Speeditwin 6039 Oil Considerations

[sedover]

Here we go again, another oil question.

It is important mention that the fuel used will be non-ethanol 91 octane marine gas and the engine will be used in a non-racing application.

Yes, I have read the various threads on what to use for oils. As a J/E tech since the early 70’s and then Mercury, going back in time technically (bushed cranks)forces one to view lubrication requirements with an open mind.

I assume to protect our cranks and bearing we want a rather high viscosity. I do not believe there is a TCW oil on the market that is not diluted for "injector" systems.

What about BRP’s XD 100, anyone tried it?

I have also been around racing 2 stroke motorcycles, track and off road, for just as long. This seems to be the only place where one can find 2 stroke oils where there are diluted and non diluted oils, in other words "injector" and pre-mix oils. The old racing standbys were the castor bean oils like Castrol A747 which I have used in my Yamaha TZ. There are others on the market. The bean oil is still the choice of some of the engine builders out there.

Does Blendzall still make a marine pre-mix bean oil.

Anyone ever played with the bean oils.

Is having a TCW rated oil really that important, I’ve never seen a 4 stroke oil rated in such a way.

What about the vintage racers out there what are you using and at what ratio.

Comments

Steve

[Casey Lynn]

I have used pretty much everything from bean oils to Klotz (for racing).
There was a thread on here not too long ago that covered exactly what you are asking and your thinking is spot on. The general consensus is that the square tank engines run better with a thicker oil in them.
As an example, in my square tank engines I run a blend of TCW3 Johnson/Evinrude XD-30 oil and aircraft ashless dispersant oil.

[stanley]

quote Pappy:

As an example, in my square tank engines I run a blend of TCW3 Johnson/Evinrude XD-30 oil and aircraft ashless dispersant oil.

. Pappy what proportions do you use in your blend of oils,50-50?

[Mumbles]

Here’s a link to some oil talk:

viewtopic.php?f=2&t=2341&p=12600&hilit=aircraft#p12600

[jeff-register]

I had a 1942 Military Dodge powerwagon 4 wheel drive. I ran Cat diesel oil in the dodge 318 V-8. Everyone said not to run it but I did & had great performance from it. Very high detergent oil & it got the inside so clean the oil was clear. I ran regular car oil afterwards high detergent.
Garry has posted to use 50 wt non det oil & 50% regular pre mix together for the older motors.
Would it hurt to run bean oil in my OMC ?l

[Casey Lynn]

50/50 is a good mix.

Does it hurt to run bean oil? No. But…Bear in mind that most "bean" oils these days are now a blend.
Straight bean oil does leave a varnish on the hotter areas of the pistons if you are running on the lean (power) side. One of the main reasons bean oil (blend) is one of the oils of choice in racing is that it has a tendency to "run" to a hot spot which aids in protection.
Straight bean oil does not run as clean as a TCW3 oil. Running straight bean oil at the richer ratios that we have a tendency to run and then leaving the engine sit for a season may also allow that oil to get a bit gummy on the rotating parts if using only bean oil instead of a blend of some kind.
Model aircraft engines used to use bean oil plus alcohol and nitromethane for a long time. Those engines were varnished up pretty good when left un-run for a while. They now run much better oils.

[sedover]

Mumbles, thanks for the links. I’ve read both.

Pappy; thanks for your input. I assume the now offered de-gummed castors are of what you speak

Without question our goal is to operate these engines in such a way as to maximize engine life. We also want to take advantage of any lubrication technologies that will make this possible.

Seems like a course in lubrication technology is in order.

To begin I think I’ll mix some non-detergent 40wt with some TCW3 at a 50/50 ratio and start with 3/4 pt/gal.

Steve

[jeff-register]

Pappy,
If I understand you I can run 50%/50% TCW & Caster oil in say my KG7? I love the smell of bean oil. Does it lube better than TCW oil? My old 1953 Firestone says to run mineral oil @ 100% mix, no TCW oil. What is your thoughts on mineral oil please. Thank you so much!!
Jeff in Arizona, 🙂

[Casey Lynn]

Jeff, I can’t see where it can hurt at all when mixed as you describe. Walk into a motorcycle store and look at the various ones they have in there and try some. Am betting there are some in our group that have been there and done that with the engine you want to run it in.
I ran some in an early Franken-engine I put together consisting of a 57 35hp midsection and 74 40hp powerhead and gearcase. I too enjoy the smell of it.
As far as a stand alone mineral oil goes I have never explored that. That oil is used as a base in some TCW3 oils however.

[Mumbles]

OK, what am I missing?

What is ‘BEAN‘ oil???

[Author]

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