Engine for pylon training
 

Hi all,
I recently got into pylon racing, our rules only allow OS .46 or similar,
Running that engine to its peak gives very short life.
I hate the cost of replacing piston and liner $50 everytime just to be able to practice properly.

I was thinking to practice with different engine or plane to help reduce the cost in the long run,
even that means buying faster expensive engine and run it below peak to reach similar performance OS .46

I have looked into jett engines, .56XL is tempting even though its more expensive, it probably will last longer,
but if I run it below its peak performance, might result in colder running and also shorten the life span.

Other option is to get a ASP 52, get a tuned muffler to get similar speed with lower cost since I could get piston and liner at half the price of OS.

If any one has an idea, please do share you exprience.
Thanksssssss

Don't overlook the Evo, my .40 seems to outrev most of my OS, T Tiger, Supertiger and even an old Picco. They are at least still made and fairly cheap, as is the ASP, but it is maybe a bits sketchy lately for parts support. I can't say much for flight speeds, as I have only done bench tests.

I thought OS was the best?

Engine for Pylon Training
 

The Evaluation 0.46 with the one piece muffler is approved for 424 racing. This uses a 9 x 6 APC propeller.

Some people add an extra head gasket for easier needling.

http://www.horizonhobby.com/evolutio...ffler-evoe0461

Note the OPs location. Indonesia may have different rules as far as what engines are allowed.

What are you using for fuel? i have engines that ran exclusively on red max synthetic and after 20+ gallons were still like new... and that was all hard running...

You are correct, in competition only 4 engines are allowed, asp, supertigre, os and I dont remember the last one.
I have used ASP before however, OS turns 500 more RPM.
However, everyone uses OS .46 and some only use it for a few races before changing the piston and liner,
the only fuel allowed is coolpower 15%.
I guess running the engine screaming at 16, 17k shorten it lifespan by huge factor.

That is why I am searching a better way to power the plane for practice routine,
The need to practice with similar speed is important to get good feeling,
Alternatively, I can build a plane with may be less drag to achieve similar result, however, right now I opt for engine change.

OS cylinder liners are poorly manufactured. The ASP liners are much better made and often used to replace peeled OS liners. Most folks that use ASP liners in OS engines have noted identical or better performance with longer life.

Running engines at the RPM they were designed for will not shorten their life. Using substandard fuel (cool power is horrible fuel in my experience) and improper needle settings will however shorten their life. Of the engines you listed, the SuperTigre is the better engine of the bunch. If RPM and speed are what you're after, Dub Jett engines are fantastic, however if you cannot use them in the race, I'd not spend the money on one.

If it were me, I'd use the ASP engine and put an OS carb on it.

Whiskey29, I'll give you a speed secret. If you want to improve your racing skills, practice with something that is faster then what you will be flying in competition. That way when you get into a race, you will have more "time" to concentrate on your "lines and turns". A couple of days before the race, practice with your contest airplanes to work on your "timing". Good luck.

"If it were me, I'd use the ASP engine and put an OS carb on it." --> I must try that.
Last time I measure it, asp venturi is smaller

Thanks Greg for the ideas too

dump that green fuel, go with red max or morgans Omega 15. The Omega has some castor in it, parts will last then. That Coolpower all synthetic. green in color, is not a good fuel for racing. too dry.

OS "ABN" liner/piston assemblies are made for easy handling and short run-in time. Hard use in competition could lead to loss of top-power but they would still be ok for Sport flying.

I've converted several OS Max 46FX to the ringed piston/liner from the helicopter FX46 engine. They run great and 16-17000 rpm is exactly the optimum for these engines.

The steel liner with ringed piston should last very long with consistent power output.

To buy the spare parts for the conversion may be a little expensive. OS part numbers are listed here: http://www.osengines.com/parts/xr15470.html

I got the parts from cheap offers I found on eBay because the 46-size is not very common anymore in heli-flying.
You can also drop one of the 46FX-H Heli engines in as-is and fly it as an airplane engine.

What props are you using according to you competition rules?

PS: 10 years ago I used Super Tigre G40 ringed for Q500 Sport (tuned muffler and 10x6 APC) and a G500 ABC for open Q500 Pylon racing (ST G500 tuned muffler 8,75x7-8 APC) and they both ran great. Fuel was FAI 20/80 Castor mix. Especially the G40 had great power output compared to the OS and other engines and I still use it today with smaller props and more nitro just for fun. The engine is still running strong and really likes the rpm range betweet 15k and 17k.
If you can get some Super Tigre 45 ABC you might have a competitive and long lasting engine.My experience applies to the "Made in Italy" versions.

Hi Stone I am sorry for the long reply,
I have forgotten about this for a while :)
I got one 46FX and I did replace the liner and piston from asp, which I believe is chrome,
I havent fly the engine yet, right now preparing for an upcoming regional race here,
we have two kind of race here, one is a F3R indonesian rules for the main event (baby steps to the real F3R in near future)
the other one is F3R entry level rules.
in 2017 I won the entry level rules, and came second with the main, this december I will representing our city for the regional race.
i am not fast, but I am the only who can build the pylon racer here in town, so I have a some planes ready.

Now the props is not limited, however everyone else have been using APC 9x7.5 and a guy claimed he used 9x8 with fresh engine.
I tried the pylon race prop 8,75x8 or 8.25 I believe, it didn't go as fast, most likely wrong engine for the prop.
I haven't got a change to try bigger pitch yet as I must purchase it from Singapore.

I will have a look at the super tigre too.

