Kevlar timing belts vs OEM timing belts... thoughts?

[AdamVR4]

@ Cherry Hill, the OEM timing belt is $133.51... Barely cheaper than the gates racing belt.

I do agree though, it's hard to justify anything other than OEM today.

[HilbillyHomeboy]

That's got to be a msrp price, unless the price has skyrocketed in the last few years. I wasn't paying anywhere near that for them.

Yeah, I jumped on the Kevlar wagon when they first hit the market. After consideration, it just wasn't worth it, so I switched back to the OEM belt.

Jeremy

[92RT-TT]

Thanks for the info guys. I think OEM will be just fine then or that Gates one. I am planning on running High tension valve springs and 280 Crower cams but I dont plan to spin the motor past 7k.

[aaronatstate]

Just an FYI, the Kevlar belts, at least when it comes to Gates, is not the tensile member (the cord), but rather the fibers in the Jacket material (what actually makes contact with the pulleys), and there is Kevlar fiber in the rubber compound to make it stronger. This is also why they make more noise, because those fibers don't give as much when it contacts the pulleys, leading to higher noises. But the Kevlar fibers make the jacket material last a lot longer. The fibers in the rubber, and therefore the tooth make it a lot stronger.

The Gates timing belts for the 6G72 are made in Japan. Both standard label and the racing belt version. I know here in America we actually use blue rubber to make the belts, but in Japan they use black rubber, and paint the back of the belt blue, which is why blue comes off on the pulleys sometimes.

And there's nothing wrong with OEM, either All we've got is very limited anecdotal evidence. It would be great to see some tension test and CMM (or however the heck you would accurately measure a belt) comparisons.

Definitely do tension tests, along with various other tests on an Instron to determine the belt strength. Also we have various dynamic and life tests we do as well. As for measuring the dimensionals, its pretty straight forward. Length is done a machine with 2 equal size pulleys, width is done with a caliper, and thickness is done with a caliper or modified snap gage.



As for my personal recommendation for which timing belt to use? It would go in this order.

Least Desirable - any non-brand name. These are made by major belt makers, but with cheaper materials.

Next Desirable - any Brand name belt. These are made to meet or exceed OEM standards, and they do. Just as an FYI, the Gates Label, NAPA Label, and Carquest Label belts are all identical, except for the label on the belt, and the box they come in. Made with the same materials, on the same mold, and sometimes even at the same time.

Next Desirable - OEM. OEM belts have the best standard materials in them. This is why they are more expensive then regular aftermarket belts.

Most Desirable - Gates Racing. These belts have the best materials in them period. The rubber is designed to exceed OEM performance by up to 300%. They have the strongest tensile member, the best jacket material, and the strongest rubber. These belts are incredibly strong.

[DuTTch]

My Kevlar belt stretched on me. OEM or Gates FTW

[93SlugTT]

i went to a gates belt.

[aaronatstate]

I would say that OEM or brand name replacement (Gates, NAPA, CarQuest, Dayco, Goodyear, Conti) are good enough for about 90% or more of the people on this board. The other 10% I'd recommend the racing belt too (high hp applications, or people who do a lot of racing). Of course you can't go wrong with the racing belt either.

[AdamVR4]

My Kevlar belt stretched on me. OEM or Gates FTW

How do you know that?

[Vantage]

I've had no squeeling or anything yet from my Gates Racing belt. **KNOCK ON WOOD**

[aaronatstate]

How do you know that?

I to would like to know. Timing belts should not stretch more than a .001 to .002". The fiberglass cord in them has an extremly high modulus.

I've had no squeeling or anything yet from my Gates Racing belt. **KNOCK ON WOOD**

Sweet! Another thing that can cause noise, is if there is too much rubber bleed through through the jacket. It doesnt make the belt bad at all, but it can make them noisier.