $120 / $160 other higher quality engines, plus they are faster, and some impossible to get. Personally, I have a lot of respect for the Thunder Tiger Pro 40's, mine have all ran good, and I have "NEVER" been able to wear one out, in the last ten years.......Remember the Golden Rule......Keep the event cheap, simple, & fun, and try to keep the equipment equal in APRA / 424....Thats the secret to it's success..... :sunsmiley

Should the 424 rules be changed to allow only wood wings and wood tails since that is the common airframe restriction? I don't know of any rulebook events that prescribe the materials for planes, but if this is a big issue, maybe 424 should be changed to match the intent.

Should the NMPRA test engines and create a recommended engine list for 424? Should the task be delegated to a group such as APRA?

I personally don't like monopolies. Thunder Tiger currently has a monopoly on 424 engines. They have been consistently into backorder status at Tower Hobbies over the last 6 months. I don't feel that it makes sense to depend solely on a second tier producer.

Barry, what does it take to get a new engine tested and approved for APRA? Bill Vargas did finish 10th in 428 at the NATS with a wood fuselage and wood tail plane, but it had a Vortex wing on it.

At PGRC 424 races, the TT 40 is NOT the only engine allowed. I believe it is the most consistently strong engine allowed. We have had a few ST 40s, but the TT 40 dominates. (I think I saw a HP 40 run last year.) I have been using old K&B 40s. And I believe any AMA legal 424 engine would be allowed. I would assume that APRA would follow that allowance as well. (Is that correct?) The problem, as I see it is two fold. First: the TT 40 is not an AMA legal 424 engine - but genie is out of the bottle . And as has pointed out, it has become the de-facto 424 engine. It is a great out of the box engine for less than $75. But since the TT 40 fails to meet AMAs definition of a legal 424 engine, we have a catch 22 situation. It would not be allowed if/when 424 is flown at the Nats (and 90+% of 424 fliers are then shut out). That brings up the second: Do you modify the rules to make the TT 40 legal? How would you do that so as to prevent speed creep (which would undermine the intent of the class )? I would like to see the 16.5k rule enforced. You would not need to check after every heat, but fast time and maybe first and second (or on challenge). Also add the $100 claim to AMA rules. (Then let the last place racer have first claim.) And you could allow any make engine. What would it take to de-tune the TT 40 to make it meet the 16.5K rule?

A Thunder Tiger Pro 40 is not the only engine allowed in APRA. There are other engines on the list, Super Tiger GS 40, etc. The TT Pro 40 is a AMA 424 legal engine, along with others.......Read page 123 prargraph 16.3.3 424 Special provisions. Looks like APRA rules, down to the letter.......In fact, read the AMA rule book.........The way an engine makes it on the APRA engine list, is by extensive testing. I know because Jim Allen & I were the APRA engine committee, at one time, and Jim & I tested lots of engines, and not just one of each, 5-10 of each as I remember. We tested them with a APC 9-6, & a unload prop. If the engine turned both of these props, at to high of an RPM, they were not allowed, plus they had to retail, for $100 or less. These two props are in Jim Allens possesion, and stored in a neat little box, for consistancy. Things may have changed since I was involved in the testing, but that was the basis. Nobody wanted any particular engine to monopolise, but the TT Pro 40 was the engine of choice on the list.....This too is old news, but every three, or four years, the new guys start asking these same questions. This the third, or fourth time we have told this same story, but I don't mind.....What are use old farts for ?

Barry,

Your post was right on the money. Great explaination! I like the whys and why nots. I understand according to MDP and Gary Schmidt (previously) that extensive testing was done to determine legal engines, but why not fix the AMA RULE BOOK, so that all participants in 424 fly by the same rules? And why choose an engine that doesn't meet the rules? Some limit must be there or else you can run Nelson's and Jett's.

I think APRA has done enough homework to know what works and what doesn't. I also gather that this region of the country has done the most to promote the class. Great, let the rest of the country benefit from your knowledge under one umbrella called 424 AMA rule book.

As to wood airplanes, I have always flown wood wing, wood tail quickees and have done decently at the nats. Gary Freeman Jr previously flew my airplane with great success (I say previously only because I don't know what he flew this year). And it sounds like the Racer II is an awsome airplane. And let's not forget the revolution! I think the composite thing is more about who is going fast with them, rather than the material they are made from. The fast guys fly composites because they can. They work great, you can fly the latest and greatest and they are straight. Plus, they are easy to build but, not so easy on the check book. Therefore, I agree with the no composite thing. However, I don't know how to get that in.

Regis, I think your comments on claiming and only checking the trophy winners is right on target as to where the rules need to go.

As to the OLD FART comment, I am not that OLD trust me!!!!

MDP, does the TT 40 meet AMA 424 rules??

