Lets set the record straight about belts.

You're late to this thread padner! LOL!

Read back to the start....it's off the rails and it ain't comin' back!

It was a theoretical statement about personal anxiety, I didn't mean I actually worry about it..........much.

If you can't be the first, you gotta be the best!! The story of MY life.....

 

trapazoidal is the cross section of the cog or tooth on the belt. the belts that run the accesories and PS WP are 'v' belts. the replacement to the trapazoidal is a curvelinear cross section. less stress and more contact.

 

Vern, did you see him in Vegas too, I was there last April, times must be tuff for Elvis, he was working all over the place.

Doug

 

Ok, that why mom liked Brian better

 

I understood exactly what you are looking for and you are 4th, 5th or 10th to the party starting threads on the exact fact finding mission.

Thats why I suggested a search. Might be easier to look at all the previous reaserch and learn from it.

 

The only cars that I have had personal experience with a belt breaking have been the 308/328 series. The belt does not actually break in the sense that the loop of the belt opens up, but rather the small drive pulley pulls enough of the "lugs" or "teeth" of the belt that the pulley spins. The belt and the cams stop and the valves are bent. None of the cars that I have done have had any more damage than bent valves.

 

And just to throw gas on the fire, the same engine damage can occur from a failed/exploding tensioner bearing, road debris entering into the covered area and causing damage, we have even heard of new bearings being defective out of the box.....

It's really about minimizing the odds of a failure, you'll never reduce the probability to zero.

Also consider my NON CAT cars have reduced engine compartment temps vs. later CAT equipped cars, which the Tech Bulletins are addressing, so there's just too many environmental variables to come up with a "one size fits all" determination.

You'll see some belts removed that appear in like new condition, maybe with a shape 'set' as carreaper mentioned, and you'll see some that were within miles/minutes of failure.

 

Do the 308s all have 2 cams per head or is that just on the QV's?

Doug

 

No, 2V cars are DOHC as well.........

 

Not to get far off a subject that has been beat to death here, it was reported both victims were alive when the car landed upside down, the female or model was trying to get out. Cause of death was burning.

 

agreed.......

 

My 1985 308QV shredded a belt in Dec 05, with about 6.5 years on the last change, and about 20,000 miles...cost about $6000 do basically do it my self.. I have had the experience, bought the books, wear the T shirt and I would say that you are an IDIOT if you think you can safely go more than the reccomended mileage or time without changing the belts!

The plain fact is these care not toyotas, and demand lots of maintenance... so if you dont do the reccomended mtns... then I think you are on borrowed time... some folks live years like that ... others ( like me ) dont! I posted the whole mess showed how much damage was done - every valve bent... and by the way me and my friend Walt P... dropped Sodium valves all day long and guess what ... they did not do a damn thing!.... so before you trust your bank account to someone on this site that says " yea I've ahd 40,000 miles and 20 years on my belts and my mechanic said that looked great" I would simply do the Freaking maintenance...and dont worry about it! or sell the car!

P.S. I have also had an engine rebuild on a 308... & I can give you 17,000 reasons why you dont want to do that either!

 

So 3-5 years or 30k miles, whichever comes first is the consensus?

 

Ferrari says 3 years/30k miles. That started in 99 with the intro of the 360 and later was applied to all belt drive motors.
Prior to 99 they said 5 years/ 30k miles.

In other markets it has always been lower than that. I think in the UK they say 2 yrs.

 

I'm assuming OEM belts are still being made and are not old inventory sitting around for 20 years or more oxidizing? And is there a "better belt" to be had?

 

What a facinating thread, hard to imagine no one discussed this before

 

Yes, you heard that...

"6".

Not any in the F car, as when I got it, it broke them both and took out 6 pistons and every valve in it. Thus why I have the car. But I've taken out 6 in my Sol's. Usualy it's because she's on a fresh build, and because I spin over 10K with it. I usualy don't break them on accelleration, but on engine braking at 11K plus. Most of the time when I pull them down for the valve and head work, I find they were tagging well before she stripped the belt, thus why I think she looses belts so often. Using the pistons to close the exhaust valves on engine braking gets expensive, but it's what I do.