THankss

Here in Canada we have 2 engines we use in 426, Q500 racing. We essentially fly by the AMA rules for 426, with the exception we allow using a Nelson SS Q500 engine with the mini pipe inside the muffler removed. The result is a detuned Nelson SS Q500 engine.

The JETT engine and the Nelson run side by side in our races with no noticeable speed advantage to either.

If you are looking for an engine to practice with why not get a second hand Q500 Nelson, Aero sells the mufflers with mini-pipe removed. These engines are operating below their design and last forever, and in the long run will probably be cheaper.

The downside is they are probably faster than the engines allowed in your area, but practicing with a faster airplane will only put you further ahead of the crowd in a real race.

.... just a thought

Whoa.. cant believe its been more than 6 months since I replied.....
This year local race has been called off. Been slacking lately :)
I havent been flying the pylon for a while, except this apst two weeks.
Using old 46fx with asp liner, ran 9x7, with about 10% nitro and got about 15300 rpm.
I think I will just stick with that 46fx, and practice to tidy up my flying for better consistency.

Find yourself a Thunder Tiger Pro .46 on eBay or something. It will give you better performance and long life for practice.

Thank you :)

Its been a while and this forum is very quiet :)
After some consideration, I am using now a used OS 46FX, with ASP liner and piston (cheap), use bigger exhaust volume and got it quite close to racing speed,
I am using the combination to practice for cleaner flight path.

I'm not sure what your goal is, however a TT.40 on an APC 9x6 will turn 16.5k RPM on the start line. On 15%nitro and a .003 head shim. And do that for at least two seasons before it starts to go over the hill.
Some will claim 17k but check their tach.
We use that engine on both Club 40 racers and AMA 424 racers. Being able to throttle the engines is a bonus over the Jett and Nelson engines. The Jett have addons to detune the engine to the TT .40 specification.
I suspect that the TT.46 will perform similarly too. The EVO .46 has issues with MFG quality and poor materials so while they run well as sport motors racing them has been an adventure. I've had several break (two of three) from internal failure. I haven't tried the OS .46 and admire their quality but other's have tested the .40 for our racing and the TT outruns them, or so I've been told.
Tower used to sell a tuned exhaust for the tower .46 It has the same bolt pattern as most of these engines and it will boost power a noticeable amount.
I'm curiorous are you racing 2 pole or three pole racing? perhaps you could post your rules. I wold like to see what you guys are doing.

Sparky

Hi Sparky,

I was looking for TT .40 but changed my mind since its very hard to source.
We do 3 pole race, no composites except wing joiner, landing gear and firewall reinforcement.
(this put covering fiber cloth or koverall in question)
Only 4 engines are allowed, ASP 0.46, OS 0.46, Super Tigre 0.45, TT 0.46 with 15% fuel nitro.
Max displacement is as stated by mfg 0.46, no modification is allowed at all, except removing baffles, everything else has to be factory stock(except glow plug, bearing).
Wing span between 1270mm to 1320mm, 500 sqr inch (3200cm2), minimum 30mm thickness up to 1200mm wing span.
minimum fuse height 89mm and width 73mm inside the chord section.
minimum weight is 1700 gram and max 2200 gram.


That OS 0.46 running 9x7.5 start to lose power for about 5 races session or so, since I believe we are running it well beyond its designed RPM.
I know better flying has significant impact on lap timing, my goal was to have a similar running speed to racing speed but with better lasting engine.

Of those engines listed i would focus on the TT.46
so is a 424 style racer we use her in the US acceptable?
the Quick V-6 (ARF) is a excellent airplane for three pole racing.
Sparky

Thank you for the suggestion. I have always wanted a TT, I dont know why, you reckon TT .46 will give better run assuming I can run the lap consistently ? Any suggestion for the propellers ?
I am not familiar with 424 class, will have a look.
As for the plane, i currently fly a seeker, and after prolonged delay (years) now trying to finish the other two :)
I recently read about the analysis of airfoil in one of the article, have a few things to try too.

By the way, I just looked the 10 lap distance from the AMA pylon racing guide pdf, and turns out we are running F3D course.

That was my next question about what size pylon course you are flying. What are the times you are turning? What RPM are you getting and what prop. We just got done with a Club 40 race today using the TT.40 with APC 9X6 prop also the 10.5X4.5 "toothpick" seems to give equal performance. Because the TT.40 had been discontinued the NMPRA tested a bunch of engines and came up with the EVO.46 as an equivalent engine. To match the TT to the EVO .46 it must run the APC 9X6 due to the disparity in performance. (Club 40 rules). In NMPRA /AMA 424 class everyone runs the APC9x6. Both of those engines have been discontinued so we will run out of engines eventually. They now allow the JETT .40 with a restricted intake and exhaust and it doesn't have a throttle and about 3 times the price of the EVO or TT but at least its available.
The EVO .46 is a real POS. Major engine failures are frequent due to poor materials and MFG standards. Some run real well but most encounter difficulties sooner or later. Today we had one EVO broke a nipple on the Carb and then we had one break the Crankshaft! Both very unusual failures for a model engine.
Sparky

Here is the Club 40 rules.
Attachment 2268361
This is two pole racing for the Silver and Gold class under 1:30 is competitive in 10 Laps on a 400' course.
Are you using suction tanks or bladder tanks like the Tetra tanks.
Sparky

THank you for the link.
It slightly different rule.
Any way, there is no limitation on tanks,
I do have some tetra tanks, but have to practice filling them first :)