timing belts are crap

green123

from another thread Originally Posted by unkel

"All cars should have chains though. My Micra had a chain. My Porsche has a belt "

so why not just use timing chains on all cars and save all the hassle ?

whats the advantage of using belts ?

blackbox

Timing Chains are crap.

They stretch (interfering eith timing)

They rattle

They break

All cars should have timing belts.

eringobragh

blackbox wrote: »

Timing Chains are crap.

They stretch (interfering eith timing)

They break

SO Timing Belts don't break? :rolleyes:

groupb

I think belts used to be regarded as quieter. Chains can stretch/break too. My mx5 has a belt but its a non interferance engine.

mike65

Belts are crap they give no warning, chains do (if you know what the look/listen for)

Mike.

groupb

blackbox wrote: »

Timing Chains are crap.

They stretch (interfering eith timing)

They rattle

They break

All cars should have timing belts.

It causes quite a bit of "interferance" when pistons meet valves.

Anan1

Belts are quieter.

mike65

Never understood that argument, having owned cars with both I can declare both equally un-noisey.

Mike.

Plug

Belts are quiter than chains, they dont rattle, they dont stretch over time and they are cheaper. Once you change your timing belt over your recommend milage then nothing will happen.
I also think that a belt has a less rotating mass on the engine therefore delivering more power or else its the other way around.

jon1981

is there a website or anything that lists cars that have timing chain or belts? i prefer to have the piece of mind with a chain

eringobragh

My timing chains done 180,000 and still going strong. I don't find it noisy either

Darwin

A few examples I know of that have timing chains are a lot of Fords (Ka, Puma, Focus) and the new BMW engine used in the Cooper S and 207 GT/GTi...I'm sure there's loads more

kona

dont chains have a tensioner???? so they dont strech and ruin the timing??

and with the amount of milage the average ca does before being scrapped/sold on, a chain will last this distance. a belt will not.

Plug

kona wrote: »

dont chains have a tensioner???? so they dont strech and ruin the timing??

I dont think they have a tensioner but they do stretch and thats the sad reality.

kona

Plug wrote: »

I dont think they have a tensioner but they do stretch and thats the sad reality.

afaik the chain on my mini has a tensioner, i must check this before i get complacent!!:D

colm_mcm

Most VVT-i engines have chains, but a few (like the RX300) have belts.

mike65

Chains have tensioners or at leasts Mercs do, the duplex chain is bomb proof (are Mercs still made with dulpex chains?). Replace the tensioner every 80,000 miles are you're grand.

Mike.

Plug

kona wrote: »

afaik the chain on my mini has a tensioner, i must check this before i get complacent!!:D

Ok see the first black thing I think there is a tensioner on the left of that but maybe I'm wrong, you can see the same thing on the third black thing.
Anyone know what the black things are called?

kona

mike65 wrote: »

Chains have tensioners or at leasts Mercs do, the duplex chain is bomb proof (are Mercs still made with dulpex chains?). Replace the tensioner every 80,000 miles are you're grand.

Mike.

yup my mini has a duplex timing chain, and a tensioner, but its not a standard A-series so i dont know if they left the factory with a duplex and a tensioner, i reckon it has one as it doesnt rattle as much as other engines ive heard!.

kona

Plug wrote: »

Ok see the first black thing I think there is a tensioner on the left of that but maybe I'm wrong, you can see the same thing on the third black thing.
Anyone know what the black things are called?

id say those black things stop chain slap.

lol the mini aint that complicated, its basically a 2 double teeth pulleys and 2 chains lol.

bet a tenner thats a over engineerd german yoke!!!

mike65

That has two tensioners the "bolt" like thing on the left side of tensioner arms.

Mike.

Plug

kona wrote: »

id say those black things stop chain slap.

Yeah thats what there for but I wonder if there the tensioner aswel?

lol the mini aint that complicated, its basically a 2 double teeth pulleys and 2 chains lol.

bet a tenner thats a over engineerd german yoke!!!

You'd be right there! But wrong about over enginnered. The more its emginnered the better:cool:

Plug

mike65 wrote: »

That has two tensioners the "bolt" like thing on the left side of tensioner arms.

Mike.

Yes, my spider senses thingled when I saw them.

kona

Plug wrote: »

Yeah thats what there for but I wonder if there the tensioner aswel?


