J.C.Kløve skrev den 09 aug 2009 i
news:4a7ee4d1$0$296$14726298@news.sunsite.dk:
> Hvad skulle man da også opnå ved at være "brutal" ?
Citerer hele artiklen fra
http://www.one-ring.net/vfrfaq/general.html#breakin :
...den opsummerer "den brutale"
"The first few hundred miles of a new engine's life have a major impact on
how strongly that engine will perform, how much oil it will consume and
how long it will last..... We ask four top engine builders what they do to
ensure peak power output and optimum engine life..........piston ring and
cylinder seating is critical to get a proper seal for power output and oil
consumption.....If the wrong type of oil is used initially or the breakin
is too easy, rings and cylinders could glaze and never seal properly. A
fresh cylinder wall needs some medium to high engine loadings to get the
piston rings to seat properly for good compression but don't lug or
overheat the engine either. Use high quality low viscosity oil (Valvoline
30 weight eg.) no synthetics, too slippery, if used during initial breakin
the rings are sure to glaze. Initial run should be used to bring oil and
coolant up to temperature only, with little or no load, then shut off and
allow to cool right down. After thorough cool down (ambient temp), start
up and ride under light loads at relativly low rpm 3000-5000 rpm, keep out
of top gear, lugging is more detrimental than high rpm. Key advice,
constantly vary load on engine, a constant load is not ideal for breaking
in bearing tolerances. This run should last only 10-15 minutes before
another complete cool down. The next run should be slightly higher rpm,
5000-7000 and under light to medium loads using short bursts of
acceleration to seat the rings in early. Again 10-15 minutes of running
should do it and again avoid top gear. Allow to cool right down. The third
run should consist of light to medium engine loads with a few more bursts
of medium-high rpm, 8000-9000 rpm max, and lasting just 10-15 minutes
varying the engine load and avoiding top gear. Next while the engine is
still warm drain the oil and change the filter. This gets out the new
metal particles that are being worn away. Al Ludington from Vance and
Hines feels most of the metal particles will break away within first 50 -
75 miles, get them out soon after. To ensure the rings seat well, use same
high quality oil and don't be shy about short duration high rpm blasts
through the lower gears after the oil has been changed. A few more 15-20
minute sessions should be used to work up to the engine's redline
gradually increasing the engine loads. After some definite hard running
and 250-500 miles it's a good idea to check the valves. After 500 miles
retorquing the head is suggested. Switch to snythetic oil but not before
500-1500 miles. Most of the engine experts warned of the danger of
breaking in the engine too easily and ending up withwith an engine that
will always run slow whether it is from tight tolerances, inadequate ring
seal or carbon buildup. Engine load is more detrimental than rpm, so avoid
lugging the engine but rev it freely especially in the lower gears. Muzzy
summed up his break-in concerns most concisely: Basically, be sure not to
get it too hot but be sure to seat the rings properly. Its that
simple...........
So that's it, sure a lot different than keeping under 4000 rpm for 500
miles then under 5000 rpm for 1000 miles. Maybe bike manufacturers are
being super cautious at the expense of your motor's performance? I think
that they take the cautious route that works over time (1000 miles, or
about 20 hours of break in) versus a faster route that can be more easily
screwed up. FWIW, on the VF1000R, the slower break-in showed better
leakdown at 4000 miles than at 1500, and I suspect that the go-slow method
of the factory recommendations are looked at more for simplicities sake
than for other effects."
--
Mvdlh - Arne Lorenzen - dmcn # 626 - dfmc # 183
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