I was just looking at the AMA rules for Q-500, really 424, and it talks about a "List of approved engines." Where can I find a list of "Approved" engines? I'd like the "Black and white" from the AMA.

The black and white is included in the CD's AMA sanction package for sanctioned events. The ONLY engine on the list is the Thunder Tiger 40 Pro. I am working on getting the "official" copy to make available on the NMPRA website along with all the various AMA racing oriented board members and contact info. The various processes is another project for inclusion.

But for now here's the list:
1) Thunder Tiger 40 Pro

Thank You Stan,

One would think that AMA would add that little bit of info to the 424 rules, instead of just "Qualified engines"

Personally I would like to see the Chinese made SuperTigre GS-40 added to the list. Even though it may not be as strong as the TT Pro 40 (when running an APC 9x6), I kind of like the ringed design as it seems to be more tolerant of lean runs. I worry a lot less about burning one up.

I don't have a ton of experience with the GS-40 yet, but I've had no problems with the idle or transition. And it seems to be getting stronger the more I run it.

I think that most people would still opt for the TT Pro 40, but at least there would be an official alternative. If we run into supply problems with the TT Pro 40, there would be less of a panic situation if there is at least one alternative.

The GMS .40 may also a worthy contender. Maybe we can get the racing committee to look at them and give us some choices?

Why not add others to the list, maybe the Evolution engine?

Yep I'd go with the ST, but the OS FX would be my first pick, (Before it got dropped). Anyone also notice the ST is only $50?
I'd really like to see us be able to run ANY sport .40 engine as long as its box stock.

What about a Evolution .40NT Glow Engine w/Muffler
EVOE0400 by Evolution Engines

My list for [link=http://www.rcpro.org/html/rules/club_40/engine_list.htm]Club 40 Engines[/link] has the GMS 40 and Evolution 40 on it. It also has the discontinued OS engines that possibly need to come off at some point. Based on some work by the RCPRO Board of Directors, that list will be changing, but the Gold class list is pretty well set.

The SuperTigre GS-40 being priced at $50, whiile the TT Pro 40 has risen to $85, may be the value some people are looking for. The GMS's are currently backordered, or I would get one to test. They are $60.

I have talked to Jim Allen about the 424 engines and he explained the reasons behind the TT Pro 40 being the only choice. One reason given for the Evolution 40NT was that it is not competitive with the TT Pro 40. I don't think that is reason enough to not allow it. There have been a number of versions of the GS-40 with different parts and mufflers. I think that the specific model now being produced could be the only allowed version.

I think it may be ok for local groups to use their own discreation for Club 40, but it is probably best to keep 424 limited to easily specified and currently available models of engines.

Has anyone else noticed the backwards claiming rule? You are allowed to spend $120 (street price) for the motor, but someone can claim it for $100! How can I justify trying to talk someone into getting into 424 when his engine can be claimed for less than he paid for it?

Not to belabor the point, but, I'm sure I used to see the explicit statement in the rules that, "the TT Pro 40 was the only approved engine at this time" (maybe not an exact quote, but close to it). Does anyone else remember this? I purposefully looked this up a number of times when I was getting back into 424 a couple years ago. I looked it up within the last six months also. Since I don't have a copy of the CD's paperwork package, it couldn't have been there where I saw this.

Doug Bebensee

Please read my previous post on the engines allowed. The actual list seems to have been omitted when the AMA website site was re-done.

SD

Doug,

Your quote is inaccurate. There is no "at this time" in the statement. Also, the $120 rule is a qualifer for an engine to be considered for the official list of approved engines. The only approved engine is only $75 - $85, so if you were offered $100 for an $70 - $85 engine, why would you complain? So following your logic as to how can you convince someone to fly 424 and have their engine bought for $100, why wouldn't they want to make $15 - $30 for a used engine? I will do it anytime.

As to why the approved engine list is not in the 424 rules, think about it. If it was a rule,it would require a rule proposal and voting to get it changed. If it is a seperate list, the list can be modified (in accordance of the rules) at any time needed. It is the same concept as your club by-Laws vs. the field rules and other documents. The main document (By-Laws) spell out the law and is more or less not up for a quick change. The supporting documents are able to be changed quicker, but must follow the origional intent of the law (By-Laws).

If you guys are that worried about the exact quote, I can post the document from our race last weekend. I have it at the office with all of my CD information.

Let me know...

Stan - can you tell us how to contact the engine selection committee and the process for submitting other engines for consideration?

