Engine Modding

[SSSavage25]

Anyone else mods there motors?

here's my first attempt at modding an XTM 24.7. This was done last summer when i didn't have the right tools. I since then have purchased a new P/S set and did the same with a carbide cutter. Much better results. The new sleeve is sitting in the motor right now though. It's a whole new beast after the port job!!

the sleeve had conservative porting in stock configuration. I cut the intake port further down and made it a little smoother than stock. I also cut fangs for the boost ports on both sides. Didn't go as deep as Crash did though.

If anyone else mods their motors post some pics here!

 

[chrisw]

i know crash just modded both his mils

 

[CrawlinClodKiller]

I have modded one or two. I always forget pics though. I should be doing a couple more soon and I will get pics this time. To give an example I did the stock x 4.1. Running 18/49 gearing it will flip on the roof at any speed now. It also gets way better run time and holds a tune like you can't believe. I did not use any tutorial on how to do it. I am just mechanical like that I guess.

 

[scrogathon]

Here are some pics of my current sleeve and crank in my axial .32
this porting rips and I'm running longer without needing gas.

I have some pics of my friends power racing .27 that I did an extreme mod on, and a few hpi .15ss motors for my brothers mini rs4 that I will post at a later time.

 

[Crash]

Here are some pics of my current sleeve and crank in my axial .32
this porting rips and I'm running longer without needing gas.

I have some pics of my friends power racing .27 that I did an extreme mod on, and a few hpi .15ss motors for my brothers mini rs4 that I will post at a later time.

Thats looks sweet

did you do it?

 

[AB Mods]

Theres alot more to making power with these engines them just the flow mods that i see here. Not downing anyone at all.. looks good guys... But the timing changes and alteration are what really brings the power out. But you have to know where and to what degree to alter timing at on the ports. THATS the part where u need ALOT of experience. A dyno helps as well :jamout: As it puts an end to all guessing. :FarleyParty: <--- love this smilely lol. Also a mirror polish is something that you don't want to do.. All you really need to do is hit it with a buffing wheel to clean it up. Taking hours to morrior finish the internals actually does no good whatsoever. I have tested these engines for years and years. Just sharing some stuff with you guys to help out.

 

[Crash]

Theres alot more to making power with these engines them just the flow mods that i see here. Not downing anyone at all.. looks good guys... But the timing changes and alteration are what really brings the power out. But you have to know where and to what degree to alter timing at on the ports. THATS the part where u need ALOT of experience. A dyno helps as well :jamout: As it puts an end to all guessing. :FarleyParty: <--- love this smilely lol. Also a mirror polish is something that you don't want to do.. All you really need to do is hit it with a buffing wheel to clean it up. Taking hours to morrior finish the internals actually does no good whatsoever. I have tested these engines for years and years. Just sharing some stuff with you guys to help out.

Awesome post

Thank you for your insight:beforeme:

 

[scrogathon]

I know this post is old and all but thanks ab for that info, I'm pretty sure I went overkill when I modded my motor, but it was great practice, and I enjoyed doing it, it made my motor rip better, but I couldnt imagine what it would be like if you touched it up with some timing tweaks and some dyno runs.
Ive done alot of reading on timing and all that stuff but I never really had the guts to try it, I think what I did to my motor did bring out some good in it, but I'm sure theres more power to be found without such a drastic change in apearance(to me at the time, that seemed to be all i was after(looky here I ported this and this).
I love to learn more about this stuff all the time.

 

[AB Mods]

Modifying and learning more and more about these engines is a blast! I enjoy it alot, still... and I do it as a business... it never gets old for me!

 

[scrogathon]

its so much fun if you ask me, my buddys say I'm crazy to touch the inside, they always say the factory knows best, i say no my hand skills no best, all motors are machine built to a certain spec that still makes them money and doesnt take forever to do, imagine hpi had to hand modify every motor they release just to get that extra .2 HP

 

[Chris]

its so much fun if you ask me, my buddys say I'm crazy to touch the inside, they always say the factory knows best, i say no my hand skills no best, all motors are machine built to a certain spec that still makes them money and doesnt take forever to do, imagine hpi had to hand modify every motor they release just to get that extra .2 HP

I've been learning about this for years now...just finally got brave enough to actually change some timing in a motor.

Adam is correct when he says there's *way* more to it than just some flow grooves and such. Those small things can certainly be done with little chance of a negative effect.

The timing is the real trick. It took me a while just to get the math worked out (and I'm good at math). Well more geometry with the angles and such.

I've got an S-25 that I changed timing on and man that thing flies!!

 

[RC-Crazy]

Modifying and learning more and more about these engines is a blast! I enjoy it alot, still... and I do it as a business... it never gets old for me!

Thanks Adam, have you mod any of OS 30VG? how much diff. after compear to stock? I'm think send you mine to mod. I did send you my 21VG to you & still waiting it come back.