How the Timing Belt Tensioner Actually Moves

[Chris@Rvengeperformance]

Not only are they still making them, they still USE them in Hyundai and Kia.

Hmm my 2012 Kia shortage has a chain. I know 2011s had a belt.

[RealMcCoy]

Hmm my 2012 Kia shortage has a chain. I know 2011s had a belt.

It's possible I overstated that... I really haven't payed much attention to what they are offering in the last couple years, I was primarily stating what I'm seeing in the shop, which is often at least 2-5 years old.

I'm still seeing DOHC 6G74's in pretty late model vans and SUV offerings from Hyundai/Kia, hence my statement they still use them.

[AdamVR4]

Great footage. Thank you! The gauge needle is basically a blur @ 5000 rpm's swinging over a ~10(?) mil* range... Do you think that's due to vibrations, actual movement of the tensioner, or both?

*mil = .001" for the newbs

[J. Fast]

Interesting. I would be really surprised if the timing belt is stretching. Would be interesting to see how the slack event is impacted when using solid lifters.

[sergechronos]

Well, solid lifters are out of my price range, but I was going to buy a solid tensioner and kevlar belt anyhow, so Maddog if you would be so kind as to do a video showing OEM hydraulic with the kevlar belt and then the solid with the belt, I'd happily have Chris ship it to you first and then you can just ship it to me once the videos are done.

[Maddog]

Well, solid lifters are out of my price range, but I was going to buy a solid tensioner and kevlar belt anyhow, so Maddog if you would be so kind as to do a video showing OEM hydraulic with the kevlar belt and then the solid with the belt, I'd happily have Chris ship it to you first and then you can just ship it to me once the videos are done.

I would be happy to test a kevlar belt with a stock tensioner. I'm not sure what I could measure or look for with a kevlar belt and a solid tensioner.

I do have a video of the engine warming up. Basically it pushes the tensioner in around 30 mil as the engine warms up. Its 12 minutes long and I havent uploaded it. I can if someone really wants to watch 12 mins of and engine idling.

green-lantern I should be at NG. thanks for the thanks

Adam, I think the movement is due to vibrations of the engine acting on the mount. When i press on the body of the dial indicator it seems to dampen it but I dont want to mess with the readings so I have been looking at the middle of the needle blurr for an idea of where its actually at. I dont think the tensioner would be able to move that quick but I could be wrong.

J Fast if the belt isn't stretching what do you think is causing the movement? I'm open to ideas.

[sergechronos]

I can't imagine that the solid tensioner and kevlar belt would move at all, but would be interesting to see if there is any movement from anything with the solid and kevlar set up. If increasing RPM/load causes any kind of flex or movement or undue strain on any of the gears or pulleys. I think that the kevlar belt with the hydraulic will be the most telling of anything as far as measurement (if the movement from before is due to belt stretch or something else.) PM me your address, and I'll have Chris ship it out to you when I order it.

[futurevr4man]

I thought McCoy hit it on the head. The belt isn't stretching (much at all), the slack is just shifting. There is a little slack all throughout the belt when the engine is sitting still, but that slack gets shifted over when you increase rpm. That's also why I'm not real fond of the solid tensioners. Sure they aren't hydraulic which means they won't fail, but they also don't take up the slack. Increase rpm with a solid tensioner, and you will get a significant (comparably to stock) amount of slack in the belt. I'm not sure how much a belt stretches out over a period of 50,000 miles but its possible that an old, stretched belt could get so much slack that it would skip a tooth on the crank if using a solid tensioner. I don't think it's likely at all, just possible.

[green-lantern]

I thought McCoy hit it on the head. The belt isn't stretching (much at all), the slack is just shifting. There is a little slack all throughout the belt when the engine is sitting still, but that slack gets shifted over when you increase rpm.

I'm a fan of this theory also.

[Jimvr4]

I love that we have people running tests like this, helping to explain why Mitsu engineers did what they did.