ausmini :: View topic - Timing Chain Breaking

If you have high lift cams or high lift rockers, I'd imagine it would be serious. I think I'd survive with my car, as it has heavily dished pistons, but who knows.

Either way I have a double timing chain, which would be very hard to brake.

Jaguar 4.2 (and probably 3.

has a complicated twin chain system for it's twin cams, now, that wouldn't brake, but imagine trying to time it!

For my 4E-FTE I've got 'Gates' Racing timing belt, ready to put in later, claims 3x the strength, we'll see.

Also, I forgot (form looking at "U pull it") The 4.2 Jags, had recesses in the pistons for the vavles, was this a protective measure from failing timing chains (not likely to fail!) or so that on normal running the valves don't hit the block?

I've seen recesses in pistons for valves on other cars, usually of the high performance variety.

All the other belts for it now appear to be made in China- I tried one and found it a VERY loose fit.

drmini in aust wrote:

All the other belts for it now appear to be made in China- I tried one and found it a VERY loose fit.

India was the creator of my new timing chain. Is it a little loose?? its hard to tell the difference between it and my old disintegrating chain o_0

Author:	Asha [ Mon Aug 13, 2007 5:59 pm ]
Post subject:	Timing Chain Breaking
Hi all, Has anyone had a timing chain break on them? Can anyone tell me what the effect would be? I have just had the timing belt in my excel break and it's gona be an engine rebuild by the looks. Just wanting to know if this would be the case for a mini. Thanks, Ash

Author:	buztoy [ Mon Aug 13, 2007 6:07 pm ]
Post subject:
the time chain on my dads/part mine volvo was $220 and $250ish labour, i wouldn't say rebuild,

Author:	gerg [ Mon Aug 13, 2007 6:12 pm ]
Post subject:
Hi Asha, The damage done to a motor when a cam belt/chain broke would be the same weather its a modern motor or an older motor, and the amount of damage depends on the revs at the time it breaks and a bit of luck. I've had mates who have broken belts at speed and only had to replace the belt, and then I've seen motors totaled when the belt let lose... Gerg

Author:	Asha [ Mon Aug 13, 2007 6:19 pm ]
Post subject:
Volvo's are different to hyundai excels. My last car was a volvo and timing belt broke on it too. Just a matter of replacing it. But when excels do a timing belt it wreck something in the valves aswell.

Author:	simon k [ Mon Aug 13, 2007 6:21 pm ]
Post subject:
the main risk is that the valves on one cylinder are all the way open when the cam stops, and a piston smashes in to it - luck of the draw

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Timing Chain Breaking https://www.ausmini.com/forums/viewtopic.php?f=2&t=34772	Page 1 of 2

Author:	Asha [ Mon Aug 13, 2007 6:26 pm ]
Post subject:
My dad used to be a mechanic and a good friend of ours still is. It seems to be a problem with excels that when they do break a timing belt they do a lot of damage. I may be lucky but the likelyhood isn't good. Will have to pull the head off and have a good look.

Author:	jbeenz [ Mon Aug 13, 2007 6:31 pm ]
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It depends on whether or not you have a "non interferance" valve train, clearly excels do not, the mini should be fine, unless there has been some serious engine work, also, its fairly rare for a mini chain to break, modern betls are ore likley to snap.

Author:	jbeenz [ Mon Aug 13, 2007 6:33 pm ]
Post subject:
It depends on whether or not you have a "non interferance" valve train, clearly excels do not, the mini should be fine, unless there has been some serious engine work, also, its fairly rare for a mini chain to break, modern betls are ore likley to snap.

Author:	Asha [ Mon Aug 13, 2007 6:33 pm ]
Post subject:
Well Oscar's engine is standard so he should be fine. Its just that the volvo did it to me and now the excel. Just wanted to know what the risk is in a mini.

Author:	slinkey inc [ Mon Aug 13, 2007 6:41 pm ]
Post subject:
If you have high lift cams or high lift rockers, I'd imagine it would be serious. I think I'd survive with my car, as it has heavily dished pistons, but who knows. Either way I have a double timing chain, which would be very hard to brake. Jaguar 4.2 (and probably 3. has a complicated twin chain system for it's twin cams, now, that wouldn't brake, but imagine trying to time it! For my 4E-FTE I've got 'Gates' Racing timing belt, ready to put in later, claims 3x the strength, we'll see.

Author:	buztoy [ Mon Aug 13, 2007 6:56 pm ]
Post subject:
slinkey inc wrote: If you have high lift cams or high lift rockers, I'd imagine it would be serious. I think I'd survive with my car, as it has heavily dished pistons, but who knows. Either way I have a double timing chain, which would be very hard to brake. Jaguar 4.2 (and probably 3. has a complicated twin chain system for it's twin cams, now, that wouldn't brake, but imagine trying to time it! For my 4E-FTE I've got 'Gates' Racing timing belt, ready to put in later, claims 3x the strength, we'll see. i thought the same as that, how much valve clearence would a stocko excel have, had a look when they did the volvo and it had heaps of room, i always would have thought that manufactures would have kept this in mind if a time chain snaps then a vavle could snap aswell and saving the dealer ship a lot more time of conning people into changing tyres that dont need to be changed and oil that has just came out of a bottle being to old.

Author:	slinkey inc [ Mon Aug 13, 2007 6:59 pm ]
Post subject:
Also, I forgot (form looking at "U pull it") The 4.2 Jags, had recesses in the pistons for the vavles, was this a protective measure from failing timing chains (not likely to fail!) or so that on normal running the valves don't hit the block? I've seen recesses in pistons for valves on other cars, usually of the high performance variety.

Author:	drmini in aust [ Mon Aug 13, 2007 7:16 pm ]
Post subject:
slinkey inc wrote: Also, I forgot (form looking at "U pull it") The 4.2 Jags, had recesses in the pistons for the vavles, was this a protective measure from failing timing chains (not likely to fail!) or so that on normal running the valves don't hit the block? I've seen recesses in pistons for valves on other cars, usually of the high performance variety. Years ago in Hong Kong I rebuilt a 4.2 Jag motor, a cam sprocket had broken. It bent MOST of the valves. Yes the pistons have cutouts but that's for the domed pistons to clear the valves in normal driving... it's not enough to clear valves at full lift. Asha, As for a Mini, breaking timing chains is pretty rare, even the single row ones. Some race Minis (and my 1360 roady) use a timing belt- these have been known to strip teeth but I've never seen one break. I now run a Gates Kevlar one, available only from Mini Mania in USA. Nobody else seems to be able to get them, even from Gates. All the other belts for it now appear to be made in China- I tried one and found it a VERY loose fit.

Author:	deleted [ Mon Aug 13, 2007 10:31 pm ]
Post subject:
drmini in aust wrote: All the other belts for it now appear to be made in China- I tried one and found it a VERY loose fit. India was the creator of my new timing chain. Is it a little loose?? its hard to tell the difference between it and my old disintegrating chain o_0

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Author:	drmini in aust [ Mon Aug 13, 2007 10:44 pm ]
Post subject:
deleted wrote: drmini in aust wrote: All the other belts for it now appear to be made in China- I tried one and found it a VERY loose fit. India was the creator of my new timing chain. Is it a little loose?? its hard to tell the difference between it and my old disintegrating chain o_0 Most new chains now are c-r-a-p, even duplex. I've seen new chains in UK boxes as loose as what I took off. Once upon a time the Poms sold us good (Renold) chain. Not now it seems. Best duplex ones now I reckon are the Jwis, and Rolon. Not as cheap as some..