Hey I have a few questions on modding engines. Does anybody know somebody that modded their engine that I could PM and get a few pointers on?

Take your pick,

Me, SAVAGEJIM, Downunder, supertib, J-blaze, HPI apolo (I think is his name) and the list goes on. Here's a good thread to read if you haven't already http://www.rcuniverse.com/forum/m_52..._1/key_/tm.htm

What mods are you asking about.

I asked the same question a few months ago: Don't expect a lot of help from many of those guys listed. The ones who are in business doing this for others are keeping their secrets pretty close to their chest, rightfully so, but most of them have brushed me off completely concerning even the general basics.

Read that thread JB linked you to, and you will get some help from some of the guys listed: Downunder, JB, and SavageJim have all been helpful to me in particular. Regarding the REAL mods to your engine (port timing, etc.) you'll have to do a bit more research, especially since that information is the real heart of the engine. JB started a thread here a while back and there's some good examples of what other manufacturers are using for port timing. It should give you an idea of what kind of parameters you should be looking for, but unfortunately it doesn't tell you much about the operating range, overall power, or fuel efficiency of the motor in question. It's worth the read though: http://www.rcuniverse.com/forum/m_7452102/tm.htm

Basically all the sleeve mods & crankshaft mods center around the fine tuning of airflow and direction and lower crankcase mixture motion. Lots of it is common sense, but much of it is nitro-specific. There are a few threads going on this - do a search and read them all for a general concensus, but from what I understand all of this stuff is best for efficiency and smoothing out the powerband, not for actually gaining power or moving the power peak upwards. THAT comes from opening up the ports, but there are so many combinations of port timing, it's going to take either lots of trial/error, an expert, or a really good computer program to tell you exactly what to do.

Unless you've taken one apart, you can't appreciate how small these parts are and how precision the work will have to be, and the scale of the tools needs to match the scale of the sleeve. For $50-100 (what many modders charge), it's a heck of a deal in my mind to send the motor to someone who knows what they're doing and has the tools to do it.

There are only a few that actually do timing mods and there are the only ones that I know of that do timing mods AB mods, EB mods, and RB mods, EB closed down and I heard alot of people having problems with the RB mods and they charge $100 so AB mods is the only I would send my engine to and they only charge $85 - $105 and he has a dyno to prove the power gains he can get from a engine.

Just alittle FYI, EBMods hasn't closed down.

I'm not looking to send it in for 80-100 dollars. For that money, I could just get one of the high end engines. That's why I'm looking to do it myself. I think I'll try that link you sent me JB. I'm looking for better fuel and air intake into the engine because mine doesn't seem that smooth. Thanks guys.

A port and polish job is not that hard to do with a little skill and the proper tools. It can give you a decent power increase will little money.

It doesn't make more peak power, but I'm not sure if it helps here and there. Maybe Adam at ABmods will tell us if it helps power or not.

what motor do you want to mod? maybe someone can send you pics. its not hard once you understand the concept and what the goal is. here's another link that can help a bit too, read as much as you can, the read some more, then save up enough money to buy another motor or piston/sleeve (or fix an old one) cause one mistake will ruin the motor. 1mm too much in the wrong direction could spell disaster and the motor not run better, maybe even worse than before.

http://www.e-maxximumrc.com/html/nitro_motor_mod.html

I'm going to mod the T3.0. I've overheated it quite a few times, so it's no big deal. I was going to upgrade to an OS when it blows anyways. Maybe even if I mess up, I will have another excuse to get a new one :P

Ive seen some small power increases doin "flow mods" on the dyno with these engines. But the real power is had within the engine timing profiles. And changes there are critical.... You cant just go jacking up timing alot in EVERY port thats for sure...

Good luck on the engine modifying venture Doonagoowin. It can be alot of fun to learn about and work on these nitro engines!

Ok, so I already did a minor mod... Not really sure if it would be considered a mod though.
So I drilled out the stinger to make it a tad bigger. Off the line, this thing is killer. No glitches, no bog/stall/any of that. With the right tune, it's very good off the line.
However, top end dropped a little bit. Not sure if it was because of the transition from yellow to red pinion (HPI) or just the feel/look of it when acceleration kicked into top speed gear.

Tomorrow, I'm going to take apart the engine because I have nothing better to do... I stripped the second gear (modified chassis) and I'm going to need a new spur and chassis anyway.