C.a.s Adjustment Question..

[Paulusc44]

Heya guys,

Does anyone know exactly what the ratios are for adjusting the C.A.S?

(As in 1mm movement of C.A.S = how many degrees difference at crank)

I know rotating the C.A.S clockwise retards timing, whilst anti-clockwise will advance it.. Also the slots on the C.A.S are exactly 20mm wide..

I also know that the factory position for the C.A.S is centered to achieve 15 degrees..

But if I move the C.A.S 1 mm how many degrees does that change? On HKS timing gears, its 2 degrees at the crank per mm, would that be relative?

Cheers

[GTSBoy]

This stuff is done with a timing light, not a ruler.

[hardsteppa]

I also know that the factory position for the C.A.S is centered to achieve 15 degrees..

but do you really know it though.

it is very approximate, and a timing light from supercheap is less than a slab of beer; it's a basic tool to have if you're going to touch your car.

[GTRPSI]

Yeah pretty easy to calculate....

Every 1 turn of the CAS is 2 turns of the crank.

So move the CAS 1 degree is 2 degrees in crank timing or 30 seconds of CAS movement for every crank degree.

Convert your degrees to mm taking into the consideration of the outside diameter of the CAS unit using simple basic high school math......

[r32-25t]

How do you know what the timing was before and after you moved it though?

[hardsteppa]

exactly, my learned colleague.

Just get a timing light, set cas in middle. Check timing. Set it all way advanced. Check timing. Now you know how much the range of adjustments is.

You'll find once you've tried setting timing you'll throw any notion of turning the cas to the closest mm out the window, you only need to turn it a smidgin to get a change in timing, and add in a cas that's hot as f&k to touch at operating temp, won't turn because the bolts are still too tight and jumps too far cause you used too much force to turn it, then you loosen them off, and timing changes back/fwd slightly when you do them back up so timing's no longer where you had turned it to, and so on.

Use a bloody timing light. Preferably along with an on-screen display like ecutalk, consult, etc.

[r32-25t]

The answer is easy! get a timing light and do it properly, any other way is just stupid and won't be accurate at all

[GTSBoy]

Did anyone mention a timing light yet?

[iruvyouskyrine]

If you don't have a timing light you can always use a torch and a wristwatch.

[GTRPSI]

Who cares if he has a timing light, thats not what he asked for.

Waiting for the ive lost compression thread.

[Hadouken]

Timing lights are over rated.

I just look down and blink my eyes really quick to check the timing

[Ben C34]

I advance till max ping.

Pop gasket or ring lands.

Back off 2mm.

[Paulusc44]

Why doesent this dickhead just get a timing light?!

[Paulusc44]

Haha Ive just fitted a brand new cambelt so I know timings at exactly 15 degrees.. Allgood guys was just wondering if there was any easy calc

Yeah pretty easy to calculate....

Every 1 turn of the CAS is 2 turns of the crank.

So move the CAS 1 degree is 2 degrees in crank timing or 30 seconds of CAS movement for every crank degree.

Convert your degrees to mm taking into the consideration of the outside diameter of the CAS unit using simple basic high school math......

This was pretty much what I was thinking based on the HKS adj. cams.. it was only a reference.. cheers

[GTRPSI]

Haha Ive just fitted a brand new cambelt so I know timings at exactly 15 degrees..

Ummm....no.....its set at the stretch/tension setting of the last belt that was on.

Belts stretch, belt tension varies, head gasket thickness vary, heads can be skimmed making them sit lower, lots and lots of variables.

Even a brand new engine has its timing checked on assembly.

You have been warned by many above my posts....use a timing light.

[hardsteppa]

Also, u have to remove cas to put on new timing belt, so, cas is not at same position it was with the old belt....if that was set at 15 deg.

[Ben C34]

[JustinP]

1) Take the car outside at 2:30pm.

2) Align the top of the CAS with the sun.

3) Profit with all that cash you saved buying a timing light.

Thats the way the Mayans used to do it.

[89CAL]

Throw CAS away, you've already set the timing with the belt

[SargeRX8]

Ontop but off topic, is this an alright timing light? http://www.supercheapauto.com.au/online-store/products/Stanley-Inductive-Xenon-Timing-Light.aspx?pid=9702#Recommendations

Does the pickup sit on the look to coilpack 1?