Our collective experience doesn't match this.
I and half a dozen good friends all race spridgets extensively. All
bar one of the cars uses synthetic oil (specifically Mobil 1) in the
engine. The other car uses Penrite HPR 30 (we all use HPR 30 in the
gearbox).
This was not an arbitrary decision, but rather a deliberate switch
from HPR 30 to Mobil 1 after one of the cars (Jeff Smith's racecar)
used Mobil 1 for a full season.
Prior to the switch, Jeff's racemotor was was always completely
rebuilt at the end of the season and always required new bearings,
rings and camshaft. The valve seats also needed a freshen up.
Two things were tried at once during the trial season a) Mobil 1 oil
b) idle speed was set at 2200 RPM (this was to ensure better oil
delivery to the camshaft/lifters at idle)
After the trial season, and every season since, his engine has not
needed bearings, rings or camshaft replaced at all. He still replaces
the bearings and rings each season anyhow (insurance) but it isn't
*necessary* due to wear. Naturally, the valve seat situation hasn't
changed...
Since that season (3 or 4 years ago?), most of us have run Mobil 1 and
seen the same results.
I think the synthetic oil is *terrific*. The only time I don't use it
is for the engine run in (I use HPR 30 for the run-in on the rolling
road dyno and a secoond batch of HPR 30 for the first meeting - then I
switch to Mobil 1).
I still use HPR 30 in old engines that haven't been rebuilt, but for
any new engine I wouldn't use anything else. period.
Mike
_______________________________________________________________________
Mike Gigante
3D interactive graphics, Virtual Reality, british sports cars, and wine
http://mega.cgl.rmit.edu.au/~mg/ mg@mega.cgl.rmit.edu.au
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