353 Detroit oil recommend

[Corley5]

In the past year that I've had a 3-53 I've used 30wt, 40wt, 10w30 and 15w40 all Rotella.  Doesn't make any difference.  It still uses oil  ;) ;D

[Ox]

Best.  Post.  Ever.   :D

[shawn55]

I used delvac 1300 all winter long and never had any problems. I also pre heat with hot water hook up. Best way in my mind.

[lshobie]

15/40 in ours and starts way better.  Old timer down the road has used 0/40 in his since it came out.

[Wood butcher]

The DD mechanic in the twin cities said straight 40 year round.
I use hot hoses, 300 watt magnetic heater on oil pan, & a frost plug heater.
Once your running it still wants straight 40.

[larry1]

We always use 15x40 in all of our diesels winter and summer . My buddy is using 0x50 synthetic in his 6cyl  perkins C5  and it seems to be fine so far .

[Plankton]

I run Rotella t straight 40w in the summer and 30w in the winter after my rebuild.

Before the old 353 blew up I was running delvac 15 40 and it leaked over a gallon a day but I think it was the motor not the oil choice. Decided to do it to spec and only run straight weight after I got her rebuilt. No leaks and it builds good pressure while cranking.

[dgdrls]

I'd really love to know exactly why.  You know, the science behind it.  It's common knowledge that multi viscosity oils protect better than straight weight oils.  I want to know why this isn't so for Detroit 2 stroke diesels.

A great question Ox,  I think this is a big part of it

Ref: 7SE270 0510 Copyright © 2005 DETROIT DIESEL CORPORATION


LUBRICATING OIL SELECTION CRITERIA

Temperature Limits for Oil Viscosity Grades
3.2   HIGH TEMPERATURE/HIGH SHEAR VISCOSITY
High Temperature / High Shear (HT/HS) Viscosity is measured at 302° F (150° C) under shear
stress conditions similar to very thin
film lubrication areas such as those found at the piston
ring-to-cylinder wall interface. The value obtained from this test provides an indication of
temporary shear stability of the viscosity index improver used in multigrade oils. In 15W-40
grade oils, a HT/HS viscosity below 3.7 centipoise (cP) indicates that the oil will not perform as a
40 grade oil at engine operating conditions.

Seems if you can find multi weight with a 3.7 centipoise (cp) rate or better you would be set.

D

[Ox]

Thanks for finding that - it's very counter-intuitive to what I've read and been taught over the years.  Maybe it's time for me to rethink what I thought...  ???

[dgdrls]

"Seems if you can find multi weight with a 3.7 centipoise (cp) rate or better you would be set."

I'll condition that statement by adding you should meet or exceed the Sulphated Ash spec as well.

D

[soperlogan]

Rotella T6 synthetic. Lowest ash content of any oil on market including Delo straight weights.
It's all I use. You would never crank a Detroit up here in winter on 30w.

[coxy]

run what ever you think is best for you 

[dgdrls]

Rotella advertises sulphated ash at 1%

As i understand Delo 100 reports out to 0.8 wt/%

Detroit spec'ed the 2 strokers oil to sulphated ash less than 1%

From what I have learned  the old DD 2 strokes need a specific oil, straight weight 40, low ash,
the challenge is how to start them in the cold and is modern multi weight oil up to the task??

IMHO a block heater is the best solution even with the challenges that may bring
D