Just wondering if it's possible to increase engine power?

I have a 15 size OS MAX. Can't remember what model, but it's slide carb, 1.2bhp, 36,000rpm with up to 40% nitro

I have good exhaust on it, but can I add bigger carb? Raise compression ratio? Port the crank/cylinder?

And how about those supercharger kits? Are they real? Do they work?

Thanks guys!

the best way to get more power from an engine is tp up the nitro percentage in the fuel, this can mean re shimming the head to allow for more room for the fuel though, otherwise you have over compression which can destroy your glow plug, possibly sending the plug wire into the engine causing a lot fo damage, so you don't want much more compression then what it would have stock, that also explains raising the compression.

as for modding the engine, yes you can mod it, and it can up the power significantly, but it takes a lot of practice to get it right, and a very steady hand, so if you've never modded a nitro engine before i don't recommend it, you could send the engine into one of the good engine modders, i recommend Adam at AB mods, or Rick at RB mods as two of the best.

as for superchargers, [link=http://www.rcuniverse.com/forum/m_5796062/tm.htm]here[/link] is some good reading on forced induction on a two stroke glow engine.

Engine modding to advance the timing profile of your little .15ci engine will give good best results, probably the best power gains possbile. But you will need to know what you are doing and what new timing profile your engine must have. Also, once you hog the ports open, depending on your new profile and your new port configuration, you will have to replace the pipe with a new one so that the return pulse will match the new profile.

Be sure to read the post ttoks linked, this will tell you why forced induction does not work and why you should steer clear of them for our 2stroke nitro engines.

I was kind of hoping for DIY stuff

Regardless, how much % more power can I gain if I send it to a pro to mod?
I guess this matters a lot though on how well tuned the motor is from factory

With bigger ports, does this mean I can utilize more RPM?
Will my motor handle this? I have already snapped a rod from running too high rpm + leaned out I think as the brass snapped where it connects to the crank

A much better way to reduce compression is to make the head button bigger. Adding too many shims will make the distance from piston to the squish band too big and will also cause detonation or rather pre-ignition. A reason for that is that the heat transfer from the hot piston to the cooler head will decrease with a bigger gap, making the fuel ignite too early. A big gap will also reduce squish velocity and reduce power. Aim for a gap of ~0.4mm for a .21 engine.
You can easily run 9.5:1 compression with 40% nitro or higher if your engine is set up properly.

Well the owners manual for the motor already stated that it is safe to run up to a maximum of 40% nitro

Either way, the motor has plenty of power, I just wish it had more torque as the car has no centre diff and therefore no front wheel wheelspin to aid it get of the line instantly, so it bogs and then lashes with a gush of power

ie, I drag my friends car, which has my stock tamiya 15 motor in it, and he takes off hard on me, but about 2-3 metres later my car storms on his and just add tremendous amounts of space on it

Maybe get the 2 speed going so it has more power through out but I have played with it plenty and never got it t kick into 2nd

The change would be audible wouldn't it? 2nd gear has separate clutch and one way bearing to go past 1st

thats sounding to me like your low speed needle may be to rich if it's bogging.

I haven't run the car for about 2 years now, so my memory is a bit vague

The car is 2kg, no centre diff, and although it takes off ok, even a electric car with a 540 motor in it would out launch it, but mid and high range is very powerfull with my car

Also, 12, 15 and 18 size engines all fit in the same mounts?

yes they all fit the same mounts, and just to clarify, many electric motors these days will easily out power even the most powerful of nitro engines.

Yep, I agree here. Nitro engines, especially of .12ci and .21ci race grade designs are maxed out of what we will even get out of our single cylinder nitro engines.

To all thse who want to out do electric, forget it. our nitro engines are simply outclassed. The only way for a geven engine to outperform elctric is to go with multiple cylinders. But nitro engine makers are not willing to make those.

hmmm damn if I knew 18 size would fit I would have bought one of them instead...

Though, I heard even with 12 Vs 15 size, that some 12s have the advantage of being able to rev harder therefore a better choice
True or not?

some .12 engines have the advantage of having very aggressive port timing, while not many .15's you'll see have this, so some .12 engines make more power then .15, or even some .18 engines.

I just had a look at some OS engines,

And found a 12 that does 1.65hp and revs to 43,000rpm

So then, definately with a 15 you should beat that?
What governs the rpm of the motor? Does it just run out of puff and doesn't rev more due to small ports/carbie?

If I was to get the engine ported by a pro, would the internals sustain 40k+ rpm?

Also, if a nitro motor is free revved, will it blow up?
And, if I up the compression ratio by putting a spacer/washer, can I boost the nitro content too? Or is 40% really as much as I should think of?

I don't think the engine needs the power, I just have an addiction to getting more power from engines...