Adventures In Oil Modification
by Tony Donisi, donisit@macom.com.
This will chronicle the successful installation of the head oiling
system described previously by both Landry & Schoeb. I want to thank
them both for the invaluable information they supplied. I modified
their basic application which I will describe below.
Parts Acquisition And Description
Noting the parts list on the previous two versions of the modifications,
I first saw that there were a lot of NPT adapters. This was especially
true on Schoeb's modification, which used the NPT's at the junction.
After some research, and my own experience with automobiles, I modified
a few things, which I hope improved the overall design. Some of the
information below may be obvious to most readers, but was not obvious to
me at first.
NPT Taps
The NPT (National Pipe Thread) male/female connection works as a seal
because of a tapered thread design. The thread is tapered at an angle
of 47 degrees. This angle causes the thread to sort of self seal by
threading it in only part of the way, since the threads are constantly
widening. When tapping the hole, as stated by Schoeb, be careful not to
tap too deep. I don't think the point was emphasized enough. The tap
is tapered, so tapping too deep will cause the hole to be too wide. If
the hole is too wide, then the male connector will not seal at all. I
first tried the tap on a piece of scrap aluminum - and I'm glad I did.
From my experience with regular taps & dies, I just tapped to almost the
end of the tap itself, not realizing that the tap was tapered. The hole
came out too big, and the NPT male did not fit snugly in the hole as it
should have. I found that I only needed 2 - 3 turns or so after
breakthrough to complete the thread and provide a proper seal.
The NPT connector is useful for connecting to the engine block, as
described in both previous modifications. However, for all the other
connections there are better choices as outlined below.
A/N connections
The A/N (Army-Navy) style fittings have been used for years in
automotive and aircraft applications. These connections provide a high
pressure seal (Up to 3000 psi) by way of their specially machined mating
surfaces. They come in a variety of sizes, usually designated by dash
numbers. There are AN-3, AN-4, AN-6, etc. For this application,
Aeroquip makes a series of AN-4 connections to the -4 braided steel
Teflon(R) line, the same teflon line used by both Landry & Schoeb. No
Teflon(R) tape is needed with these connectors. There is also an adapter
from 10mm Banjo bolt to AN-4, along with various Tee's, elbows and the
like. To get information on these connectors, and the hoses, there are
plenty of automotive mail order houses which will send free catalogs.
Two of them that I deal with are Summit in Ohio (216-630-0290), and
Jeggs (800-345-4545).
I ordered a whole bunch of parts, because I am always tinkering anyway,
but the ones I used are listed as follows. From the block, I used the
Aeroquip NPT male to AN-4 Male adapter. This is the connection to the
block at the main oil gallery. I ran a hose under and around to the top
of the head, this hose I measured and test fit first, one end I used a
90 degree AN-4 to hose adapter, and at the other end I used a straight AN-4
to hose adapter. At the output of this I installed an AN-4 male "Tee".
This allowed me to branch to both the cylinder heads. To the closest
head port, the front, there was a short piece of hose with AN-4 straight
connections on both sides. The opposite end of this hose with the AN-4
Straight was connected directly to an AN-4 to 10mm banjo bolt adapter.
For the rear head, the same hoses and adapters were used, with the
exception of a longer hose (of course) and instead of a straight AN-4 to
hose adapter, I found that a 45=B0 one worked better. Figure 1 shows
the schematic of the hose routing.
Figure 1
Hose Routing
The AN-4 fittings not only look better, they are easily connected and
disconnected without excessive torquing and Teflon(R) tape. They provide a
great reusable seal. Just look under the hood of any serious race car.
Parts List
Part P/N Qty Cost Each Total
-4 Teflon(R) [1] Braided Steel Hose FCA0410 4' $ 5.00/ft $20.00
AN-4 To 10mm Banjo Bolt FCM2948 2 $20.69 $20.69
AN-4 to 1/8 NPT FCM3088 1 $ 6.39 $ 6.39
AN-4 Straight to -4 Hose Connection FCM1101 3 $ 5.50 $16.50
AN-4 45 to -4 Hose Connection FCM1111 1 $11.39 $11.39
AN-4 90 to -4 Hose Connection FCM1121 1 $ 8.50 $ 8.50
AN-4 "Tee" Connection FCM2061 1 $ 9.39 $ 9.39
Total: $92.86
Notes:
1 The AN-4 to 10mm Banjo bolt comes in Packages of 2 Each.
2 The 4' Length of braided hose is a conservative estimate. I actually
bought 10', I will use the rest in other applications.
3 All parts manufactured by Aeroquip except the Tee connection
which is from Russell.
The connectors above are specially made to connect to the Teflon(R) hose.
The ordinary AN-4 to -4 Hose is not suggested. Aeroquip makes a line of
"TFE Fittings" which are recommended. The AN-4 "Tee" can be of any
manufacturer. It is suggested that anti-seize compound be used on the
connecting threads. The parts listed above are more expensive than the
normal brass fittings, but well worth it.
Doing the job
Weekend 1: Hose Assembly 1.5 Hours
I assembled all the hoses using test fits before I even started the job.
Surprisingly, the hoses went together easily, I thought that it was too
easy, that they were sure to leak -- but they didn't.
Weekend 2: Bottom Hose Connection 3 hrs.
