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Timing mark alignment

Posted: Tue Jan 25, 2022 4:37 pm
Author: Skid Mark
Hi all,
Can anyone advise if this alignment looks correct?
I though it might be a little low, but if I go one cog higher the mark is above the surface.
Thanks in advance.
P

Re: Timing mark alignment

Posted: Tue Jan 25, 2022 7:38 pm
Author: warren3200gt
Bit of chain stretch makes the alignment a little out.

Re: Timing mark alignment

Posted: Wed Jan 26, 2022 9:07 am
Author: rickm
If the front chain run is taut, then I'd say that you could be a tooth out.
If the chain had stretched then the timing mark would be ABOVE the line of the cylinder head rather than below it.
Have you timed the inlet cam yet? That would tell you whether they both look out by a tooth.

Re: Timing mark alignment

Posted: Wed Jan 26, 2022 11:56 am
Author: z1bman
what position are the cutaways in the end of the camshafts ?

Re: Timing mark alignment

Posted: Wed Jan 26, 2022 12:27 pm
Author: zed1015
That's ok if the tdc marks etc are all lined up correctly.
You are only a mill or two below the gasket face which is a degree or so on the crank from perfect and the closest you will get .
Camchain tolerance, Deck height and gasket thickness govern how close to spot on the pin is to the gasket face and even then the timing is not forced to be exactly to factory spec which can only be achieved with slotted sprockets.
As it is any settlement of the camchain once run or of the head on re-torque will only bring the mark closer to it.

Re: Timing mark alignment

Posted: Wed Jan 26, 2022 8:57 pm
Author: Skid Mark
Thanks Guys,
Really appreciate the advice.
I'm happy with it where it is I think, the chain is well with in service limits and the next tooth on is much more noticably off and as Zed 1015 says, it should only get better. I have the inlet torqued down also, and the chain set to 44 links links, I see a lot of you butcher a cam cover to ensure correct timing, is this necessary?
If the exhaust is correct, and I have 44 pins to the inlet cam mark I presume if I fit cover and fit tensioner I should be ok?
P

Re: Timing mark alignment

Posted: Wed Jan 26, 2022 9:11 pm
Author: zed1015
Skid Mark wrote:
1 - I see a lot of you butcher a cam cover to ensure correct timing, is this necessary?

2 - If the exhaust is correct, and I have 44 pins to the inlet cam mark I presume if I fit cover and fit tensioner I should be ok? P


Simple answer =

1. NO. ( Chopped camcover is only usefull for degreeing slotted sprockets ).

2. YES.

Re: Timing mark alignment

Posted: Wed Jan 26, 2022 10:01 pm
Author: Skid Mark
zed1015 wrote:
Skid Mark wrote:
1 - I see a lot of you butcher a cam cover to ensure correct timing, is this necessary?

2 - If the exhaust is correct, and I have 44 pins to the inlet cam mark I presume if I fit cover and fit tensioner I should be ok? P


Simple answer =

1. NO. ( Chopped camcover is only usefull for degreeing slotted sprockets ).

2. YES.


Sound!

Re: Timing mark alignment

Posted: Thu Jan 27, 2022 8:27 am
Author: rickm
Maybe being over cautious, but if it's an old cam chain and a bit stretched but within service limit... I still think you might be a tooth out.
I've just timed up a Z1000J with new chain and the "Ex" arrow was spot on with the face of the head.
A bit of stretch and you could easily be a 1-2 mm above the face?

Re: Timing mark alignment

Posted: Thu Jan 27, 2022 9:39 am
Author: zed1015
rickm wrote:Maybe being over cautious, but if it's an old cam chain and a bit stretched but within service limit... I still think you might be a tooth out.
I've just timed up a Z1000J with new chain and the "Ex" arrow was spot on with the face of the head.
A bit of stretch and you could easily be a 1-2 mm above the face?


Regardless of chainwear the arrow needs to be as close to the gasket face as possible whether slightly above ,below or spot on.
Going a tooth either way now will put it even further off and at the current position any future wear will only bring the arrow closer to the correct position.
In reality due to manufacturing tolerances the timing could actually be closer to factory spec in it's current state than if the arrow was exactly aligned as it's the cams relation to the crank which really matters.
If you took a brand new engine and degreed the cams it's very likely that the figures would be a degree or so out from the design spec.

Re: Timing mark alignment

Posted: Thu Jan 27, 2022 9:46 am
Author: rickm
Fair point :up

Re: Timing mark alignment

Posted: Thu Jan 27, 2022 7:35 pm
Author: Mr Bump
On those motors (z1000j/gpz1100b etc) the timing advance unit on the end of the crank isn't very accurately located, so there's a degree or two of float when it's loose. Likely the slight misalignment is because the advance unit (which carries the timing mark) is slightly out of position relative to the crank, rather than the camshaft being out of time relative to the crank.

As zed1015 etc have said, what you have looks fine and moving it a tooth will make it wrong.

If you are curious, try finding 'true' top dead centre using a dti and see if the timing mark on the crankcase aligns with the advance unit tdc mark. I did this on mine, positioned the advancer so that its correctly aligned at tdc and magically the cam marks lined up perfectly.

Olly