Why does the 1UZ have F heads and not G heads?

[Adamal]

This is something that I have often wondered.

As we know, the G series heads are wider and offer better performance at the top range of the RPM range. The F series head is narrow and offers more torque down low RPM ranges, but nothing up high, for better economy.

So can anyone tell me the reason that Toyota only made (as far as I am aware) a 1UZFE and not a 1UZGE. Sure, theres the fact that its already a V8, and would consume a fair amount of gas, but surely a performance don't-care-about-gas model should have been made too?
Would it perhaps be that because the width of a G spec head would be TOO wide, preventing the possibility of an efficient intake plenum? Or would the actual cost of the production be way too much to justify it?

Anyone know?

[RomanV]

A 'G' series head has a cam belt that runs around two cam gears... the 'F' series head only has one, and is far more compact.

And 'F' series head means that the engine takes up far less room.
also, since all of the cars that the engine goes into are big automatic barges, a torquey engine is better than a peaky one, taking into account the type of people that are buying the cars.

[Lloyd]

I think the point was that having an 8 in the first place gives you reasonable torque down low, why not have a G head on to give a bit all over the place

[sergei]

they probably did not want to pay Yamaha...
But if they would make a V8/V10/V12 G headed engine it would be in same performance niche as Ferarri engines..
Imagine a 5.0l V12 1GZ-GE with over 500 hp... fitted in new Supra.
Or a 1UZ-GE over 400Hp fitted in some new MR vehicle.

[UTERUS]

Damn that would make the size of the motor quite large, Adamal do you want to have a look in my engine bay and actually see how much room (lack of) there is in there

[Malcolm]

yes I'd definitely say it's for packaging reasons. With a wide G type head it might be difficult to get a good intake manifold design also, not to mention most of the cars it went in probably would have to have the exhaust manifold inside the chassis rails at the front

[Mr Revhead]

yep, size and cost.
and lack of need.

also there are some F heads with two pulleys.

[MasCam]

since all the japanese maufacturers were using the 206kw limit (in theory) then thier would definatly not be a need for a 1uz-ge.

Chris