9.4:1 or 10:1 pistons?

[thanos]

Guys, i have a question about my pistons, i replaced my pistons when i rebuilt the engine, and the code was 13101-16030-02, but from what i red some people say that the 13103 only are the 10:1 and other say that the 16030 are 10:1 and 16010 and 16020 are the 9.4:1, which of them are the 10:1 pistons?

The old pistons had the tall center ,but unfortunatelly i didn't see the new ones before the installation so i have no clue...

[Project D]

hard to tell with just the PN :\
Best chance to be sure, find someone with a borescope, remove a sparkplug and look inside.

[thanos]

I see thanks!

[ga_goosh]

9.4 slug STD: 13101-16020
9.4 slug O/S .050: 13103-16020

10.1 slug STD: 13101-16030
10.1 slug O/S .05: 13103-16030

the 10.1 piston is a europe only part.

the 13101 is the STD bore size 13103 is the O/S version of the same piston. the 16030 (10.1) and 16020 (9.4) is the comp type

you can tell by looking at the piston dome. the 10.1 has the protruding dome and the 9.4 does not

[thanos]

Thank you very much
Glad to know that i have the 10:1 pistons!

[Alex170984]

Apart from the lower comrpession, is there any disadvantage of having the 9.4s? I have these but now 81.5 diameter.

[oldeskewltoy]

thanos Wrote:Guys, i have a question about my pistons, i replaced my pistons when i rebuilt the engine, and the code was 13101-16030-02, but from what i red some people say that the 13103 only are the 10:1 and other say that the 16030 are 10:1 and 16010 and 16020 are the 9.4:1, which of them are the 10:1 pistons?

The old pistons had the tall center ,but unfortunatelly i didn't see the new ones before the installation so i have no clue...

Above is the oversize (81.5mm) 10 to 1 piston. 13103 = O/S, 13101 = std size

16030 = 10.0 to 1

[Ivan141]

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.

[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

[Alex170984]

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.

I bought the 9.4:1 pistons in the UK for £100 which is $61

Do you know anyone that has used these? I only ask as they are sitting in my rebuilt engine...I have the 20mm pins in mine.

Any ideas as to what the weight of the 20mm npr pins are opposed to the 20mm toyota pins?

And what about the weight of the 10.1:1 pistons and 9.4:1 pistons?