Detroit Diesel 2 stroke straight weight VS multi

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I rode a greyhound bus about 1000 miles and it had a green leaker/screaming demon in it. Non sleeping with all that racket going on.

Guy up the road from me just had a well drilled and the drill rig was powered by a turbo's 8-71
 
We had a few AutoCars with Silver 92's in them. As I recall we had separate drums of engine oil for them from D.A. Lubricants. Everything else had 15w40 in them.
 
Originally Posted By: meadows
You can still find them in boats.


In 1984 a friend of mine bought a brand new 42'Bertram Sport fishing boat. He called me up invited me on a fishing trip. The boat had twin 6V 92 Detroit Diesels. Twin turboed & supercharged, 700hp per motor.
At the end of the trip he asked me if I would be interested in maintaining boat.
I agreed. The manual for the Detroit's said Straight 40 wt. and then had about 20 pages on why only 40 wt.
40WT is what was used. At that time boat was worth around 700K or more.
 
DO NOT use a multi viscosity. Straight weights ONLY. Head my advice. I've had many V6 and V8s 2-smokers and they are bulletproof IF using straights. Using multi and it will die. Also, where the slobber tube is take a big plastic gator aide bottle and use some wire to rig it where the slobber tube empties into it. Don't move the tube any or the engine won't be happy. The bottle will catch all the nasty that gets puked out instead of ending up on the back of in my case the coaches. Empty the puke catcher w each oil change. Think same as a soup can to catch grease on a grill.
 
I've used Delo 100 for so long I don't remember what I used prior. DD 2 cycles still see heavy use in offshore marine, off road, industrial and outside the US. Places the EPA has yet to screw up. I've been using DD and prior Gray Marine engines since the early 1960s. Now I have a pair of IL 671s built in 1947 & 8. They are the most reliable engine for ocean work I have ever found. Most marine DDs have an oil catch pan underneath as part of the installation. They burn oil even when new. If you keep the rpms down they last 10,000+ hours in marine use. I've seen some with twice that. Before the bigger engines came out it was common to see double and quad 671s (2 or 4 engines on one shaft).
 
When I was in the army I drove a 1972 IH transtar with a DD 12V71tt with intercooler. We used 10 weight in the winter and 30 weight in summer just as DD reps told us to do, as I was in Europe. I don't remember the engines using a lot of oil, and we ran the #$%* out of them. I was assigned to 3rd Armor and we hauled M60's and M88's. There were times we were over 200,000 lbs. These engines were as tough as they come, I have never seen another one. At that time they were experimental for the military with about 550 hp. Many years later a mechanic told me that a lot of people loaded the cylinders from the top and they were supposed to load them from the bottom then install the crank then it wouldn't slobber and use oil. Just what I was told. I haven't driven a big truck in years.
 
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Originally Posted By: Oceanmariner
I've used Delo 100 for so long I don't remember what I used prior. DD 2 cycles still see heavy use in offshore marine, off road, industrial and outside the US. Places the EPA has yet to screw up. I've been using DD and prior Gray Marine engines since the early 1960s. Now I have a pair of IL 671s built in 1947 & 8. They are the most reliable engine for ocean work I have ever found. Most marine DDs have an oil catch pan underneath as part of the installation. They burn oil even when new. If you keep the rpms down they last 10,000+ hours in marine use. I've seen some with twice that. Before the bigger engines came out it was common to see double and quad 671s (2 or 4 engines on one shaft).
I drove a couple of semitrucks with the 6v71, they put out 17 horsepower at WOT !
 
After 30 sec. or so there was nothing amazing about the sound of a 2 stroke Detroit. Between the blower howling and the pistons firing every time up the noise was unbearable. The turbos did temper them somewhat, but compared to a modern 4 stroke they were LOUD.
 
Originally Posted By: roadrunner1
After 30 sec. or so there was nothing amazing about the sound of a 2 stroke Detroit. Between the blower howling and the pistons firing every time up the noise was unbearable. The turbos did temper them somewhat, but compared to a modern 4 stroke they were LOUD.


We used to (I think they are all retired now) have a few city busses around with the 2-stroke Detroit mills in them and yes, the sound was impossible to associate with anything else; very distinct. They always sounded like they were going a million miles an hour, LOL!
 
For years we had a 2 valve 6-71 in a boat, it was then replaced with with a silver series 6v-92. I have too many years with jimmy-itis!!!
 
Drove trucks with those 6v92s they were really powerful for a small cubic engine and really quiet. I really liked them.It was the only time I ever got a speeding ticket in a Semi.
 
These engines were redlined at 1950 and pulled like a mule to the redline. Even with 550hp we could only get to 9th gear with a m88 onboard. We weighed about 225,000 lbs with the m88 tank retriever on board. this engine had a sound I'll never forget. About 1.5 mpg loaded like that.
 
The Emergency Standby power generators on the LNG tankers I helped build, were 12 71s . They were loud. The Boston Harbor water busses had a pair of them in pressurized housings. The boat was wicked fast.
 
We have a HET1070 with a 8v92 Detroit - even in the SD winters we run T1 40W with oil pan heaters. It will eat 15w40 and 5w40 like none other.

Two years ago we were going through 1 gal every 5-10 hours of 5w40 - last year with 35 hours use over the winter and 40w in the sump... 1/2 a gal.

They like the straight weight
 
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The issue with 2-stroke diesels is they require a low-ash oil. Particularly to prevent accumulation of deposits (ie: chunks of carbon) on the exhaust ports which, after a significant period of idling, have a tendency to migrate, upon application of load, to the turbocharger and cause FOD damage. Traditionally multi-grades required a lot of additives in order to achieve their 'multi-grade' status, hence, multi-grades were discouraged in such engines.

The bigger 2-stroke diesels (ie: EMD 710, EMD 645 with EFI kits, etc.) modified with EFI have moved to cylinder deactivation to combat this problem (ie: heavier loading on a lower number of cylinders causes a reduction in deposit formation, and thus, less likelihood of FOD-induced turbocharger failure).
 
Hi,
Pitzel - You are correct, DD 2 strokes had an allowable Ash level of 1% mass as part of their lubricant Spec.

Some Brand formulations perform better than others in these wonderful engines
 
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