John to answer your question, in the higher rpm situations the oil pump can
pump under pressure the oil volume from the pan faster than gravity can return
the oil to the pan. Our system and virtually every auto engine made has a
gravity return, unless it is using a dry sump setup, which I will not go into
here. Since the size of these oil return holes and gravity are responsible for
the oil returning to the pan, it is important that we don't run into the
potential of pumping a majority of our oil into the heads leaving too little in
the pan, which could "slosh" to one side and uncover the pickup tube, causing
air to be sucked into the oil system, which is the type of starving I am
talking about.
I am running the stock oil system with oil cooler and filter in stock
locations, so my oil pressure volume only needs to be what a new pump is stock
on a new engine per Chevy. Mark Jones is running longer lines and remote setup
and I agree this can/will cause some drop in the system pressure, delay in
volume circulation, so it is appropriate for his system, and anyone like it
(Mark L, & Bill Clapp) to do the same with in reason. Just remember that
anything beyond stock pressures is probably excessive, and is also requiring
more internal horsepower to generate, leaving a little bit less for the prop.
Multi-viscosity oils are rated by the detergent additives that allow them to
thicken and thin based on the outside ambient temp, and their temperature of
operation. Serge, you probably saw numbers changed into the metric system, we
here would see them posted on literature in F. The first number before the "W"
is the winter rating, oil's ability to thin, and the second is the summer
rating, and ability to thicken, or withstand high temperature before breakdown.
The manufacturers do not add the "S" because it would be redundant.
Doug and anyone who believes that running straight weight oils is just as good
as multi-viscosity oils, just look at how long your engines last presently
compared to the late 60's early 70's. This is pre-dominantly due to 2 things:
oil technology, and internal temperature, which both work together to control
wear. Filter technology also contributes here. Harley engines for years failed
after very short times as compared to the Japanese motorcycle engines which
were modified to take advantage of modern oils and technology. Not until this
latest emergence of the Harley Evolution series of engines did Harley enter the
world of truly modern engine design. The use of 20W50 oil in any engine that
doesn't match the temp of the application for continued use, not just startup
temp is foolhardy and an act of ignorance to what 50 years of development have
accomplished. I do not trust "independent" testing in a lot of cases because
typically the scope of the test is too narrow to be of much value, since it
will only apply to a limited case/application. Assembly lubes are thick
because of the need to maintain lubrication inside the engine in the case that
the new oil system doesn't prime initially, or there is a delay in the oil
pressure coming. All my assembly manuals have you run the engine for a short
time, drop the oil out, change the filter to remove that assembly lube to
prevent engine clogging, and then refill and run the engine for approx 50 miles
or 10 hours of use and change again. This gets the additional metal out that
gets shaved off parts as they seat themselves, hopefully not much.
We are still running auto engines, and just like our previous discussion on
oils, need to run what is appropriate for an auto engine, not aviation oils.
Aviation oils are designed to both handle the particulars of those engines as
well as deal with the much greater internal clearances that those engines have.
Mark Jones' post shows the breakdown of the design of the oil he is using, and
a review of the chart shows that his 15W40 has the ability to handle -33F
temps, the 10W30 will go down to -40F. Thank you for that post Mark. This is
what I was trying to illustrate. This looks like a very good "designer" oil
for use since it covers a very broad range of oil temps and use, and does
include that it is designed for both gasoline and diesel engines. The
detergents in it for use with diesel engines should also help with the lead of
100LL that it will be exposed to also. Thanks again Mark. This will be my oil
of choice as well after break-in.
Colin
crain...@cfl.rr.com
http://kr-builder.org/Colin/index.html
KR2(td) N96TA
Sanford, FL
Apex Lending, Inc.
407-323-6960 (p)
407-557-3260 (f)
crai...@apexlending.com
