And tensioner bearings seldom fail. Back at the market bottom when these cars were going for $50-$60k dealers with drop the engine, do a belt swap, and sell the car. They weren't changing seals, bearing..... So where are all those car with old bearings that are falling apart 6, 7 years later. Where are all these failures? Belts, bearing, water pumps.... People post here when they blow a fuse. Where are the major failures? The worst thing I've seen posted is a little oil weeping from a seal. Something I certainly wouldn't be running off to have corrected before some schedules service.
i got my personal experience on my hill eng. 360 tensioner bearing. replaced my 360 belts and bearing in sept.2013. Replaced belt and bearing again Jan.2019. so 5.5 years of service(8000 km) of this hill eng. bearing. It has noticeable play in the rotating part.
i wouldn't say that. because I didn't compared the play with OEM bearing's play. I'd think the play is to be expected. I am not an expert, so I don't know. Hill engineering reps may chime in a have a take on this?
There is a good topic for a new thread. It would be interesting to see when and how many. "When" being the most important, because it can be argued that as time goes by the materials, lubricants, and manufacturing technology keeps getting better. Yes? I would be confident that the bearings that were installed in my last major are much better and will last longer than the ones that came with it from the factory in 1995.
No, not really. One of the reasons Hill has been so embraced is Ferrari has been getting really cheap on sourcing bearings. For a very long time it was a non issue but about 10 years or so ago the bean counters have had them sourcing bearings form low bidders around the world. It used to be that every bearing from Ferrari was a top brand. That is ancient history. Also the entire fleet of Ferraris with belt drive engines has reached an age they are not driven nearly as much. The newest V8 is now 15 years old.
Yes the belt drive engines are no longer used nearly as much. Now if you thought the belt drive system was problematic, check out just how bad the late model chain drive engines are. Many makes falling victim to chain failures
Cam drive failures have been an issue and a very real engineering problem since OHC engines were invented. When I switched from working on domestic cars to imports a long time ago I was really struck by how much of our time was spent repairing or servicing cam drives. Gear drives are better than the others and is why they are almost universal in aviation recip engines but are expensive and noisy. Chain and belt are really the other 2 options and both have pluses and minuses. Chains in push rod engines have never been maintenance free either but failures almost never do engine damage and they are reasonably inexpensive to repair due to the simplicity of most pushrod engines.
Adding to my last post, cam drive issues in Ferraris are big news primarily due to the expense of repair or service. If the motor didn't need to come out it would not be any bigger news than routine chain and tensioner replacement in virtually every Mercedes Benz in post war cars or any flat 6 Porsche. I had a Ford Explorer that needed chains. When I found out the motor needed to be removed and disassembled I sold it instead. These stories are finally becoming more common.
They were bad before and now really bad on someengines because of the variable valve timing. We had a dozen or so ford f150 that needed cam chains, sprockets, and variators all between 50 and 90 thousand. All 2006 to 2010. Likely this was a poorer design mind you.
Modern chain drive systems seem to be more trouble than belts. The chains and sprockets used today are very narrow, great for friction and economy but the life span is short. Coupled with inferior chain guides and rails the best you can do is keep your engine oil clean. Some of today's services schedules are 30,000kms apart. This is just a recipe for disaster. Chains need only stretch less than a link over the full length and on comes your cel. Code= cam / crank correlation. Ill take a belt drive system that is indeed designed to be serviced rather than the chain drive that is hidden inside your engine. Jaguars x300 range of 6 cylinder cars were prone to munching up the chain guides and getting sucked up the oil pick up, blocking oil flow and destroying engines. Choose your poison gents! ☺
Oh and unless you are talking about using joiner link in a flat 6 porsche, the engine does in fact need to come out and then dismantled. By the time an early 911, pre 90' needs a chain it will also require many other things, of note particularly would be the replacement of all cylinder head studs.
And on some mainstream cars the drives can be bizarrely complex. Hyvo chains are a great design but not when they are 5/16 wide.
You must be referring to something like the Audi/VW 4.2 V-8 where the chains are up against the firewall and look like a mechanic's worst nightmare... Image Unavailable, Please Login
That looks like the result of an over active imagination and too much compute simulation. Snowflake engineering. Not only "who though that was a good idea, but what manager approved the design?