You'd be right there! But wrong about over enginnered. The more its emginnered the better:cool:

tell BMC that:D:D
just spent 3 hours today , unseizing a handbrake, and adjusting it. then questioning the engineering wisdom of leaving everything metal un treated and open to the elements:D, then turning the adjusting bolt was fun!!!

and who puts a dizzy on the front of a engine behind a gaping grill???

stupid english no wonder BMC went to the dogs.

BenFoldsFive

Wasnt Issigonis Turkish?

kona wrote: »

tell BMC that:D:D
just spent 3 hours today , unseizing a handbrake, and adjusting it. then questioning the engineering wisdom of leaving everything metal un treated and open to the elements:D, then turning the adjusting bolt was fun!!!

and who puts a dizzy on the front of a engine behind a gaping grill???

stupid english no wonder BMC went to the dogs.

Run_to_da_hills

The best engines made were side valves! No complicated timing belts, chains or pushrods, and no dropping of valves and bursting pistons or bending rods if the timing fails!. Timing belts are a racket for main dealers to make a killing on major services by conditioning you that "Genuine parts" must be fitted. Timing chains are noisy and awkward to fit and pushrods can bend. With sidevalve technology the timing is set once and for all, it cannot slip and if it dose go out, ie one of the timing gears strips, highly unlikely, it will have no damaging effect on the engine. Morris and Ford used these engines for years when cars were real cars instead of the rubbish that they are producing to-day.
http://en.wikipedia.org/wiki/Flathead_engine

kona

BenFoldsFive wrote: »

Wasnt Issigonis Turkish?

yup, but that muppet lord stokes was english!!
who makes 2 cars to compete with each other!!!
issigonis just designed the car, not the bits that went on it. he was a stubborn bloke too, didnt want john cooper to tune the mini:D:D

BMC designed the A-series, and the transverse design of the mini unit, on MGs the dizzy is at the side!!!
but i suppose this is because the engine is mounted differently.
best 8v engine imo, will do 185 bhp with a few mods.

best idea has to be the rotary engine, pity they aint durable

Timmaay

Run_to_da_hills, here's why we dont use side valve engines, from your own link:rolleyes::

On the downside, the flathead also requires the airflow to make at least a 90-degree turn to enter the cylinder, which makes it less efficient, colloquially called poorer "breathing". Breathing was not greatly important for early production cars because engines could not run long and reliably at high speed, and all engines had poor combustion anyway, so this was a minor concern given the benefits in simplicity. The maximum compression ratio is also low at only about 7:1, further reducing efficiency (although it means the engine can run on low-octane fuel).

A more serious concern is exhaust, which often follows a more complicated path to leave the engine. This virtually guarantees the engine will overheat under sustained heavy use

Basically, they're rubbish, I'll take the small risk of snapping a belt/chain and dropping a valve for the better power/fuel efficency/reliability of OHVs.

zilog_jones

What happens when a timing chain breaks in a pushrod engine? I assume it's a lot less likely to happen than in one of those newfangled yokes, due to the chain being a lot smaller.

Are there any pushrods left besides the big american V8s? I know the Ka hasn't had them since 2003, but what about Skoda? Anyone else still living in the past?

Plug

When a it breaks the valves hit the pistons and CAABOOM!:eek:

Run_to_da_hills

Timmaay wrote: »

Run_to_da_hills, here's why we dont use side valve engines, from your own link:rolleyes::


Basically, they're rubbish, I'll take the small risk of snapping a belt/chain and dropping a valve for the better power/fuel efficency/reliability of OHVs.

I have a 1939 flathead motorcycle since the 1982 and still have it roadworthy, It has never overheated, siezed or left me on the side of the road with dropped valves. It depends on how these engines are treated, if they are gunned by some moran flat out they will obviously burn out exhaust valves as with any engine if mistreated.

If I was given a bike to travel across the world I would choose this configuration of engine because any back street workshop in India or Pakistan equipped with a vicegrip, hammer and chizel can work on it not like the modern junk that requires a "computer" to get it going.

Plug

Run_to_da_hills wrote: »

I have a 1939 flathead motorcycle since the 1982 and still have it roadworthy, It has never overheated, siezed or left me on the side of the road with dropped valves. It depends on how these engines are treated, if they are gunned by some moran flat out they will obviously burn out exhaust valves as with any engine if mistreated.

