On Sat, 24 Apr 2004 17:29:50 GMT, "Gord Beaman" )
wrote:

"Friedrich Ostertag" wrote:


I always find it intriguing, that almost everything we develop today as
supposedly latest techology has been there half a century ago. The only
really new thing in engines today is electronic control.

regards,
Friedrich

Exactly...and it's one of the reasons that, although I consider
myself quite knowledgeable engine wise, when I open the hood of
an ailing engine I quickly close it and get on the fone for a
towtruck...there's just so much complication in all the
electronic sensors, computers etc to squeeze every ounce of
efficiency out of a litre of fuel that I find it daunting.

I like to think I know a pretty decent amount about engines, enough to
do my own maintenance when I was too poor to go to garages. But when I
got the Puma, I didn't even bother opening the bonnet. I knew I
wouldn't recognize much of what was under there and that the key
things would be hidden from view. All I needed to convince me that the
running gear was in excellent shape was a flying trip down the local
dual carriageway :-) (Happily 3 years later nothing serious has gone
wrong)

My wife's Corolla just finished it's lease and I bought it and
leased another Toyota for her. A 'Matrix'. They have an
intriguing feature called VVTi (Variable Valve Timing). Neat
system!...hope it's rugged!...

This is on the Puma too, as Variable Cam Timing. I think it's fairly
failsafe. Taking a mechanical engineer (which I'm not - I'm an elec)
view, I'd say they do it by retarding/advancing the valve timing
according to revs and load. So if the system fails or degrades, the
valve timing wouldn't adjust but the cams would still go round and the
valves would go up or down. Not heard of rampant engine trouble in the
variable timing cars so they must have got it licked.

It seems to work on the Puma ... I moved from Rover 2.0 16 valve to
Ford 1.7 16 valve and the Ford unit has just about equal power but
it's far more flexible across the rev range. The Rover unit was fairly
quiet until about 3250 rpm where it would take off. The Ford unit has
usable power down at about 1800/2000 rpm.

Pete Lilleyman

(please get rid of ".getrid" to reply direct)
(don't get rid of the dontspam though ;-)