Detroit 6-71

John B. fired this volley in news: snipped-for-privacy@4ax.com:

Yeah... I wasn't commenting on who made them, but just when, in the line of models, they came.

They definitely were NOT on the Mk-I boats. I spent a good deal of time in the bilges on that model.

Lloyd

The dampers are a relatrively recent invention, like 1970s

Ignoramus5626 fired this volley in news: snipped-for-privacy@giganews.com:

Um.... 1969-70 was when I was in 'Nam, and the Mk-II or Mk-III boats had them on the 12V-71s.

Lloyd

I stand corrected. Was a diesel truck mechanic many years ago, but never had any close experience with the Detroits. Turbos seemed to last forever on the Cummins engines, hence my question.

Garrett

I don't know about river boats, but we had Detroit Diesel powered supply boats and one WW II landing craft on several jobs I worked on. As I remember, none of them had the damper shutdown valve. But nobody was shooting at us :-)

The dampers are common on civilian stuff. Probably typical military BS in believing the contractor knows what they are talking about when they said "Oh those things aren't needed"........ OR they were afraid that they could get tripped and kill the engine (and the crew if it occurred at the wrong time)

There is one time they don't work. If the engine somehow gets started in reverse direction of normal rotation! One of our crew did that at a fire call. He had pulled the rig into a driveway, left it in reverse and jumped out. He forget to pop the brakes!!! Thing was nice and warmed up from the trip and it turned over about twice and fired up! Was dumping exhaust out the intake boxes and gulping air up the exhaust. The driver was freaking out. I walked over, told him to jump in, pop the brakes and stand on the brake pedal. Then just shoved a traffic cone in the exhaust. It died pretty quick between the gearbox and choking it.

I said normal rotation because the Detroits were built in clockwise and counter-clockwise rotation depending on application. Plus some were both and you shifted the racks to reverse the engine.

Only time I saw a scavenger pump have issues with the bearings it ate the rotors and locked it up. Turbos on a screamin' Detroit get a LOT more heat than a 4 stroke.

The 2 stroke design is also why they sound like they are screaming even at low rpm. Twice as many power strokes per rev than a 4 so it sounds twice as fast.

Doesn't know how to use one?

Kind of reminds me of one of the Freewheein' Franklin Freek stories. Seems he was down in Mexico, and realizing he was unlikely to be able to hitch a ride north with long hair, he divests himself of his stash, and tuck his hair up into his hat. Up pulls a pickup with camper, and stock blue collar type character (buzz cut, white tee shirt) driving. After assuring the driver that he did not have any of that pernicious maryjuwanna on him, Franklin gets a ride. After they cross the border, 'Buzzcut' apologizes for possibly being unfriendly, but the camper is just stuffed full of pot, and he didn't want to be stopped. Franklin thinks to himself "How can this be? He doesn't seem 'hip' maybe I can score a little," and asks "So, what do you plan to do with all of that stuff?" Well, Mr Buzzcut then explains the going rates in various cities around the country, which causes Franklin some dismay - the man is hip to the market. Then Mr Buzzcut says "You seem to be the sort who might be able to answer a question I have about this stuff. Namely - what is it that you all _do_ with it?"

tschus pyotr

-- pyotr filipivich "With Age comes Wisdom. Although more often, Age travels alone."

And produces roughly twice the power ith the same displacement at the same speed.

This was a really funny story, though I am sure that it did not look funny in-person.

Here's a picture of this generator.

John B. fired this volley in news: snipped-for-privacy@4ax.com:

Well, John, actually, there's not a LOT of free-flying particulates in the bilges of your typical all-metal boat. There's just nothing down there that can generate such airborne waste.

In addition, except for the odd insect, there's not much in the way of particulates floating around over open water in non-industrialized countries, like 'Nam was.

I cannot remember ever seeing an engine damaged by airborne matter, except for airborne shrapnel and bullets.

Lloyd

Snow blower engines don't usually have air filters either.

-jsw

Our OMB & gig 6-71's air intake boxes were simple 'silencers', with just enough baffling to (try to) minimize air flow noise. They also served to keep idiots' inquisitive fingers out, I suppose.

Jim H.

The other factor to consider for those is that there _is_ a lot of blowing snow (Gee, I wonder where that came from.), and that can clog up an air filter real quick.