If I was given a bike to travel across the world I would choose this configuration of engine because any back street workshop in India or Pakistan equipped with a vicegrip, hammer and chizel can work on it not like the modern junk that requires a "computer" to get it going.

Are motorbikes on diagnostics aswel? Didn't know that.

unkel

As I think I said in another thread, belts suck

groupb wrote: »

My mx5 has a belt but its a non interferance engine.

Are you absolutely sure? There are versions of the engine of my car that are interference and others that are non-interference

A wise man suggested to me to treat all engines as interference unless you know for sure it is not

Seth Brundle

Plug wrote: »

Once you change your timing belt over your recommend milage then nothing will happen.

That is not true! Belts can go at before or after the recommended mileage!
I connot recall a thread about a timing chain snapping!

Plug wrote: »

I dont think they have a tensioner but they do stretch and thats the sad reality.

Here is the diagram for my timing chain.
It has tensioners as do most chain driven engines.

Anyhow, AFAIK the main reason that belts are used over chains is down to cost!

Plug

kbannon wrote: »

That is not true! Belts can go at before or after the recommended mileage!
I connot recall a thread about a timing chain snapping!
Here is the diagram for my timing chain.
It has tensioners as do most chain driven engines.

Anyhow, AFAIK the main reason that belts are used over chains is down to cost!

I never heard of a belt snapping unless it went a good bit over the milage mark to get it replaced. It probly has happened but I can't see how, this part isin't under extreme pressure anyway.
I would also think the labour replacing a timing chain would be higher.

Run_to_da_hills

zilog_jones wrote: »

What happens when a timing chain breaks in a pushrod engine? I assume it's a lot less likely to happen than in one of those newfangled yokes, due to the chain being a lot smaller.

Are there any pushrods left besides the big american V8s? I know the Ka hasn't had them since 2003, but what about Skoda? Anyone else still living in the past?

There is no timing chain in a push rod engine. Extended rods are used to open and close the valves. Leyland Minis, later Micky Minors and most classic British Motorcycles used pushrods. The only drawback would be if the tappets came so loose that the pushrod popped our or sometimes got jammed and bent if dislocated. In most cases if the push rod gets dislocated the valve would remain shut and there would be no damage to the piston. http://en.wikipedia.org/wiki/Overhead_valve

Seth Brundle

@ plug
http://www.boards.ie/vbulletin/archive/index.php/t-2054901570.html
Im sure there are more but I couldn't be bothered going through them.
http://www.google.ie/search?hl=en&safe=off&client=firefox-a&rls=org.mozilla%3Aen-GB%3Aofficial&hs=8ud&q=timing+belt+snapped+site%3Awww.boards.ie&btnG=Search&meta=

Run_to_da_hills

Plug wrote: »

Are motorbikes on diagnostics aswel? Didn't know that.

Yes unfortunitally most modern Jap would require a computer to get them tuned right. Not long ago I came across a lawnmore with computer management chip built in :eek:

Oilrig

"best 8v engine imo, will do 185 bhp with a few mods"

Not with 8 valves it won't... a genuine 145 is really pushing it, and it gets REALLY expensive if you want reliability...

Belts should be consigned to history IMHO, they came, we tried, they failed.

With modern era engineering and lubrication the old problems with chains are not an issue.

BMW got rid of belts in the early/mid '90's, the logic was that a chain will last the life of the engine - a belt won't.

Chains don't get upset when they're contaminated in oil, they don't ingest stones etc and more importantly nowadays, they cut down on maintenance costs.

Plug

kbannon wrote: »

@ plug
http://www.boards.ie/vbulletin/archive/index.php/t-2054901570.html
Im sure there are more but I couldn't be bothered going through them.
http://www.google.ie/search?hl=en&safe=off&client=firefox-a&rls=org.mozilla%3Aen-GB%3Aofficial&hs=8ud&q=timing+belt+snapped+site%3Awww.boards.ie&btnG=Search&meta=

:eek: gutted to him but at least ford paid for the damage. I wouldn't think it random snapping is common though.

Run_to_da_hills

Oilrig wrote: »

"best 8v engine imo, will do 185 bhp with a few mods"

Not with 8 valves it won't... a genuine 145 is really pushing it, and it gets REALLY expensive if you want reliability...