My point was that all a novice only has is the rules that are posted on the AMA website. The actual list of approved engines seems to not be available. It should be available on the AMA website, shouldn't it. If it is expedient to not have this list in the main body of the rules for the reasons you list, then at least there should be a pointer or directive as to where one could actually find it. If he sees that $120 can be spent on the motor and someone can claim it for $100, then it may be a deal killer as far as him wanting to fly 424. He doesn't know that the TT Pro 40 is the only approved engine because it ISN"T listed on the official AMA website rules for pylon. He only has word-of-mouth authority that this is the only engine that is approved. Where is this list for us all to see?

Doug Bebensee

"The List" of one engine is rather humorous to say the least. For years AMA refused to name an engine on the pure fact that it would appear that they were marketing towards a specific manufacture, so "the List" will NEVER be published by AMA.
In responce to Jim Allen and others making a desicion for the rest of us because other engines weren't "competative" is limiting new entries and new interest. Even if an engine like the "NT Evolution" isn't as competative, why should it be disallowed? There could be alot of guys that might like to give 424 a shot, but they don't want to purchase another engine just "to give it a try" . By allowing other engines, whether they are as fast or not, is limiting interest acrossed the board. I would think that allowing other engines ( St. GS 40, GMS, Evoltution. Etc: ) would possibly give a potential pilot a chance to see what racing is all about.
Now I know that some of our more expereinced racers have there blood pressure going up because the "Engine of the week" thing is coming to mind.
I know that back in the mid to late 80's, there were several engines that people were trying,
( OS, St. Como, Hp, HB, Mvvs, Irvine, Rossi, Webra, just to name a few) and aot of people were suddenly feeling the pressure that "my engine isn't as good as there's" or whatever. It turned into the "engine of the week" and people were getting frustrated that "all weren't created equal" .

Well Guess what, they aren't all created equal!

So why cant "The board", that ruled on the TT40 , from doing testing, produce an engine list with basic spec.s ? ( weight, Hp Rating, Rpm figures on a 9X6, and average price) Let the consumer make the choice. If the TT40 is the HOT engine and 424 pilots want the best possible speed, let them make that choice. But to say that an engine isn't legal because it isn't fast enough is possibly stopping growth and limiting participation . I know of a hand full of club racers that might like to go to a 424 race and try 3 pole, BUT they won't go because they don't want to buy another engine because there OS. St. GMS, Or Evolution isnt legal!
Lets open it up support the potential and realise what 424 is supposed to be and who our FUTURE racers might be .

Just my Humble 2 cents worth.

People need to keep one thing in mind. I'm not aware of any area of the country that runs AMA 424 stricly to the rulebook. Most have variations in one way or another, usually more strict, but not always. If running other engines would help racing in your areas, ALLOW THEM!

The current 424 rules were bases somewhat on the APRA rules. I'm not aware of exactly who or how the 424 engines are decided, so I'm going to state what I know about the APRA class used on the west coast. When the APRA class was started, the engine list was much larger, and included almost every "sport" 40 size engine under the price cap. People would go and buy whatever listed engine that their local hobby shop had. They'd then show up at a race and find that their engines were uncompetitive, and complained that they bought a listed engine, so they thought they'd be competitive. Some never came back. To prevent it from happening in the future, the engine list was substantially shortened and limited to engines that were competive. As some of them then went out of production, the list was left with the Thunder Tiger. Yes, there are engines that are similar in price an performance, for example the Magnums. A handful of Magnums were tested and found to be far more inconsistant from engine to engine, from considerably stronger than the best TT tested, to well below the worst. It was decided to stick with what had been fairly stable and had been working. Also keep in mind that APRA rules do have a provision to allow other similar engines (IE no Rossi's, ect) for a competitor's first race or two, with the CD's approval.

Personally, I'm not in favor of the entry level events being AMA rule book events for one primary reason. The AMA rules cycle is too limiting as far as making changes. Rule changes can take well over a year to get done. As an example, if the Club 40 events, which are very successful in some areas, were in the rule book, what would happen if the manufactures of those airplanes were to quit making them for one reason or another? Legally, other airplanes couldn't be used per the rules, therefore effectively killing the event. If the class was left as a grass-roots event with flexible rules, other airplanes could easily be made legal.

GREAT point made Gary!!
This brings up another problem that is on alot of minds, what if ....Thunder Tiger was to quit making the TT Pro 40??? ( it has been rumored ) this is one of the reasons to make sure that there are alternatives for our future if this engine is possibly deleted from manufacturing !!

Yes, it's a problem if TT were to quit making the engine, but since most areas don't use 424 strictly by the rulebook, they are flexible to make changes. A similar thing happen in the Northeast with their NEPRO class. They used the K&B 40 for many years, probably decades. Due to availability issues, they switched to the TT 40's.

Gary,

We want AMA 424 to benefit from Club 40. It is already happening in Texas. Also Q-40 Sport is going to use the same engines as 424.

