8v92 Superchargers

It just seems contrary to logic. A blower is only Producing what, 4-8 pounds of boost? That’s why you would add a turbo. To get more boost at the top end. Much like a naturally aspirated engine. Especially since the blower is essential for a two stroke to run.

all that said. Maybe we need to define low rpm. Are we talking 1500 or are we talking 2500?

 

Turbo on a 2 stroke is no different than a turbo on a 4 stroke Cummins or Cat, it’s still performing the same job in the same manner…..

 

I realize that. And turbo’s on 4 stroke don’t really do much at low rpms. This the disconnect I’m having here. That’s also the reasoning behind turbo compounding and VG turbos. To give you boost through a broader range. To help eliminate turbo lag.

 

When I was with R&L, we ran that 81 model international for years with the 6V-92TA silver. ( turbocharged & aftercooled )

I was at the shop one day working on a truck when Roger the owner pulled in. He explained that the International was broke down close to Lexington Kentucky.

He said the driver told him it sounded good, had good oil pressure, no pecking or knocking, just simply no power like it had a few days before. Said he was dropping extra gears just to pull the grades.

I load up some tools and head that way, the whole time rolling over in my head what the potential problem was.

This truck was a S 2500 with the fiberglass tilt hood. Only you couldn’t tilt the hood because of the big hydraulic leveling Jack on the front. So it had the butterfly option to allow entry to the engine.

Got both sides of the hood propped open and looked it over, then had Kieth the driver start the engine. Engine sounded good, but I could hear excess noise ….

Back then I was limber as a wet rag and could crawl up in on that engine as a figure of speech.

Process of elimination lead me to a hole rusted out in the exhaust between the right exhaust manifold and the turbo. Being on the backside of the pipe I couldn’t see it, but was able to feel it while trying to keep from getting the piss burnt out of my hand…..

It you’ve ever lost a boot on a air to air setup, you know what the problem was with this Detroit.

 

The early 53 series Detroits would turn over 3000 rpm…. no turbo.

71 & 92 series are mainly rated at 2100 like most 4 strokes.

A 475 horse 8V-92TA will produce around 1300 ft lbs torque down around 1400 rpm’s if my memory is correct.

Ever seen a after cooler on a 6V or 8V Detroit?? Looks like a heater core under the blower. With a better after cooler and cooling system they would most likely have been a better truck engine.

As far as boost goes, I run a dinosaur engine ever week, not unusual to be at 25+ lbs at 1600 rpm. But the way my engine is set up I can push it a lot farther in boost…

 

For their era, the Silver 92's pulled decent down low, which in those days meant below 1600.
Sure they pulled harder up top, but the Slam-your-fingers-before-driving technique of 71's wasn't a necessity. For quite a few years they were the most powerful engine available, it wasn't until the electronic injectors arrived that everyone else caught up, horsepower wise.

But even the 92's rightly had the reputation that they were most efficient at turning fuel into noise.

 

Shame Detroit didn’t come up with the electronic injectors for the 2 stroke a little earlier in time. For sure made them more desirable, but a little to late….

 

I was trying to recall... Hadn't most manufacturers quit offering them by the time they got DDEC? Something rattling around in the back of my brain about the 6V92's in the busses getting DDEC while trucks had already switched to the 60 Series.

 

Rebuilt Detroit Diesel 6V92TA Electronic Engine

They made them , just not in a truck application.

 

Yes if memory serves me, trucks were using the 4 stroke Detroit, but busses and fire trucks were still getting the DDEC 2 stroke.
Pretty sure the 92’s with DDEC rated @ 500 horse in the fire trucks….