Carpokes Porsche Forum

Time to do the belts on my 951. I was curious if any one has used the Gates Racing Kevlar timing belt? And any other opinions as well. Would it last longer, is it worth it?

Thanks, Dave

I have one.

No issues but the roller bearings will fail before the belts

Ditto what Grushy said. I have one too. They might be worth it if you have a hotter cam or springs.

I always wondered about tensioning those belts. Since they are not the same in terms of stretchiness, I wonder if 2.7 on the factory tool tensions it looser (or tighter) than you'd get with a factory belt at 2.7?

I use the factory setting and have never had an issue.

I think the kevlar belts are useless. The teeth are what will shear on a timing belt after so many years. I have never seen one snap completely before losing a tooth.

naesjr wrote: Tue Jan 31, 2023 4:13 pm I think the kevlar belts are useless. The teeth are what will shear on a timing belt after so many years. I have never seen one snap completely before losing a tooth.

but they are blue..... has to be better!
As previously said - belts fail because a tensioner or water pump failed. That begin said there is no down side to the 'racing' belt.

I agree with others that the Gates blue belt is not totally necessary, the standard ContiTech or equivalent belts can last well past the recommended replacement interval (though I obviously don't recommend pushing this!). Roller and water pump condition are paramount. I just acquired another 944, an S2 cabriolet (wasn't looking for one, but it was cheap, needs a clutch) with a 12-year old timing belt that looks great, only has a few thousand miles, but I will be replacing it along with the rollers (and the timing chain tensioner pad).

I have a Gates "racing" belt on our '74 Jensen-Healey roadster with the Lotus 907 engine, as it happens to be the one readily available via the Lotus parts supplier that is local to me. The tension requirements do seem to be different from a standard belt (blue belt is stiffer and requires less tension), which sends the Jensen-Healey crowd into a tizzy as they are already neurotic about timing belt tension specs and tools and the pros and cons of each. Some swear by one tensioning tool, some by another, others use acoustic tools to measure the frequency generated by plucking the belt like a guitar string (which some OEMs use). I have a lot of experience with 944 and 928 timing belt tension, so I simply chose tension by feel/twist, and backed it off by a hair to quell whine, has been great for 20K+ miles with no visible timing gear wear.

While we are on the subject of timing belt tension, our other strange car with a timing belt, a 1981 Alfa Romeo GTV6, has a very clever but somewhat Rube Goldberg mechanism to maintain belt tension, it is actually referred to as a DE-tensioner, kinda like the 928 version but more complicated. Check out the US patent for it here:

https://patents.google.com/patent/US4077272A/en

cda951 wrote: Tue Feb 07, 2023 8:12 pm .... which sends the Jensen-Healey crowd into a tizzy as they are already neurotic about timing belt tension specs and tools and the pros and cons of each....

Sounds like my kind of crowd!!!

chris white wrote: Thu Feb 02, 2023 2:00 pm but they are blue..... has to be better!
As previously said - belts fail because a tensioner or water pump failed. That begin said there is no down side to the 'racing' belt.

I think losing lunch and beer money for a day is a downside.