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Nitro Engine Hotrodding - 11/28/2007 3:49:38 AM   
violator74


 

Posts: 24
Joined: 9/16/2007
From: chardon, OH, USA
Status: offline 		I just picked up a used Hyper .21 for no other purpose than to see how much power I can squeeze out of it. I've read the forum titled "porting and polishing" and had some good ideas in it, but I'm looking for some good theories and some good feedback on different "off-the-wall" ideas.

For instance...

I was thinking about using a small piece of pipe to raise the carb about 1/2 inch to create a "tunnel-ram" effect. Might increase torque?

Changing the design of the head and/or piston to create a more high swirl effect or more of a "hemi" effect (hemi-spherical cumbustion chamber)

Creating some kind of reed valves used used in high performance dirt bikes



Let me know your ideas or what you think of these!

P.S. I DO NOT want to get into the supercharger debate here. There's another MULI-PAGE forum for that!

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RE: Nitro Engine Hotrodding - 11/28/2007 4:18:53 AM   
annie_himself



Posts: 6009
Joined: 10/3/2004
From: Prairiville, LA, USA
Status: offline 		You can take off the button, turn it upside down and use a Dremel to make a few "lines." I can't explain it well but it disperses the explosion of the fuel mixture evenly for a more consistent and powerful engine. I've seen it done on a Orion CRV .12 and the guy saw reasonable improvements.

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RE: Nitro Engine Hotrodding - 11/28/2007 4:31:24 AM   
Jim8ightT



Posts: 92
Joined: 11/15/2007
From: cohoes, NY, USA
Status: offline 		I have a trx 3.3 and i picked up a onfa force .28 carb for it and i too am going to try to make it stand as high as i can make it because the gaskets on the bottom not the top as the stock carb is. I also use a k&N air filter. and from ebay i picked up a pipe called a bj1 it has an outlit of about 1/4 inch or more. I am waiting to get the carb and do some more testing.. I am debating in getting the os glow plugs lC3 made for the trx engines. I am always looking for more free horse power i even tried drilling a resonator pipe and it riped!! lol

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RE: Nitro Engine Hotrodding - 12/1/2007 3:39:43 AM   
nitrorcjunkie



Posts: 748
Joined: 9/30/2006
From: Ft. Pierce, FL, USA
Status: offline 		The purpose of reeds on say, a 2-stroke motorcycle or outboard engine are to act as valves closing the induction tract from the engine block on the downstroke. In our beloved nitro engines, the induction path is through the crankshaft. As the crank rotates, it exposes an opening in the crank, allowing the upward motion of the piston to pull a fresh charge of air/fuel into the block. As the crank rotates further, it closes this tract, allowing the mixture in the block to be pressurized and pushed thru the intake ports into the combustion chamber, so reeds would be redundant and useless. Not trying to bust your bubble, but if there were better ways to gain performance besides port grinding and polishing, somebody(probably an engineer specializing in micro motors) would have found it by now.

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RE: Nitro Engine Hotrodding - 12/1/2007 3:42:02 AM   
nitrorcjunkie



Posts: 748
Joined: 9/30/2006
From: Ft. Pierce, FL, USA
Status: offline 		Your best bet would be to experiment with porting on some cheap mills, and try different standoffs for the carb, along with different pipe/header combos.

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Step One: RTFM
Picco .26 T-Maxx, LST, RC18b

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RE: Nitro Engine Hotrodding - 12/1/2007 3:46:59 AM   
ttoks



Posts: 3665
Joined: 3/15/2007
From: leongatha,VIC, AUSTRALIA
Status: offline 		also talk to colt4g63 and supertib, they are both very well in touch with the specifics of nitro engine tuning and porting arrangements.

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RE: Nitro Engine Hotrodding - 12/1/2007 4:02:16 AM   
JB COMP



Posts: 4276
Joined: 11/23/2006
From: Navarre, FL, USA
Status: offline
quote:

ORIGINAL: ttoks

also talk to colt4g63 and supertib, they are both very well in touch with the specifics of nitro engine tuning and porting arrangements.


yeah but, to learn moding port timing take alot of R&D and probably alot of cash as well.

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       Post #: 7

RE: Nitro Engine Hotrodding - 12/3/2007 2:20:27 AM   
violator74


 

Posts: 24
Joined: 9/16/2007
From: chardon, OH, USA
Status: offline 		Yeah, I see your point about the reed valves, bad idea.

As far as engineers having it all figured out.....I don't think so.
Figure the regular automobile engine, they're still finding new ways to make more power and how long has that been around?
I'm not trying to bash you or anything, I just think that there is ideas that haven't been tried yet.
Take for instance the big dollar Novarossi (and other)engines. What does that company do to that motor that you can't do?
I want to "grass-roots" hot rod my motor and embarass the people who have these big dollar engines!

