Posting this as a example of an example of what can happen when a cambelts snaps. Cambelts/tensioner were changed just under 3 years ago (2000 miles since) Driving in its first day out of the years last Sunday. Driving at approximately 70mph and all of a sudden the car bogs down some what. No bad noises just loses power. In thinking some thng sill like a bad oxygen censor, or map ect. Stop the car and had a visual before I restarted and drive home with it running on half the engine. Once in the work shop I give it a full inspection and noticed the left bank pair of pulleys were not turning. I knew that that was :rollleyes:. So after removing the engine and stripping the head. I see that the belt has just snapped, for no obvious reason. All the teeth are intact, it just snapped. The tensioner and holder are working perfectly. The lower tooth pull is turning with the crank as it should be. The other side of the engine is all in perfect order for comparison. Now the damage, all 8 exhaust valves bent, and 6 inlet. Only a few shallow witiness marks on two of the piston crowns. Looking closely at one of the valves, there is a crack in the valve. Luckily this did not break of and bigger up the piston and bore. Its will be sorted our soon. But about the belt snapping like this? I am wonder what the hell is that about. Anyway lime I said I am posting this for an example and reference for who ever might be interested. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
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Well.....that shouldn't have happened.....the belt was manufactured in 2020. I haven't seen one snap like that. It is hard to tell what happened first the belt or something stopping the camshafts from turning. Paging @Rifledriver
As far as the camshaft, they along with the can jurnals are in perfect condition. Once the head was removed that was one of the first things I checked. Both cams were free. Nothing jamming or catching. I am 100% sure the cambelt just tore. Very strange. I'm interested to hear if anyone has seen this type of snap before.
Can’t say this is a direct link, but you’ve boasted in the past running headers with no shields. Possibly introducing too much heat in the engine bay?
Looking at my Gates belt failure doc it looks most closely like a "something got in there failure". Sorry to see that.
Lol, don't start old wives tails on here bud. They might acualy believe it. There again I had slightly low air pressure in my rear left tyre which might have caused it.
I didn’t start anything. But you should divulge your setup so readers know and let them decide for themselves.
So I run naked headers just like many others do If you think that has caused a belt to suddenly snap, then bully for you. fyi I have had two belt services while I have had naked headers. You know mate. I have only posted this to show ferrari chat members, not to start an argument with you. Its all no biggie it's being fixed. I'm showing this for any one who is interested to see a snapped belt.
Do you have a reading comprehension issue? I started my post by saying, “I can’t say this is a direct link…” I’m not here to start an argument with you either, but it’s obvious you’re defensive about your no-need-for shields (or any other heat coating) stance. I’m only listing a plausible cause, which is what you asked for in this thread. In any case, you’re more than welcome to be a guinea pig. If the belt snaps again for no other apparent reason. Keep doing you. Not my car .
Are you going to pull both heads and clean out the carbon? Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
What a bastard! Sorry to see mate. Which brand of cam belt was it? I can't explain it, might be one of life's mysteries this one. Hope you're back on the road before you know it.
@Jackie and bill When you inspect the broken belt, can you determine if the break occurred at the point where the waxy tooth coating shows visible threads ? On nearly every 184986 belt, there is a single tooth (sometimes maybe a tooth-and-a-half) where the waxy coating is not fully present, and visible strands of belt material can be seen. I'm (probably like everyone) curious to see where on the belt this tore apart. (Also, sorry this happened. )
As a neutral observer, I see nothing wrong with your initial post. You clearly stated, at the beginning of your thread, that "I can't say this is a direct link...". I took from your post that you are merely trying to assist the OP in finding out what caused the belt to snap. Oddly, the OP took offense to this.....and I say oddly because it is posted on a public forum where a million different opinions and theories will be posted as to why the belt snapped. Such is life on F-Chat. The lesson learned (and when I say "learned", I'm not referring to this specific thread, but from the very first thread on F-Chat) is that if one doesn't want to hear something, then don't post it publicly. If, on the other hand, there is something one is looking to hear, then privately message those that will tell you the answer you want to hear.
Weird isn't it, but not once in my original post did I ask for any one opinions on why they belt snapped, not once. All I did and my intentions was to simply post it on here for others to see the strange was this belt snapped. I was trying to add to the ferrari chat resource. I was in two frames of mine about posting it because I have see how nasty things turn quickly among certain members. But not once did I ask for an opinion, I was only showing and documenting that a 355 belt snapped. So lesson learned here.
Hi, I will post close ups of both sides of the belt later when I get home. The belt is in perfect condition other than the place were it snapped. Nothing seemed to have got in between the belt and pulley. That would not be possible.
That's right, the expression what the hell is going on, is one I use about many things. Including all this nonsense.
I tell you what I will not bother posting on this thread anymore. I was hoping this snapped thread might have helped in some way. But as always on fchat, it's a siht show.
Only way looking at snapped belts can help us is by trying to figure out plausible causes and what we can do to help prevent it. Especially, since it snapped at the 3 year mark. Is it just a case of bad luck? Who knows?
Seriously man, I don't know why you're so offended, you could have just said "yep, uncovered headers" and been done with that. I think anyone would understand that's extremely unlikely to be the issue, looks more like a rock or something got kicked up in there and cut the belt. https://www.royalsupply.com/downloads/Gates/Belt_failure_analysis_Final.pdf Does not look at all like temp failure, looks like crimp failure.
