Engine Mods
 

Anybody mod their own engines? Post pics and techniques, I am going to give this a shot on an old mt 12 i got in a trade. But I have no clue :sweat: I do have a carbide bit and a dremel, some polishing compund bits and stuff.

Try to look at any modified motors to get an idea...then test motor afterwards to see the effects.

Engine modding is 80% crankshaft work and about 20% sleeve work.

plenty of info on the net to satisfy your curiousity.

I was afraid I had gone too extreme with my port mods but it fired up first try, idled smooth and accelerated quite a bit faster..

not enough info
 

I really can't find any good info as stated above. I have searched high and low and can only find people offering to mod the engine for you. I have seen many pictures of port work and crank work but I don't think it is any good if you don't know why and what you should do and what is stage one and so on,,Is there any videos or books or websites that take you through the whole process from stage one mod to lowend mods high end mods and what you need to get started. IF not someone should make one and sell it to me!

The one think that you have to think about is that most of the good modifiers, and there are very few, learn waht works and what doesnt with trial and error. They used their own money to buy engines and modifie them, and when it didnt work they were out the money of the engine. They're not just gonna come out and tell you all the secrets.

If want to learn you will have to do it yourself.

Jammin: Do a search here, lots of great modifiers posted photos of their work, but take car, don't copycat without knowing what you're doing and the most important, WHY. Some time after, you'll start to think by yourself and know what, when and why to do.

The best advice you could have received has been told now. Artificial-I told you to see the sleeve and look for streaks on the sleeve, this is only one part of the equation, the other is have a grasp on crankshaft degreeing (do a search on engine degreeing and study how to do it).

Hoopdog: Your figures are partially correct, no matter how you mod the crankshaft, if the porting on the sleeve is crap, your engine will be marginally better, but not much more. Alas, the carburation and clutch adjustment are the key, remember, raw power isn't the only variable on your equation, they enter a lot of other.

Heres a couple pics of a OS .18TZ engine I modded. Pics of the boost port didnt turn out.. But basically what I did there was put 2 'fangs' on each side of the boost port and angled them down and outward twards the bottom of the sleeve.


http://i3.photobucket.com/albums/y55...dsstage2OS.jpg

http://i3.photobucket.com/albums/y55...ou7/ABmods.jpg

Heres a 3.3 traxxas engine out of the Revo I did also. Both of these engines showed very nice gains. Theres more work that I did to them other then what you can see.

http://i3.photobucket.com/albums/y55...u7/ABmods3.jpg

:D I prefer the sleeve only.

I don't have the guts to mod the crankshaft :D

Very nice :cool: You have the skill :cool:

Did you balance again the crankshaft ?

No. As its not possible to perfectly balance a single cylinder engine. Ive ran my modded engines like this for YEARS and ive never had an issue. Only thing I see if gains :sneaky:

I wont argue with anyone on here as thats not why im here.. But I'll state a fact. Its not possible to perfectly balance a single cylinder engine bottom line. I dont care what TNT mods says... But this in know way means that TNT doesnt do a good job on there engines, please dont get me wrong there.

where can i get those bits to cut the fine intake poets, this sleeve pic looks very good

Hey Colt. Welcome to the family!
It doesn't make sence to argue here because we came to learn from each other expirience. Can you open please one of your secret-how much % balancing is your target when you mode crancks-I have confused data collected over the years and it seems like your data can clear up something.
thanks a lot.

EdwardN I dont have any secrets :)

Does anyone know what type of "epoxy" is used for ramping the crank porks. I am only assuming it is epoxy because this is what it is commonly called.

Thanks

Keith

FIRST LET ME SAY I'M NO EXPERT,BUT I DO HAVE EXPERIENCE IN MODDING ENGINES.THE ERROR MOST PEOPLE MAKE IS THINK THAT A CRANK IS BALANCED,AND IT'S NOT.THE COUNTER WEIGHT ON THE CRANK IS TO OFFSET THE WEIGHT OF THE PISTON AND CONNECTING ROD.SO IF YOU REMOVE MATERIAL FROM THE COUNTER WEIGHT YOU MUST REMOVE WEIGHT FROM THE PISTON AND ROD.THE CRANK IS STEEL ,VERY DENSE METAL.THE ROD AND PISTON ARE MADE OF ALUMINUM ALLOY,MUCH LIGHTER MATERIAL.SO IF YOU THINK ABOUT IT IF YOU REMOVE 1/4 GRAM OF WEIGHT FROM CRANK YOU NEED TO REMOVE THE SAME AMOUNT FROM THE PISTON AND ROD.(JUST CUT THE ROD IN HALF! :lol: )SO YOU SEE IT'S REALLY NOT POSSIBLE TO REBALANCE AN ENGINE PROPERLY UNLESS YOU ADD THE WEIGHT BACK ON THE CRANK IN THE FORM OF A PLUG OF SOME SORT,IVE SEEN MOTORS WITH WEIGHT PLUGS ADDED TO COMPENSATE FOR CUTS MADE TO A CRANK TO INCREASE PERFORMANCE.JUST MY OPINION,NOT LOOKING TO START A DEBATE. :D

I use what was recomended to me by Brian AKA MXwrench. Threebond 1211 This stuff is awsome and it lays smooth as glass if done right! The only bad thing is that it takes a good 2 days to setup nice and hard. I usually let the engine set for 2-3 days just to make sure its totally cured. This stuff hasnt failed me once! And when I test engines I down right ABUSE them!! :sneaky:

Thanks Colt4g63, where do you get this stuff?

