76 replies to this topic

[maystro]

Hi,

 

My engine has been a little bit noisy lately so I am changing the timing gears.  It is an A+ with duplex gears.

 

Just a couple of questions for when I fit my new gears and chain.  

 

First up, do I have to drain the oil?  I know I have to drain the coolant obviously because I'm going to have to remove the radiator to get access?  

 

Secondly if I remove both gears and don't change the position of the cam or crankshaft, can I just slot the gears back on without having to retime the camshaft which is beyond my abilities and equipment?  

 

The more I read the more confused I get about lining up the dots and camshaft degree keways.  I have a Kent 276 cam.

 

Lastly do I keep the chain tensioner if it has one.  I'm not quite sure till I take off the timing cover tomorrow and if it is broken and worn should I buy a new one.

 

Thanks

 

Brad

 

 

 

 

[timmy850]

You can keep the oil in

Rotate the engine around until the dots line up before you remove them, that’ll make your life a bit easier

[MatthewsDad]

In case you plan to refer to Haynes there are confusing / contradicting references to how to set TDC. There are several threads on the forum which clarify things.

[nicklouse]

You don’t need to know where TDC is unless you are wanting to correct the can timing.

 

things to note if you have no info on how it was originally set up. If the timing was adjusted with a offset cam key make sure you fit it the same way.

 

if it has adjustable cam gear then you will have to re do the cam timing so when you have removed the cover have a look at what is there before going to far.

 

I suggest getting a proper flywheel locking tool. 
 

tensioner use one.

[maystro]

Thanks,

 

I put a kent 276 cam in 18 years ago and I don't remember worrying about cam keyways in them days so I'm guessing I have none.  

 

My new gears are just standard lightened duplex gears with a Iwis chain.  

 

So hoping to do a swap without upsetting anything?

 

Brad

 

[nicklouse]

Thanks,

 

I put a kent 276 cam in 18 years ago and I don't remember worrying about cam keyways in them days so I'm guessing I have none.  

 

My new gears are just standard lightened duplex gears with a Iwis chain.  

 

So hoping to do a swap without upsetting anything?

 

Brad

 

So it sounds like you did not time the cam in.  And yes you will have keyways and keys but may note be offset ones. Which means that the cam may not have been timed in correctly. And I hear that the quality of new gears can be of interesting quality. 
 

I have to ask why are you changing them?

[Cooperman]

Bring the engine to TDC on 1 & 4 before taking the chain and sprockets off. The two dots on the sprockets should be in line with the centre line between the cankshaft and camshaft centres. Check this with a 12" steel rule. If the dots are not adjacent, turn the engine until 1 & 4 are again in line, which will bring the dot;s around until they are adjacent.

Remove the sprockets and chain without moving camshaft or ctankshaft. Fit the sprockets and new chain in the same positions. Note that it is easy to be a tooth or two out and have topull the sprockets ont to slip the chain onto the next tooth. The crankshaft must still be at TDC and the dots must line up before you tighten the cam sprocket nut. Make absolutely sure that this is the case.

The tensioner is optional with a duplex set-up. The original Cooper 'S' didn't have a tensioner, but the tensioner can be fitted. Check its condition before fitting as they can break up in use.

Once you are absolutely the sprockets are corectly aligned and the chain is fitted, you can fit the camshaft lock washer and nut and re-fit the cover and end pulley.

If you get stuck or are in any way uncertain, come back on here and we will give further advice. It is not vital to use offset keys. They just make for more accurate cam timing and help to get the very best power & torque.

[weef]

When you remove the chain/sprockets make sure the camshaft does not move. Sometimes the camshaft can "rock" due to the pressure exerted on freed camshaft from the valve gear and you find when you come to refit the sprockets the keyway on the camshaft may not align with that of the gear. Before you start you can slacken off the tappet adjusting screws to help prevent this from happening. The crankshaft TDC can be noted from the inspection port , ensuring the 1/4 mark lines up with the point on the cover.

[Spider]

All very good advice above.

 

The only thing I'll add is that I wouldn't refit locktabs at all, but clean the threads and use Loctite 243. This will be on the Camshaft Nut and the Crankshaft Bolt.

 

When refitting the cover back on, ideally you need a centralising tool to get it in the correct location for the seal to work properly. You can do it without the tool but will need a great deal of care to do so. Offer the cover up with the gasket and sealant on it, put the Harmonic Damper or Pulley on the Crank and that will centraise the cover. The trick is keeping it steady in that spot while getting 2 bolts in without disturbing it from that spot, it is very easy to move it when fitting the bolts.

 

The other thing is if the Front Seal is a double lip type, fill between the 2 lips with grease.

[maystro]

Thanks Guy's for some really helpful info.

 

As you would have guessed I'm back with more questions

 

Here is a pic of my chain.  It looks a little stretched.  Would this be enough to make a slight rattling tick noise?  
It's a double row on a A+ but it doesn't have the tensioner nor the timing cover to take a tensioner like the UK A+ blocks.

 

Just a question about the dots, when they are aligned is that suppose to be at TDC of the compression stroke?  Because to me it looks like its 180 degrees out.  My dizzy is at 8 oclock instead of 2oclock when the dots are aligned.  

 

This motor has been running great, so I find it hard to believe the timing can be this far out.  

 

Thanks 

 

Brad

Attached Files

•  chain.jpg   48.45K   4 downloads

[nicklouse]

Ok so you can’t run a tensioner. Yes it does look a bit worn. Rotor arm at 8 O’clock actually means nothing if the lead it is connecting to is also connected to 1 spark plug. But again check the valves are closed on one that is to say the Rockers free to move. While on 4 they should be being moved by the camshaft.

[maystro]

Nick I put this new dizzy in recently and when I did it I thought it was as at TDC and the rotor was at 2 oclock.  So spark plug wire 1 is firing at 2 oclock not 8 oclock.  

 

Do the dots always align up at TDC on the compression stroke?  Maybe I put the cam 180 degrees out 18 years ago.   Is this possible which I find hard to beleive since my motor has been running so well?

 

Thanks

 

Brad

[Spider]

When the dots are lined up on these engines, it's No. 4 that's at (firing) TDC not No. 1.

 

There is a bit of slack in that chain, but it doesn't quite look like it would be noisy just yet - have a look inside the cover to see if it's contacted it anywhere.

[maystro]

Thanks Spider,

 

Are you the only guy that knows this about No.4 firing at TDC and not No.1?  when the dots align?

I was contemplating pulling my camshaft out and my dizzy to check things which would have been a big waste of time.  

 

Timing cover looks pretty normal with no contact with a chain.  

 

I ordered the wrong timing cover gasket anyway thinking I had a A+ cover so I might get a new set of cam lifters which you originally suggested.  

 

Thanks

 

Brad

[Spider]

I ordered the wrong timing cover gasket anyway thinking I had a A+ cover so I might get a new set of cam lifters which you originally suggested.  

 

Thanks

 

Brad

 

I think you ordered the wrong Gasket on my advice there and you know, I was going to say, for the small cost of them, order both,,,, oh well,,,, I can send you one for postage if you like,,,

 

Before changing the cam followers, have a look at the condition of what's in there, just take them out one at a time, what ever you do, don't mix them up.