19 replies to this topic

[Littlefella]

2000 Cooper Sport JCW

What are people's thoughts on changing the timing chain? Haynes manual suggest 60000 miles.
If this is required at the suggested interval, what could/should be done at the same time.

[DeadSquare]

2000 Cooper Sport JCW

What are people's thoughts on changing the timing chain? Haynes manual suggest 60000 miles.
If this is required at the suggested interval, what could/should be done at the same time.

This is like the proverbial piece of string.

 

How much do you want to do.

 

There is a lot to be said for  "If it ain't bust, don't fix it".

[Littlefella]

Well......

Next on the list was to finish the suspension/steering by fitting the camber/toe brackets and lower arms/tie rods and get it all set up properly.
Then probably a gear box rebuild to include changing the final drive and usual improvements. Possibly a new cam in the future if there would be much gain. I know the ecu is restrictive and would also consider replacing this if it was a straight swap.
However the order of the list depends on the need to replace the timing belt.

[MiniMadRacer]

I am a fan of i it aint broke leave well alone, on the timing chain, I have only ever replaced when very noisey or if having it all apart for a CAM change or an oil leak anyway, as I feel I may as well do it as I am here, and they are not silly expensive but....if you do decide to replace the chain, do not get a cheap one made of polystyrene and chocolate, buy a decent one, and check the sprockets for wear too, and the tensioner if indeed fitted.

[Steve220]

Well......

Next on the list was to finish the suspension/steering by fitting the camber/toe brackets and lower arms/tie rods and get it all set up properly.
Then probably a gear box rebuild to include changing the final drive and usual improvements. Possibly a new cam in the future if there would be much gain. I know the ecu is restrictive and would also consider replacing this if it was a straight swap.
However the order of the list depends on the need to replace the timing belt.

All that engine and box work I'd do at the same time. Ecu wise, there is no direct replace for mems and the MPi inlet system. However there are options to map mems a bit.

[Ethel]

All the above, there's no fatigue life, like you'd have with a flexible belt. When it stretches & wears it'll be more rattley. You could probably check its effect at the rockers while turning the crank pulley to 'n fro - can't offer you an figures. If it is worn, then you really ought to replace the sprockets too.

[Spider]

If it's a Simplex Chain (which if stock, that's all it will be), I'd be changing the chain and sprockets at 40 000 miles.

 

The factory doesn't provide a recommended interval when they should be changed.

[Littlefella]

Thanks guys for your input.

@Steve220 can you expand on what you mean by there are options to map the mems a bit, do you mean just by simply tuning?

[absx2]

I once had a Rover Cooper that lacked any real get up and go, in fact the 998 I was running at the time would eat it for breakfast.

Anyway after going through all the things that could make it a bit sluggish I decided to replace the timing chain and gears as it had covered around 78000 miles and what a transformation it made, It pulled like a train as the worn chain had lost around 11 degrees of cam timing and that`s over a tooth out.

The timing chains don`t rattle any more due to the tensioner and I don`t take it for granted that the dot to dot timing is okay anymore as I`ve had a couple of sets that were way out so I would suggest getting a timing disc and checking it.  

[Cheeser]

If you have the engine/gearbox unit out to overhaul gearbox in my opinion you would be mad not to change the timing chain and sprockets. As has been said the timing could be a long way out and fitting a vernier or using offset keys to get the timing right could make a huge difference to performance/economy, good luck.

[Ethel]

Don't expect such a huge improvement from a car with no distributor, but on the flip side you'll have more to beneficial gains to chase on emissions.

[Cooperman]

The timing chain does stretch quite a bit as it wears. I found that in the first 1500 - 2000 miles it retards the can timing by around 2 degrees, but the stretch slows after that.

However, it is surprising how much the cam timing has retarded when it's quite worn at, say, 40.000 miles plus. That can have a significant effect on performance and when changing the chain, and probably the sprockets, it's best to use a crankshaft protractor and DTI to check the actual cam timing and correct it as necessary with an offset woodruff key of the correct size. I always swt cams to 2 degrees advanced from recommended to allow for initial chain stretch.

[Littlefella]

Many thanks Cooperman, I will start saving for this and gearbox rebuild and look for someone reputable to carryout the work as I am a total novice and void of this skill set!

[stuart bowes]

= post deleted =

 

asked a question then realised I didn't read right to the end where it was already answered duh 

 

Edited by stuart bowes, 23 December 2023 - 07:33 PM.

[Steve220]

Thanks guys for your input.

@Steve220 can you expand on what you mean by there are options to map the mems a bit, do you mean just by simply tuning?

The rom chip gets placed with a programmable ones, but its still limited by the size of the injectors