After assembling the hoses the previous week, I started the job. At
this time, I did not disconnect the original head oil lines, I decided
to do the modification in steps. The first step was to hook up the
bottom feed and hose, drive around for a week and check for leaks.
After it was verified by driving that there were no leaks, I would
connect the new oil feed to the head. I want to stress that at all
times during the modification, some head oiling was used, either the
stock or the modified. I did not start the engine without oil to the
heads!
Disconnecting the muffler system was easy, as well as the right
engine cover. I've done both before on many occasions. Drilling the
hole was a little difficult because of the cramped space, even with the
bike jacked up. What I did was to stuff a lint free rag into the oil
gallery before drilling to catch the metal filings which could find
their way up into the engine. When I was finished drilling and
tapping, I pulled out the rag, and cleaned everything extremely well.
The NPT connection fit fine, I used Teflon(R) tape, and one of my machine
shop friends told me that there is even a Teflon(R) tape in liquid form,
which I did not use. I connected the hose from the bottom to the top
only, and used an AN-4 plug to seal off the hole in the end that came
up near the heads. Driving this around for a week, I notice no leaks,
not even a dribble! Hooking up a pressure gauge to this connection,
I read about 80-90 psi, when cold, at idle. This is the pressure that
should come out of the main gallery.
Weekend 3: Top Hose Connection 3 hrs.
The next week, with the success of the lower line, I decided to hook up
the uppers. I hate removing the carburetors, so I tried it with just
removing the radiator. This worked fine, however the rear head
connection gave me a little trouble. I removed the old oil feed lines
without cutting, but it was difficult, and they did get quite bent up.
On both heads, I had to bend the banjo bolts slightly, as did Landry &
Schoeb to make them fit easier. With the AN-4 fittings, connecting was
a snap, and I plan to hook up a pressure gauge in the future.
The blocking of the original oil feed bolt went fine, the bolt was a
10mm X 1.25. At this time I started the engine and checked for leaks.
There were none. I was amazed. Out of curiosity I checked the pressure
at the original feed line to get a number for comparison. The pressure
was about 35 - 40psi at cold idle, a full 50psi below the modified
version. I've read previously that its the volume of the oil to the
heads that matters, not the pressure. This may be true, but pressure
and volume are intimately related, and increasing the pressure by 50 psi
increases the volume of oil to the heads significantly.
Results
I bought the bike in September 1995 with 13,000 miles on it. It now has
only 23,000, since I did not get to ride much during this miserable
winter. The modification was successful, and there were no leaks or
snags. I've literally been through every inch of the V65 which probably
helped a lot. The engine does not run much cooler, but it takes a lot
longer to reach operating temperature. The gas mileage increased, by
about 3.3 mpg. This is astounding by itself. The gas mileage number
came from an average of 6 tankfulls before the mod, and 6 tankfulls
after (A total of 1-1/2 months time). The engine did not run noticeably
quieter, it was quiet to begin with. I have adjusted the valves at
20,000, and will adjust them again soon. I will relate the difference
in the clearance and the cams. The only engine modifications from stock
are a Dynojet jet kit, and a K&N filter, and of course, always synthetic
oil. I took it down to the track just before the oil modifications, for
fun, and I did 11.9 @ 110mph in the quarter mile. This was with
"normal" non destructive riding, I shifted at 8500 - 9000 rpm, using the
clutch smoothly, as I would on the street. I think I could have got
another second if I power shifted and revved higher, but I didn't want
to. There is no reason to beat on the bike to get another second in the
quarter mile. I will report in the future if the quarter mile time
improved any with the modification.
I don't see how anyone could fail to see the value of the oil
modification. An engine that is running right, and lubricated correctly
should not be able to gain over 3 mpg just by re-routing the oil lines.
This is a drastic change.
Addendum: An Oil Pressure Gauge
On my 1984 Magna, I connected a 1.5" diameter mechanical oil pressure
gauge, which worked fine. The way I connected it was to use a brass
1/8" NPT female "T" and connected that to where the original sending
unit was. This was because I didn't want to disconnect the original oil
pressure light. From this tee, I used an adapter to 1/8" compression
fitting, with which I ran 1/8" copper tubing to a convenient point at
the frame by the handlebars. Since copper does not flex easily, I had
to run the nylon type 1/8" hose from the frame to the handlebar mounted
gauge. I used a 1/8" compression to 1/8" compression adapter to connect
the copper to the nylon tubing. I surrounded the nylon tubing with
small diameter rubber hose just for added security and resistance to
possible rubbing. I had this gauge connected for about 20,000 trouble
free miles.
I plan to connect a gauge to the above oil modification setup.
What I will do is put another AN-4 Tee connector in line (with a female
to female connector) and then use Aeroquips' AN4 male to NPT female.
(Don't ask me how I found out about this adapter, it wasn't easy). I
will adapt the female NPT to 1/8" copper compression tubing. This I
will run up to the space between in the frame by the front of the gas
tank covered by those little plastic covers. I will relocate the
original sending unit here, using an NPT female tee. I am mounting the
original sending unit there because I think its ugly sticking out the
side of the engine.
Footnotes:
[1] DuPont's lawyers have warned that this footnote must be shown.
"Teflon(R) is a registered trademark of DuPont for its
fluoropolymer resins."