R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 07-31-2010, 09:50 PM   #1
Tech Adept
 
Join Date: Feb 2008
Posts: 192
Default piston and rod mod

here are some pic of my piston and rod not done all the way. still need to even my piston and polish every thing up. tell me what you think bad or good if bad tell me y just dont say crap.
Attached Thumbnails
piston and rod mod-dsc02594.jpg   piston and rod mod-dsc02596.jpg   piston and rod mod-dsc02597.jpg  
gatorage is offline   Reply With Quote
Old 07-31-2010, 11:12 PM   #2
Tech Elite
 
jmaxey51's Avatar
 
Join Date: Dec 2009
Location: Athens, GA
Posts: 3,917
Trader Rating: 7 (100%+)
Default

have you tried running it? if so did it run? looks way off balance and to weak but i may be wrong....
jmaxey51 is offline   Reply With Quote
Old 07-31-2010, 11:58 PM   #3
Tech Adept
 
Join Date: Feb 2008
Posts: 192
Default

Quote:
Originally Posted by jmaxey51 View Post
have you tried running it? if so did it run? looks way off balance and to weak but i may be wrong....
iam not done with it yet. but i did not cut the center of the rod like some people do. this is a sirio rod and piston so the rod is super strong and the piston is cnc. no jap crap here.
gatorage is offline   Reply With Quote
Old 08-01-2010, 01:14 AM   #4
Tech Champion
 
Roelof's Avatar
 
Join Date: Aug 2007
Location: Holland
Posts: 5,981
Send a message via ICQ to Roelof
Default

Quote:
Originally Posted by gatorage View Post
iam not done with it yet. but i did not cut the center of the rod like some people do. this is a sirio rod and piston so the rod is super strong and the piston is cnc. no jap crap here.
The rod is something not to play with. In your hand it may feel strong but running 40.000 rpm you will be amazed what kind of forces are build up, it can run up to 20~30kg for just such a rod....
If it could be made smaller within a safe use then it would be smaller.....
By the way, the rod does flex to take out the peak force, if the rod is made from a very stif material it would shatter into 1000 pieces within 10 minutes. Been there, done that......

Looking at the surface you have to polish a lot, for sure sharp edges are the places where it will crack first and that will also go for the piston.
__________________
Speed is only fiction but a 130+km/h MRS4 is for real.
Roelof is offline   Reply With Quote
Old 08-01-2010, 02:11 AM   #5
Tech Elite
 
Join Date: Sep 2001
Location: Some where
Posts: 3,015
Trader Rating: 44 (100%+)
Default

I am no guru but your mod looks like it does nothing. It looks like you got a dremel and just starting cutting with no specific goal in mind. I hope it works for you please post your findings...and be honest
__________________
T5M 7.5
22 3.0 7.5
SickWitiTRacing(Jayson)
NitroLuver is offline   Reply With Quote
Old 08-01-2010, 02:53 AM   #6
Tech Addict
 
Join Date: Mar 2009
Posts: 725
Trader Rating: 12 (100%+)
Default

Quote:
Originally Posted by NitroLuver View Post
I am no guru but your mod looks like it does nothing. It looks like you got a dremel and just starting cutting with no specific goal in mind. I hope it works for you please post your findings...and be honest
+1

Looking at your cuts and where you have them I'd have to say that the most you did to your crank was lighten it and put it out of balance. The rod is another story. I'm also no pro, but I think you may have gone too far in knife edging the rod. At the RPM's these motors pull, that's a bit much for the material we use and what we put our motors through.

I'm not sure why we would want to really modify our motors nowadays? Back in the 90's, we used to cut cranks and sleeves for more flow and power back then. But now, the motors are so overpowered I'm not sure why you might want to risk the motor to get a little more power. Before cranks and sleeves were plain with no turbo cuts or porting cuts which is why we did it back then. I've run modified's from EB mods, RB mods, CEO, Hot Mods, OS Speeds, and JP's and while they are great motors it's hard to justify these costs to newer racers who need more track time in order to use the power.

Good luck with your motor and I hope you will still have a reliable motor when you're done.
__________________
HB D8T with BCE Chassis, ACE Shock towers and motor mounts, M2C Rear Suspension system, KH front steering plate and chassis braces, Lunsford Ti-turnbuckles & hinge pins, OS Speed motor, Hitec 5995TG steering, Futaba 9351 throttle/brake, OS 2060 pipe, and J concepts Punisher Body.
HB D8: CEO Mods Novarossi P5K with JP4 tuned pipe, JR 9000T steering, JR 8800T throttle.
gotspeed_2000 is offline   Reply With Quote
Old 08-01-2010, 05:44 AM   #7
Tech Master
 
j_blaze14's Avatar
 
Join Date: Feb 2008
Location: Tampa, Fl
Posts: 1,693
Trader Rating: 34 (100%+)
Default

all modders started somewhere, a few i tried at first were pretty ugly, but ran. some of the guys that have been doing this a while are so good you see the parts and you almost don't want to run them.
__________________
aGama A8 EVO - Werks B2 - Sidewinder
aGama A8E - TrackStar 150a, 2560kv, 3 and 4 cell
FlySky GT3B, Turnigy HV servos, SKY Lipos
AKA, Proline, Hotbodies Rubber
Elite Performance - HORRC.com
j_blaze14 is offline   Reply With Quote
Old 08-01-2010, 07:50 AM   #8
Tech Adept
 