Dan is "NOT" an old fart......... Yes the Thunder tiger Pro 40 is legal in 424, and so are a lot of other faster, and more expensive engines. In AMA 424, the only criteria, is the 16,500 RPM range. This number is a little bogus on the start line in my opinion. There are some high dollar engines that might peak out at over 19 K, that like to be backed off to the 16,500 RPM number. I have seen some guys throttle back, & even have a switch on the TX set, to attain the 16,500. The honest guy that has a lesser timed, smaller venturied engine, that runs best backed off 300 RPM to 16,500 suffers. But as it is, they check RPM on the line, ready for the flag.........I think peak RPM should be considered......

Mike,

I agree, the RPM thing is not measureable with the current wording. I also understand that this why the APRA group produced a list of legal engines.

How can we incorporate some limitations on engines in 424?

Whether it be peak RPM or a legal engine listing similar to APRA, I don't know. I just would like it written into the rules. Maybe we should consider a price cap of $110 or less retail?????

Dan

(Sometimes I feel like an OLD FART, can I join the club now??)

I'm so confused!!!
I am new to organized racing, having only raced in club events before this year. I just joined the NMPRA in an attempt to get into more regional racing and will race (at least this year) in 424. I understand the TT 40 is allowed (right?) and I actually like the engine. But my engine will easily run 17K+ on the ground with a 9X6 prop. Do I need to "detune" the engine to limit it to 16.5K before racing? Its no big deal if I do (real easy actually), I just need to know. The last thing I want to do is be percieved as a cheater because of a vague rule or misinterpretation. (Maybe this is the reason 424 isn't more popular.)

Good discussion going here guys. I think before we get all carried away trying to implement a set of truly workable national 424 rules some additional issues need be addressed. As I understand it Jimmy, Gary, Mike and others configured APRA rules as a vehicle to attract new people to pylon and serve as a training ground for an eventual move to 428. By enforcing the existing rules and making small adjustments over the years it has worked pretty well. Gino, Randy, Bill and many others as well as myself started in APRA. As we got better most of us saw it really wasn’t fair to continue flying against the new or not so serious guys and moved up to 428 followed by 422. (Remember we fly all three classes at all local races in the Southwest). An example of what I’m talking about here is as follows. The average “casual” APRA flyer out here runs 10 lap times in the high 130’s to low 140’s. A couple a years ago when all the “Slow 428 down” stuff was going on I wanted to see just how quick I could fly a good APRA plane. I took a VORTEX, APRA legal then, pulled a TT40 from mothballs, set up some poles and gave it a whirl. Got 2 clean heats out of 4 and both were 129 something. Fast enough to lap the field in any APRA heat in the last two years except Whittier this year where Gino was flying. When I moved from APRA to 428 my best APRA time was 136 now after several years of 428/422 experiences I can beat that by 7 seconds. What I’m saying here is we need to be careful we don’t turn 424 into a slower version of 428. We need to always keep in mind that first and foremost we need an event that will attract new people not be a “fun fly” event for seasoned 428 and 422 pilots. I realize we are little different because we always fly 3 classes and therefore can encourage experienced fast pilots to stay away from APRA. We might consider 424 and 428 like intermediate and expert in pattern. Once you move up you can’t go back without permission from the GODs. I can’t stress enough how important I think it is that 424 is not turned into just another expert pylon event.

Just read the post from RPM. He is exactly the guy we need to be supporting.


Just my opinion

Barry

Barry,

You have said everything I hope to accomplish with unifying the rules. Keep the new people in mind and make it simple.

Dan

I think I have straight now. I buy "legal" engine. If it is capable of 22K on a 9x6 no problem. Just set it for 16.5k on the line. WOW! (This explains a lot!)

Sorry Dan....You are too young for the old fart club !!.....The newest AMA rule book, on page 122, paragraph 16.3 Tells all about 424: Sport Quickie. Read that whole section on 424. It goes on to say on page 123 paragraph 16.3.3 (424 Special Provisions, section B) Quote....."The engune rules specified below, have been used successfully on a local basis to limit the cost or power output of engines used in this event".......It says just to note the changes in your sanction, and, or publicity.....It practically spells out, word for word, the APRA rules, no kidding ! Read it. Looks like APRA rules, have AMA's blessings already, minus the nine lap rule.......About the nine lap rule.....The only reason for the nine lap rule, was to allow a more advanced pilot to be able to fly Pylon, without being forced to go faster, and spend more money for a Nelson / Jet engine, and still not be able to beat up on the new, 424 pilots. Barry & Bill have mentioned that experienced pilot do not belong in 424 / APRA, and should be forced to move up to 428. I think this is wrong. There are lots of guys that have improved, only a little, gotten older, don't have the money, sight, physical ability, talent, & most of all desire to fly or buy a Nelson / Jet & fly 428. Some guys just don't have the competitive heart it takes to go fast, and travel like some of us. I don't think it is a good idea, to shut them out. I agree not to let them beat up on the new ones. I have been thinking a two lap handicap between novice & expert will work better. It has been a little too easy to break out. There are no nine lappers left at most races.....The perfect setup, would be to fly two seperate classes, 424 expert, & 424 novice, but there is just not enough time in a race day, for this to happen....... :sunsmiley keep it FUN, SIMPLE & CHEAP

Just a coincidence - I am sure.

