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Timing chain

Posted: Fri Jun 02, 2017 8:23 am
by andrew.searston
Hi everyone
Building my first morris engine
Just want to check timing chain before fitting rest
No1 is on tdc
Does this look correct

Re: Timing chain

Posted: Fri Jun 02, 2017 10:15 am
by andrew.searston
Cant unload pic can someone send picture of chain alignment while No1 on tdc

Re: Timing chain

Posted: Fri Jun 02, 2017 10:16 am
by philthehill
Andrew
With No: 1 piston at TDC and the camshaft and crankshaft marks next to one another and in line with the centres of the crank and camshaft all should be alright.
Phil

Re: Timing chain

Posted: Fri Jun 02, 2017 11:22 am
by andrew.searston
So the crank key is at 12 o clock and the cam key about 1-2 o clock

Re: Timing chain

Posted: Fri Jun 02, 2017 12:39 pm
by philthehill
Andrew
There are marks on both the crankshaft sprocket and the camshaft sprocket - with all four points in a line the timing is correct.

That is:

1. crankshaft centre.

2. crankshaft sprocket mark.

3. camshaft sprocket dimple.

4. camshaft centre.

Whilst the sprockets in the photo below are Marina and are not in line the marks are the same i.e. dimple and mark on crankshaft sprocket which can be seen facing the camshaft sprocket. The dimple on the camshaft sprocket is half a turn out but when the engine is rotated the two marks will come into line at the right timing sequence as the camshaft rotates at half the speed of the crankshaft.

Re: Timing chain

Posted: Fri Jun 02, 2017 1:11 pm
by IslipMinor
Andrew,

The correct alignment between crankshaft and camshaft, and the distributor set to fire on No.1 cylinder, is shown in the diagram below:
Timing Chain Alignment.jpg
Timing Chain Alignment.jpg (78.6 KiB) Viewed 2496 times
The two 'dots' must be opposite each other. The picture of the Marina engine is set to fire on No.4 cylinder, and will result in the timing being 180° out if used for No. 1 timing.

The official Minor 1000 Workshop Manual is available as a .pdf download. We are not allowed to post a link, but if you search for 'Morris Minor Workshop Download', you should get a site that provides an easy download - has a sort of 'fishy' name to the site!

If you are having problems uploading picture, it may be that the file size it too big. Reduce the picture resolution and try again.

Re: Timing chain

Posted: Fri Jun 02, 2017 3:17 pm
by philthehill
Richard
The camshaft timing of the Marina engine is correct - another complete rotation of the crankshaft will bring the timing marks into line as described above (1/2/3/4) with No: 1 piston at TDC.
The photo was originally taken to show the configuration of the timing chain tensioner. The timing marks just happened to be as they are when the photo was taken.
The dimple on the crankshaft sprocket was used on early engines and was latterly replaced with the mark as shown on the Marina crankshaft sprocket.
Phil

Re: Timing chain

Posted: Fri Jun 02, 2017 4:00 pm
by IslipMinor
Phil,

I agree that the timing of the camshaft is correct, but bear in mind that the OP said this is his first Morris engine build.

Lining up the 2 dots when they are directly opposite each other, especially if the engine is still in the car, is much easier than if the camshaft dot/'mark' is on the opposite side of the large sprocket.

As in the original post - 'So the crank key is at 12 o clock and the cam key about 1-2 o clock?'. Yes, exactly right!

Re: Timing chain

Posted: Fri Jun 02, 2017 5:20 pm
by Declan_Burns
Here's a photo also showing the tensioner.
Regards
Declan.

Re: Timing chain

Posted: Fri Jun 02, 2017 9:05 pm
by andrew.searston
im pretty convinced that ive got it right. crank 12 oclock and cam 1,2 oclock. its the standard 1098 chain with the rubber rings to tension.
Also would putting a mini dampened crank pulley make any differance? Whats the benefits

Re: Timing chain

Posted: Fri Jun 02, 2017 10:59 pm
by philthehill
The damped pulley (Pt No: 88G3052) was fitted to take out some of the vibrations experienced by the later 'A' Series engines.
A useful modification on all 'A' Series engines.
If buying S/H make sure that the rubber bonding between the centre and outer parts of the damped pulley is not overly cracked.
The later pulleys had a timing disc attached which needs to be removed when used with a Minor timing chain case - it can be removed by drilling out the rivets holding the disc to the pulley. Removing the timing disc does not upset the balance of the pulley.