3UZ Heads on a 1UZ ?

[SC & RX]

I have talked to a Lexus Tech for 12 years. He stated it would not work. It has to do with VVTi.

Do you mean he said it would not work to mod the cams for the 3UZ heads, or that it would not work to put the 3UZ heads on the 1UZ, or both?

 

[qca]

the 1 uz vvti and 3uz vvti head are basicly the same they will bolt straight onto a 1 uz 2uz or 3uz block , the piston need to suit the vvti heads though
these heads have greater flow potential over the fixed cam early versions, they also have shim under bucket arangement if the vvti actuator is not plugged in the oil pressure is constant on both the advance and retard sectors of the actuator (fixed)
one thing too note is that the workshop manual does state DO NOT OPEN THIS ASSEMBLY !!! i will post pictures shortly as too what is inside the actuator
i have one thats been taken apart never to be reassembled again , they cost $490 aud too replace

 

[Lextreme II]

the 1 uz vvti and 3uz vvti head are basicly the same they will bolt straight onto a 1 uz 2uz or 3uz block , the piston need to suit the vvti heads though
these heads have greater flow potential over the fixed cam early versions, they also have shim under bucket arangement if the vvti actuator is not plugged in the oil pressure is constant on both the advance and retard sectors of the actuator (fixed)
one thing too note is that the workshop manual does state DO NOT OPEN THIS ASSEMBLY !!! i will post pictures shortly as too what is inside the actuator
i have one thats been taken apart never to be reassembled again , they cost $490 aud too replace

What QCA stated above is true. Only 98+ 1UZFE would bolt right onto the bigger cubic uzfe. However, there will be an electronic mess to deal with especially with pre 98 1uzfe. I think there are cheaper and easier way to get more hp then swapping heads or cams.

 

[cowboy bebop]

So in other words, there is no way that the VVt-I 1uz-fe heads will work with the early 1uz-fe blocks?

Eric

 

[Lextreme II]

Yes it will only if you replace the complete uppers and change of electronics.

 

[cowboy bebop]

Hmmm, good information. I know there's another thread on it, but I will also ask here. It looks like a set of 2uz-fe heads were fitted to the and early 1uz block. Was it verified that these will work since it's not VVt-I?

Thanks Lex,

Eric

 

[SC & RX]

What QCA stated above is true. Only 98+ 1UZFE would bolt right onto the bigger cubic uzfe. However, there will be an electronic mess to deal with especially with pre 98 1uzfe. I think there are cheaper and easier way to get more hp then swapping heads or cams.

Thank you for your reply. I have already changed to a 2,800 stall T/C, installed headers with a complete 2.25" exhaust system with "X" pipe, modified my intake box and had the Apexi S-AFC II programmed while the car was on a dyno with a wideband plugged in the O2 sensor. Yet I am only at 225 RWHP which is why I was looking for more power and thought the VVTI might be something to consider. With the exception of nitrous, which incidentally is probably my next move and/or waiting on a US spec supercharger, do you have any other ideas?

 

[pops]

vvti actuator-pics & explain how it works

Looking forward to any info on actuator for vvti- pops

the 1 uz vvti and 3uz vvti head are basicly the same they will bolt straight onto a 1 uz 2uz or 3uz block , the piston need to suit the vvti heads though
these heads have greater flow potential over the fixed cam early versions, they also have shim under bucket arangement if the vvti actuator is not plugged in the oil pressure is constant on both the advance and retard sectors of the actuator (fixed)
one thing too note is that the workshop manual does state DO NOT OPEN THIS ASSEMBLY !!! i will post pictures shortly as too what is inside the actuator
i have one thats been taken apart never to be reassembled again , they cost $490 aud too replace