--

"Short Wave Sportfishing" wrote in message
...
On Sat, 18 Sep 2004 20:22:09 -0400, trainfan1
wrote:

dixon wrote:




This isn't exactly answering your question but, I have done a lot of
dynomometer work on two stroke outboards. Contrary to popular thought
50 and
100 to one oil mix is detrimental to horsepower gain. In every test
I've run
we get the most h.p. with very rich oil mix. On a recent test, a 50
h.p.
Merc. made an actual 39 h.p. with 16 to 1 mix. When the ratio was
changed to
8 to 1 (yes 8 to 1 ) it made just over 40 h.p. Even at 8 to 1 there was
no
noticable smoke at high speeds. Idle was a diff. story. The extra oil
seals
piston skirts,reeds and between cyl. crank seals. If motor life and
max.
h.p. is your bottom line run as rich oil mix as poss. to a point where
plug
fouling becomes a problem. I have a PWC 951cc. that runs 6600 rpm with
factory set oil injection. With the addition of 32 to 1 premix along
with
oil inj. the rpm is high 6700 to 6800.


Now that is really interesting.

I assume you are addressing the horsepower numbers available at the
prop shaft?

Later,

Tom

Actually no, the readings were directly off the powerhead. I always assumed
mercury under rated h.p. The reason I didn't use prop h.p. is that I put
several hard winter hours testing a mark 58 and didn't feel the need to put
the hours on the quicksilver gearbox. A fresh 50 h.p. four cyl. merc.(44 cu.
in.) is at best 41 h.p. I worked on expansion chambers until I developed
just under 60 h.p. I had over 100 dyno runs recorded. The dyno not only told
peak h.p., but you could plot the h.p. on a rpm curve. On a 12 or13 ft hydro
41 h.p. (stock & quiet) will easily go 75 mph or 79 to 80 with a lot of fine
tuning. Strangely, the 60 h.p. mod motor would never go any faster than 80.
I adjusted the power curve to be making the max h.p. at 80+ mph, but never
could beat the speed I could get with 20 less h.p. The accelleration was
much better than stock though. The next years project was turbocharging the
four cyl. merc. The results were far beyond anything I could have hoped for.
The 1st. dyno run was 85 h.p. With 18 lbs. of boost h.p. was just under 100.
If you are familiar with the porting of a 2 stroke, it would seem that
turbocharging would not work because there is never a time that the intake
port is open that the exhaust port isn't also open. If you are interested,
I will explain later.
Dixon

I consider Castrol four stroke oil to be upper end. I've never run
anything else in anything with tires and a motor. When their TCW-3
came out, I bought a gallon. I'm still finishing off the last of the
Quicksilver before switching over.

--
Chuck Tribolet

http://www.almaden.ibm.com/cs/people/triblet

Silicon Valley: STILL the best day job in the world.


"Camilo" wrote in message ...
OK without getting into a full blown TCW3 debate, is your personal opinion
that Castrol would be considered an "upper end" oil or a "lower end". I
don't want to debate whether the "upper end" is actually better than the
"lower end", because I know that is debatable. I just want to know if
Castrol TCW3 has a good reputation for marketing a quality product.

This is the Castrol Super Outboard oil, NMMA TC-W3 certified.

I've burned a gallon or so. The only distinctive thing about it is that the
smell of the oil itself is distinctly different than the OEM bulk John/Ev
and Quicksilver I've been using this season. I've never noticed this
distinctive a smell for TCW3. Haven't noticed any difference in smoke or
performance.

By the way, I am not of the school to save $5 on a gallon of oil just to
save the money. Given my use of approximately 200 gallons of pre-mix a
year, the savings just doesn't amount to much, so I just don't worry about
it.. I'd save a LOT more money by price shopping for the gasoline! (which
I don't really do - I go to the station that's most convenient and provides
easy access for the car and trailer.)

The reason I'm trying the Castrol is that it is quite a bit more convenient
to me to buy it at the local hardware store than drive across town to the
Merc or Johnson dealer to buy the OEM oil in bulk. Price for the Castrol
($11 /gal) is about half way between the cheapest ($5-7/gal for off name,
el-cheapo) to the most expensive ($15 - $20 for OEM or Penn. full synth).
Like I said, price is NOT the factor, but convenience is. Store is right on
my route home and saves a good 30-40 min round trip to the boat store.

Cam

On Sun, 19 Sep 2004 02:32:14 GMT, "dixon"
wrote:

Interesting.

Later,

Tom