cam timing

have recently put my 1800 dx engine back together and it won't start. thinking it might be the cam timing 180 degrees out. Can anyone confirm the timing mark (to the front or the back of the head).

Thank you

The cam timing mark should line up with the top of the front of the head.

Cheers
Rajan

thank you. as i thought. have to explore other possibilitys.

Another good way of doing it is to get the No 1 piston at tdc, then make sure both of the valves on the No1 cam are fully upwards. Then look at the No4 cylinder valves should be closed by exactly the same amount and the cam followers level in height  with each other.

I find doing it this way easier because the timing mark that Haynes suggests can be miles out!

HTH

Nick..

This may be a daft question, but how can you tell when No.1 piston is at TDC?  ops:

I am just about to swap my fast road cam out for a standard item. SHould it just be a straight swap (assuming I don't disturb the relative position of the pulleys)? Or would there be some timing adjustments needed going back to a standard profile cam?

Cheers,

Chris

will look at that cheers.


to my knowledge TDC is found by aligning the mark on the crank pully with the mark on the pully for the the distributor. will be neccesary to remove cam belt covers and then replace the alternator pully back on to the crank

although i did get these from haynes!

you can also find it by looking through the hole in the top of the gearbox and look at the fly wheel. When you are close to the No1 being at the top, look through and turn the crank at the same time (easier with plugs out) and you should see a diamond shaped cut out. Make sure that is central in the hole. Check by looking into the cylinder too. Thats the way I do it.

It is always better to use a vernier pulley to make sure you are spot on with the cam timing, especially if the head has been skimmed but you can do without .  It is a must on a flowed head though, to get the best from it.

This may be a bit of a dim question but is there a specific stroke im looking for TDC on, as mine is still not firing (has good spark, fuel etc.)

mattgti said

This may be a bit of a dim question but is there a specific stroke im looking for TDC on, as mine is still not firing (has good spark, fuel etc.)

Yes, every second stroke of the piston is when it doesn't fire (scavenge stroke), which is used to drive the exhaust out of the cylinder.

The way to discover which stroke of cylinder 1 is TDC and not the other (scavenge) stroke is to look at the cam lobes (cam-cover off). Bring the piston to the top, and ensure that the two lobes for no.1 are pointing upwards (like ten-to-two on a clock-face) - if not, wind the crank round one more time, and you'll be at TDC.

also its worth noting that vw in there wisdom sometimes put two marks on the cam pulley- one inside towards the head and another on the other side?, you need to line the inside mark up with the top of the head not the outside one.

cheers.
I can't recall seeing one on the inside. Will have a look. The one on the outside is miles out.

The reason that there are two marks is that this wheel is also used on the intemediate shaft, where it needs an outside mark to line up with the crank pulley, but it's a confusing ecomony too far, in my opinion…

Type17 said

The reason that there are two marks is that this wheel is also used on the intemediate shaft, where it needs an outside mark to line up with the crank pulley, but it's a confusing ecomony too far, in my opinion…

arrhh that explains it then :roll:

Thanks very much everyone problem solved. inside mark took a bit of finding.

Matt

Now you've found it, put some white touch-up on the timing mark (same for t'other's if you haven't covered them up! (ignoring the dummy mark on the outside of the cam pulley of course)

Cheers