Join Date: Feb 2008
Posts: 192
Default

if you think i cut to much look at this pic. this is a onroad rod it is thick and this more has a smaller piston than most .21 i think the rod might belonger to but the crank is longstorkeand being long stork it will have a little less stress on the hole motor.
Attached Thumbnails
piston and rod mod-dsc02598.jpg  
gatorage is offline   Reply With Quote
Old 08-01-2010, 08:20 AM   #9
Tech Addict
 
Join Date: Mar 2010
Location: Connecticut
Posts: 711
Trader Rating: 14 (100%+)
Default

You went this far, run it. No reason for all that work and not seeing how it performs, who knows, maybe it's not as bad as it could be. As Roelof said, you need to polish the hell out of that rod. You need to round off all of the pointy surfaces, anything pointy and not rounded off is a stress spot waiting to happen.
DuckStang is offline   Reply With Quote
Old 08-01-2010, 08:40 AM   #10
Tech Champion
 
Roelof's Avatar
 
Join Date: Aug 2007
Location: Holland
Posts: 5,981
Send a message via ICQ to Roelof
Default

Quote:
Originally Posted by gatorage View Post
if you think i cut to much look at this pic. this is a onroad rod it is thick and this more has a smaller piston than most .21 i think the rod might belonger to but the crank is longstorkeand being long stork it will have a little less stress on the hole motor.
One rod isn't the other.... The material is making the specs and if a rod is much thicker then you can imagine it is made from a less stronger material.....
__________________
Speed is only fiction but a 130+km/h MRS4 is for real.
Roelof is offline   Reply With Quote
Old 08-01-2010, 12:29 PM   #11
Tech Elite
 
22Racer's Avatar
 
Join Date: Mar 2002
Location: Wanamingo Mn
Posts: 3,078
Trader Rating: 67 (100%+)
Default

I wouldn't take any material off a rod, way too risky. You probably could not tell a difference or even measure a difference in weight. When modding an engine timing is everything.

Rex
__________________
Rw modding and engine repair http://www.rw-mods.com
Sleeve resizing $15.00/ motor rebuild $30.00
Argus engine distributor/Avid bearings/ Alpha engines/
Fx Royal engines/ Maxy Engines
e-mail rwmods@yahoo.com Rex Welch
22Racer is offline   Reply With Quote
Old 08-01-2010, 12:34 PM   #12
Tech Champion
 
Roelof's Avatar
 
Join Date: Aug 2007
Location: Holland
Posts: 5,981
Send a message via ICQ to Roelof
Default

Yep, ony tiny change at the crankshaft timing will do a lot more than all tose fancy cuts.....
__________________
Speed is only fiction but a 130+km/h MRS4 is for real.
Roelof is offline   Reply With Quote
Old 08-01-2010, 01:01 PM   #13
Tech Elite
 
Join Date: Sep 2001
Location: Some where
Posts: 3,015
Trader Rating: 44 (100%+)
Default

Quote:
Originally Posted by j_blaze14 View Post
all modders started somewhere, a few i tried at first were pretty ugly, but ran. some of the guys that have been doing this a while are so good you see the parts and you almost don't want to run them.
This is 100% true all I was saying is that it looks like he was just cutting and didn't have a certain goal eg more overall power,more bottom, more fuel eco or more top. I will say this you have way more gull than me because I would never cut my engine at least not to that extent. The most i've done is mod an old side exhaust opening so it would match the port on the engine(increased flow). I have toyed with the idea of doing small knifing on the sleeve but I haven't found a motor I am comfortable trying it on. Anyway good luck with your mod I hope it works out for ya!
__________________
T5M 7.5
22 3.0 7.5
SickWitiTRacing(Jayson)
NitroLuver is offline   Reply With Quote
Old 08-01-2010, 01:21 PM   #14
Tech Master
 
captain america's Avatar
 
Join Date: Nov 2005
Posts: 1,425
Trader Rating: 9 (100%+)
Default

Quote:
Originally Posted by gatorage View Post
tell me what you think bad or good

It doesn't really matter what "we" think. The only thing that matters is, when you re-assemble your mill, does it run better or worse than it did before?

The fact that it looks like it was vandalized and mutilated is irrelevant, but humorous from a story-telling perspective
captain america is offline   Reply With Quote
Old 08-01-2010, 01:28 PM   #15
Tech Adept
R/C Tech Elite Subscriber
 
Join Date: Jun 2009
Location: Evansville, IN
Posts: 240
Trader Rating: 13 (100%+)
Default

Quote:
Originally Posted by captain america
The fact that it looks like it was vandalized and mutilated is irrelevant, but humorous from a story-telling perspective
McFly505 is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:13 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net