I understand that alot of engine builders have trade secrets but wondered what internals of an X30 are changed in and out to get more performance.
Any help appreciated
The main focus is on smoothing gas flow. Polishing the openings and remove any material burrs so the gases can flow more freely through the motor.
Squish gap at minimum legal
If scrutineers open it up though you can be DQd if it’s all polished up inside.
What kind of gains can you see with some work?
Is this legal for x30? I was under the impression that all surfaces are intended to be untouched.
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No it’s not. That’s why I said after if scrutineers open it you’ll be DQd
A little bit you can get away with
If the question is what can legally be done, then I think not much. Piston diameter at larger tolerance limit, squish gap at lowest tolerance permitted. I think not much else, I’d love to hear if there is.
Check port heights against the regulations and make sure they’re open for the right number of degrees - but they’re usually right against the limit from the factory.
Set squish height to the minimum legal - but remember that also changes the port timing, so make sure that’s legal too without ruining the cylinder.
Match the liner to the cylinder casting - but most IAME cylinders aren’t bad.
Set the timing accurately to the legal limit - this one’s a little controversial because you’re not supposed to change it, but it matters.
Set pop-off correctly in the carburetor, use a good oil like the Elf HTX 909 IAME recommends, and fresh gasoline, jet it lean enough to get maximum EGT at 1100 F - that matters a lot more than the preceding, being 100 degrees low on EGT is giving away whole horsepower on the top end.
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Curious, anyone have a dyno of these engines? Always interested in the area under the curve for various engines.
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What most people here in the UK buy a lot of engines to find the best ones and get rid of the rest. it’s pretty blunt, but you can’t make a good engine from a bad one. I’ve seen people try every trick in the book, but the only tried and tested route is buying a ton of motors, mixing and matching (carbs and exhaust etc… ) if possible and that’s it.
I know some might disagree but this is modern single-make karting 
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Makes sense. 20 char
Or using that as a cover story for blatantly cheating on fuel. A water test or Digitron test isn’t enough to catch anyone running an engine on mostly xylene and toluene.
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Maybe, but I’ve seen drivers bolt on motors with same fuel and find tenths.
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First I’ve heard of this for karting. Is there more performance to be had by increasing the octane rating even further than 100+ octane race gas? Compression ratios and ignition timing are normally set by governing bodies so I don’t see an easy way to take advantage of increase octane ratings. I know old school hot-rodders that do this as a back shed version of making race gas.
It’s not just about octane - it’s about combustion speed relative to piston movement, as well as energy released when burning with a given quantity of oxygen.
Try running an X30 on 100LL avgas. That’s a really slow-burning fuel, high octane, low energy per unit oxygen (but high energy per kg of fuel which is why it’s nice in an airplane). Then enrich both jets 1/4 turn and switch to 93-AKI E10 street gas. You’ll feel the difference in power, especially when the engine is cold or out of the powerband.
Wierd… i run my engines at around 1220f at maximum 660 dgrees and around 400 degres low… runs like a dream
Worked whole last winter with a engine for a european driver with my builder. We ran stock dyno and it had around 29.1hp (senior)
Started with polishing the exhaust manifold, carb throttle house carb chanells reed hole and we were at 30.3hp
After that we started experimenting with squish, tolerances etc and where up at 31hp
And after some more work and experimenting with oild and stuff we peaked at 34hp thats 4hp over maximum for x30. He won with engine and they took it all appart and that said it was legal within reallt small marginals.
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When you say experimenting with oil and stuff you mean the mix ratio?
Oil/fuel mixture, oil in gearbox (instead of normal iame oil, change to something like mercedes Atf oil)
5 hp more on x30? you are kidding, right? Why would you even write such things? Really, you should know better than propagating fables like this one…even if it were true that you can get 5 hp by doing the things you say you did, (btw all illegal) there is no way an x30 is legal with 5hp more than a new engine straight out of the box. That’s ridiculous, 5 hp more you’d leave everybody behind by half a lap. Just because you can write some stuff on the internet, you should be cognizant of the fact that you are potentially leading people reading your assertions completely in the wrong direction. If they do what you wrote, they WILL BE DISQUALIFIED. You are also hurting the reputation of a company, IAME, that tries very very hard to keep their engines as equal as humanly possible, with very sophisticated quality controls, and also very strict technical restrictions! Please refrain from giving the public the wrong impression about the parity of IAME engines, in such a blatant way. For an engine to be legal you have to follow all the rules as required by the national federations, and IAME. If you cheat and for some reason don’t get caught, that does not mean the engine is legal! Some tuners think they are smarter than the scrutineers, but many end up being caught and regretting their cheating.
IAME USA CT
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In not kidding No! Thats the reality engines come underpowerd from iame in this case 29.1hp charts say 30hp, as i said scrutineering took the whole engine appart checked every gap and it was inside the tolerances… nothing wrong with optimizing the egine within the gaps of regulations…
And yes i know that Iame works hard to get the engines as equal as possible and dont want tuners making it harder for people that dont have the knowledge or money to tune it!
I can bet to you that not a single driver in the top 10s has a out if tge box iame, and if Iame doesn’t want builders and tuners to make the engines better within the regulations maby make all engines so that they have 30hp? And not. 1hp under… maby intruduce a lock like rotax has
In sweden we race some races rotax/x30 ans rotax is stronger and faster on most tracks this year. Heck top 5 rotaxes rev up to 15300rpm. So its like a x30 on stereoids, really fast bottom end and a almost x30 top ens…
Supersvensk racing, Mikael Drozdz