[DocG]

Originally Posted by iMakk

This confuses me a bit coz chain technology is an outdated technology. Why would Maruti go back to a 20-year old technology? So the questions are:
1. Whether the engine actually has a chain instead of a belt
2. What is the advantage they are seeking with a chain, if at all there is one

What makes you say that Timing Chain technology is outdated? Chain drive was adopted by BMW in 1990.

Chains provide a few advantages such as lower maintainance. If you ever have a belt snap on you, you'll understand the difference!

1) Yes there is a chain
2) You never have to replace it, it's much more robust

[arunforu1]

Originally Posted by anupmathur

Hey, Arun, while I'm not an engine designer, I do have experience in the field.
For high performance the clearance volumes are so small that it is not possible to leave the kind of margins that you consider so basic.
Which is why an engine with a timing chain is inherently superior from this POV. Gears are even better.

In all fairness, a timing belt is not supposed to break randomly! That you might have friends who've had to suffer this fate only highlights poor maintenance and/or very poor manufacturing quality controls.
The least you'd expect a timing belt to last would be 60,000 kms. And it ought not to sever before at least 80,000 or so!

Thanks Anup Ji for throwing light on the matter, i thought so also, to achieve higher comression ratio it is necessary to reduce clearance volume. But there must be a way out by playing with Head-side surface of compression chamber & piston dome. Or altogether thinking of a new valve system, if it is so, it is indeed a failure prone desing till date.

A belt lasts more than 60k but if snap does happen it should be taken care while designing, anyway thats my personal opinion. If it is so then we have to live with it, till some one changes the technology of valve mechanism.

We have CRDI in injection system, the valves must also get rid of mechanical or hydraulic system. Being a part of industry i have heard it few times, that fellows are already experimenting with electronic controlled solenoid valves.

[sgmuser]

SX4 Wagon I am driving has timing chain, I can confirm. Btw, I am driving a VVT.

[D.V.R]

How do I know if my car has a Timing Belt or a Timing Chain?