IAME X30 engine performance

What’s the recommended replacement interval from Grice?

Generally larger clearances come at the expense of shorter running between services.


And that’s was what I ran to, the coating went bad faster😄

But the people who run their engines generally put a new piston in after 2 races


Whats the benefit of running larger clearences?
I was under the impression that thighter would decrease compression loss and make more power, with the risk of seazing the engine.

Larger clearence is for when you have higher temperature applications such as turbos.

Or do these builders recommend higher egt?

The compression is mostly down to the ring seal.

Higher clearance can reduce the frictional loss between the piston and cylinder wall. The downside is that you get more piston rocking which can lead to premature failure…. Ie if you run it for too long it can crack or even shatter.

That makes sense…

As for the ring gap. Is that according to the manual?

Yes, 0.3mm is fine :raised_hands:t2:

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So next to “bore to piston clearance”, “ring gap clearance”, “squish”, “gaskets to port opening matching”, what else can be done that are static → Carburetor is dynamic based on weather…

Very minor ignition timing adjustment, atf oil in gearbox (3h interval)

You also have different gaskets for exhaust manifold to shorten or lengthen exhaust. I don’t remember exact measurements that was legal. But very minor as well.

That’s basically it

I am aware of an exhaust spacer of 3mm.

I was under the impression that ignition timing cannot be adjusted on an X30.
Care to elaborate more on that?

It can be adjusted very very little, but not that it is worth it basically

You can hold it either left or right when tightening. If I remember correct it is 0.1mm max of timing difference. It has some play in it

Some builders swear it makes a difference, but to me when experimenting - nothing :smile:


i do it like this: Manual clearance is not really the most optimal for performance, Usually i take a 0.13 gap which is sweet spot for my engines, around 6hr imtervals, Also important to measure multiple pison from same size they can differ in size (minimal)

For a quick prepp for a engine like this often for me consist of removing any carbon buildup (if there is any) from piston and exhaust ports and openings, Clutch etc.

when it comes to egt i run around 560 degrees on 15000rpm, reason i measure at 15k beacuse not alll track can reach 16k and maby has some bumps on the straight i find 15k good measurement,

you can read about the settings i reccomend on my webside: Motor renovering tjänster | AWA Racing

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also as i listen above, Make sure carb is allways up to spec, cleaned, fresh gaskets, right popoff, Usualy 0.610 to 0.70 bar, That what i find the easiest to tune and turn out good on the dyno, If you are into that you can take some autosol and polish with a coth or a soft dremel wheel the ( i lost the english word i will post a pic) so that its shiny and has no imperfections that can stop air and fuel.

last thing that is pretty important is the sparkplug cap and sparkplug head. If it gets dirty (black sut) inside the cap clean it so that it gets better contact. i dont know if it helps its just i habit that i do to keep y things clean and always performing well!

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I normally run 0.005” piston clearance and replace the piston at 6 to 10 hours depending on level of competition, but have run out to 12 hours without issue. Here’s a link to Remo’s (AUS IAME importer) site which has some useful info. http://www.remoracing.com.au/iame-engines-m/iame-x30-125-tech-info-downloads

is it in mm? or in that wierd amarican measurement?

Ok i searched and its around 0.127mm
I find that a big tight causting abit to much friction… I think thats what factory iame engines come with… 0.12 or 0.13

Ha ha, showing my age using imperial units in Aus.

I don’t understand Swedish… Do you / are you planning on an English version?

You could read some stuff here, he has basically straight copied all the info from there :grimacing:



I see a pattern forming…

Very unfortunate, at least give some credits to the original “owner” of the info that is available.


Mike… this should be setting off alarm bells. Do you want to make a career in this sport?

It’s the respect of others that will find you in seats I suspect. This appropriation of others work without crediting them is gonna be a problem unless you nip this in the bud pronto.

Guess who I have been paying for seats? Young folk I respect and want to see grow as drivers. I’d be thinking twice about having someone on my team that has a rep. I’m just a casual though so maybe I’m placing too high a priority on “I like this kid and will pay for the seat”.

Last time I pipe up on this. You are your reputation not your racing results or how well you tune an engine.