23 replies to this topic

[postve]

Morning fellas,

Should I not see a mark on the smaller crankshaft sprocket in order to line up with DOT on the CAM sprocket. Just adding a new woodruff key and starting the reassembly.

Note the key in there now is what will be replaced

Picture of sprockets below

Thx

[Dusky]

Mark looks to be at +-1 o clock. That's where it's supposed to be too.

[Spider]

Withe the Crank Key at 12 O'Clock, that'll be in the right place, then just line up the Dot on the Cam Sprocket with the Cam and Crank centres.

[postve]

Thanks so much guys I was assuming but wanted to be 100 percent

Edited by postve, 11 August 2021 - 12:49 PM.

[postve]

Quick point as something I noticed - here’s pics of it lined up but key on CAM sprocket is slightly off?

Note my twist ties solution for lining it up - in black

[postve]

Is this as simple as adjusting the small sprocket as thinking I just answered my own question

[Cooperman]

With pistons 1 & 4 at correct TDC, you only move the cam sprocket until the dot lines up as close as possible with the one on the crankshaft sprocket. A straight edge through the centre point of the ends of the crankshaft and camshaft line up with the dots.

For more accurate cam timing and to remove the manufacturing tolerances, a DTI and crankshaft protractor are necessary together with the required offset woodruff key after the measurements have been made.

[postve]

Interesting was always advise never to move CAM sprocket, ok thx Cooperman, I will double check TDC by checking flywheel markings through dome hole and piston.  I checked Haynes and will use a metal ruler for spawn the two sprockets as well.

[Spider]

Bit had to say for sure if it's aligned as per the dots would usually be from that angle, but keep in mind here too, that the dots when checked with a ruler across them and the centre line of the Crank and Cam seldom align spot on, they are usually a little off.

[postve]

Without touching CAM sprocket - which I am reluctant to even do - this is as close as I can get with keys lined up

Flywheel at TDC
Piston 1/4 at TDC

Edited by postve, 11 August 2021 - 10:08 PM.

[Homersimpson]

Its hard to say from the angle of the photo but it looks wrong to me, as mentioned above, a straight edge (like a ruler) run betwen the centre of the cam sprocket and the centre of the came sprocket shoudl be directly above the dot on each sprocket, when its all in line its fine.

 

As mention though there might be some degree of tolerance and it won't be exactly bang on but it should be fairly close.

 

I got this off an MG website but it shows the basic prinicple of what you are trying to achieve.

 

 

 

[postve]

Agreed and just throwing it out there as doing my dam best to line it up - issue is CAM sprocket is at 1pm but I am very reluctant to move it - as one thing I would have to take to my very expensive mechanic to re time- almost out of options and I cannot figure why it would not line

According to Haynes CAM sprocket generally at 2pm which would be perfect

[postve]

With pistons 1 & 4 at correct TDC, you only move the cam sprocket until the dot lines up as close as possible with the one on the crankshaft sprocket. A straight edge through the centre point of the ends of the crankshaft and camshaft line up with the dots.
For more accurate cam timing and to remove the manufacturing tolerances, a DTI and crankshaft protractor are necessary together with the required offset woodruff key after the measurements have been made.

So Cooperman I can move the CAM shaft to line up as looks like a small degree or so to the left? I am worried I would have to get some to set up the CAM all over again - is this a fair concern?

[postve]

Ok, I rotate cam sprocket 1/4 inch now all lines up with piston 1/4 TDC and flywheel TDC.

But, dizzy shows 180 degrees out, should I flip around so rotor pointing at piston number 1?

[postve]

flipping dizzy around today and will slap it back together - see if she fires up..