Offset in Pistons

[Fasteddie]

UZ-fans,

while looking at the new aftermarket pistons i was told there are 4 "left" pistons and 4 "right" pistons...because of the 2mm offset in the pistons..

Can anybody please explain why this is done....and I guess because of this we can't order 8 similair pistons (with no offset)...?

Thx !

 

[Fasteddie]

anybody ?.....

 

[ToranaJudd]

I didn't think there was a Piston offset but mearly the rods were offset at the big end?

Can anyone confirm?

 

[rms]

Std pistons
4 pistons are marked L, 4 pistons R. The offset is towards the thrust side.

After market pistons can be either offset or equal.

 

[XR8tt]

The piston offset is to reduce side thrust on clinder bore...
A piston with no offset can be alittle noisy when cold..
But really there are too many variables, as in piston quality, clearance etc...

 

[Fasteddie]

Thx for the feedback...
We are now looking at CP or JE pistons to do the job in the 3UZ....

 

[LondonBenji]

I'm still confused as to why you are using the 3UZ when the 1UZ has proven strength?

Surely also the 3UZ will cost a lot more to buy initially?

 

[Fasteddie]

Just wanted a more "modern" engine....I was able to buy a 2004 3UZ block for a good price...we will probably swap the 3UZ in a 2000 car, so we wondered about emission and decided for a 3UZ....
The block will be fully build anyway....target is "1000 bhp"....a 1UZ would have got the same internals...ok, a 1UZ block is a bit less expensive to buy....

 

[LondonBenji]

Yes true, but as far as I am aware they are both alu blocks but the 3UZ only has 2 bolt mains or something doesn't it whereas the 1UZ has more....

 

[Lextreme II]

Yes true, but as far as I am aware they are both alu blocks but the 3UZ only has 2 bolt mains or something doesn't it whereas the 1UZ has more....

3UZ has 6 bolt too but its a weaker block than 1uzfe due to lack of block material both in the sleeve support and main support.

 

[XR8tt]

For turbo I'd go smaller engine, run boost. Rpm with in reason doesn't matter...
The bigger engine seems more fragile? Where rpm and boost may be an issue ??? The bottom ends can be supported through sump or better girdle???

 

[Fasteddie]

3UZ has 6 bolt too but its a weaker block than 1uzfe due to lack of block material both in the sleeve support and main support.

That's also why we will cement the bottom...3UZ sleeves are 3mm thick but still fine for our goal. The 3UZ block we have only ran 100miles or so...
Upgraded Sleeves (eg. Darton) are not necessary...upgraded bolts are !