Timing Belt+which Timing Light

[Sydneykid]

The new timing belt will be shorter than the old belt, hence you WILL have to rotate the camshaft pulleys a little bit to get the teeth to line up. Puting the CAS back in exactly the same place is not as easy as it sounds, remember 0.5 degree at the CAS mounting = 1 degree at the crank. So both the camshaft and ignition timing will most likely be different than they were before the new belt was fitted.

If you use an adjustable exhaust camshaft pulley (as I did) to retard the camshaft timing, you will retard the ignition timing at same time (the CAS is connected to the exhaust camshaft). Let me tell you 4 degrees of ignition retard sure as hell kills the response and power.

The ECU has no idea whether or not the CAS is lined up with the timing marks, the ECU just assumes that it is. That's why you need a timing light, to check and correct (if necessary) that alignment.

The DIY thread shows you how to connect up the timing light sensor to the loop in the ignitor lead. My home garage timing light is a Haigh brand that cost around $80 from my local AutoOne/AutoPro.

Cheers

Gary

[kidafa]

Thanks Gary... Was always going to use a light not go without like some have said....

[Terminal]

just quickly, what's the easiest way to get the engine to line up TDC?

[kidafa]

Got my 13 piece harmonic balancer puller today, from supercheap for $26. Seems to be the same one as SK used in his how to thread. Also got a timing light, Inductive xenon timing light, TFT brand cost $60.00.... Plus the usual tyre shine, leather protector and coolant....

Anyone care to answer terminals question:

just quickly, what's the easiest way to get the engine to line up TDC?

[GoldZilla]

There should be marks on the crankshaft pulley and both camshaft gears - it's been a while since I did mine, so I can't remember exactly, but a good idea is to use a little bit of liquid paper or similar once you have everything at TDC and BEFORE you remove everything. It makes it easier to line things up when you're doing the reassembly.

[Stinky Rooster]

Yeah, good point Nick - the thing you need to look at is on the face of the timing case, there are a series of tabs that the timing mark on the harmonic balancer line up with. They are actually numbered too if you look closely (well, a couple are anyway) and 0 is TDC.

Another handy hint, for when the balancer is off, as in mid timing belt change, is the woodruf key (half moon shaped jobbie) for the balancer is at exactly 12 o'clock.

For the cams there are a dot cast in to the front face of the head and a corresponding dot cast into the face of both cam gears, but these are only visible one the timing case is off, and to get the case off you need the balancer off, hence where my hint about the key comes in handy

[mitchy_]

actually, the top part of the timing belt cover can be removed with the harmonic balancer still attached, so its a good idea to make sure it all lines up at that point.

i'm doing the timing belt on kylie's stag this weekend, yay!

[Terminal]

I understand what TDC is and how it aligns with the tabs on the cam gears, but that wasn't what i asked. how do i initially get the engine to TDC? do i spin the pulley around by hand with the gearbox in neutral? do i just crank the engine until it stops at TDC like wheel of fortune? what's the easiest way to do it?

[mitchy_]

breaker bar + 24mm (i think, something around 23-27mm anyway) socket, and stick it in the middle of the harmonic balancer until you get TDC

[Stinky Rooster]

^^ but you may need to turn it. Just sticking the socket in there probably won't help you out much.

(don't mind Mitchy, he is never in much of a hurry to get things done )

[Terminal]

Awesome, thanks. that's the method I was going to apply, but i wanted to make sure it wouldn't f**k it somehow. I realise having a manual will make it easy to crack the nut on the harmonic balancer too, i can just leave it in gear on the ramps.

[Stinky Rooster]

It will only cause death and distruction if you turn the crank once you have removed the belt. (plus, hilarity will ensue for the rest of us) Just make sure you have your handbrake on. I did that once without it and damn near ran over myself with a corolla.

[Terminal]

Haha, yeah I'll take all the other precautions, i'll probably get a mate to help me just to be sure i don't mash my valves into my cylinder.