Chain vs Cambelt

Author
Discussion

topless_mx5

Original Poster:

2,763 posts

218 months

Sunday 18th January 2009
quotequote all
Whats the difference betweem chains and cambelts?

My current car has a chain, which apparantly doesnt need replacing. On 130k miles now and its still on the original.

Cambelts need changing every x miles (usually 80k ish, dependant on car obviously). And I have heard stories of cambelts snapping and killing the engine, but never heard of a chain destroying an engine.

So why is it that the majority of cars have cambelts? Whats the disadvantage of a chain?

havoc

30,069 posts

235 months

Sunday 18th January 2009
quotequote all
Price.

leeeeshad

1,479 posts

187 months

Sunday 18th January 2009
quotequote all
a chain has to be lubricated as well

magpie215

4,397 posts

189 months

Sunday 18th January 2009
quotequote all
chains do occasionally let go and the result is the same as with a cambelt engine dead unless you have a car with a non interference engine.

chain "should" last the life of the engine/car
cambelt should be changed as per the cars maintenance programme usually XXX miles or XX years whichever occurs first.

LocoBlade

7,622 posts

256 months

Sunday 18th January 2009
quotequote all
Chains used to be considered a bit noiser too, but I don't think thats necessarily the case now

Superhoop

4,677 posts

193 months

Sunday 18th January 2009
quotequote all
It used to be that chains were very noisy, hence the move to cambelts.

However, chain technology has moved on a lot in recent(ish) times, thanks in part to the development of chains used in 4x4 transfer boxes, and are now far quieter in operation.

Another driving factor in the use of chains is the ever more dufficult to achieve emissions laws. Cambelts suffer far more deflection than chains, meaning that cam timing is slightly less accurate, leading to higher emissions.

Chains are once again becoming far more common, for not only the reasons listed above, but also, as they tend to have no maintenace interval, leading to cheaper servicing costs for the owner.
this is something that is of particular importance to car manufacturer's whole sell to fleet companies, as fleet costs are heavily dependent on the whole life cost of running the vehicle. This includes all servicing costs, also part of the reason why service intervals are becoming ever longer

Seight_Returns

1,640 posts

201 months

Sunday 18th January 2009
quotequote all
magpie215 said:
chains do occasionally let go and the result is the same as with a cambelt engine dead unless you have a car with a non interference engine.
Yup. Any anyone who knows about Dolomite Sprint engines.

shouldbworking

4,769 posts

212 months

Sunday 18th January 2009
quotequote all
I've found that chain type drives suffer from tensioner failure if anything, and being lubricated by engine oil are subject to owners actually doing their basic checks.

I'd go with the conspiracy theory view that continuing to use belts is a way of getting greater service income.


300bhp/ton

41,030 posts

190 months

Sunday 18th January 2009
quotequote all
Seight_Returns said:
magpie215 said:
chains do occasionally let go and the result is the same as with a cambelt engine dead unless you have a car with a non interference engine.
Yup. Any anyone who knows about Dolomite Sprint engines.
I've not known any issues on three different 8v TR7 engines with chains.

BigLepton

5,042 posts

201 months

Sunday 18th January 2009
quotequote all
300bhp/ton said:
Seight_Returns said:
magpie215 said:
chains do occasionally let go and the result is the same as with a cambelt engine dead unless you have a car with a non interference engine.
Yup. Any anyone who knows about Dolomite Sprint engines.
I've not known any issues on three different 8v TR7 engines with chains.
Do you mean V8? I know more people who've won the lottery than I do people who've had a Rover V8 chain go! smile

One of the things that appealed about my Mazda MPS was the chain instead of the usual cambelt, several of which I've broken before now at inconvenient moments. mad

zektor

583 posts

247 months

Sunday 18th January 2009
quotequote all
Chains... I swear by them.

I've had cars with cambelts, and ended up paying through the arse to get them changed regularly due to risk of failure. I've heard plenty of horror stories from friends and family due to belts failing way before the service schedule. From what I have heard in the past, Renaults are the worst.

My missus has an MX-5... and the fact it runs a chain was a major selling point for me.

Me... I'm into V8's of the American variety... and all the American cars I've had have chains.

Cambelts are lame in my opinion.

Modern chained systems are not noisy, last considerably longer... possibly the life of the engine now days on modern cars. And if it were to 'let go' you are more likely to hear a racket from the engine before the impending disaster. Giving you some warning before it actually goes.

You won't hear anything from a failing cambelt... apart from right at the moment your valves crash into your pistons... unless of course like others have mentioned - your engine is a non-interference one (like a Ford Probe 24v for instance)

Trouble is, I guess that generally people that do not know an awful lot about cars, really do not understand the difference. To them it's just an engine... Only when the cambelt fails do they then realise that it's a critical part of the cars engine!!!

topless_mx5

Original Poster:

2,763 posts

218 months

Sunday 18th January 2009
quotequote all
zektor said:
Chains... I swear by them.

