Improving Engine Performance, any way necessary?

Improving Engine Performance, any way necessary?
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Improving Engine Performance, any way necessary? - 12/5/2005 8:18:05 PM

iflynething

Posts: 1914
Joined: 8/23/2003
From: Charlotte, NC, USA
Status: offline

So you pylon racers need that extra edge, and that .1 of a HP that might make the difference between winning or loosing.

I know some of you might do some special things to the engine to get the extra edge, but you might not want to tell...but what are some things that most pyloners do to get more power, efficiency, performance, fuel consumption lengthened, and others?

One thing I do is to polish EVERYTHING and enlarge the intake on the carb. I just take the to piston, sleeve, intake ports, exaust, and everything in between and polish them to a chrome finish (mind you, I'm not taking anything off, just polishing the components)

~Michael~

_____________________________

Michael Carr
Funtana, S100, Fut. 3050 / Rap 30, OS 32, JR 537, Fut. 401

Post #: 1

RE: Improving Engine Performance, any way necessary? - 12/5/2005 8:25:42 PM

HighPlains

Posts: 2663
Joined: 3/2/2003
From: Over da rainbow, KS, USA
Status: offline

Buy a Nelson or Jett. That's what we do.

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Post #: 2

RE: Improving Engine Performance, any way necessary? - 12/5/2005 8:39:48 PM

iflynething

Posts: 1914
Joined: 8/23/2003
From: Charlotte, NC, USA
Status: offline

That's pretty good when all you have do is get one of those engines, and you already have the modification that it would take for like an OS or something!!

~Michael~

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Michael Carr
Funtana, S100, Fut. 3050 / Rap 30, OS 32, JR 537, Fut. 401

(in reply to HighPlains)

Post #: 3

RE: Improving Engine Performance, any way necessary? - 12/5/2005 9:39:36 PM

daven

Posts: 6891
Joined: 12/7/2001
From: Andover, MN, USA
Status: offline

Most racing classes don't allow "modifications" to engines.

Things like enlarging the carb would not be allowed in nearly all classes that I'm aware of.

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Dave Norman

klasskote.com
supertrc.com

(in reply to iflynething)

Post #: 4

RE: Improving Engine Performance, any way necessary? - 12/5/2005 10:18:56 PM

DHG

Posts: 896
Joined: 4/24/2002
From: Arvada, CO, USA
Status: offline

Michael,

Polishing is removing. No way around it. Sorry!

Besides, there's something magical about the pebbly finish inside the ports. It improves the flow under some circumstances. Polishing in there may actually slow you down.

Best things you can do are to adjust the head spacing using shims (perfectly legal) ... keep the engine clean ... flush the bearings with lacquer thinner and after-run oil after every flying session to prevent rust ... and never run it over-lean.

It's very true, when you buy a Nelson or Jett you are just as well off (actually better off) as if you start with a cheaper engine and then invest time and money afterwards in replacement parts and modifications. The going rate for a competitive 2-stroke .40 is somewhere around $350. You can use whatever combination of money, time, effort, and expertise comes easiest for you, but eventually you will get to about that level no matter where you start.

Duane Gall
RCPRO

(in reply to iflynething)

Post #: 5

RE: Improving Engine Performance, any way necessary? - 12/6/2005 2:07:03 AM

iflynething

Posts: 1914
Joined: 8/23/2003
From: Charlotte, NC, USA
Status: offline

WOW. Thanks for the replies. I was thinking about getting into either pattern or pylon, but I'm leaning more toward pylon. Both are a challenge, and there's alot of meets that I'd like to go to.

About the shims, me and my dad sand the shims under the head just a little. I'm sure we aren't taking that much off, but just put the shim up to 1000 grit sandpaper and do some sanding, just a little bit though. That improves compression I would think, but what else would it do as for performance?

Why is it you are able to buy something LIKE a Nelson or Jett that have those type modifications, but you can't physically modify like an OS or something. What exactly is done to the Jetts to increase performance? I know they like to run at the higher RPMs, but at what RPM's are most pyloners running their engines.

