Why The Demise of Timing Belts?

[SnowDrifter]

In some ways, I'm glad were moving over to timing chains again. Don't need to worry about things like your cam seals leaking and compromising the belt. On the other hand.. Because its not a maintenance item, chains can be more expensive if you have problems. Especially in the euro cars where you have 4 chains and VVT. It's give/take.

Although for most people its better IMO. Most owners think all they need to do is change the oil sometimes and add gas. They don't give a thought to any of their other fluids, most don't eve know what they are... Let remember to do the timing belt 10 years down the road

 

[threeputtpar]

I was one of those that was bit by the Ford 4.0 OHC issues, too. I guess that's why I don't mind that both of our current vehicles have timing belts. With the Ody being purchased new, my wife will likely tire of it well before the first belt job is due. Even if she doesn't, I've done 2 TB jobs on the Audi already and the Ody can't be nearly as involved.

Sure, I'd rather have a no maintenance timing chain but I don't purchase vehicles based on chain vs. belt.

I too am interested to see how the oil immersed belts do. Typically, it's not the belt itself that's the root cause of failure. It's often one or more of the bearings in the pulleys or water pump that seizes and takes out the belt. Having all those parts inside the oiling system may mitigate or eliminate bearing failures.

 

[SwampSurvivor]

I don't think the oil bathed timing belts are anything new - just new in automotive applications. From what I understand, they may be popular in industrial engine applications? Can anyone confirm?

I think the biggest thing that would keep me from a 1.0L ecoboost Fietsa is the lack of interior space.

 

[KGMtech]

Originally Posted By: leeharvey418
There were also promised NVH improvements from timing belts that didn't end up being worth the tradeoff in M&R costs... especially when engineers started looking for other ways to cancel or abate noise.


Exactly! I've done TB jobs on Honda, Mazda, VW 1.8T and the VW is the WORST!

If these ever come back in style...God forbid, they must be easy to service.

 

[Eddie]

TB have several advantages. They use less power, are quieter, and subject the valve train to less shock. However; the down side is relative expensive replacement due to labor and or dealer greed.

 

[E365]

Originally Posted By: Miller88
I don't think the oil bathed timing belts are anything new - just new in automotive applications. From what I understand, they may be popular in industrial engine applications? Can anyone confirm?

I think the biggest thing that would keep me from a 1.0L ecoboost Fietsa is the lack of interior space.


I think so.

From the Dayco website "Belt in Oil System

Dayco's newest technology is the world's first timing-belt-in-oil system for automotive applications. The belt-in-oil system, which includes Dayco's patented belt and tensioner, weighs less, has lower stretch, reduces friction and is quieter than traditional chain-drive components. For our customers, this translates into higher engine performance, lower emissions and improved fuel economy."

A Google search for "oil bathed timing belt" doesn't bring up much outside of the Ford 1.0. Someone else probably know much better than I do.

The Fiesta is too small for me too, so once they announced the 1.0 in the Focus it had my attention. The order guides are out but no pricing or MPG figures.

 

[millerbl00]

Sorry, with all the negative posts I lost track of Friend vs foe!


Originally Posted By: Mykl
Originally Posted By: millerbl00
Wow really? Going out of your way to hound us....


Yeah, I'm going out of my way to hound you by openly sympathizing with your views on a particular subject.

 

[DB_Cooper]

Originally Posted By: friendly_jacek
I've heard that timing belt interval was 30,000 miles in Yugo. Not sure if true. Mine didn't last that long.


The timing belt was a very good service item on the Yugo..no problems.

However the only reason Yugo had a rear window defroster.....to keep your hands warm, in the winter, when pushing the car.

Timing chains can be problematic too.When they need repair the costs are much higher. In the case of Audi..about $4000.

 

[sasha]

Originally Posted By: DB_Cooper
Originally Posted By: friendly_jacek
I've heard that timing belt interval was 30,000 miles in Yugo. Not sure if true. Mine didn't last that long.


The timing belt was a very good service item on the Yugo..no problems.

However the only reason Yugo had a rear window defroster.....to keep your hands warm, in the winter, when pushing the car.

Timing chains can be problematic too.When they need repair the costs are much higher. In the case of Audi..about $4000.

German engineering. Bleh

It has 5 chains? or am i seeing things.

 

[supton]

Originally Posted By: DB_Cooper

Timing chains can be problematic too.When they need repair the costs are much higher. In the case of Audi..about $4000.

Crazy! Although to be fair, on these motors... is really expected to take them past 150k?