My missus has an MX-5... and the fact it runs a chain was a major selling point for me.
I might get flamed for this if I'm wrong (especially with my PH name) but hasnt the MX5 got a non interference cambelt? What year is her MX5? Mine was 1990 and I'm sure it had a cambelt, was a few years ago though when I had it so maybe I just got it wrong...

300bhp/ton

41,030 posts

190 months

Sunday 18th January 2009
quotequote all
BigLepton said:
300bhp/ton said:
Seight_Returns said:
magpie215 said:
chains do occasionally let go and the result is the same as with a cambelt engine dead unless you have a car with a non interference engine.
Yup. Any anyone who knows about Dolomite Sprint engines.
I've not known any issues on three different 8v TR7 engines with chains.
Do you mean V8? I know more people who've won the lottery than I do people who've had a Rover V8 chain go! smile

One of the things that appealed about my Mazda MPS was the chain instead of the usual cambelt, several of which I've broken before now at inconvenient moments. mad
I meant the 2.0 litre engine from the TR7, it's an 8v valve variant of the Dolly Sprint engine, runs a timing chain also.

I also agree on the Rover V8 though, never known a single one with chain failure. In fact 3 or 4 of my cars at the moment all have chain over belt.

Superhoop

4,677 posts

193 months

Sunday 18th January 2009
quotequote all
topless_mx5 said:
zektor said:
Chains... I swear by them.

My missus has an MX-5... and the fact it runs a chain was a major selling point for me.
I might get flamed for this if I'm wrong (especially with my PH name) but hasnt the MX5 got a non interference cambelt? What year is her MX5? Mine was 1990 and I'm sure it had a cambelt, was a few years ago though when I had it so maybe I just got it wrong...
Mk 1 and MK 2/2.5 both had a belt, the latest MX-5 has the MZR engines fitted, which run a chain

dickkark

747 posts

221 months

Sunday 18th January 2009
quotequote all
Seight_Returns said:
magpie215 said:
chains do occasionally let go and the result is the same as with a cambelt engine dead unless you have a car with a non interference engine.
Yup. Any anyone who knows about Dolomite Sprint engines.
Its the jackshaft(runs water and fuel pump and distributor) that siezes or breaks and snaps the chain not the chain going first.

sniff diesel

13,107 posts

212 months

Sunday 18th January 2009
quotequote all
The chain in my 325tds is a bit rattly now it's on 145k, especially when cold. If it was a belt then I could have had it changed but the chain would cost a lot more to replace so it's almost not worth it.

minimatt1967

17,097 posts

206 months

Sunday 18th January 2009
quotequote all
sniff diesel said:
The chain in my 325tds is a bit rattly now it's on 145k, especially when cold. If it was a belt then I could have had it changed but the chain would cost a lot more to replace so it's almost not worth it.
yes A mate of mine his F.I.L2B has just done the chains and tensioners on his 525TDS and they cost an absolute fortune, we supplied some of the bits, what we couldn't get he had to use BMW for and I think they were out of stock of lube that day wink

Oh and it still fking tapping, even though the tensioners were fked and have now been replaced, it presumably is a tappet rolleyes

Merlot

4,121 posts

208 months

Sunday 18th January 2009
quotequote all
Superhoop said:
topless_mx5 said:
zektor said:
Chains... I swear by them.

My missus has an MX-5... and the fact it runs a chain was a major selling point for me.
I might get flamed for this if I'm wrong (especially with my PH name) but hasnt the MX5 got a non interference cambelt? What year is her MX5? Mine was 1990 and I'm sure it had a cambelt, was a few years ago though when I had it so maybe I just got it wrong...
Mk 1 and MK 2/2.5 both had a belt, the latest MX-5 has the MZR engines fitted, which run a chain
But is an interferance engine, so if the chain does let go - oops!

Nobody You Know

8,422 posts

193 months

Monday 19th January 2009
quotequote all
Get a MK2 Golf 16V GTi and then you get a chain and a belt... Belt drives the exhaust cam and the chain then goes between the two cams to drive the inlet cam. The Posche 3.0 I4 from the 968 also has this set-up (IIRC).

It seems that as technology improves chains seem to be the better option once again, when belts came onto the scene they were quieter and easier to tension but now that has changed more engines have chains.

I believe the 40V V8 used by Audi now uses timing chains. Improved accuracy/emission and reduced service intervals. The lifetime service interval is a mjor issue on the front engined Audi V8's as I think the whole engine needs to come out to change the chain, so minimal changes are required.

JBL930

1,837 posts

216 months

Monday 19th January 2009
quotequote all
BigLepton said:
300bhp/ton said:
Seight_Returns said:
magpie215 said:
chains do occasionally let go and the result is the same as with a cambelt engine dead unless you have a car with a non interference engine.
Yup. Any anyone who knows about Dolomite Sprint engines.
I've not known any issues on three different 8v TR7 engines with chains.
Do you mean V8? I know more people who've won the lottery than I do people who've had a Rover V8 chain go! smile

One of the things that appealed about my Mazda MPS was the chain instead of the usual cambelt, several of which I've broken before now at inconvenient moments. mad
A V8 with 8 valves silly