12 replies to this topic

[speedwell1]

Ive got a leyland 648 cam in my car, , everywhere ive read says cam timing should be 100 atdc , ive checked it today and found it to be 111 atdc,
What effect will that have?
Im goong to time it in properly, think im going to move a tooth on and adjust with an offset key,

Does the cam " cog" move clockwise to advance?

Which way is the offset key fitted?

Thanks

[mk1leg]

get yourself a proper vanier adjustable set then you can get it spot on

[Dusky]

With 11 degrees you can just skip the cam COG 1 tooth and it ll be fine.

[speedwell1]

Isnt a cam tooth 18 degrees?

[Guess-Works.com]

Yes, which is why you get offset keys in 1 to 9 degrees.

 

As you're timing is 11 degrees out, then yes you need to rotate the cam gear 1 tooth clockwise ( so it opens earlier ) but with the 18 degree shift, 7 degrees too early, so you then need a 7 degree offset woodruff key put in rotating the cam gear 7 degrees anti clockwise,

Always measure the cam timing turning the crank clockwise, never anti clockwise.

[mini13]

bottom line is it will be pretty crap at 11 deg out, you can expect it to be in the region of 10-15% down on power

[MRA]

HINT:  The offset cam woodruff key can be fitted either way...

[speedwell1]

I thought the offset is to 1 side of the key so you put it in with offset different sides to advance or retard was wondering which way is which

[Swift_General]

.

Edited by Swift_General, 20 March 2016 - 12:28 PM.

[Swift_General]

The crank (and cam) turn in a clockwise direction when viewed from the timing chain end. Therefore if you want to advance the cam fit the key such than the offset part of the key that sits in the sprocket is offset in an anticlockwise direction (and obviously vice versa if you wish to retard cam).

[speedwell1]

Thanks very much

[speedwell1]

Out of interest would the following problems I ve been having been down the cam timing,

Difficulty starting particularly when cold

Poor performance, on the rolling rd car didnt want to rev at all,

Lower than expected compression

Cheers

[MRA]

Out of interest would the following problems I ve been having been down the cam timing,

Difficulty starting particularly when cold

Poor performance, on the rolling rd car didnt want to rev at all,

Lower than expected compression

Cheers

 

Yes it could cause of the above issues, however so could other problems be causing those issues.