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Spiralling cost of AA Battery
Laverda Dave:
I find it amazing that you not only know all these high tec engineering methods Nigel but you can remember them as well. I've never heard about sintered con rods that are actually snapped in two to make fit. Considering the high level of engineering and innovation VW use in designing engines the question has to be asked why do they use plastic (or fibre) timing gears that have a habit of stripping their teeth. I know of two people that have suffered with this failure leaving the engine as scrap. Back in the 70’s we were lucky to get 80-90k out of an engine but now the engines last forever and it's the failing electronics that scrap cars. Motorcycles are the same, electrical problems are the reason why modern bikes fail.
Interesting read though, thanks for posting 👍
McCabe-Thiele (Ted):
I agree with Dave's comments - until yesterday I had never heard of sintered con rods.
When I was in the car trade in the 60's owners would boast about not breaking down during a journey from Derby to Cornwall.
As a salesman we would tell customers about Opel Rekord C owners who were still on original clutches at 90 k miles!
Times have changed for sure.
K2-K6:
It's quite amusing that each mind stores all sorts of detail, with varying success in how we recall it and the motivation that drives the search. I joke with my kids that my warehouse of mind-crap is just much much larger than theirs and it may take a little time to find a competent answer which "must be here somewhere" ;D
I find accurate details of failure fascinating (not from a morbid point of view) but that it informs so much in how to look after that item and avoid potential failure if that's possible. Look at the aircraft industry for a run through of monitoring and knowledge of why things fail as example.
The VW stuff (a few friends share knowledge/labour etc on our own vehicles) and make it interesting to study them in more detail to look after them. The cam drive wheels, if that's the failure point Dave, are another component that's well made but you have to handle carefully to avoid compromise in their structure. You can never even tap them, only using specific puller to remove if necessary too, that's absolutely vital. Some of those aren't even keyed to camshaft and just driving on a long taper joint (cams locked, belt installed, tension applied while all drives can move freely to distribute overall tension, then tighten the cam to drive bolts to set everything in place) some of these routines people don't understand the reason why they are that way by design and fall foul of loadings running out of range for component. Some (vauxhall i believe had a period of them) have plastic based idlers on cambelt that failed because of not being replaced at correct interval.
Another problem is with cambelt driven water pumps, originally they were plastic impeller that would fail in the event of frozen coolant, being a sacrificial component (perfectly logical) they are often replaced with "real metal" one's, but if they do freeze the system the result is a shredded cam belt/missing teeth and catastrophic failure.
Engine life has improved hugely in cars though, principally I feel because of fuelling not being to excess (not diluting the lubricant is paramount)with very good control of this, along with "synthetic" oil. It's not because the oil is fundamentally better lubricant, but far more consistent flow characteristic can be achieved for optimum supply, but that's been enabled by the fuelling being better. A circular achievement but far reaching in terms of engine wear.
Bryanj:
Used to be common to hear from the escort cvh owner " its only done 28000" when there 6 year old belt broke
flatfour:
I believe that fibre timing gears were originally introduced to cut down on noise. In many cases, metal gears were an aftermarket "mod" in the day to improve durability, however that did come at the expense of considerably more noise from the gears.
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