What would be a good class to get into and which Jett engine?

laquer thinner. Do you just put that in the engine, and turn it over a couple times? Then when you go back to start again, just start like you normally would?

Thanks for the help on this. I'm always trying to get the most out of my engines. How exactly would a judge know that you modified and engine. Do they physicall check the engines, sometimes, kinda like a random search or somethign?

Thanks again

~Michael~

_____________________________

Michael Carr
Funtana, S100, Fut. 3050 / Rap 30, OS 32, JR 537, Fut. 401

(in reply to DHG)

Post #: 6

RE: Improving Engine Performance, any way necessary? - 12/6/2005 2:14:18 AM

splatt

Posts: 651
Joined: 1/30/2002
From: splattsville, MN,
Status: offline

the story told to me about a guy who won all the marbles back in the late 70's was he bought fifty .15 K&B's that were the hot item for Q-15 racing and he took them all apart, miked 'um, took the biggest piston and put it in the smallest cylinder he had out of the fifty.

He won the 1979 NMPRA Q-15 Champ race, got inpounded or whatever they called it, they sent the motor to the factory and while the motor was in spec, it was barely.

They couldn't understand how a big piston got mated to a small cylinder.

Now what I hear is folks who have access to measuring equipment that involve laser beams and atomic reactors and such machines. They buy mulitble piston sleeve combo's and measure them and mate the the parts together that they want.

Break them in carefully and go do there thing.

there are things that will produce more RPM's but at last years NATS Dubb Jett and Henry Nelson checked the top engines for cheating and there was no cheating found.

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race, race, race. Racing toward my grave

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Post #: 7

RE: Improving Engine Performance, any way necessary? - 12/6/2005 2:25:14 AM

splatt

Posts: 651
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From: splattsville, MN,
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Nelsons and Jetts are examples of engineering taken to the max.

disasamble a OS and lay it next to a Nelson and for the most part they don't look that far apart. Just the level of engineering.

Lets say you want to drill out the muffler bolt hole to the next size up cuz you stripped the threads, too bad. There's not enough meat in the casting because the transfer ports are so big that if you do drill you will break into the port, maxium engineering.

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race, race, race. Racing toward my grave

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Post #: 8

RE: Improving Engine Performance, any way necessary? - 12/6/2005 2:30:25 AM

splatt

Posts: 651
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From: splattsville, MN,
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My nelson spins 19,000+ rpms

For Q-40 they spin a 7 inch prop 23,000+ RPM's

On these engines the compression and sleeve height are adjusted for local conditions.

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race, race, race. Racing toward my grave

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Post #: 9

RE: Improving Engine Performance, any way necessary? - 12/6/2005 4:48:03 AM

js3

Posts: 1142
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From: Arvada, CO, USA
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Michael,

After you're done flying/practicing/racing/testing, remove the glow plug and squirt a few drops of lacquer thinner in the cyl. Squirt a few drops down the throat of the carb. Hold the plane such that the thinner will pool in the crank case. Move the prop/crank shaft back and forth between compression--don't turn it over compression especially with the glow plug inserted. Rock the plane forward and backward so that both bearings get a good shot of the thinner. When you're satisfied, turn the plane so that all the thinner runs out of the muffler. Now do the same thing with your favorite after fun (I mean run) oil. Don't be too concerned about getting all the lacquer thinner out; it will evaporate leaving behind the oil. What this accomplishes is to flush the residual methanol out of the motor. Methanol attracts moisture which is bad for the innards.

That's how I do it. However, I am compulsive about such things.

_____________________________

John
I feel a lot more like I do now than I did earlier!

(in reply to splatt)

Post #: 10

RE: Improving Engine Performance, any way necessary? - 12/6/2005 4:59:10 AM

js3

Posts: 1142
Joined: 1/30/2002
From: Arvada, CO, USA
Status: offline

quote:

Why is it you are able to buy something LIKE a Nelson or Jett that have those type modifications, but you can't physically modify like an OS or something. What exactly is done to the Jetts to increase performance? I know they like to run at the higher RPMs, but at what RPM's are most pyloners running their engines.

