Re: Dipstick Accuracy & Oil Level

["Tom Casey" <ragtop88@domain.elided>]

Well not having been on the list long, not sure what has been discussed.
Definitely running the pump dry is a bad thing.  You don;t want your
bearings spinning at a few thousand rpms without any oil on there.  Even
worst case scenario, having the oil "froth" up can actually cause your pump
to cavitate as it sucks in air and oil which is another bad thing.  Best
case scenario is that the extra oil will only drag a few ponies off as the
crank has the extra friction of whipping through the oil/oil mist.  Having
never seen the inside of a Stag pan, I ask, anyone ever look into adding
some sheetmetal baffles inside to contain the oil around the pump pickup??
I'm guessing that stock the pan must have a shallow sump area.

Tom
'88 Ragtop
'64 SS
ragtop88@domain.elided
http://home.sprynet.com/sprynet/ragtop88/main.htm
http://www.prism.gatech.edu/~gt6231a/
-----Original Message-----
From: Daryl Gatenby <Daryl.Gatenby@domain.elided>
To: Stag Digest <stag-digest@domain.elided>
Date: Friday, March 05, 1999 8:46 PM
Subject: Dipstick Accuracy & Oil Level


>I noticed on one occasion that the dipstick retaining tube on my engine was
>slightly bent (as a result of something coming in contact with it when the
>engine was being removed I suspect). I applied pressure to the tube in the
>direction required to straighten it and noticed that it had some up and
down
>movement. I think the retaining tube relies upon an interference fit to
>secure it in the block. It moved downward about an eighth of an inch and
>stayed there. So I suspect the dipstick itself goes further down into the
>sump cavity these days and therefore shows the oil level as being slightly
>higher than it really is.
>
>I was once told that one of the dangers of overfilling an engine with oil
>was that if the level was too high the crank can thrash around in the oil
in
>the sump and aerate it. If this were a problem, I can't see it easily
>happening to a standard Stag engine. The oil level would have to be really
>high before the crank would contact the oil in the sump. Not long ago I had
>the dipstick reading 3/4 over the high tide mark and didn't notice any
>problems during operation.
>
>I think also that there may be a benefit in having a higher than normal oil
>level.
>
>Like some of you I have noticed that during heavy braking the oil pressure
>takes a dive momentarily. This is most likely as a result of the oil pickup
>running dry while most of the oil rushes towards the front of the oil pan.
>Whether this fluctuation is detrimental to the engine's longevity was a
>matter debated on this list not so long ago I recall. In any event I can't
>see the phenomena as being beneficial. I'm not sure what quantity of oil
>equates to 3/4 inch on the dipstick but I suspect it may be 0.5 - 1.0
litre.
>I noticed that having the extra oil, presumably mostly in the sump during
>operation, seemed to alleviate the surge factor during hard braking.
>
>I don't recommend it as a fix to this problem though. It is an untested
>theory based on simple anecdotal observation.
>
>Daryl
>