I just started this forum to see what ideas you all had. Even if they sound off the wall. It's what's commonly called "Bench Racing" in the racing community.



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RE: Nitro Engine Hotrodding - 12/3/2007 2:32:47 AM   
violator74


 

Posts: 24
Joined: 9/16/2007
From: chardon, OH, USA
Status: offline 		I appreciate your input so far. Some good ideas!
I just was watching the tv show "Pinks" when I had a thought.......NITROS OXIDE!!!!!
I could fill a C02 cartridge with nitros oxide and use the third channel on my radio to control a solenoid to inject it.
I might have the first nitro cylinder head launched into outer space

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RE: Nitro Engine Hotrodding - 12/3/2007 2:57:34 AM   
twomanytoys


 

Posts: 4464
Joined: 1/23/2007
From: , PA, USA
Status: offline 		They already have nox kits for rc engines. Like nitrorc said if there were more ways to get power from a nitro engine it would have been done. Car engines are nothing like 2 strokes so you cant even compair the two. 4 strokes have soo many more different variables to make hp. 2 strokes are simple. Power gains are made from porting, timing, compression and boring. 4 strokes are way more complicated and cars now days are controlled by computers which also help to increase hp. If you can figure out a way to get more power from a nitro without distroying it then great but i really dont think you can.

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RE: Nitro Engine Hotrodding - 12/3/2007 3:45:26 AM   
JB COMP



Posts: 4276
Joined: 11/23/2006
From: Navarre, FL, USA
Status: offline
quote:

ORIGINAL: twomanytoys

If you can figure out a way to get more power from a nitro without distroying it then great but i really dont think you can.


there is a way,
you let Adam at AB Mods mod it, hes one of the best modders around.


_____________________________

LX Comp: STS21B, JP-3, DX3.0 - CRT: STS 30 Rev2 or Mach 427, STS 0702, DX3.0 - T-maxx: TRX2.5
Airtronics. BlueBird.

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RE: Nitro Engine Hotrodding - 12/3/2007 7:53:17 PM   
Colt4g63


 

Posts: 311
Joined: 4/30/2005
From: New Albany, IN, USA
Status: offline
quote:

ORIGINAL: JB COMP


quote:

ORIGINAL: twomanytoys

If you can figure out a way to get more power from a nitro without distroying it then great but i really dont think you can.


there is a way,
you let Adam at AB Mods mod it, hes one of the best modders around.


Sounds like the best option to me

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X-Dyno equipped

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RE: Nitro Engine Hotrodding - 12/3/2007 9:14:43 PM   
JB COMP



Posts: 4276
Joined: 11/23/2006
From: Navarre, FL, USA
Status: offline
quote:

ORIGINAL: Colt4g63


quote:

ORIGINAL: JB COMP


quote:

ORIGINAL: twomanytoys

If you can figure out a way to get more power from a nitro without distroying it then great but i really dont think you can.


there is a way,
you let Adam at AB Mods mod it, hes one of the best modders around.


Sounds like the best option to me



it should

_____________________________

LX Comp: STS21B, JP-3, DX3.0 - CRT: STS 30 Rev2 or Mach 427, STS 0702, DX3.0 - T-maxx: TRX2.5
Airtronics. BlueBird.

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       Post #: 13

RE: Nitro Engine Hotrodding - 12/4/2007 2:35:36 AM   
downunder



Posts: 3279
Joined: 10/10/2002
From: Adelaide, AUSTRALIA
Status: offline 		There are literally millions of reed valved model engines with the Cox line up being the most famous. Below are two of mine with one showing the reed valve removed. The big advantage of the reed valve is that it automatically alters the intake timing to suit the revs but has more restriction than the usual fixed intake port so isn't suitable for very high revs. They also run backwards just as well as forwards which can be interesting .

Using a long intake tract might have some affect but would need to be somewhere around 3" long just to work at full revs. It's better to use a smaller trumpet shaped extension (about 1" on top of the carb. This gives a cleaner airflow (less turbulence) over the lip of the inlet and helps stop fuel spitting back out of the carb which helps economy. Opening up the bottom of the carb to more closely match the crankcase casting also improves airflow.

Modding the combustion chamber to get the optimum squish clearance and compression works very well but is all trial and error. The factory heads are usually pretty good but they still have manufacturing tolerances and have to make allowances for the different fuels everyone uses. Converting a head to use tapered seat plugs (especially the Nelson plugs) gives a much cleaner combustion chamber.

Altering port timings and so on is done at your own risk. All engines are a compromise to allow for reasonable low down power (torque) for acceleration while still giving good power for high speeds.

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