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Old 06-14-2010, 08:38 PM   #1
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Default boring a RC car nitro engine?

ok so I was just looking around on ebay and noticed that you can buy cute little rebuild kits... cranks, pistons, and sleeves!

I rebuild high power/performance 2 and 4 stroke dirtbike engines every 2-3 days so im pretty experienced in that area. I have tons of experience with gas engines but pretty much nothing with nitromethane engines.

I was wondering if theres any mods that a guy without million dollar CNC machines can do to an average RC car engine for a reasonable price to make them even crazier!! (boring, stroking, port + polish, etc..)

thanks.
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Old 06-14-2010, 08:43 PM   #2
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ok so I was just looking around on ebay and noticed that you can buy cute little rebuild kits... cranks, pistons, and sleeves!

I rebuild high power/performance 2 and 4 stroke dirtbike engines every 2-3 days so im pretty experienced in that area. I have tons of experience with gas engines but pretty much nothing with nitromethane engines.

I was wondering if theres any mods that a guy without million dollar CNC machines can do to an average RC car engine for a reasonable price to make them even crazier!! (boring, stroking, port + polish, etc..)

thanks.
yes you can do it.My dad is a machinist and says he could take stuff to work but i think if you cut something to big etc it will throw off the timing. You would haev to ask someone who mods engines for help there. you can even do stuff with a dremel. Heres a link
http://www.rcuniverse.com/forum/m_5226191/tm.htm
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Old 06-14-2010, 08:53 PM   #3
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yes I was actually just reading that same link... read about 10 pages, very interesting stuff. little bit different than a bike engine but I would definately like to give it a try.

are all these engines usually the same size bore or what? how would I find spare sleeves, piston, rods/crank for my engine, or would any work?

it is a HPI nitro star f4.1
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Old 06-14-2010, 08:59 PM   #4
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go ahead, ask any guy who mods engines for a living...

They may tell you some stuff... but they wont tell it all... they all have there own tricks and they wont tell anyone!
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Old 06-14-2010, 09:01 PM   #5
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go ahead, ask any guy who mods engines for a living...

They may tell you some stuff... but they wont tell it all... they all have there own tricks and they wont tell anyone!
exactly. They wont tell you what they do but im sure they will get you going in the right direction. I recommend just starting with any piston and sleeve and going from there. Start small and go big. try and find some beat up engines for less than 50 dollars and play with them. The worst that can happen is it doesnt work haha
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Old 06-14-2010, 10:44 PM   #6
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NO you have to re-plate the sleeve and hone it. I don't think you what it takes in plating parts. It's not straight honing (it's a taper thats why the pinch at the top piston travel). Then what you going to use for a piston custom job or one another engine?
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Old 06-14-2010, 11:35 PM   #7
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http://www.rctech.net/forum/exclusiv...=Adjust+timing
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Old 06-15-2010, 07:39 AM   #8
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There is several engine modders on this site, you just got to look for them
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Old 06-15-2010, 10:06 AM   #9
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What most do is do some porting on the sleeves and reduce the weight of the inside of the crankshaft, by boring out the air passageway and placing an epoxy ramp in the very front. Also, you can play with the counterweight by concentrating the weight in a certain point of the stroke, or changing the shape to modify airflow.

When all is said and done, it's about efficient flow of the fuel/air mixture (like any engine). If you've got a 5 or 7 axis mill, you could do some serious port work on the sleeves. Probably with a lathe/mill combination too.
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