Spin them to the moon, break them, do it again.

The rev limiter chip is set to 9,800, I engine brake to 10,500-11,000 and sometimes higher depending on the conditions. Once she gets "broken in" the valves seem to come closed a little better up there, but I'll tell you what, there's few things that make a FWD car stop faster than revving her over the chip on engine braking. I don't hit fuel cut untill 12K, so when she's on engine brake, she'll spark cut at 9,800 and go rich on the fuel by program. This basicly locks the wheels up with no brake input at all. The only issue is when she's engine braking that high and hard with the chip popping you can't tell if she's "breaking" or if she's backfiring. It's once you get BACK on the throttle that you know if she held together.

Call me nuts, but I LOVE the sound and the feel of running her that high. I built her to do just that. Occasionaly, she breaks. When she does, I don't cry, I slam a set of crappy slugs back in her, check the valve springs and retainers, slam a set of used rockets in her, check the cam, and drop a set of crappy used valves with a nice face cut on her. My autocross engines are glorified, well machined, stock part trash cans. When a kid wants an "engine swap, dog!", I'm left with the old single cammer out of the car. At one point I had over 30 of them. What's the easiest way to "scrap" leftover engines? Go out and BREAK them, then you don't feel bad about taking them to the scrap man. I havn't had more than $500 in ANY of my autocross engines. Stock rods, stock pistons, stock valves, Crower cam and springs/retainers. Spin it till the head holds the pistons in it. When it lets go, I have 18 more just like her on the shelf I can slam together in less than 3 hours and have in the car in 2 more. In the class I run, you have to have "all stock internals, or OEM compatible replacements". Valve springs and retainers aren't considered "race" parts, so long as they have the same specifications. The crowers I use are so close to factory specs, it's considered aftermarket replacement. Thus why I still drop valves. If I had REAL springs and valves in her, she'd NEVER come apart, even with stock rods and slugs.

As for "high end" timing belts, like the HKS blue silicone etc... No difference. I ate one of those $250.00 belts the first weekend. I've found that Gates makes the best belt for a whopping $16.80. I've chewed all 16 valves right off and not broken a Gates. As a matter of fact, this last Gates belt has outlived 2 heads and slug sets. OEM Honda won't live past the 2nd valve tag. Goodyear? Breaks the main belt portion at 10,500 under acceleration. Kelly/Springfiled looses all the teeth the first time you reverse load it at 11K plus.

If you want to know about broekn timing belts and valvetrain parts... Just ask me. I've broken everything there is to break.

Did I mention that this engine spins to 7,200 from the factory yet??

Stick

 

There is a sad truth that with many of the Ferrari that sheared a belt, the owner went into hiding, the car got repaired, and then was shuffled off through someone else never to be seen again. No record, no history, and no one talking. People can say all they want, but money talks. Many come here and tell how far they can run belts, how many miles or years they can go, how its poor economy to change the belts or service the engine to Ferrari schedule, but wait until these people are on the buying end. Watch how suddenly they want the car they are looking to buy serviced and have up to date records. Same with mileage. They say mileage shouldnt matter, but how many times will the ones saying it pay good money for a high mileage car.

And how many who think banging pistons into open valves after a belt shears would ever want to buy that car? None of you. At least you dont want to pay good money for it even if it were repaired properly. I dont like heads that have had welding work done on them if I can help it.

These threads on this subject are popping up every few weeks or so, same stories, same old BS. There should be like a sticky on it, and a FAQ everyone has to read before subscribing, just to keep from discussing it anymore, because there are to many of us with differeing opinions. I for one will never concede to running these belts past 5 years of 30K miles. At least I would never recommend anyone else do it. Not someone I called a friend anyway.

 

this brings up a valid point I have always thought that reverse loading puts the most stress on these belts, probably causes a lot of slack and other stress in the belts as well, tracked cars will have had hard reverse loading happen at each track session.

 

Just wear the same color belt as your shoes and you will be fine...