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

[MWP]

Damn it, i guess that means another rep point for you.
You already have too many

The more photos of 1UZs (esp the VVTI) i can get, the better.

[MWP]

So are you sure that the exst or inlet camshaft doesnt rotate on the inside of the scissor gear?
Having one camshaft move independently from the other seems like a likley reason for moving the gears to the front.

[SL666]

interesting that it looks like the top cam gear has allen head bolts on it.. adjustable? it looks like there might be something on the inside of the other gear too..

[Hen]

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

OT, but I believe the V8 in a Porsche 928 ran this setup. A belt/chain (can't remember) to one cam on each bank, then a chain joining the two cams on the bank.

Hen

[CrUZida]

When Ed opened up his and looked at it, he saw nothing funky with the scissor gears.

[CrUZida]

A pic of 1UZ NON VVTi for comparison.

[oldcorollas]

interesting that it looks like the top cam gear has allen head bolts on it.. adjustable? it looks like there might be something on the inside of the other gear too..

the bolts you see on the intake gear would be to attach it to the VVT mechanism....

so that the VVT can operate INDEPENDENT of the exhaust cam timing..... ie, the crank to gear timing and crank to exhaust cam timing never change, but the VVT changes the phasing between the intake cam gear, and the intake cam itself, via the mechanism on the front...

maybe.....

[SL666]

I am intrigued by your theories and would like to subscribe to your newsletter or magazine.

[MWP]

so that the VVT can operate INDEPENDENT of the exhaust cam timing..... ie, the crank to gear timing and crank to exhaust cam timing never change, but the VVT changes the phasing between the intake cam gear, and the intake cam itself, via the mechanism on the front...

Or the other way around.
The VVTI shifts the cam gear, but keeps the inlet cam shaft in the same position.

[oldcorollas]

Or the other way around.
The VVTI shifts the cam gear, but keeps the inlet cam shaft in the same position.

hrmm...
i phrased it that way because the gear (both gears) remain at the same position relative to the crank, but the inlet cam is rotated, relative to the exhaust cam, crank, gears and evrything else.... ie, only the intake cam is moved by the VVT...(relative to the rest of the engine...)
so to say the camshaft is in the same position is kinda not correct, .. unless you say that the VVT changes the position of the exhaust cam, both bears, the timing belt and the crank and pistons and dizzy too ...

but you know what i mean

[ed]

hehe - i love how clean this engine is

cheers
ed

[Celica RA45]

i think you will find the inlet cam will move about 25 cam degress with out any problem ed and the exhaust will stay where it is ,looking at the pics you put up see the hex part on the inlet cam put shifter here and turn either forwards towards tdc and then you should be able to turn it back .but keep a socket on the crank as well when you are doimg it so you dont move the cam ,then get back to me as my vvti 3sge moves both ways constantly

[ed]

reckon? i hope so.. i was a bit disappointed to find it like this. i have a funny feeling its fixed - but ill have a crack at it and let you's all know

[gianttomato]

The scissor gears will ensure the exhaust cam has the same timing relative to the intake cam. Prove it to yourself with a dial indicator.

Get adjustable scissor gear ftw.

Ummm.....I should have put a bet on this......

Glenn, he will get stacks of VVTi action but because it's all happening one one cam and because that cam is driving the other cam, then the whole lot moves around as one.

I want to know what is going on with the scissor gear on the intake cam....what's the go with with the little cap screws? What are they securing? Does it move?

[Celica RA45]

its not worth having vvti if all you are going to do is change the over lap to where the piston is ,it doesnt make sense remember the cam pulley stays in the same place ,its the cam it self that moves back wards and forwards ,im betting that it will move and and the cap screws will move with it