Keith

I get mine off the net here.. http://www.pro-flo.com/three_bond_products.htm#Sealants

hey guys I will start off by saying i'm not even claiming to be good , here is a p5 i did it turned out some great gains. i feel you just start off doing little things see what they change and take notes of your mods, what each thing did.i did this in my garage, the sleeve took about 1 hour, the crank took almost 3. the case not shown about 15 min. any questions or comments are welcome obviosley. :sneaky:

iv never seen a crank like that befor,what dos it do for you.

well first i want to say i hope like hell this is not going to get stuff started like i'v seen in the other mod threads. i saw a pic of a crank like this done on a 12, i ran my p5 for some time before i did this and after doing this the fuel burn was more efficiant, throttle responce was way more crisp and sensitve, rpms increased on the top end at lower temps and the powerband started way sooner with the same pipe.it was explained in great detail what this mod does, it sounded like what i was looking for so i did it myself.

and also my pic does not show the skill and amazing craftsmanship of the one i saw.

what did you do to the crank case ?

removed the front and rear bearings and polished the area were they sit in, i found by doing that it will free up just a fraction of the preasure that can sometimes bind the bearing. :sneaky:

Hey Nugenb.
I am not bushing you, I just want to help you. When engineers are designing the engines they put press fittings for bearings in purpose. Usualy it is .015-.020 mm press interference. When engine works and heat up, crancase expend more then bearing ( material expention rates) and interference will be smaller (still will be there to keep beaqring steady in case) and will not slow down bearings. You can do whatever you want to, I just try to help and understand what is behind press fit.
Use this tool to make sure you are not overploishing bearings seats.

mugenb46, where can we get a link on this explanation? Sounds like it will help me understand what modding each area does for the engine. Or at least put us newbies to modding one step closer.

what did the three slits cut by the crankpin do for you?

warmac, i'm not a newbe or a pro by any means i don't know of any mod spacific web sites, i just see pics in magazines and try them myself. when i do a motor know i will start of withe the sleeve first. motors have there own timing depending on what brand and style of motor, what i mean is you can have 2 motors different types of motors and do exactley the same mod and get different results you just do little things one at a time unless you are a pro and do everything at once and know what it will produce

german muscle, as i have said befor i am not a pro. i do these mods on theory only and what i can pick up on what other pro mod guys do. so any way those cuts help to cut through the fuel and air when it is being forced into the combustion chamber, when ever you can cut the fuel into finer particals you want this. it will burn or create a finer mor efficiant burn. a mist of fuel will burn or combust better than drops of fuel, if you can picture that.

Edwardn, thank you for that info, it's good to have someone who is willing to give ideas or facts about this stuff. i love doing this mod stuff to my motors, it intreges me to see what different things would do. i am glad i donn't know everything about modding motors, when i do it myself i learn more, learn from my mistakes. :sneaky:

Edwardn: do you know if "rifling" the crank intake has ever been tried by tuners/manufacturers? i know polishing has been done, but i've always thought that if the intake was given a proper rifling, that it could help to force air into the sleeve. just wondering. thanks.

mugenb46: thanks for the reply. I've only modded the sleeves of a few engines myself, but I've never touched the crankshaft and probably wont until I find a way to get around that 'balance issue' that's always there for crank mods.

In short, I'm not sure what I'm doing there :o ...doing more research on the timing for now.

warmac, no problem. i'm working on that my self. it's hard to find anyone that will give expierenced advice, you can change timming by port work and crank work i believe. by removing some of the top or bottom of the intake ports on the left and right sides of the sleeve, plus put the downward cut like most people do. i have also seen people make the bottom of the sleeve thinner and round of the bottom of it this will help flow. :sneaky:

warmac, also if you find any pics of a crank balencer or see what one looks like let me know. i am trying to talk a buddy into machining one out for me. then i will be stuck with trying to figure out how to actuely balance the crank with the rod and piston on the crank.

What you should do is do a search on 2-stroke engine modding... Putting pretty cuts and the like will only go so far... And keep in mind when you cut on the crank, there is a good chance of added vibration, which can lead to worn bearings and con-rods just to name a few... Unless you've seen a good Modded motor done the right way... Murnan, Motorman and Edwardn are the 3 guys I would pick there brains when it comes to true engine modding... If they are willing to share some sound info... You're lucky... What most guys do is have one of there motors modded by someone that says they know what they are doing at the local track... One of the fast guys... Then they just copy there work the best they can... When I saw the work done to the OS-Speed TZ-12, I knew I could copy the sleeve work, no problem... The crank was a different story... Most guy can cut and guess and hope for the best... The names listed above know how to figure out the hard numbers and have the right equipment/machines to do the work the right way... Shoot them a PM and see what they say... .02

RC_Alan

rc-alan
i was able to meet murnan at fernando's, ya he for sure is on top of his game on that stuff, to see his motor in his car and frank sosabee's was unreal, i can only explain them as formula 1 or F1. that is excactley what they sounded like blistering power. i have seen his work and it is flawless, very clean and you can tell there is pride and knowledge in that kind of work. i know he is a busy guy, and i know people are not always willing to give up info. i would just like to know how they balence the cranks after moding and what they use to make the cuts into the cranks. CNC machine? i used a dremel on everything and it took forever, and realy does not look as clean. crank balencer is what i'm digging for though.

What you do to balance the crank is, you weigh the sleeve/conrod assembly on a very sensitive scale. Then you take that weight and make a sleeve that fits on the crank pin. Then, you take 2 rasors, and set the crank on top of them, you remove (or add) weight until it fails to stop on the same spot everytime.

nitrodude, why do use the sleeve in that equasion, or maybe i missunderstood. thout you only weigh the conrod and piston with the crank. is there not a device that has two bearings to place the crank with the rod and piston in it like the engine is set up. I'm sorry this description is hard to picture, please explain.