8V92 Detroit and Synthetic

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I am purchasing an RV with a 8v92 silver mechanical. Owner has been using Amsoil synthetic. I know this goes against Detroit's use of non synthetic 40 weight. But the unit is a high miler and runs great. I would like to switch to the recommended oil. Is there any problem in going back to a conventional CF2 4o wt. Detroits can use more than normal amounts of oil and I sure don't want to have that problem. Thanks
 
It will be fine on conventional. I'm a semi mechanic and am a little too young to have worked on the old two-stroke Detroit's. I love the sound they make!
They supposedly consumed oil by design. Like a quart every 150 miles of operation when new. So forget the Amsoil and consider
buying a 55 gallon drum of oil and filling milk jugs to take with you for trips. I think those old engines spec a low ash oil, but I'm not sure.
 
I have worked for many years on Detroits - driven many miles with them, also.

All I have EVER used in them has been Rotella T1 (30 or 40)

I have never used 15W-40....ever.... but some people do and say it works fine. YMMV.

There are NOT "deigned to use oil" deliberately....
But by design, they do use oil - - - There's a difference.
 
I second the straight weight opinion. I ate a lot of square meals - and bought a lot of diapers - thanks to Detroit Diesel. The relatively small exhaust valves combined with the lack of valve stem seals would allow the build up carbon on the stem if you used the wrong oil. The valve would hang up a bit and then burn itself.

AFA burning oil: we always said "If there's oil in it, there's oil on it". The crankcase is pressurized. That makes it a great engine for off-road environments but the repeated heat and cool cycles eventually causes gaskets to harden. And leak. I could keep one dry for a 100,000 miles but after that they would mark their territory every time you shut it off.
 
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Originally Posted By: Linctex
I have worked for many years on Detroits - driven many miles with them, also.

All I have EVER used in them has been Rotella T1 (30 or 40)

I have never used 15W-40....ever.... but some people do and say it works fine. YMMV.

There are NOT "deigned to use oil" deliberately....
But by design, they do use oil - - - There's a difference.


I lobe watching the ice road.trucker Joey barnes with his ancient fleet. Especially his "screaming ford"

https://youtu.be/eZ67oVw1HGU
 
there is absolutely no sound reason to run a syn oil in the 8V-92. They are really nice powerful engines. The 6V-92 and 8v-92 are decent engine lots of torque and in their time good mpgs. I have had plenty of Detroit 2 stroke diesel driving experience and I would never have one that is not turbo charged.
 
Originally Posted By: skyactiv
It will be fine on conventional. I'm a semi mechanic and am a little too young to have worked on the old two-stroke Detroit's. I love the sound they make!
They supposedly consumed oil by design. Like a quart every 150 miles of operation when new. So forget the Amsoil and consider
buying a 55 gallon drum of oil and filling milk jugs to take with you for trips. I think those old engines spec a low ash oil, but I'm not sure.
Other than the 92 series ,Detroit 2 stroke were only popular because they were low priced and easier to start in freezing weather. I wouldn't want on in a tractor unless I got it for free. I did lots of San Francisco Bay Area to Los Angeles Valley area turn arounds back in the day and they used about a gallon of oil per tank of fuel.
 
I wouldn't bother with a synthetic on a Detroit 2 stroke even if it was allowed or advisable. They just consume too much oil for that. I've always run Delo 100 (not Delo 400) SAE 40. However I may start running the MileSyn SAE 40 that is sold by the 5 gallon bucket or 55 gallon drum that meets the MILSPEC and DD requirements. It's a fair bit less expensive than the Delo. Rotella T1 is right on the SA limit for the DD requirements so I avoid it.
 
Royal Purple does make synthetic monogrades formulated especially for Detroit Diesels if you're serious about spending a lot of money on oil.
But really, it isn't necessary. They ran forever on conventional monogrades. Some people never changed the oil in them, just kept them topped up and changed filters every once in a while.
 
We called them green leakers. There is some sort of box that is supposed to capture the oil and return it to the pan. When the box gets full the geysers start. The last couple years of the silver 92 had a sticker that said factory filled with 15w40 delo synthetic.
 
I had a hospital call me once and ask me why their 16V-149 was eating oil like candy. I get there, pull the dipstick and feel the oil. I said let me see the drum that this oil came from. They walked me into their boiler plant up to a 55 gal drum of Black Bear compressor oil. I asked what on Earth made them think that was a good idea?
Needless to say, the next few hours of that day were spent getting the compressor oil out and getting 40 wt back in.

I'm still amazed that engine sustained no damage from that. To the OP, 40 wt Rotella will be fine. I also agree with gman2304. Why is this a good idea
 
We owned alot of Detroit's and the 8v92 was my favorite. It will run forever on conventional 40 HD like another poster said. Synthetic is a waste of money. The really don't use the oil as much as slobber it. Don't be alarmed if it always marks it's spot. Typical Detroit trait. My dad loved them. Run them hard and the oil usage is less.
The like to be ran and not a good idling engine.
More they idle, more they slobber.
I d buy one in a minute just for the sound.
 
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I always loved the sound of the 12v71 Detroits. The "Buzzen Dozen" Those Detroits would take abuse and keep on going. The harder you ran them, the better they liked it it seemed. The used more fuel and leaked a lot of oil especially when they racked up the hours due to hardening of the gaskets I was told. Classic old diesel that had a sound of their own. Straight 40 weight in the summer and straight 30 weight in the winter is what I remember being used in them.
 
I certainly would never use that high priced oil. I was just worried that going back to say Delo covnetional could cause problems. Am I just worried about nothing? Thanks
 
Originally Posted By: CT8
.... and in their time good MPGs.


What time was that?!?

No one I know has ever accused a Detroit of getting good MPGs!!!!
 
Originally Posted By: xxch4osxx
I always loved the sound of the 12v71 Detroits. The "Buzzen Dozen" Those Detroits would take abuse and keep on going. The harder you ran them, the better they liked it it seemed. The used more fuel and leaked a lot of oil especially when they racked up the hours due to hardening of the gaskets I was told. Classic old diesel that had a sound of their own. Straight 40 weight in the summer and straight 30 weight in the winter is what I remember being used in them.


27 years ago, when I was working understudy for the guys in Scientific Services, we were doing performance tests on the GT25 gas turbines.

"Starter motor" was a 12V71...the air starter would go, then the 12V71 would give two big revs, then run to full throttle while the fluid coupling between the V12 and the gas turbine was filled up, transferring the torque to the GT.

That was the bestest part.
 
Originally Posted By: Linctex
Originally Posted By: CT8
.... and in their time good MPGs.


What time was that?!?

No one I know has ever accused a Detroit of getting good MPGs!!!!
I drove truck out of the line drivers local 468 in the San Francisco Bay Area [It was the late 1970 through the early 1980s] to make extra $$$.The freight trucks had 290 or 350 Cummins and 290 318 hp Detriots and some 6v and 8v 92 which got much better mpgs than the non turbo Detroits and a bit better than the the Cummins The 8V92 came with either 360 HP which would leave a 350 Hp Cummins like the Cummins was standing still . I never drove the 430? hp version.
 
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