Timing Mark ...

[Hilly_70]

Guys

Can you just clear something up for me ..

I know its obvious and I should know but I keep questioning myself on this ..

Here is my bottom pulley :



See the notch on the rear face?

Is that TDC?

can't really see on the pic clearly but to the left on the picture on the top of the front part is a dimple about 11 to the left of the notch .. what is that mark? ..

I am using a timing gun with advance to time the notch to the case line with the gun set at 7.5 degrees ..

Would you agree?

Im questioning myself as I have running issues and want to rule this out before other things..

Cheers

Hilly

 

[bac2ba6]

Not 100% sure but think the dimple is tdc and the small v notch is 7.5 degrees, take number one spark plug out and carefully with a pencil down the hole turn the engine until you feel the piston is at it's highest point ( pencil the furthest out of the hole) one of those marks should line up with case, that's tdc, be careful not to snap the pencil or similar, been a while since if done this so think that's right

 

[Trikky2]

Centre of dimple on a stock pulley is TDC.

The 7.5 BTDC notch will be 11.5mm to the right.

 

[Hilly_70]

Cheers guys

I did do the pencil test but it's difficult to check between the 2 with such a small difference ..

The notch seems to be 11.5 mm right of the dimple so that would suggest the notch is the 7.5 degree mark.

Thanks guys

Hilly

 

[aogrady]

Thanks, answers my questions too!

Cheers

Alistair

 

[vwcanuck]

An easy way to check TDC for any pulley is to remove the right valve cover and keep turning until #1 cylinder's valves don't move when you turn the pulley (as when you adjust the valves). Now that you have TDC-ish located, take out #1 cylinder's spark plug and put the unsharpened end of a long pencil (tie a string on it and take off the eraser!) in the spark plug hole until it hits the piston head, turn the pulley back and forth very slowly and never force it, until the pencil sticks out the most. Correct me if I am wrong, but this should be the exact TDC.

BTW not all engine set-ups are timed to 7.5 BTDC. Are you making all of your engine/dizzy, carb adjustments in the correct order? If not, it won't be set for optimum performance.

 

[TakeLifeEasy]

vwcanuck, thanks for this, I have read this somewhere else as well so I will being doing this tomorrow as I have to adjust the tappets anyway. My engine has always run a bit hot so I am beginning to worry I have been timing it against the wrong markings :-( On my pully, I have a dimple at the front a marking just left of that at the back of the pully and one to the right of the dimple at the back (the distance is greater to the one on the right than to the one to the left of pully). I will assume the dimple is TDC but I will use your method to see if that is the case!