4M40 Head Replacment - what to do with timing chain & sprocket

[Jhooper]

Hey guys the head is coming off my 4m40 at the moment for relacement. Its ready to come out, all thats left is the timing chain.

Some people have said leave the chain on the sprocket and slide head up - how is the new cam matched to this timing ?

Another has said take sprocket out and let the chain drop (with a piece of wire to pull it back up) becuase the sprocket has a locator on the cam and can only go back on one way (can this be 180deg out?) - Also how is the new cam matched or timed properly?

At the moment ive just taken heaps of pics and hope that i can turn the new cam into the same location and drop the head in, reconnect sprocket with the chain and start it up?

[Martynhpajero]

I have recently done mine.
Left the chain on the sprocket with a cable tie for added security. It just sat there. Don't turn the motor over. Brand new kiwi head fitted just lined up the keyway and turned the motor over afterwards to double check the timing marks were right. Pretty straightforward job.

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[Jhooper]

So if the new head is put in I should just turn the cam so the keyway lines up to the sprocket and it should be right? I can see myself popping the engine becuase the cam was 180 out or something

[TimTams]

just visually line up the cam so it matches the head you're removing. It will be fairly obvious if it's 180deg out as different valves will be open/closed

good time to do the timing chain if it hasn't already been done - it's a lot harder to do later on with the head still fitted. If you do it, make sure to grab a Nason kit.

[Jhooper]

The timing chain tensioner doesnt have a gasket or oring, is this correct? Seems odd

[Pickles77]

Tensioner has a gasket