I have called Club 40, AMA 424, and Q-40 Sport the "trinity". 3 racing classes that use the same engines, but that have increasing skills demands. People can start with Club 40 and move to higher performance and higher skills demands without having to buy all new engines.

Clubs are following the AMA 424 rules. Many groups now using the TT Pro 40 exclusively because it is the "official" engine.

With Club 40 and Q-40 coming on board preferrably using the official 424 engines, I would like to see the list appended to add the Chinese made SuperTigre GS-40, the GMS .40, and the Evolution 40NT.

How can we make that happen? Can you get Jim Allen and the 424 engine board to read some of the discussion online here?

There is no reason that "potential" racers cannot be allowed to fly with whatever engine they happen to have. The CD would simply need to verify the subject engine doesn't have a performance advantage and let them fly. In fact the APRA Quickee Sport rules that the current 424 was based on has a clause that allows this:

*4.3 First Time Pilots. A Sportsman pilot entering his/her first race may enter the event with a different engine than those listed above at the discretion of the CD. The entered engine may not provide any performance advantage relative to the normal Quickie Sport entries. This exception may apply to the pilot for two races only.

I fought strongly to not make the engine list "National" because of how difficult it is to tightly manage the rules with a 2 year (3 years at the time) rules cycle. At the 424 level, it is my opinion that each area of the country should adapt to whatever is best for their area. I was outvoted and then asked to run the engine approval committee because of my years of experience managing the topic. The decision was made that the engine to start the list with was the TT40 because it is so widely used for lots of reasons.

The primary criteria for the list is performance, but not the only one. Stability of the company, variability of versions of the engines and the parts supplied for the engines is also considered. We have been very fortunate that the TT40 is such a good product that is relatively consistent, durable and reliable (especially the last few years), and they are strong company who has done a good job of keeping the supply of the engines strong. There was one period where the supply dried up for a few months several years ago, but they worked through that. WE ABSOLUTELY CANNOT ALLOW AN ENGINE ON THE LIST THAT WILL OBSOLETE THE THUNDER TIGER 40!!!! It would be the beginning of the end for pylon as we know it. We've had the "what if TT goes away" arguement thrown at us several times over the years. If that happens, there are ways to get things done quickly if it is deemed a true emergency for the event. As long as TT is selling engines, we do not have an emergency. If that emergency happens, there are a TON of TT's out there that will keep things going while we make a good, well thought out decision and take the necessary steps. Will people panic, YES. Can we let the panic force us to make a bad decision, NO. Till TT goes out of business we'll manage the event to maintain the stability we have enjoyed for quite a few years.

At the time the "list" was added to the AMA 424 event, the ST40 was unavailable. Believe it or not we used to have the ST40 on the APRA list. Good engine, but there were lots of problems with mufflers (three different ones) and lots of variation in the engines and parts. It got bad when they started shipping with a muffler that made the engine quite a bit slower than the previous muffler. Now a guy has to buy an engine and hope he can find a dusty version of the previous "faster" muffler to be competitive. Some inventive racers found that the cylinders sold as spares at the time had different and a LOT faster timing than the cylinders installed in the production engines. You can imagine the BS that caused!!!! That problem could still surface. It was a very durable engine in a lot of ways and we all know how good an ST carb is (or at least used to be).

We have tested the Evo 40. Horizon Hobby sent me four new engines to test. The are a good engine that are surprizingly consistent, but they're on average 1200 rpm below the Thunder Tiger. Many people are dismissing the thought that this is a problem. As Gary Schmidt said very well on the forum recently, In the 17 year experience managing the APRA class here on the West Coast, it IS a problem, but it is a problem that a CD can easily deal with for first timers by using a tach and verifying the engine brand the new racer has will not have an advantage and let them fly. Adding an engine to the list was interpreted as an endorsement of the product for the class. There were some pissed off racers who found out that the engine they just bought, because it was on the APRA list, wasn't competitive at all. If you haven't been there and been through that, of course you think this wouldn't be a problem, but is definitely was. I gave Horizon feedback on how I felt they could make the engine competitive. They said thanks but have chosen to not take that approach. I respect that. I am sure it didn't make good business sense for them. With a little work, it could be a good engine for the list.

The Magnum 40 was tested a couple of years ago. I was given two new engines to test and allowed to test a few more that belonged to other modelers in CA. The engine is well made, but was found to vary quite a bit in performance from engine to engine. A few were noticably down from the TT40 most were similar, and a few BLEW AWAY the TT40. A LOT!!! That kind of variability would kill the event. Having to buy 5 to 10 engines to get one or two of the killers when everybody has several TT40's would be a BIG problem. That engine will not be added to the list. Good engine, but it would definitely "upset the apple cart".

