Any - Cambelt Vs Cam Chain | Motoring discussion | Back Room Forum

Fri 3 May 2013 08:22

Any - Cambelt Vs Cam Chain - iFocus

Why is it HJ advocates Cam Chains and loaths belt cam engines? It seems to be the focus of some of the reviews in the car by car?

The reason I ask is I've had issues with the chain on my Golf TSi 122, its on its 2nd chain in 50k, and I note that the BMW N47 has a habit of chain failure, amongst other cars too. Plus chain replacement appears to be vehemently expensive?

Now this is the first car I've had thats had a chain, and will be my last. As its far easier in my opinion to have a belt cam engine, and replace it as the service schedule states.

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Fri 3 May 2013 09:29

Any - Cambelt Vs Cam Chain - skidpan

In the 39 years I have owned cars I have had both and had problems with neither (other than a noisy one on a 78 Mini but they did have rubbish tensioners).

With belts they have been changed when the schedule said to (only a couple of times in truth since I rarely keep cars beyond 6 years when changes are scheduled).

Very few owners have issues with either, belt failures are virtually always down to not replacing them and chain issues are virtually always down to not servicing or not using the correct lubricants.

My advice is not to base your views on what you read on forums, over 99% of the motoring public never visit them and of the tiny percentage that do only a tiny percentage of those have issues.

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Fri 3 May 2013 09:36

Any - Cambelt Vs Cam Chain - Collos25

Originally all engines had a chain, direct drive or were push rod but modern chain cams are no better or even worse than the alternative belts,long life belts 160k cost peanuts to change compared with a chain and all its running gear .The recent debacle with VW and BMW and on going problems with older Nissans why anbody would want a chain engine is beyond me ASs far as HJ is concerned he is a bit of a Luddite when it comes to new tehnology I wouldn`t take too much notice of him.

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Fri 3 May 2013 10:04

Any - Cambelt Vs Cam Chain - unthrottled

I agree with the above. 100k+ mile belt change intervals means that the average engine will require one belt change in its lifetime.

I think the popularity of chains is driven by the perception that chains are an indicator of quality-a questionable theory to put it mildly.

It just isn't cost effective to make a good quality chain drive. A poor one is a far less appealing option than a belt.

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Fri 3 May 2013 10:47

Any - Cambelt Vs Cam Chain - 659FBE

I entirely agree with the previous comment.

Years ago, when OHC engines were becoming popular, a chain drive was the transmission of choice. As these engines were usually the products of premium makers such as M-B and BMW, they were engineered to last. The solution adopted was almost invariably a duplex chain, sometimes (M-B) with a rolling sprocket tensioner. Good for the life of the engine.

As the OHC and the diesel (which required a high torque timed drive to the pump) have permeated to lesser brands, a cost effective timing drive has been sought which is now generally a belt. Cost reductions to a chain drive are a disaster, as an old engine will require an uneconomically expensive repair and be prematurely scrapped.

In my judgement, a single chain (as opposed to a duplex) is not fit for purpose, remembering also that engines in general have a longer life than was formerly the case. There are very few duplex drives now being made - the examples above from VAG and BMW are single chains and nearly all have given trouble.

Belt drives are extremely durable when properly engineered, the tensioner and roller bearings being generally the point of failure due to grease degradation. A new generation of oil-immersed belts (Ford, Honda) will overcome this problem as the idler bearings will be oil lubricated. Lifetimes approaching that of a duplex chain drive may then be expected.

So, on this occasion I would also disagree with HJ. A single chain drive as used by VAG, BMW and several others can be a potential financial disaster for its owner.

I do wish vehicle makers would improve the accessibility of their belt drives. A bit more thought would save hours of unnecessary labour. You don't have to position an engine mount in the centre of the belt run and the lower belt cover could be diametrically split to avoid the need to unbolt the crankshaft pulley.

Some hope.

659.

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Fri 3 May 2013 12:05

Any - Cambelt Vs Cam Chain - Engineer Andy

I would caution those who disagree with HJ over this issue, as I note most cite cases of European manufacturers having problems with timing chains. I would point out that some of these makes (BMW and VW) have in the last 10 years moved to longer service intervals, which isn't exactly condusive to keeping a timing chain in good order - they need to be well-lubricated and once a year at least.

I can't speak for the Nissans generally (although from a personal prespective my old Micra never had a problem on that score [10 years old and the engine was still going strong]), but I haven't heard of problems with other Japanese makes, who appear to put more money into the engineering of their cars (as opposed to interior quality and gizmos) than European manufacturers. If I recall correctly, VAG cars have had numerous problems with engines, gearboxes and related items over recent years, possibly (not confirmed) like M-B where quality of engineering appeared to fall to keep prices keen and levels of gizmos up to keep up with the competition.

