R/C Tech Forums

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

Thread Tools Search this Thread
Old 07-17-2009, 03:31 PM   #16
Tech Master
rossoh10's Avatar
Join Date: Jul 2006
Location: Bakersfield Ca
Posts: 1,091
Trader Rating: 9 (100%+)

I have recently researched modding engines and have found some research.....As far as modding the crank I will stay away from that...There is a couple things you can do to the crank without throughing off it`s balance,but only on cranks that are stock and don`t have any factory work already done to them..Anything more than this and you will need to rebalance the crank and fill with putty...

I would recomend practicing on worn out sleeves,cases and head buttons.You need to get the feel for the correct speed to run the dremel at..After you have practiced and get the feel for the dremeling speed(along with a steady hand) only then would I proceed to mod a budget engine.Why a budget engine..It`s easier to seen gains and if you mess it up its a $100-$150 mistake and not a $300+

I will take little material off at a time...Its easier to take material off,cause you can`t put it back on
rossoh10 is offline   Reply With Quote
Old 07-17-2009, 06:21 PM   #17
Tech Lord
wingracer's Avatar
Join Date: Nov 2007
Posts: 12,869
Trader Rating: 24 (100%+)

You can't perfectly balance a single cylinder motor. Grind on that crank all you want. Just try to take some material off of the pin side too when you do.

Besides, I really wasn't talking about that kind of grinding. There is one absolutely VITAL part of a crank that can be modded to your hearts content without really affecting balance.

Also, that "putty" has nothing to do with balance. It is simply a lighter (and cheaper/easier) way of ramping the fuel window.
Sean. Certified speed crazed mowron.
Team Shepherd USA
wingracer is offline   Reply With Quote
Old 07-18-2009, 09:48 PM   #18
Tech Adept
chunk t's Avatar
Join Date: Nov 2008
Location: Elgin, IL
Posts: 225

Originally Posted by Semple View Post
Yeah, just for fun. I have no intentions of starting a business or anything. I like to learn everything I possibly can about the things I enjoy.
Semple, you're a man after my own heart. Listen to Monty, he's got a good head on his shoulders (we've swapped a few PM's). Most of my mod'ing is for my boat engines & I've done some to car engines as well. What I've learned from others and self inflicted damage is... know exactly what you want to accomplish before you make your first cut and make sure you understand how that little two-stroke pump works.

Two suggestions I'll offer -
1. blue print the engine before you make your first change. You need to know your starting values for port timing (induction, transfer & boost, and exhaust), rod length, stroke, head bubble volume, head clearance, squishband area, head shimn thickness (if any), crank case volume, carb bore, port area & shape. it's a lot, but you need to know your stock numbers.
2. A cheap and effective way to give you hands-on cause and effect on a GOOD engine would be to pick up some head shims and sleeve shims. Swapping head & sleeve shims will allow you to alter the compression ratio, elevate exhaust, transfer & boost port timings. Adding & removing, individually or in combination will change the engine's performance. Head shims you can pick up at the LHS or an on-line hobby shop. Sleeve shims can be picked up on-line form Chris Wood at Wood's R/C Boat Products (woodrcboatproducts.com) these guys can make them cheep in an assortment of thicknesses.

& while your at it.. read up on how a tuned exhaust works. 'Cause once you begin changing sleeve timings you need to make adjustments to the pipe &/or header length.

But it's all in the name of fun.
chuck "chunk" thomas
1:10, 2-wd Stadium Trucks
B-Mod Tunnels
If ignorance is bliss... I must be in heaven!
chunk t is offline   Reply With Quote

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 12:06 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net