I'm planning to have my Evo x engine and SST built and I'm also considering a stroker kit, mainly to help preserve bottom end power with bigger turbo. I'd be looking at a 2.2l

Apart from cost, are there any downsides to stroking. Eg. Like noisier rattly engine, vibration, overheating etc.

I'd just like to be aware of all the consequences.

 

You might go blind.

 

There's always one smart a....

 

Besides chafing and the aforementioned blindness? Only real downside is a lower theoretical max rev limit.

 

Everything is a compromise, but for the sake of keeping things simple. The "downside" of lengthening the stoke of an engine are:

1) Higher piston speeds, which creates greater stress on components like wrist pins, rod bolts, connecting rods, rod bearings and crankshaft bearings. However, if the pistons and rods you're replacing yours with are light enough, then the loads can be reduced to near stock levels or even lower. Remember the basic F=M*A. If the piston speeds increase (which they do with longer stroke), you can reduce the force seen by the components by reducing their masses.
If that can't be achieved, then acceleration of the internals must be reduced to keep forces to to a manageable level. This is done by not allowing the engine to rev as high.

The benefits of a longer stroke:

1) Greater ability to fill cylinders more quickly and efficiently on down stroke.
2) Longer strokes will create more torque at any given RPM given all other factors remain the same.
3) Longer stroke engines have reduced side load on pistons during the upstroke and therefore the piston skirts can be shorter reducing friction with the cylinder walls increasing longevity and reducing frictional losses.

There's tons more from metallurgy standpoints etc. But these are the ones we care about lol.

 

+1 on everything except #3. When it comes to that, the rod/stroke ratio is what is important to consider. A short rod with a long stroke will create excessive side load. You're gonna need to talk to builders experienced with the 4b11t on what they deem as acceptable limits for r/s ratio. Some people have taken the crank from the 2.4 L 4b12 and put it in the evo, but they all now regret their decision, likely because the R/S ratio was too low. The only other crank any builder uses on the 4b11t now aside from stock is a manley stroker crank, and many people take those to 8500 rpm as a max, which isn't too bad considering that's the upper limit of our stock oiling system.

On the flipside, builders with 2.2l overbores and stock cranks won't take the rpm limit beyond ~10k rpm, though they'll need a drysump if they're to rev that high repeatably and reliably.