----- Original Message -----
Sent: Thursday, April 28, 2005 12:50
AM
Subject: [FlyRotary] Re: Re : oil
injection pump
Hi Al,
Our contretemps about BMEP aside, it
looks like we are in most violent agreement about oil injection!!
(]:>) This oil injection pump removal/replacement/2 stroke
oil nonsense was just another of Lamar's ratbag theoretical
boondoggles that he misled everybody into believing, like Hurley seals
were better than stock Mazda ones!!
I remember several years ago trying to set him
(and his ACRE acolytes) straight on the causes of carbon build-up on
rotors, and all I copped was abuse. With all due apologies to David Staten, for sure, the
carbon build up does come from sump oil, but NOT from what was
injected. Where did David get his info? Personal experience and
observation of thousands of stripped engines, or from ACRE?? (my money
is on the latter!!)
The carbon build-up that has been reported
is from oil that had refluxed past hardened rubber oil control O
rings. Even so, that carbon build up on the rotors only ever
happens in cars that are driven slowly in traffic, especially on short
trips for most of their life (where the engine never reaches proper
operarting temp). Run the engines hard and the carbon build-up never
occurs (which is what will happen in aircraft apps). But then
again, what would Dave Atkins or I know??
While we always use pre-mix in the race
car engines, I still leave the metering pump in place (but with the
actuating rod permanently set at about 1/4 on). That way, I
don't empty the sump un-necessarily, but there is always a
dribble of engine oil in case somebody forgets to add premix in the fuel and
is enough to save an engine. Very klittle oil is actually
needed.
I had it happen once to my own race car - (I
let somebody else drive it when I was away on holidays and he forgot to add
the premix). I really didn't appreciate having to rebuild a $10K
engine). Over the years, I've seen it happen to
many other young & not so young players as well.
I'm a great fan of sump oil injection for
normal use, and I'd have to wholeheartedly agree with Dave Atkins
experience. It tallys directly with mine. While not having any
direct experience in aircraft apps, I've seen dozens of correctly
serviced RX7 12A engines go anywhere from 350,000 to 550,000 km in the last
20 years or so, especially the '84-'85 Series III units.
As an example, a buddy of mine just
bought his #1 son a one owner '85 Limited Editon RX7 last week.
275,000 km on the clock, original motor, oil changed
religeously every six months (Mobil 1). Yep, for
sure, it's definitely a bit smokey on start-up (but it still starts
first hit every time), it still goes like a rocket, and
compression is still around 7.5 Kg/sq cm. 'Nuff said??
We'll give it a security overhaul at some
stage, but all it will need will be apex seals, corner
seals, oil control O rings, and a full set of new springs.
Then it'll probably go anothe 200,000 + km.
Cheers,
Leon
Leon why do you use premix in your race
car?
Ian Beadle W. Australia
----- Original Message -----
Sent: Thursday, April 28, 2005 12:50
AM
Subject: [FlyRotary] Re: Re : oil
injection pump
Subject:
[FlyRotary] Re: Re : oil injection pump
Al....
I would implore you
to NOT do that... unless you plan to lube the whole engine with clean
burning oil. This one issue will likely contribute to early wear and loss
of compression than any other factor.
Well; I
understand that most folks have gotten on the bandwagon for mixing 2-cycle
oil with the gas; or feeding 2-cycle oil. However; there is at least
one “expert”; also the rebuilder of my engine, David Atkins, who says that
his experience (which is considerable) shows that it is not
necessary. David says that he has seen no evidence that there is any
problem injecting pan oil, IF you use high quality oil (Amsoil is his
choice) and change it regularly. He has examined the longest running
engine in an aircraft (rotorcraft, over 1500 hrs is last I heard about)
that injected pan oil, and saw no evidence off carbon
buildup.
I have asked
this question in the past (maybe not on this list): Is there evidence
that, with the good oil and regular changes, that using the pan oil is a
problem? No evidence has been provided. The concern about
carbon buildup and stuck seals comes primarily from engines run for street
use, of unknown servicing and oil usage, many of which came from junked
cars.
Using 2-cycle
oil makes sense to me as well; but I prefer to avoid the added hassle of
mixing oil with gas, or adding another tank and carrying another kind of
oil unless there is a reason to do so for our
application.
Al (ready to
accept all evidence)
>> Homepage: http://www.flyrotary.com/
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