3UZFE Vs. 1UZFE

[Lextreme II]

I just picked up a 3UZ shortblock with one piston and rod missing for $50.00. I am thinking using a 3UZ bottom with 1UZ heads. I will take some pictures side by side for comparison.

 

[JBrady]

David, Along with a larger bore the 3UZ uses angled quench pads. this should be seen as the pistons coming slightly out of the bore at TDC. This will not work with stock 1UZ heads. You will need to modifiy the pistons, heads or get different pistons.

BTW, if there is nothing else wrong with that shortblock you got it for a STEAL!!!

Good job.

Also, the 3UZ went with an even thinner sleave, 1.5mm vs. 2.0mm. An overbore is out of the question.

I am very interested in knowing if any of the companies that do over bore sleaves for other Japanese engines could do a big bore xUZ engine?

 

[Lextreme II]

If i got for it... i would need custom forged pistons. I dont know the history of this shortblock, but one rod and one piston was missing. I assume eighter the rod or piston was bad.

1UZFE Rod Vs. 3UZFE Rod


1UZFE Piston Vs. 3UZFE piston

 

[Zuffen]

David,

What happened to the 3UZ. There's a piece of land missing from the piston which would normaly indicate bad detonation?

 

[Lextreme II]

Not sure, but few pistons ring lands were busted...... very sad..... the more i know the more i am dissapointed with the new motors.

 

[turboandrew]

David, Along with a larger bore the 3UZ uses angled quench pads. this should be seen as the pistons coming slightly out of the bore at TDC. This will not work with stock 1UZ heads. You will need to modifiy the pistons, heads or get different pistons.

Yikes. Does the 1UZvvti have the same angled quench pads? If so, I guess I can't use my new Ross pistons...

 

[Lextreme II]

Ross pistons was for 1uzfe...

 

[cribbj]

David, Andrew does have the 1UZ, but it's the '99 VVTi model, as I do also. So we're both wondering if the Ross pistons will work with this later engine, or only the earlier one?
According to the Toyota tech docs, the later engines went to the taper squish design for the piston crown, similar to the 3UZ, so these Ross pistons may not work in the newer motors.

John

 

[turboandrew]

I think I am going to tear apart the 1UZvvti this weekend, so we'll find out for sure. Also, If you want to sell that 3UZ bare block Lex, let me know...

 

[Lextreme II]

Andrew,

Please tear the vvti and take some pics... we can all learn from it. If the Ross pistons doesnt fit work on the vvti, please let me know. We will work out something for you guys....

I might not going to use the 3uz, but would like to keep it for now just for r&d sake. Beside the shipping will be high. I am looking for a 2uz right now and thinking about stroking it and put some FI into it.....

David, Along with a larger bore the 3UZ uses angled quench pads. this should be seen as the pistons coming slightly out of the bore at TDC. This will not work with stock 1UZ heads. You will need to modifiy the pistons, heads or get different pistons.

Yes John,
The 3UZ pistons are totally different design and i have no plan to use those. I was thinking of 3uz block with 1uz rods and 1uz heads. 1UZ style pistons with 3uzfe bore size. This mods would work on the 1-3uz combo...
david