Simple test for oil quality on bushing engines

[jim-moffatt]

i would like to determine if synthetic or TCW3 oils are better than 30 or 40 wt for bushing engines.

I thought of sliding a heavy steel weight over a bras sheet lubricated with oil to see which slides easier.

does anyone have any other ideas?

[Casey Lynn]

Great test if that is all you are testing. Check out "Bob the Oil Guy", his findings can be sourced to provide your answers, possibly without having to do the testing. Interesting reading for sure.
Am assuming you are not planning on changing oil ratios based on your findings. If so, you are attempting to address only one of the areas of the engine that need more lubrication.
There were a myriad of other changes that came about that allowed later, more advanced engines, to run on less oil.
Piston material (a biggie), piston pin location, piston design, ring count, ring design,ring location, ring tension, dowel pin design, dowel pin retention methods, bearing design, bearing cage coatings, crankshaft hardness, seal designs, cooling system changes, etc.
All of these changes came about and evolved in order to provide a decent service life at a reduced oil ratio. And this is just a partial list!

[frankr]

If I remember what I learned from my engineer mentor, that is a test for co-efficient of friction. But that’s as much as I know on that subject. Anyhoo, to bear the NMMA logo and TC-W3 certification, an oil must pass the NMMA test. It doesn’t matter what the oil is made of, it can be made of cow flops if it passes the test. Having said that, I’ll bet a 10 spot that you won’t find any 30 or 40 weight straight oil with the logo.

Look at an old Evinrude factory service manual and note that part of a "Tune-Up" was removing the cylinder head and scraping the carbon out (if it had a head). Today’s TC-W3 oils are far superior in that respect. Of course, unleaded gas helps too. But not venturing into the Ethanol subject.

Also, my own personal observation over the years is that if a motor has been subjected to severe overheating, it’s chances of survival are much greater if it was running on synthetic TC-W3 when it happened.

Just my opinion, which together with $1.95 + tax will buy a cup of coffee at the corner gas station.

[wiscoboater]

But your opinions are priceless here Frank!

[1957evinrude]

Frank your opinion is worth much more than a cup of coffee !!!!!

[equad99]

i have not had great luck using tcw-3 oil in motors that call for 40 weight. particularly johnson model a and k rotary valve motors, and older piston port motors.the rotary valves and piston ports just dont seem to seal up with the lighter oil. poor low speed, and being a cantankerous !!!@#$^&(*!!! to start. they also seemed to run hotter. i have had good luck using amsoil sabre in these motors at 16-1 ratio.im not sure of the exact weight of the sabre, but its a lot more robust than the tcw-3. i have not experimented with leaner ratios, aeroshell w-80 (40 wt ) ashless dispersant oil works well but is not as clean as the amsoil. if you try it get the red label not the blue label. the non dispersant type blue label type forms a lot of deposits. they have engineered newer motors to run on lighter oil and a lot less of it, but i have found that the older ones still require the same weight and mix that they did 50 plus years ago, and newer and better oils do not make up for this. for older motors that call for 30 weight, tcw-3 oil has been great for me,mixed at the engine manufacturers recommended ratios. it was made to replace 30 wt oil. art b

[frankr]

I’ll have to concede on that issue. The real old stuff that you are talking about are a special category. The question simply said "bushing engines". Some of the old iron engines needed fuel mix almost like tomato soup in thickness in order to even run.

[equad99]

one time i was looking at the oil charts out of my johnson manual, (3rd edition), and noticed that it calls out 40 weight for the hd,td,sd and others. i have these motors,and had been running tcw3 in them. i tried 40 weight, and it made a very noticeable difference in their running qualities in a positive way, especially the sd-20. they really like the 40 wt at 16-1…..i had thought that they were new enough to run best on tcw-3. not so much i found out. this and an a-50 that ran like a turd on tcw-3 leaned me towards using 40 weight if its called for….art b

[outboardnut]

i always heed frank’s advice

[fleetwin]

Thinking of you Jim, please take good care of yourself. Don

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