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Why do some car makers use cam belts and other chains, why is it that certian German marques use plastic on such critical components such as cam belt pulleys and belts? then when they switch to chians the design them so the oil feed is poor - is it basically to make more cash in service and repairs? any replies welcome, thanks.
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Don't think it's as cynical as that. Two types of design, engineering led and cost led, guess which type car makers use (clue: beancounters in charge). This is the reason why the vast majoirty of us drive FWD cars. Its cheaper to make (Cue RF).
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Alas PU the bean counters are taking over at your favourite bavarian marque as well.
Its all cultural...
German cars - built by engineers out of girders
French cars - built by classy designers ouf of chiffon
British cars - built by the workshy out of woodbine packets.
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TourVanMan TM < Ex RF >
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British cars - built by the workshy out of woodbine packets
Well I would normally agree but did you see that Submarine Rescue programme, how the British meccano kit beat the Americans'
multi million bit of state of the art kit to rescue those poor Russian Sailors.We can still cut it !
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You may be right, PU. But I am just old enough to have signed up to the FWD idea when the Mini and 1100 came on the scene, which I did because it seemed to make logical sense to generate torque in the orientation it was needed, and to have a centre tunnel which only had to accommodate an exhaust. I would be interested to know more about how much cheaper FWD is to build.
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Well there is no propshaft, diff, or rear axle to design and purchase, plus rear suspension can be made of much lighter materials.
The real saving however is a commonality of deign. Your FWD package can be slapped in your entire range of cars from super mini up to much longer cars.
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TourVanMan TM < Ex RF >
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Likewise RWD with simply a longer or shorter propshaft, also why do VW have longtidudinal and tranverse FWD installations of the same basic engine.
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FWD? I can see it only being very very marginaly cheaper. Have a good look at a old sierra and rear drive shafts out of diff are similar to any FWD. So you have a separate diff and a prop shaft that are extra.. Can't see that adding up to much
Suspect it is more to do with packageing
Don't know about certain VW models using same engines longitudinaly & transverse but i worked on a friends 1.7 renault 21 (transverse)next doors 21 diesel is longitudinal...
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I came across a very small item the bean counters missed.
I replaced a very plain rear door mounted Mondeo speaker grill.
I was very surprised to find there were LH & RH grills.
The difference in shape was tiny.
Well I am all for nice looking trim but who is going to eyeball up close such trim than exists in relative darkness by a passengers knees.
A common Lh & RH model /part number would seem obvious.
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>>A common Lh & RH model /part number would seem obvious.
Yes, this very issue, I am told, is one of the ways that the Renault/Nissan merger is currently helping Nissan take cost out of their cars (hopefully!) without sacrificing reliability.
Number_Cruncher
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I wouldn't necessarily call these design faults. There are pros and cons for each engineering choice.
For example belts are cheaper and quieter than chains, but they have a shorter life before replacement is required.
For most buyers (backroomers being an obvious exception!) whether their new car has a belt or chain camshaft drive is not important.
So, when taking a decision to improve the trim quality, or to improve the quality of the cam belt tensioner pulley, which is more likely to bring a higher price and profit margin for the car? *Every* punter will criticize a poor fitting, but non-functional piece of trim, but perhaps only one in a hundred would be concerned about a detail design feature of the camshaft drive.
We get the cars we deserve, people at large witter on about "build quality", but remain technically illiterate - so they get a market awash with naff FWD euroboxes with swish interiors.
Number_Cruncher
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We get the cars we deserve, people at large witter on about "build quality", but remain technically illiterate - so they get a market awash with naff FWD euroboxes with swish interiors. Number_Cruncher
Agreed - there's no consensus on what is meant by build quality, and for most of us it's difficult or impossible to tell how good it is just by looking, based on my definition of how well screwed together and reliable the complete vehicle is.
I recently had a lift in a Focus (not a bad car I understand) and was seriously impressed by the interior finish and materials - but it doesn't say anything to me about build quality in itself. I do believe that the build quality of the three Hondas I have bought so far is very high - based on the fact that nothing has dropped off or failed - but an assessment based on the amount of hard black plastic would be average.
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Are you seriously saying you would buy an dynamically inferior car because it has a chain cam engine than a superior one that has a belt?
I dont choose cars on the basis of the cam drive. Aware of it yes, but not a slave to it.
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TourVanMan TM < Ex RF >
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[Engineering design hat on]
Just because a component is plastic, doesn't mean it's worse than one in metal. When you design a part, the first thing you choose is the material and then you design the part to cope with the requirements. The choice of material can be down to cost, but also weight, static and dynamic strength, production quantities you estimate etc
Poor design, poor testing or poor specification of the requirements can make a part bad rather than just what it's made of.
[Engineering design hat off]
No, I'd better keep it on because I'm still at work :-)
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Cars without roof gutters.May be more aerodynamic and aesthetically pleasing but a pain in the backside(or a damp one) when you open your drivers door and snow drops off the roof onto your car seat!.Doh
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>>when you open your drivers door and snow drops off the roof onto your car seat!.Doh
I heard comments on this on radio today,ie phone in,most people said wipe it off the roof before you get in.Some think the rubber inserts on roof is the replacement gutter-not the mounting points for roof rails
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Steve
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Aerodynamic rain gutters can be incorporated.
Vauxhall Astra Mk3 & 4 have an effective rain gutter, which is covered by a plastic strip. Doesn't win prizes for style but keeps the drips off the seats and with a Cd of 0.291 (Astra Mk4 saloon) is quite good aerodynamically.
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A fault to one person may not be to another.
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Also the stupid design of some cars that forces you into using a dealer to change headlight bulbs.
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I've learned how to change the Renault's bulbs now, since another went last week. You need to be prepared for a few scratches on your arms and generally you need the dexterity of a chimp to do it but it's a nice feeling saving the money.
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