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Fri 3 May 2013 14:51

Any - Cambelt Vs Cam Chain - unthrottled

keeping a timing chain in good order - they need to be well-lubricated and once a year at least.

Which is a problem that doesn't need to be solved with a belt. Chain drives work very well with cam-in-block designs which have needlessly been discarded by most producers of passenger car engines. American commercial diesels (Cummins, GM duramax) and of course the LSX small block retain the OHV layout for good reason. DOHC engines are for, the large part, bulky, high friction designs and the valvetrain drive is always a headache.

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Fri 3 May 2013 12:07

Any - Cambelt Vs Cam Chain - daveyK_UK

I always found hyyundai/kia to be the best for belt access, cant comment on the latest batch of cars but every belt I worked on pre 2000 was a doddle.

That is the beauty of the MPV vans, you get alot more bonnet access than your average modern car.

The latest citroen berlingo/peugeot partner is excellent for access. Same with the fiat doblo, especially the petrol versions.

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Fri 3 May 2013 16:56

Any - Cambelt Vs Cam Chain - craig-pd130

Single-row chains are the most common cam drive on motorbikes, including sports bikes which rev to (relatively) astronomical levels compared with a car engine -- however the valves, followers etc are so much smaller and lighter which must present a lighter loading on the drive.

Even so, many bike manufacturers have failed to get the cam drive arrangements right: notably Honda with its early 80s V4 designs. It's hard to say whether those problems were caused the dodgy camchain tensioners, the fact that the cam bearing journals were not full circles around the cam, or poor lubrication ... or all three!

Eventually Honda revised the engine for gear-driven cams. End of problem.

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Sat 4 May 2013 03:25

Any - Cambelt Vs Cam Chain - 1litregolfeater

I agree with unthrottled as well. I think marketing and consumer perception play against each other, when they're both wrong, and we should surely be led by an enginerring perspective.

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Fri 3 May 2013 17:00

Any - Cambelt Vs Cam Chain - barney100

I prefer chains. in all the years i've had cars I've spent much cash changing belts but touch wood my three Mercs with chains over the last eleven years---all three well used when I bought them---have cost nothing in this department.

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Fri 3 May 2013 17:32

Any - Cambelt Vs Cam Chain - balleballe

It will be interesting to see how Fords ecoboost does

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Fri 3 May 2013 22:25

Any - Cambelt Vs Cam Chain - daveyK_UK

Is the ecoboost belt or chain?

Are the ecoboost having many turbo failures?

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Fri 3 May 2013 22:38

Any - Cambelt Vs Cam Chain - Collos25

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Fri 3 May 2013 22:22

Any - Cambelt Vs Cam Chain - Collos25

But thats the past we are discussing today.

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Sat 4 May 2013 00:21

Any - Cambelt Vs Cam Chain - brum

As far as I can tell, its almost always a failure of the tensioning system that leads to both cambelt and camchain failures. In the case of belts, poorly designed and/or poor quality (cheap) tensioners, in the case of chains, poorly designed tensioning devices that rely on oil pressure and poor quality chain guides that wear, both often aggravated by oil that becomes too contaminated.

Choosing between one and another was perhaps an easier arguement back when 40k/4year cambelt changes were insisted by VAG during the PD era, which had a belt system not really fit for purpose. Nowadays with 100k cambelt intervals the decision is not so easy. However I think VAG UK still insist on a silly 5 year interval, which is a very significant running expense. How strange that VAG cars anywhere else in the world dont have this requirement?

A good camchain setup, with regular oil changes, on the other hand,is usually for life.

But, if you want a particular car make and engine type, the decision is generally out of your hands, as you will have no choice.

Perhaps, the wise thing is to avoid all new engine designs until they prove their longevity, and the first design revisions are released (a bit like waiting for Windows SP1).

Edited by brum on 04/05/2013 at 00:25

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Sat 4 May 2013 01:20

Any - Cambelt Vs Cam Chain - unthrottled

However I think VAG UK still insist on a silly 5 year interval, which is a very significant running expense

This ignores the fact that you'll pay more for a chain engine than a belt one. It's just that the cost is hidden in the overall purchase price of the car.

As 659 points out, with a little thought in the design process, changing a cambelt doesn't always have to be expensive. The bulk of the cost of a cambelt change is in gaining access to the belt. The cost of the belt and the labour of changing the belt itself is little more than changing brake pads.

