9.4:1 or 10:1 pistons?

[oldeskewltoy]

Ivan141 Wrote:Kicking this old thread because I couldnt find a better place to drop some info.
I recently received a brand new pair of 16030 10:1 pistons, and I went to my basement to shelve them for the moment. Out of the corner of my eye I spotted my old NPR 9.4:1 piston set (also new, bought for 60 dollars on ebay long ago), and decided to do a quick compare.
I'll add some pics later.

What struck me is that the NPR items look so eerily alike (except for the piston crown offcourse), that they could have been cast by the same factory. The only real difference is the lack of toyota text down the side.
Then I noticed the difference between the wrist-pins of both kits. The toyota OEM ones are heavy fuckers, the NPR ones are much lighter.

Some kitchen-scale measurements:
OEM 16030 piston + pin: 416g
NPR 16020 piston + pin: 372g

mix & match:
OEM 16030 piston + NPR pin: 395g

21 grammes lighter.. I know which gudgeon pins I'll be using!
The difference between piston weights is all down to the amount of material in the crown.

Good to know.... when I built my engine there was about a month spent just looking for lightweight 18m gudgeon pins. Stock pins were 89 grams... I managed to get custom pins that weighed 64 grams