aaron wrote:
I think the guy at the dealer has a very limited knowldge of mechanics. The piston has to travel the same distance on each stroke, it's connected to the crank and unless the crank is flexing (which it shouldn't be) the piston travel will be indenticle from a slow low rev drive to a fast high rev drive.
Having said that, he may have meant the rockers, they travel up and down by the connection to the cam shaft. If you were to drive a car around at a reasonable even happy go lucky pace it will travel a certain distance, pretty much thruout the rev range. If how ever you get in a car and red line it all the time, you will get whats Known and VALVEBOUNCE, thats bad! Don't do it. Then yes the rockers will go further than they should and will eventually break.
Cheers
Aaron
PS, i rebuild my gearbox and it cost me $150. 1 good one from 2 average ones.
Generally if you go round using valvebounce as a gear shift indicator (like me
) then it wouldn't make much difference if the car was driven by a grandma its whole life or not, you'll still do damage eventually. I know this guy was seriously talking about the piston movement as he was making hand gestures to go with his story. I had to try not to laugh...
Seriously though, in his experience low mileage old cars were a no-no, as at least the high mileage ones have had time to iron the bugs out and have bad parts replaced. Not sure if I agree with the logic entirely, but I have seen many low mileage engines go bang, thermostats sieze up etc, because the next service interval isn't for another five years.....
Anto.
