Wait...what?

Why would you not just weight match the pistons and pins? I mean if that's something you want to worry about. I can tell you one thing, Toyota didn't when they built it originally(not much anyways). From tearing a couple different Toyota engines apart, I've learned they only weight match the connecting rods(to well within 1/10 of a gram of each other, or rather, pretty much dead-nuts exactly the same weight as each other so far as I can tell). But the pistons and pins are typically only within a couple grams of each other(weighed together as pairs). Which is probably just luck of the draw. It doesn't appear that they care that much if they're any closer than that to each other in weight. Actually, I kinda doubt they even weigh them at all. Since that discrepancy seems to be about the industry standard weight difference between any given pair of "non-weight-matched" pistons and pins. Regardless of the maker. Pretty sure they just grab one of each from their respective piles, throw them on a connecting rod, and call it good. But I could be wrong. Maybe they do weigh them. But only care if they're within a couple grams. So they might be doing that on purpose. As senseless at that would be.

Anywho...and more to the exact point I'm trying to make here...there's no reason to rebalance the crankshaft. It's already been done. Unless you've done something to it that might affect that. Which wouldn't be the case in this instance.

I'm afraid you might have over/under thought that one.

 

just to clarify, you took a 81-84 Toyota 22r piston with the 16cc dome and a compression height of 38.95 mm and machined it flat across. this gives it the same compression height as a 85-95 22re dished piston which is 34.95 mm? and you didn't just run a 85-95 dished piston because you didn't think you cold get the compression right? im just trying to understand how you out this together...

 

You know what? I highly doubt this is the first time this has been done. I believe I've heard of it being done before. And IIRC, somebody makes off the shelf pistons to do it too. I might just have to see if I kind find those. Not to burst your bubble. Just to set the record straight.

 

I have seen this done the other way around, a late block running special pistons with an early head that was shaved down to the same height as a late head but not this combo discussed in this thread...