As much as I want to dis timing chains as being short-lived, the average consumer doesn't want to run a car to 200k, and doesn't want to pay one cent for parts that would last longer than necessary.

I have to wonder when 150k service plans will come into vogue. 100k warranties now, with an option to pre-pay for 100k (with the first 25k free)... 150k is the next thing, and I'm pretty sure the maker&dealer don't want to do a timing belt job on their dime. Even if they got you to pay for it up front!

 

[d00df00d]

Originally Posted By: sasha
Originally Posted By: DB_Cooper
Originally Posted By: friendly_jacek
I've heard that timing belt interval was 30,000 miles in Yugo. Not sure if true. Mine didn't last that long.


The timing belt was a very good service item on the Yugo..no problems.

However the only reason Yugo had a rear window defroster.....to keep your hands warm, in the winter, when pushing the car.

Timing chains can be problematic too.When they need repair the costs are much higher. In the case of Audi..about $4000.

German engineering. Bleh

Pretty sure this kind of madness is fairly unique to Volkswagen/Audi.

 

[d00df00d]

Originally Posted By: supton
Originally Posted By: grampi
Why belts or chains? Why not something that truly would never wear out like gears?


My understanding is that they can have higher noise, and higher requirements to set up properly. Not impossible (otherwise transmissions and rearends wouldn't work). But kinda hard on SOHC/DOHC setups, not without lots of gears. Each of which would be yet another wear surface.

Exactly.

Por ejemplo: http://i.imgur.com/AtrI37O.jpg

 

[d00df00d]

The optimal setup, IMO, would be to have no gears or belts whatsoever except for the alternator. All the accessories including the oil pump can be electric, and soon the valvetrain will be, too...

 

[rjundi]

Timing belts never bothered me until I got an interference motor.

In my life time of vehicles I have paid out personally $1500 in timing belt changes on Civic x2($300/each) and Acura MDX($600) and our Legacy GT($300). I never went for all the extra's people get nervous nellies about like cam shaft seals, water pumps etc.....

 

[SwampSurvivor]

Originally Posted By: E365
Originally Posted By: Miller88
I don't think the oil bathed timing belts are anything new - just new in automotive applications. From what I understand, they may be popular in industrial engine applications? Can anyone confirm?

I think the biggest thing that would keep me from a 1.0L ecoboost Fietsa is the lack of interior space.


I think so.

From the Dayco website "Belt in Oil System

Dayco's newest technology is the world's first timing-belt-in-oil system for automotive applications. The belt-in-oil system, which includes Dayco's patented belt and tensioner, weighs less, has lower stretch, reduces friction and is quieter than traditional chain-drive components. For our customers, this translates into higher engine performance, lower emissions and improved fuel economy."

A Google search for "oil bathed timing belt" doesn't bring up much outside of the Ford 1.0. Someone else probably know much better than I do.

The Fiesta is too small for me too, so once they announced the 1.0 in the Focus it had my attention. The order guides are out but no pricing or MPG figures.


I'm not sure how it's going to do in the Focus. I think it may be a bit much for weight. But as long as the mileage isn't terrible, it's definitely an option for me!

I hate the MTX-75. I'd pay to get the 1.0L ecoboost just so I could get a focus with a 6M.

 

[Hokiefyd]

I think one of the major reasons timing chains have become more common is the general move to transverse FWD powertrains. Timing belts physically require more of a footprint, and for two reasons. They are physically wider than timing chains, but they also require room to remove timing covers and to allow for the in-situ replacement of the belt, the water pump, the tensioners, etc.

There's a fairly commonly available "whitepaper" that summarizes various design details of Toyota's 1ZZ-FE engine that they used to put in Corollas. They evaluated four different valve timing systems and decided on a compact chain. One of the factors was the physical footprint: the engine can be made physically smaller, and put into a smaller space, with a timing chain.

 

[Hokiefyd]

Honda's GC- and GCV-series small engines have an oil-bathed timing belt. They generally last for a very long time. The GCV-160 I have is 10 years old, and the timing belt looks just like I assume it looked like new (when I adjusted the valves last year).

 

[CT8]

They are a stick it to the consumer design.Good for the shop bad for the consumer.

 

[MinamiKotaro]

I prefer belts. They're easy to replace. If you need to replace a chain, might as well just get a whole new engine.

 

[stephen9666]

I don't mind timing belts if they're easy to replace and have a reasonably long interval.

But many aren't easy to replace. On our VW Beetle it was a huge pain. At least many modern ones have gone to longer intervals like 100k miles.