In our area, we mix the experts with the beginners, and everyone flies against everyone.

At the end of the day, after all the points are counted. We seperate the Expert fliers from the beginners and award 1st, 2nd, and 3rd to each class.

This way, the beginners get to fly against the better pilots (which makes them better), but at the end of the day, they are only competing against the other begginer class fliers.

If we have a beginner that starts to dominate that class, we use the ol' peer pressure routine to get them to move up. It has never been an issue, and its usually pretty obvious when someone is ready to make the move.

At PGRC's annual pylon planning meeting last Nov., I suggested the adoption of APRA rules for 424. Now I understand why no one agreed.

When I first moved to Denver a while back, they were running two pole races, and pretty much APRA rules. They told me they weren't worried much about the engines, as long as they tached only 16,500 on the line. I said what about engines that we not stock, which I knew there were a couple, and they said as long as it won't does not turn over 16,500 on the line they didn't care. I tried to explain that the higher the timing, the bigger the carb bore, the more the muffler stinger was bored out, the more you would have to back off the needle, to keep it from going lean in the air. They said they didn't care if the engine was stock or not, that the 16,500 number would take care of it, and that a modified motor could not run that good at that RPM......I went home, and modified a Thunder Tiger Pro 40, and left nothing to the imagination. It turned a APC 9-6 prop, with 15% Power Master fuel at 19,100 RPM peaked. In order for it to run 10 laps without going lean, I had to set it on the line at 15,800. It had no competition, and at the next race, they changed the rule....No modified engines, and the top three would be torn down. The next few races. we tore down the engines, and caught a couple blatant reworked engine projects, but that was the end of that. From then on, no modified engines, 16,500 max RPM on the line ( was checked a lot), and a engine list......No more problems.....PS.. I was asked not to use the engine again.....I can't remember for sure, but I think I sold it to a fella named Bill Vargas on the west coast..he he.... ( that was lie "Billy V." )

PGRC for Prince Georges R/C - where the Bowie JR Gold Cup is held in May. We scheduled six 424 and six 428 races this year. We conform to NEPRO (thus the TT 40) in hopes of drawing a few from up North. We do draw some in 428, but few if any in 424. We get a few from NJ. When I moved to So. MD 20+ years ago, there were three local clubs holding Q500 races. Now PGRC is the only club in the mid Atlantic states scheduling races.
If the engine is [Q]...capable... [/Q] of exceeding 16.5k - anyway you slice it - it compromises the intent of "Sport Quickie ". But as I said, the genie is out of the bottle. 424 has picked up since we began using the TT 40. Catch 22!

If I remember correctly, that was the TT PRO 40 with the Nelson
sleeve and piston, and you ran it backwards, that's how you got on the Canard kick

HI LEFTY !............YEP !!

I just had to change it,,, to something more appropriate

BV

Hello,
I think it is wonderful that we are getting all this feedback regarding the 424 events, this shows there is interest in it. I belong to the group, NEPRO, which originally submitted the 424 event to the AMA. At the time the rules were drafted, the K&B 4011 was the engine it was drafted around even though it did not come right out and say it. We knew as time went on the event would need to be modified, but we wanted to get a good starting place. I understand that people don’t want to be told “ YOU HAVE TO RUN THIS ENGINE” and on a national level you may be right. Regionally if you stick to one engine, it is much easier to police people from playing with the engines, and believe me there are those who do.
If there is to be a NATIONAL rule on the engines allowed in 424, I do not think price restrictions are practical. I do however feel if you pick a given “unloaded” prop and state a maximum rpm on a given nitro fuel you will have a much more even playing field. The unloaded props would most likely have to be a carbon type prop supplied from APC so they are uniform in performance.
There were 9 different engines we evaluated as a group after the demise of the K&B 4011 engine. Out of the 9 engines, including Enya, OS, Rossi, Super Tigre, ASP, Magnum, Thunder Tiger, and Webra, the Thunder Tiger was the only engine that was on target with all of our criteria.

1) User friendly for the average sport flier
2) Available in the local hobby shop
3) Consistency from engine to engine in performance on the same prop
4) Good parts availability and factory support for repairs
5) No extended break in time prior to racing
6) Airspeed not to exceed 125 mph in a straight line
7) Low cost to entice new fliers


Please keep up the discussions they are important for this event to thrive. Just remember, before rules are put into place, close the loopholes or you will just end up with another version of 428 flown on the short course.