Our rules specifically state that the motors must be "stock". No mods allowed. It just so happens that Henry Nelson and Dub Jett make their products with the racer in mind so we get the benefit of having race-timed motors and can still comply with the rules. The average Joe cannot do any better with another motor "like an OS or something" than the purpose-built motors that are now available.

There is a class where engine mods are allowed--F3D. I think the only requirement is that the displacement not exceed what is specified by the rules. Any other mods are fair game.

< Message edited by js3 -- 12/6/2005 5:04:10 AM >

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John
I feel a lot more like I do now than I did earlier!

(in reply to js3)

Post #: 11

RE: Improving Engine Performance, any way necessary? - 12/6/2005 5:29:34 PM

Clark L

Posts: 147
Joined: 1/22/2003
From: So-Cal, USA
Status: offline

Hey Michael,
If you're really thinking about giving pylon a try, the best way is to start with 424 Quickie. They use a basic airframe (there's several arf's or kits available) and a stock inexpensive motor. The Thunder Tiger pro-40 is the ticket. Inexpensive and easy to get. There are a couple of legal changes you can make to bump up the power a bit too. Any questions you have can be answered on these forums. Do a little search and if you can't find what your looking for just go ahead and ask. These pylon guys love to help out new guys.

give it a try, you'll love it.

Clark

(in reply to js3)

Post #: 12

RE: Improving Engine Performance, any way necessary? - 12/6/2005 5:46:28 PM

Clark L

Posts: 147
Joined: 1/22/2003
From: So-Cal, USA
Status: offline

Actually, make sure you check around in your local area. That TT40 is whats popular out here on the west coast. I think there's some guys in your neighborhood that may use a slightly different setup.

Hey you southern racers.....speak up.

(in reply to Clark L)

Post #: 13

RE: Improving Engine Performance, any way necessary? - 12/6/2005 9:24:26 PM

iflynething

Posts: 1914
Joined: 8/23/2003
From: Charlotte, NC, USA
Status: offline

Wow, you guys are great. Many reponses that I thank you for.

19......23,000RPMS. I know that, to me, seems like a little over kill, but the Jett and Nelson are made to run at these RPMs while an OS would crumble (for use of a better word)!

I have seen some Jett engines, and they ARE some engineering marvels. Very geeat looking, and to know that they are Jett or Nelson is just the icing on the cake.

I will definately look around and see what I can find out. When you say stock for the engines, you get the stock extreme from the Jetts and Nelson where you couldn't use a stock OS or something.

Thanks for the help guys. What about the Predator or some other Q-500. I do like the looks of Q-40 racers though.

Thanks again

~Michael~

_____________________________

Michael Carr
Funtana, S100, Fut. 3050 / Rap 30, OS 32, JR 537, Fut. 401

(in reply to Clark L)

Post #: 14

RE: Improving Engine Performance, any way necessary? - 12/24/2005 7:23:20 AM

smokingwreckage

Posts: 242
Joined: 7/7/2005
From: , TX, USA
Status: offline

My club races stock .25 sport engines with stock mufflers and street prices of under $100. Engines must idle 45 seconds sitting on the runway before the start. Most folks run Predators, Vipers, and other Quickee 500 planes. Some run other scratch built planes. I ran a LR1 from Wild Hare and it was very competitive. I started with a scratch-built S.P.A.D. which saved a lot money during the learning curve. Actually, you'll need at least 2 planes and a lot of hanger time to be competitive because air-to-airs are common. Under our rules you can build a S.P.A.D. using all new flight pack and power system ready-to-fly for a tad less than $200. Now I'm back to the S.P.A.D.s since the Wild Hare exploded due to an air-to-air. See if you can find a similar activity to sample pylon racing on the cheap.

(in reply to iflynething)