1UZ Vs. 2UZ Combustion Chamber

[Lextreme II]

This is very interesting. There are lots of mistery of the two heads or none-vvti Vs. vvti combustion chambers (CC).

Here are CC. The first CC is the pre 98 1uzfe and the second one is the 2uzfe or similar to the 98+ VVTi heads chamber. The two chambers have very similar configurations.

 

[cowboy bebop]

With the bore being slightly smaller with the 1uz-fe, than the 2uz-fe, will the overlap cause probelms? If you were to install 1uz heads on the 2uz bottom end, would this be a problem?

Eric

 

[Red Supra]

The squish pad shape and angle were mainly changed to improve engine combusion efficiency.

 

[Toysrme]

Good compairo. Look at the difference in squish area!
Looks like Toyota's been using the same 4 valve head pattern on low angle heads for a very long time!

Daaaang guys the carbon buildup is awful! Talk about a bad case of pre-ignition LoL!
My 3vz-fe:
@around 95,000 miles
(disregard any fluid you see, just check the black carbon)

(This is misleading because I had already cleaned with a 5hp pressure washer & done some wiping with simple green)


About 6 months after doing Seafoam




100% normal!

 

[Toysrme]

Water injection!

 

[cowboy bebop]

Looks like they made the most of the available space for the squish area. Here's what the 2jz-GTE sqiish area is like.

Eric

 

[Red Supra]

Hoot Hoot! for water injection!

 

[Lextreme II]

I played around with the heads at home few years ago. I used a grinder and grinded some portion of the pre-98 chamber and it looks like post-98 heads.