I was given MVVS engines to test several years ago. The version sent to me was a very nice engine that was well made, but it wasn't even close to the TT40 in performance. About 1500 down with the 9-6. THE VERSION SENT TO ME. Further research and testing of engines that friends in my club had showed that there were several different configurations of carb bore and muffler. The parts were interchangeable with the parts in the engines I was supplied. The engines with the larger carb bore and different muffler BLEW AWAY the TT40. They're as strong as a Rossi. It would have created a CD's nightmare to control. Again, great engine, but one that would have had detrimental effects on the event.

Now, with all this said, are we open to investigating other engines? ABSOLUTELY. Trouble is, the manufacturers have not been beating our doors down to supply us engines to be tested. We would need at least 4 examples of a prospective engine. They will be inspected for quality and potential problems. Then they will be broken in carefully, and tested on the bench with not only a 9-6, but two different levels of unload props. One engine tested (I won't say which) didn't show the higher performance than the TT40 until I installed the lightest unload prop. Then at least one will be installed on an airplane and flight tested. We will then compare this data to two TT40's that I have. One is on the high side of average, the other is quite strong. This way we eliminate the variability of fuel and weather conditions. Only then can we be sure we have an appropriate engine for the class.

Remember there should be no reason that a CD can't apply common sense and let a new racer use whatever engine he has, as long as it doesn't have a performance advantage over the "approved" engines. Down the road, if he sticks with the sport, he'll want to get one of the "approved" competitive engine. Some of you might not agree with me on this, but it comes from 17 years of experience maintaining the rules that became the basis for the current version of 424. We know how to keep the stability. Our sport cannot survive the loss of it.

Jim Allen
AMA 424 Engine Sub-Committee Chair.

JIm,
Thanks for the quick responce to the engine dilemma. I only wish that AMA had published the engine ruling from APRA that would allow beginners to try the event twice ,with the engine they already had as long as it didn't outperform the TT40 . If someone was to look at the rules as they are read, it would seem that ANY engine that met the measurements as decribed would have been legal, but in fact, it might not be. For the average AMA member that might have "interest" and not know of the "list" from APRA , they might drive to a race and be declined a chance because there engine could be faster, this could be more bad publicity.We need to somehow make available to the rules, a link to the List". One more thing, was there ever any testing done on the GMS and if so, what were your findings?
Thanks

No, the GMS has never been submitted for testing.

Part of the point I was trying to make is you need to contact the CD and find out if they will let you use the engine you have. Yes, when the "LIST" was created with the TT40 on it, most people took it for granted and there was no follow-up to create a web page to list one engine. Stan Douglas is offering to do that on the NMPRA web site. That is really the best we can do.

Jim

Jim,

Thanks for the messages and for your efforts.

Can anyone submit the engines for approval, or does it have to be the manufacturer/distributor? It may be more expedient to just get a donation of current, new, and never opened engines from a supplier like Tower or a dealer. I would like to see the Chinese made SuperTigre GS-40 considered and added to the list. RCPRO and/or myself may sponsor a batch of engines for consideration. Let me know and I will see what I can do about getting some shipped directly to you from Tower or Hobbico. Could I get the engines back at some point after testing?

I will contact GMS about submitting their engines also. They currently appear to have supply issues. Or maybe Tower just ran out and it is a problem with Tower.

I agree that the TT Pro 40 is a very good engine. I have no problem with them at all. They run well, are easy to maintain, and seem pretty consistent.

Ok, Here is the document as sent to all CD's when they hold an AMA 424 event. Article 3 Section 4 says 4 engines must be sent in for approval from the Manufacturer. I don't know if it would be legal for a layman to give them 4 engines for review, I have no idea other than the statement in this document. The acceptance or rejection letter goes to the Manufacturer, so I would think they would need to submit it. At any rate, here is the info most of you have been requesting.

A PDF version of better quality will be posted on the [link=http://www.nmpra.org/]NMPRA[/link] site soon, Stan told me!

Don,

We prefer that the engines be submitted by the primary supplier so we can work with them directly, as we did with Horizon on the Evo .40. This also ensures that they are involved from a supply standpoint. The supply problem you mentioned is the first red flag for the GMS. That said, as long as they are shipped from the primary supplier, we could consider them. Parts supply is another issue. TT has been pretty good about that too. It ALL has to be considered.

There are LOTS of benefits of having one "official" engine defined and letting CD's at local events make adjustments for their area or race by letting the newcomer run the Evo, or ST40 that he happens to have. We have to be VERY careful adjusting the National rules for local needs.

Jim