14 replies to this topic

[mrbridger]

Does anyone anticipate any problems before i turn the ignition key and hear a load of crunching, thrashing and knocking??

I have just replaced the simplex timing chain on my 998cc A+ mini.(I bought a kit from Minispares).

Whilst the rad was out I also replaced the water pump and bypass hose and fitted a new thermostat.(All new gaskets.)and a new fanbelt.

The Haynes manual made mention of a woodruff key. I didn't see anything that looked like a woodruff key and certainly didn't have to remove one to do this job.

After carefully removing all the necessaries and noting their positions as i went, the chain went on without any hassle. I only had to remove the cam sprocket to get the chain on (i only had to slide the lower crank sprocket outward slightly).

Is it correct that the cam sprocket can only be fitted at one position due to a locating slot in the end of the cam?

I replaced and adjusted the tensioner so that it was applying maximum tension against the chain. Is this the correct way to set this up?

If it was this straightforward and i've done it all correctly, I'd advise others to DIY and avoid handing over hard earned cash to your local garage.
Cheers
Andy

[Purple Tom]

All sounds ok to me - obviously there's no way to be sure, but providing the cam and crank didn't move relative to each other, and the chain is correctly tensioned then I can't see there being a problem at all!

Good idea on doing the cooling system components too, at least you won't have to worry about them for a while now

[lrostoke]

You can't miss the woodruff keys they are the small locating bits that the internal slot part of the cam gear and crank sprocket slide onto.

Also you did make sure the two dots on the cam gear and crank sprocket were correctly aligned after fitting the chain ??

[liirge]

Irostroke:

Does anyone anticipate any problems before i turn the ignition key and hear a load of crunching, thrashing and knocking??

I have just replaced the simplex timing chain on my 998cc A+ mini.(I bought a kit from Minispares).

Whilst the rad was out I also replaced the water pump and bypass hose and fitted a new thermostat.(All new gaskets.)and a new fanbelt.

The Haynes manual made mention of a woodruff key. I didn't see anything that looked like a woodruff key and certainly didn't have to remove one to do this job.

After carefully removing all the necessaries and noting their positions as i went, the chain went on without any hassle. I only had to remove the cam sprocket to get the chain on (i only had to slide the lower crank sprocket outward slightly).

Is it correct that the cam sprocket can only be fitted at one position due to a locating slot in the end of the cam?

I replaced and adjusted the tensioner so that it was applying maximum tension against the chain. Is this the correct way to set this up?

If it was this straightforward and i've done it all correctly, I'd advise others to DIY and avoid handing over hard earned cash to your local garage.
Cheers
Andy

[Boycie]

I wasn't sure how to set my tensioner (haynes is uber vague..) so just applied light/ moderate pressure and did the bolts up. I think yours will be fine though.

Here's a pic of mine-



The woodruff key on the crankshaft nose is visable, sitting in it's machined keyway. As long as your didn't fall out it will be fine. Think there is a similar setup on the camshaft pulley.

Dots should be lined up as shown, again, if you didn't alter the position, I can't forsee any problems.

[GreaseMonkey]

The woodruff key on the crank should be pointing at 12 o'clock like it is in the picture and the camshaft key slightly at 2 o'clock. Like Boycie said if nothing moved and the dimples lined up all should be okay

[mrbridger]

Thanks everyone...
I didn't remove or lose either of the woodruff keys and I'm 99.9% that there was no positional changes.
I remembered to knock the lock tab washers down and torque the cam and crank bolts as per haynes. Hopefully I can start the engine again without any grief.
Cheers
Andy

[Boycie]

It'll be fine

keep your fingers crossed for no oil leaks..

[mike.]

As has been mentioned, the main thing that you need to get right is the cam timing.

You need to make sure the woodruff key hasn't came out. If you didn't take the cranksproket off, this won't have happened. Then, when you took the old chain off, you shouldn't have disturbed the cam sproket too much. Then when your putting the new chain on, you need to line up the dots on both sprokets.

Its pretty vital that you line those dots up. If you've moved the cam sproket alot whilst the chain was off, its even more important, because when the cam timing is way way out, the cam can hit the crankshaft, which would pretty much write your engine off...

[mrbridger]

I became paranoid about the potentially misaligned marks on the sprockets and took everything apart again to check.
the marks on my sprockets are slightly out.
the crank sprocket woodruff is pointing to 2 o'clock ish and the mark on it is pointing to 3 o'clock.
The cam sprocket woodruff is also pointing to 2o'clock and the mark on this is pointing to the 8-9 o'clock position.
I have now removed the cam sprocket and chain...and kept the carnk sprocket on.
If I have disturbed the position of the cam, it will have been minimal.(a couple of degrees clockwise or anti..)
Is there an easy way of lining the marks up?
Is it feasible to replace the cam sprocket and manually rotate the cam anti clockwise so that the marks marry up?
Or is this a trailer job to the garage for specialist tools and etc.

Thanks
Andy

[mike.]

Well if its just a standard non adjustable gear set up, the most accurate you can get it is within one tooth on the chain.

Theres no easy way of doing is really. Just keep the crank woodruff key pointing at 12 o'clock (TDC) then put the cam sproket at roughly 2 o'clock with the chain on and see if the dots to line up. If there slightly out, you know you a tooth out on the cogs.

Best way to check you've got it right, is to get a straight edge and place it across the sprokets. Line it up so its going from the centre on the crank to the centre of the cam; the dots should then be lined up along this line when you've got it right.

[lrostoke]

The standard way on a standard cam is to use a straight edge between the centre of the cam and centre of the crank. And make sure the dots on the crank gear and cam gear line up with each other along the line the straight edge makes.

If you want to be uber accurate then you need a dial gauge and timing disk to find TDC and also to find the specified cam timing, then you use offset woodruff keys to align the cam.

The standard way is usually fine for everyday engines running standard cams.

[mrbridger]

Thanks...
Glad to hear the issue can be resolved in my garage.
What is the best way to get the crank woodruff back to the 12 o'clock?
Can I just rotate it by hand? And does it matter which direction?

[blue redtop]

best way to see if its out by much is to remove the spark plugs and turn the engine over slowly by hand 2 full rotations.

if you feel resistance ie valves hitting pistons, then your timings out. if you dont feel resistance feel free to start it.

once its started you will know if your a tooth out or not.

BUT DO TURN THE ENGEN OVER BY HAND BEFORE STARTING IT,could save your engine if your a couple teeth out.

cheers jay

[lch11189]

Hi iam new to the forum and also need help with the timing gears, ive just replaced the simplex with a duplex vernier set-up, the engine is a 998 a+ with a kent 266 cam, cooper s head, roller tip rockers (stanard lift), stage1 kit....reading the post it seems that alot of you refit the tensioner but different sources have told me to not use a tensioner!!!.. what should i do????........thanks