Belts should be consigned to history IMHO, they came, we tried, they failed.

With modern era engineering and lubrication the old problems with chains are not an issue.

BMW got rid of belts in the early/mid '90's, the logic was that a chain will last the life of the engine - a belt won't.

Chains don't get upset when they're contaminated in oil, they don't ingest stones etc and more importantly nowadays, they cut down on maintenance costs.

Ford had a serious problem with timing belts snapping in the 1.9 diesel blocks they were using around 1989. Rather than do a major recall they kept on producing this engine and offered a heavily subsidised timing belt replacement service every 40K, Im sure any Ford mechanic could do them with their eyes shut!. They have learned their lesson and have fitted timing chains in all their mark 6 & 7Transits!

crosstownk

Belts v Chains. It makes no odds to the average punter. Belts are cheaper to design and install, but require periodic replacement which costs the customer over the ownership period. Chains which are more expensive to install at factory level cost the customer at the point of vehicle purchase but have less maintenance from there on.

Both need tensioners. Belts use the pulley tensioner and chains use a static 'plate' type tensioner. Lada Rivas were well known for needing tensioners as the chain used to cut into the tensioner in a big way.

Ultimately a chain is better, imo. It is less inclined to just snap without warning - a chain will make a racket if the tensioner goes wrong which will give the driver some warning - assuming the driver is listening......

I'd favour a chain, but I would have to say that belts are almost as good nowadays.

As for the noise argument, I'd be inclined to agree that belts are, by their nature, more noisey. But modern technology and soundproofing techniques make this point irrelevant.

bushy...

Chains are also used to vary timing ( on purpose) , some porsches , audi etc use basically tensioners at each side of the chain , by taking slack from one side or the other they get a few degrees +/-.
Unless someone has a good new idea , sidevalves are for old things & cement mixers etc , pushrods can perform well, Mercedes used carbon fibre ones to show off at one stage.

zilog_jones

Run_to_da_hills wrote: »

There is no timing chain in a push rod engine.

The timing chain in my pushrod Fiesta would like to have a word with you

Even the WP article you linked says they can have chains:

...a pushrod engine has the camshaft positioned next to the crankshaft and can be run with a much smaller chain or even direct gear connection.

Oilrig

"Ford had a serious problem with timing belts snapping in the 1.9 diesel blocks they were using around 1989" IIRC this was down to incorrect tension - the dreaded whine of death...

"The timing chain in my pushrod Fiesta would like to have a word with you" Brings back memories

crosstownk

Oilrig wrote: »

"Ford had a serious problem with timing belts snapping in the 1.9 diesel blocks they were using around 1989" IIRC this was down to incorrect tension - the dreaded whine of death...

"The timing chain in my pushrod Fiesta would like to have a word with you" Brings back memories

The rattling noise from those Ford pushrod engines would put me off buying one . OHC is so much quieter.

Run_to_da_hills

zilog_jones wrote: »

The timing chain in my pushrod Fiesta would like to have a word with you

Even the WP article you linked says they can have chains:

I would not be familiar with this engine, It probably has a small chain in place of the normal timing gears. The large majority of pushrod engines would have operated their pushrods directly from geared driven cams and followers.

Oilrig

"The large majority of pushrod engines would have operated their pushrods directly from geared driven cams and followers."

Guess you're used to bigger diesels?

groupb

unkel wrote: »

As I think I said in another thread, belts suck



Are you absolutely sure? There are versions of the engine of my car that are interference and others that are non-interference

A wise man suggested to me to treat all engines as interference unless you know for sure it is not

Thats what I've read in the repair manuals , but now you've got me worried. I rarely change gear below 5,500RPM unless I'm around town.(its not a muppet motor).Anyway I'm off to read the manual again.

Senna

2 things, I've a non-interference engine (3sge), but i've been told that this isn't a guarantee, if it snaps a high revs, it can still do damage. Is that true?

also, i had a K11 micra, it had a timing chain, but Nissan still said it should be replaced every 60k miles. Is this just there way of getting out of responsibility if it snaps?
but I never did replace it, had 130k when i sold it:D

groupb

Phew! just checked the net and yep mk1 1.6 mx5's have a non interferance engine according to the mx5 clubs , but thanks anyway. Better to be sure before I visit the red line again.