cd_14

Hello, I'm having some problems taking out my piston/con rod on my STS D30M. Can't seem to pull the con rod away from the crank. Little tight for the piston to angle inside the crankcase. Any help appreciated.

dayglo

is it all the way up? and the sleeve is out? if so slip a plastic zip tie around the con rod and it should come off.

hilifemt

I fixed my first attempt at turbo cutting a little, and added the 'scoop' cut. also grinded out the intake corners a little. Thanks alot for the tips guys, especially JB for posting pics to help me out. It's so cold out now so hopefully soon I can test it out. I have some recent videos of my truck, so i'll get more video once I run it to see the difference. Thanks again guys. Your help is much appreciated!

JB COMP

hilifemt, looks good.


cd_14, you might have to remove the sleeve first.



dayglo, you can mod your engine then break it in, but I like to break it in then mod them.



what is it called when you do like hilifemt did to the crank induction port? is that whats called ramping?

cd_14

Yep the sleeve is out and the piston is all the way up. It's almost out, but won't pull off. If I pull on it, it will probably come off, but don't want to damage anything.

dayglo

that is y u use a zip tie and not pliers.

Colt4g63

I rarely say things like this... But the pic of that Vspec crank where it has added fuel ramps/turbo scoops...whatever u want to call them.... Was a waste of time IMHO and from my R&D. The Vspec crankshaft is a VERY good design and there is a reason the top engine modifiers with dynos do not cut the crap out of them... You will just end up with an engine that vibrates more then it did stock... I still firmly believe you can not "perfectly balance" these engines as you can a multi cylinder engine PERIOD. But added vibration is never a good thing... Heck these engines vibrate too much as is

As most of you know I own and operate a X-Dyno. Its my main R&D tool for my modification business "AB Mods" and it leaves all the biased results behind. The dyno measures what it does and its as simple as that... Theres no fooling it, and theres also no "well it looks faster and seems faster" What you get when you dyno and engine is what you get. And I have extensively tested these things. I now do "some" things differently because of the constant R&D I am doing as I am ALWAYS learning more and more. But hey thats what its all about!! IF your not learning and improving your work more everyday then your not doin anything.... Now I do believe in reshaping "turbo scoops" on engines that have them for a better flow as seen in the pics of Tibs.... and maybe adding one here and there as I see needed if the crank NEEDs it... Some cranks like the Vspec and the ninja cranks are already a GREAT flowing design that needs not to be messed with IMO, or you will just end up with more vibration and NO gain. Now altering timing on these cranks is a different story.

K223

True Adam it is hard to argue with the Dyno and experience better yet. I can go into a load of questions on this one, but let me ask you when you modify the timing on a given motor does it normally move the power band up or down and do you adjust timing for max motor output or say torque, depending on what purpose the owner is going to be using it for say like offroad, road, or car or monster truck. Or do you follow a basic method for extracting the most power on each engine no matter what the purpose is for it and type of motor it is? I am just curious if modding is down to more an exact science or just a total increase of power of a particular motor.

K223

JB COMP

K223, Adam has posted a few dyno runs on RCU, just do a search on the all his post and you will find the dynos. most of them are comparing stock VS modded

K223

That will be interesting to look at. But I was just focusing a bit on timing and the effects of it to various Mills.

Thanks

K223

Colt4g63

Well I had a nice write up explaining some things but for some reason the post didnt go through and I lost it all... ARRRGGGGG But to put it simple you have to work with what you have. When you get an engine to modify you look at its design and all its port timings.. And you alter what needs to be altered to make this engine more effecient and produce more power WITHOUT hurting power where u want it.. you shoot for overall power increase. Yes you can alter the engine to give power in certain areas. But it goes back to you work with what u get. Hard to redesign an engine for 105$ And impossible to teach somone to modify online... It takes experience and know how thats the bottom line. It doesnt happen over night thats for sure. There are basic guide lines of what each engines port does.. But what holds in theory doesnt always hold true in reality.. For example... It seems everyone thinks raising exhaust timing will always give u more top end RPM HP.. Well I have seen this actually kill an engines powerband and over all power out put. I have also seen an engine peak more power but lose it quicker AKA fall off faster and narrow its power band. And then I have seen rasing exhaust timing pick the engine up pretty much everywhere!! You just have to know off experience and know if the timing needs raised on this certain engine or not and to what degree.... And most importantly watch what you read online!! Its scary the mis information that goes around on engine modifying.

dayglo

thanks colt, u have been alot of help

dayglo

hay colt, if u open up more air and fuel mix to your engine by open the case ports and the motor is getting more fuel mix, don't u need to have a bigger exhaust port to get rid of the extra that was made because of the opening of the ports in the case?

SManMTB

Get an engine simulation software. You'll learn a lot by playing around with it.
MOTA is great and cheap and does all this.

K223

Adam, I agree bit time with what you said in your last line. While you can gather good basics online and in the forum's your not going to turn someone into a nitro engine Hot Rodder overnight or even get them to the point where they know what is good for what motor without getting alot more experience and just doing the RnD and testing and tuning.

Your approach to these little engines and what you say sounds quite on the professional level and only comes with experience. While similarities with all these motor's exist and how you mod them....There are major differences just the same and what works for one, can kill another. Why do you think these engine company's produce different motor's for different applications.

One thing that show's you flat out know your stuff is when you can say hey the factory has designed such a good crank design that it needs little if any mods to really make much an improvement in a particular motor and is more cosmetics or just being fancy to translating to real world power increases worth your time and somebody's extra money to have you do. We have learned this on full scale vehicles years ago....Some things are better left untouched....Unless you have all the money and time in the world to do every little thing possible to get you for example .001 faster in the 1/4 mile or on a lap on the track. Just not worth it in the real world most of the time and for what most people do with there cars.

Thanks for explaining some of your principals of timing and how it pertains to a motor, Was not looking for trade specifics to what is good for each motor...You have to make money and feed yourself just like everyone else.

K223

K223

This is for RC nitro engines??? Got a link to the site where we can check it out?

k223

JB COMP

are you talking about Adam's site? its www.abmods.com

SManMTB

It's for two strokes in general and it will do small nitro engines too. You can play around with everything and even input a shape of your custom exhaust and it will give you power/torque vs rpm, animation of all pressures and temperatures. It's cool as hell.

[link=http://www.bevenyoung.com.au/mota.htm]Link to MOTA[/link]

K223

Thanks JB but I know Adams site....Wanted to check out this software....Thanks for the link Sman.....

K223

JB COMP

Oh, my bad

K223

Hey it's all good...Thanks for trying to help ;-)

How can we get Adam to Dyno some of the newer motors out there today and see what there producing in stock form for real. Do a lineup of all the top monster trucks engines and see who has the bragging rights for real. I would like to see what I have MGT 8.0 vs CEN 7.7 motor and it's so called 5HP rating.

K223

JB COMP

well, if Adam has not already dyno them, then you could buy one, break it in, and send it to him to dyno, I think he charges like $50 for the dyno plus fuel and plugs, unless he changed it since I've talked to him about it.

supertib

that program is a neat gadget but I dont feel its very accurate for use on loop scavenging 2 strokes....tell me if i'm wrong but it takes no consideration of schnerle effect does it ?

K223

He told me there's liability in dynoing customers motors and I beleive he does not want to do it anymore or at least on the motors he modifies for customers. Have to ask him again as we just touched on this.

K223

JB COMP

I know he said he's not responsible for anything that happens to the engine on the dyno, that the engine can fail on the dyno. but he was still doing it.