It would be interesting to know how many turns of thread are exposed on the adjuster with the new chain & guides. One of mine is down to about 1-1/2 turns & the other is about 5. It is also interesting to note that one has a washer under the locknut & the other doesn't. The one with about 5 turns is also leaking engine oil from the adjuster. Looking at the parts manual it has an O-ring inside to seal this that will need replacing at some stage. Cheers Al Image Unavailable, Please Login Image Unavailable, Please Login
Al What car is that? It's not a 400i. I think my adjuster was weeping at the thread and probably the gasket between adjuster housing and motor. All will be new soon. Motor is going back together..... Ken
Here are some pics of the old tensioner and the guide along with the new guide side by side. The wear on the guide and tensioner are not enough to take up all of the adjustment, so the chain clearly had stretched. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Thanks for the pictures Ken. Looking at these I have made up my mind that the engine will need to come out of the red 400I (the first extremely dirty picture). I already have the diff & torque tube out & need to replace seals in the auto so I might as well get this sorted at the same time. Cheers Al
Instead of the rubber crap they should have put a ball bearing sprocket on the adjuster instead of a piece of rubber on a curved piece of metal. There would be less friction and it wouldn't wear out.
Hi Ken all is good because your fixing the problem. I have a thought (always dangerous) I could be wrong here but!!!! I think generally all is ok with the original design for several reasons the first is there are several ball bearing races in the front cover which wear over time and would require replacement and therefore front cover removal but secondly and vitally I think the wear on your pad is due to overtension again not through any fault of your own as the advice is reasonably rough on this but it has basically sacrificed itself! to say the least. If this was made out of something not forgiving one could end up with catastrophic engine failure ie chain bearings bits and front cover disaster the tension is high but set correctly it does not wear the pad out normally before any bearings need replacing or other front cover work. The setting requires a weight between the cam ends certain amount (check wsm) and all will be good. I would be very carefull about replacing the materials used with something different than the original not to say you couldn't but it reminds me of other arguments like replacing rubber suspension bushings with poly bushings that are ten times harder than what the whole setup was designed to be and totally the wrong item for these cars less critical mind you but not good, stick with the guys that knew ie Ferrari. Regards from Scotland and keep up the good work Alastair
If you feel the material on the new tensioner and compare it to the old you will fine the new stuff is soft and a little pliable. The old tensioner wear material feels like hard plastic. With time and heat the material gets that way and will disintegrate.
Ken, I wholly agree. In Ferrari's effort to save money and went away from the cam drive set up of short chain and gears like in the Daytona to one long chain to drive all four cams in these cars I wish they would have just gone to a belt, it would have been much cheaper to replace and lasted longer. Which is of course what they did.
According to shop doing my work, many of the V12's (older?) had sprocket type tensioner. Lucky us!! Ken
The friction material is now maybe 40 years old on some of these cars. It looks as if it is a type of rubber, and that can be replaced with many more suitable types of plastic today. These plastics can be bonded, riveted or bolted on the tensioner and will last much better and not break up, like we can see on some of these. I also think one should be very careful not to overdo the tightening of these adjusters. I think the best adjustment must be slightly past the point where the chain becomes silent. Rather adjust more frequently, in smaller increments. I would fit a piece of suitable piece plastic, nylon or teflon to the tensioner in the picture. Ford make engines with chains that need to be replaced every 250000km. I don't see why Ferrari should not be able to do that too. Properly made, I will prefer chains to belts any day, especially if the engine is an interference unit, where a break bends valves.
If Ferrari went to the effort to "save money" by using the equivalent to babbited connecting rods in the adjustor for the timing chain, they did no one any favors except themselves. This is a shoddy design using predictably problematic materials. Any form of roller bearing idler would have done a better job and would have never failed under normal service. Or maybe they should have put plastic dowels in place of the upper idlers? Then all of the chain diverters would have fallen apart within the "pull the engine every three years" nonsense time frame that permeates the later designs with rubber band timing. This isn't exotic engineering, it's pathetic engineering. Designed to fail. Unfortunately it didn't generate enough ludicrously expensive service work for the dealers, who complained as they don't get rich selling the cars, thus the leap forward to timing belts. Leaving a "weak link" device in a performance engine is never a good idea, especially to save money.
Good points however, the Ferrari chain will last 250 000 miles they only suggest replacing when the cover is off, Ford don't mention the fact that any bearings in there setup will be knackered before that mileage. Under normal tension the chain does not stretch more than 0.5 of a mm in 30 000 miles.The front cover design apart from ease of access to the tensioner is actually fantastic a piece of engineering excellence. Regards Alastair
