camshaft sprockets

[Uboat]

Gents,
How do I remove the sprockets? I have followed the workshop manual in order to remove the head . But the sprockets do not come off. Is There a pin to remove first? I also found that the timingt chain tension is not loose although I have removed the tensioner. Do I have to loose the Chain before I remove the sprockets?
Ulf

[Kerryt333]

Hi Ulf,
The sprockets are only held by the centre bolt & a dowel that orientates the sprocket.
If the timing chain tensioner is released the timing chain should have enough slack in it to just
be lifted off the sprockets,then the sprockets should at worst be tapped off gently with a piece
of wood & small hammer, but usually they come off easily by hand.
Regards
John

[mini64]

i've never been able to lift the timing chain off, but guess i havent really tried. as above, remove the center bolts being careful not to drop them or their split or large washer down the front chest, loosen the timing chain adjuster all the way out, then the sprockets should come off. often you need to tap them, towards the front of the motor, with a rubber hammer or piece of wood to pop them off.

[AussieJohn]

After backing off the tensioner push the chain between the sprockets to put some slack between the sprockets.

[PanoGuy]

And do not forget to mark which one goes where, they are not the same I am told.

[CBUEB1771]

And do not forget to mark which one goes where, they are not the same I am told.

The exhaust cam sprocket is marked "EX", should not be a problem.

[billwill]

Before you loosen the tensioner. Put the engine at top dead centre for piston 1, then look carefully at the cam sprocket timing marks. I suggest taking a photo of them. They are not always exactly lined up together and in line with the top edge of the timing case and you want them back in exactly the same place (after retensioning) later when you put the engine back together.


elan-f15/clay-test-checking-clearance-between-valves-pistons-t26441.html

Failure to line up the timing marks properly when you reassemble can result in the a piston hitting a valve and breaking it and doing havoc to the inside of the engine.
{speaking from bitter experience}

[JJDraper]

Unwind the tensioner adjuster out as far as possible, then push down hard on the top run of the chain, using the heel of your hand to give maximum slack. The sprockets will come off with a slight tap as previously mentioned. The sprockets are not always marked - usually it is some PO who has scratched 'EX' or 'In' on the sprocket. My sprockets have both Ex & In on each one! Take each one off in turn and mark them yourself, preferably keeping each one in an appropriately marked bag or tray, along with the bolt & washer.

I attach a couple of pictures of the sprocket on my inlet cam. The red circle shows the scratch 'IN'. The other picture shows evidence of past sins - some crap between the washer & the sprocket by the dowel hole, probably a bit of gasket. Must have caused vibration and additional wear on the cam chain. It also has Ex scratched on it, but is more difficult to see, even when the contrast is ramped up, as per the first pic.

I hope I have them round the right way now..... engine runs OK!

Jeremy
PS some notes on re-timing the cams & valve clearances...
elan-f15/its-easy-workbench-t25730.html

[andyhodg]

Hi All

When I remove the cam sprockets I usually cable tie the chain to the sprocket and then hold the sprocket out of the way with a bungee cord from the ceiling (or bonnet lip) to maintain some tension on the chain. It allows me to maintain the timing and not worry to much about the valve timing being "adusted" in error.

Regards

Andy

[john.p.clegg]

Nice one Andy...

John

[garyeanderson]

Hi All

When I remove the cam sprockets I usually cable tie the chain to the sprocket and then hold the sprocket out of the way with a bungee cord from the ceiling (or bonnet lip) to maintain some tension on the chain. It allows me to maintain the timing and not worry to much about the valve timing being "adusted" in error.

Regards

Andy

I just let it fall and the water pump hold it out of the sump (that for a continuous chain with out a master link), when it's time to reposition it, I fish it out with a short length of copper wire (12 gauge is nice) with a hook on the end formed.

Gary

[elj221c]

I just let it fall and the water pump hold it out of the sump (that for a continuous chain with out a master link), when it's time to reposition it, I fish it out with a short length of copper wire (12 gauge is nice) with a hook on the end formed.

Gary

Not forgetting, when you put it back together, to check the distributor timing as the chain will almost certainly have dropped of the jackshaft sprocket!

Ah, the joys of twincam ownership.....

[garyeanderson]

I just let it fall and the water pump hold it out of the sump (that for a continuous chain with out a master link), when it's time to reposition it, I fish it out with a short length of copper wire (12 gauge is nice) with a hook on the end formed.

Gary

Not forgetting, when you put it back together, to check the distributor timing as the chain will almost certainly have dropped of the jackshaft sprocket!

Ah, the joys of twincam ownership.....

Hi Roy

If you can not time an engine you probably should not have the head off of a Twin Cam. If you don't know what your doing then you need to learn as the chain will slip or the phone will ring and you get distracted and when your putting things back together, you need to be check to avoid bending valves. Nothing with the Elan or (Twin Cam) is rocket science but a the laws of physics apply in that 2 object can not occupy the same space. Take notes, get photos, put marks on parts, do what you have to to assure yourself that you have things correct. Things happen and sometimes what you have disassembled one day will not necessarily go back together the next day, we all know that a 2 day job can last a lot longer (some 30 years?). This is not what was planned but it does happen, when something comes apart, what you find is not exactly always what you expect. That job that you thought would be an inexpensive fix sometime end up costing you a lot more than you can afford. Things sit and the longer they sit the more extra work needs to be done. The expression of "If it isn't broke, than don't fix it" comes to mind with a lot of posts here, the next one of "If it not broke yet, it will be soon" comes to mind a lot more as folks with Elans today start to work on them.

Gary

[PanoGuy]

@ Russ Newton,
Some do and some don't. From Miles Wilkins, page 68, "and then mark it if it has not been marked already". Don't ask how I know. But I can tell you the engine will run much better once the correct sprocket is on the cam-shaft.

[kstrutt11]

Hi All

When I remove the cam sprockets I usually cable tie the chain to the sprocket and then hold the sprocket out of the way with a bungee cord from the ceiling (or bonnet lip) to maintain some tension on the chain. It allows me to maintain the timing and not worry to much about the valve timing being "adusted" in error.

Regards

Andy

This the same method I used, timing marks all aligned perfectly afterwards.