MR2 Roadster Owners Club

The Workshop => Performance Related => Topic started by: m1tch on June 27, 2017, 17:27

Title: Machining stock pistons
Post by: m1tch on June 27, 2017, 17:27
Hi all,

Just a quick question, I know that the stock pistons are slightly dished with some valve cutouts, this gives the engine fairly high compression and having a read up the head also has a decent squish which helps with fuel economy etc.

I was just wondering if anyone had ever machined down the stock pistons slightly as removing some of the raised parts on the piston crown as this would reduce the compression ratio of the engine without actually reducing the thickness of the crown of the piston.

I can see that the 3zz and 4zz engines have the same bore size (different stroke) and it looks like the 3zz engine had a different piston manufacturer, doesn't seem like there are any other Toyota pistons with the stock 79mm bore.