This concept seems to have more lives than a cheap politician. I don't
know where or how it got started for sure but I think it has to do with
some of the older cars and trucks that used heavy gear oils in the
trannys or something. Anyway it is dead wrong. No better way to load the
engine than to depress the clutch. The only exception would be cold
weather starts in cars with very heavy gear oil in the trans (a sure way
to ruin the trans and there is no need with today's lubricants). In that
case the fluid drag and friction losses in the tranny might create more
drag on the crank than depressing the clutch would.
When you depress the clutch you are loading the thrust washers with the
full load of the clutch (0n the comp clutch that's 650 kg or about 1400
lb.) before there is any oil on the thrust faces (and before the crank
has developed any gyro effect but that's a whole other thing and
opinions differ on that quite a bit so lets just stick with lubrication
factor). It is absolutely the worst thing you can do to your crank and
thrust washers. Over the years I got so as I could identify clutch
riders by the wear in the cranks and thrust washers. When you ride the
clutch at idle you are loading the thrusts surfaces the same way as when
starting but at least oil is being supplied to them. Do it before you
crank the engine and you are pushing bare metal to bare metal and then
spinning the one against the other. Yikes!
Not only does it load the engine and make starting harder, it wears out
the crank and thrust washers much faster.
> BTW, do you start it with the clutch depressed? I read that it is a good
> idea and makes it easier to crank over.
--
Marc Sayer
Editor/Publisher
Z Car & Classic Datsun Magazine
http://zcarmag.com
Voice 541-726-6001
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