1UZ: advancing the intake cam does 'what' to the exhaust cam... ??

[Nim]

Awesome! Now take the cam cover off so I can see inside.

[CrUZida]

I highly doubt there is any technical wizardy on the scissor gears.

[ed]

I highly doubt there is any technical wizardy on the scissor gears.

me either - its just interesting to think that VVTi goes from full variable timing and overlap on the GE heads, to plain old timing on the FE heads - kindve disappointing really

ed

[CrUZida]

Yeah, it is.

I wonder how well it will work with ze uber cams?

[CrUZida]

I think its time to adapt a couple of 3SGE BEAMS Dual VVTi heads Ed.

Or maybe a 2ZZGE head.

[Nim]

Aren't BEAMs engines VVTL-i?

[CrUZida]

Nah, BEAMS means Breakthrough Engine with Advanced Mechanism System

Basically it means the motor has VVT of some sort.

[Joshstix]

Chain drive is cool, in this situation at least.

The reason for the scissor gears was that you couldn't fit cam gears big enough to give a decent service life of the timing belt when the cams are so close together. With a chain you can get away with running a much smaller cog on the crank therefore allowing the use of two seperate cam gears.

I believe the F20C from the S2000 has one cam driven by a chain and then at the back of the head there is another chain joining the two cams to run the other one.

[horse]

dont think r20c has timing chain...i see scissor gears.

[CrUZida]

Have a look at the small (read: thin) cog in the middle. You'll find a timing chain drives that.

[horse]

ah yeah thanks Cruz. yeah they're chain driven but dont think they have a chain at the back like what josh says. but i could be wrong

I believe the F20C from the S2000 has one cam driven by a chain and then at the back of the head there is another chain joining the two cams to run the other one.

[CrUZida]

Ah k, yeah, I see what you are saying.

Chain at the front, scissor gears at the rear.

[Joshstix]

Very cool.

I guess I better track down what engine I saw with the timing chain just to joint the two cams then.

[ed]

looked at the 1uz vvti scissor gears today - nothing funky to report. the vvti will only effect the overall cam timing like a sohc, nil changes in overlap available...

cheers
ed

[CrUZida]

Pics for good measure of 1UZ VVTi