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Sat 4 May 2013 18:57

Any - Cambelt Vs Cam Chain - daveyK_UK

No reason why savvy consumers cant flip the bonnet in the showroom.

We have seen a move by some manufactures to try and squeeze as much as possible into the smallest space.

The cramped nature of the citroen synergie/peugeot 806/fiat ulleyse made the vans a nightmare to repair, having to remove part of the dash to access the top of the engine.

Other cars where a nightmare to change a light bulb, the renault megane springs to mind.

And then there are cars which had both the engine under the dashboard and a wheel off job to change a lightbulb, the dreaded renault modus.

A car which I can recall being a real pain to change the belt on was the mark 3 suzuki alto (55 plate), it took hours to get access.

Talking of suzuki, I never to to work on the very nimble and useful suzuki carry van with the eingine under the front seats.

Now sold under license in the UK by the 3rd biggest Chinese manufacturer DFSK

http://www.dfskuk.com/

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Sat 4 May 2013 19:18

Any - Cambelt Vs Cam Chain - Alby Back

I've done about 40,000 miles a year for 35 years.

In that time I've had 3 cambelts let go causing major engine damage despite none of them being anywhere near due for changing and having had main dealer servicing on the given vehicles at the required intervals.

I have never had problems with the chain on a chain cam engine.

I would not buy another belt cam equipped vehicle with my own money.

Others can and no doubt will have a different view.

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Sun 5 May 2013 09:48

Any - Cambelt Vs Cam Chain - xtrailman

I go with your view, considering your lifetime milage, chain has to be a clear winner.

I also recall on this site years ago a moderator with a 2.5 Audi diesel, the belt broke and the engine was destroyed.

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Sun 5 May 2013 13:26

Any - Cambelt Vs Cam Chain - Engineer Andy

I quite agree - the only problem I ever had on this issue was on my old (K11) Micra, which through sheer bad luck broke its water pump belt via a loosing chipping flying up under the car, through the (very) empty engine bay and breaking the belt. Fortunately tI just managed to get the car home before it treminally overheated. I took the RAC guy 1.5 hours to fit the new belt (£7.99 for the replacement part as I recall), which I'm glad I didn't have to pay at the dealership (probably costing £100+ at the time [~2000]).

Properly-designed chain-cam engines (as most good Japanese ones are) go on and on as long as they are kept well oiled and generally well-maintained. Its only when manufacturers drop their engineering quality (as seems to have been evident with some European makes) in the design and fitting of such parts to reduce costs have problems arisen. Belts are fine as far as they go, but failure can (as has been shown) still destroy engines and cost significant outlays to replace every 50-100k miles (often sooner than that prescribed to be on the safe side).

For these reasons, it is the main reason currently dissuading me from buying one of the new SEAT Leons (very appealing in most other respects), due to the VW problems with their chain-cam engines and (even if they solved them) the fact that their 1.4 TSI (my preferred choice of the 1.2, 1.4 & 1.8 turbo-petrols) is belt driven (the other two are chain-driven). Note I don't particularly like diesels and I normally don't do sufficient mileage to ever justify buying one.

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Sun 5 May 2013 21:25

Any - Cambelt Vs Cam Chain - Big John

Is the Octavia 2013 1.2tsi also the EA211 design?

It is on the latest Golf. This is a very different engine to the old one. It is now 16v (the old 1.2tsi was 8v) and the exhaust manifold is built into the head with the down pipe at the bulk-head side rather than the front. The engine is smaller, lighter and yes it does have a long life cam belt rather than a chain (supposedly to save weight).

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Mon 6 May 2013 08:46

Any - Cambelt Vs Cam Chain - Engineer Andy

Is the Octavia 2013 1.2tsi also the EA211 design?

It is on the latest Golf. This is a very different engine to the old one. It is now 16v (the old 1.2tsi was 8v) and the exhaust manifold is built into the head with the down pipe at the bulk-head side rather than the front. The engine is smaller, lighter and yes it does have a long life cam belt rather than a chain (supposedly to save weight).

To be honest, my information came from HJ's review ("What's Bad" from the new SEAT Leon 5dr) by inferrence that the 1.4 petrol was belt driven, and I therefore assumed (possibly mistakenly) that the 1.2 and 1.8 TSIs were chain driven as they weren't mentioned. I haven't found anything the confirm which are which anywehere else yet (I'm looking though).

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Mon 6 May 2013 10:39

Any - Cambelt Vs Cam Chain - nortones2

1.8TSI in our Yeti has chain drive to the camshafts. Confimed here: tinyurl.com/3wzkbhd

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