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Camshaft Lobe Alignment (HAYNES Manual Misleading)

Posted: Thu Oct 13, 2011 1:39 pm
by Clanky
Changed the title as it may help someone searching in the future.


Hello,

Today I began to start the valve clearance adjustment but when I was setting the timing mark for #1 cylinder I started to suspect that my camshafts may be mis-aligned.

The manual states that with the alternator pulley mark in line with the split in the crankcase #1 cylinder should be at at TDC and the exhaust and inlet lobes will be facing directly away from each other. My lobes don't look like the line drawing in the Haynes manual. With #1 at TDC they are both pointing upwards slightly and the camshaft markings (on the end of the shaft and bearing cap) are very slightly off but only by about 1mm - 1.5mm.

Here's a sketch to hopefully explain it better:

Image

Photos of the lobes and timing marks:

ImageImageImage
ImageImage

Any help would be appreciated.

Nigel

Re: Camshaft Mis-Aligned?

Posted: Thu Oct 13, 2011 2:41 pm
by Camala_Pillion
Nigel,
If I remember correctly the "book" is wrong or mis-leading you. I know this has been covered since I joined.
The WIKI has the ERRATTA for the book and I believe that covers it.Y-G is asleep or I would ask him .
HTH

Re: Camshaft Mis-Aligned?

Posted: Fri Oct 14, 2011 3:13 am
by Clanky
Thanks Camala,

I had tried searching the forum/wiki but the only errata I could find was for the Clymer manual. Reassured by your comment I Googled away and found that my lobes are in the right position (going by images of various engines at TDC).

The Haynes manual (top right of page 1-23) shows the lobes as a mirror image pointing directly away from each other which is what threw me. In reality they should look like the lobes in position 'A' of this image:

Image

Best regards

Nigel

Re: Camshaft Mis-Aligned?

Posted: Fri Oct 14, 2011 10:47 am
by pefrey
There's an exhaust stroke and an intake stroke. Be sure you are on the TDC of the correct stroke.

Rotate the crankshaft another 360 degrees. They'll line up "facing away from each other" as pictured in the manual.

Oh, and they won't be pointing directly (as in the center line of the lobes are on the same line) from each other. They'll just be angled away from each other. They'll be angled towards each other on the other stroke.