The belts only tend to break as a result of something like a seized tensioner. My experience with the (OEM/SKF) tensioners is that one minute they are OK & the next they aren't. Most people are fitting the Hills bearings these days it seems & we don't yet have any data for how long they are good for (and I'm not aware of anyone taking one off because it went bad yet). Its 2 1/2 years since I put mine on & I changed the belts this year (after 2 years) - but only because I had to fix a camshaft oil seal O ring leak. The intention is to change the belts again in 3 years & at that point the bearings will be 5 years old & I'll probably change them again.
I do mine every 4 to 5 years, also have everything checked and replaced as needed. Replace fluids every year also. Never have had any problems in 32 years with her.
7 years and 12,000 miles on the QV I just purchased, of course first thing being completed is a major. The removed belts looked ok but the tensioners not so good.
After all the differing opinions I heard when I first got the car, I settled on a 4 year routine so due next year. I think "time " rather than mileage makes better sense since the natural degradation of the material has nothing to do with whether it 's used or not.
I know! Ask him about a timing belt and he will lose a night's sleep in frustration. It's like me and R134.
Mine currently have 5 years on them. I plan to change this winter. Just as a data point, when I bought the car they had not been changed for 12 years. The belts were in good shape but one of the tensioner bearings was shot.
This thread should probably better be entitled "how old are/how many miles are on your tensioner bearings" - that's the real issue, not the belts (IMO).
Hey Chris, is that the single belt system or regular 2 belt set up ? I'm having issues with the Gates website. They don't match the 308 with the part number on the photo you shared. T201RB thanks
Larry, It's a 2 belt "adjustable pullie" system from Scott Mcgee. Different belts. Image Unavailable, Please Login
Every time I see a pic of the belt path on these cars I just cringe and think, "who the heck designed that?" THere's a lot more stress on the belt and tensioner than there would be with a "straighter" run. Seems obvious to me that it's the reason Ferrari put out a bulletin in the '90s to change them every 3 years. Wonder why it took them so many years to abandon belts and go back to chains. Oh, right, belts for these cars is "as Enzo intended it!"
I don't follow, the path is about the least complicated and shortest route possible, the tensioner sits exactly where it needs to as well. The life cycle on the OEM belts is due to a couple things, belt construction and that very tiny lower drive pulley, coupled with a shallow tooth design and high rpm it's not going to last long. And that is why I spent the time to re-engineer and design a new one using modern belts.
Absolutely. I cant see any better layout. Changing the belts and pulleys to the type of belt pictured is a great step forward. Ferrari should have switched to this type of belt. To bring up Lotus again (sorry ) they changed to Fenner HTD belts as soon as they were available. This is the same design as the Gates one pictured. They tested a car by driving for 100,000 miles on the same belts and found that there was no visible wear and virtually no change in the belt tension. This upgrade should be very worthwhile.
I have a slightly different bent on this. The path of the belt is to keep them securely engaged on the cam pulleys at high RPM. I believe the issues stem from using a design that was intended for a 2 valve set up but was extended to a 4 valve set up. The 4 valve set up puts about twice the load on the belts and tensioners.
"I don't follow, the path is about the least complicated and shortest route possible, the tensioner sits exactly where it needs to as well." I don't like that nearly 90 degree turn at the tensioner - it just adds strain and friction to the drive setup. It could have been done with nearly a straight line between the cams and crank pulley as it is on many engines, with a tensioner more toward the center of the run and with only a slight angle being enforced on the belt. OBviously there was some reason they opted for that tortuous routing but I can't figure out why. Maybe the engine was initially set up as a chain drive, which wouldn't have required that sort of tension device at all and then later it was determined that a belt drive would be cheaper. I don't know but given a clean sheet of paper, I don't think any engineer would have decreed that as being the best way to route a cam belt. You know what it looks like to me? It looks like they came up with a tensioner to work with a belt that was way too long for the engine. Maybe Ferrari ordered the wrong length belts, ended up with 10,000 of them and had to modify the engine so they would work! Yes, I'm kidding re the last paragraph...at least, I THINK I'm kidding.
