Exhaust driven odity, or divine inspiration? :P

[phoenix02]

Hello all,

I was just thinking- front mount additions rob power by having to be driven by the crank- Alternator, Compressor, PS Pump, etc.

Exhaust can be routed to drive something- turbos, etc.

SO, why can't someone take a split header, have one side driving a mild turbo to liven up the six a little, and have the other side driving an accessory? I was thinking perhaps taking the exhaust side of a small turbo and attaching it to the wheel on an alternator- with a good thermal barier betwixt, of course. From there, you could run an electric A/C compressor off the alternator, and if needed, electric power steering, not to mention an electric water pump.

At that point, you'd have no parasitic drag on the crank, and the turbo boost would negate any loss you would take through backpressure caused by the turbo and altenator.

Or, if this is all just a really bad idea occuring to an idiot at 3AM, then I'll just take the easy way out, like our Asiatic bretheren- I'll put some stripes, LEDs and a "Powered by Honda" window sticker on the Falcon. I KNOW that's all gotta be worth, like, 300HP. Then maybe some Mugen seatbelt pads. that's another 20HP or so at 3600RPM.


...or so I've heard.
-Michael

 

[Mercury Mike]

Heya Mike. I'm going to San Francisco on the 30th. I can stop by on the way and kick back for awhile if you're gonna be free at all. Let me know.

 

[80broncoman]

As soon as you get the alt to anything over 15K rpm it think its to explode.

 

[rbohm]

8) consider the fact that the turbo shaft spins as high as 100,000 rpm, you wouls have to have a gear box with severe gearing to lower the rpm to a maximum of 6000 rpm, and even then it woudnt be consistant.

interesting idea, but in this case a no go.

 

[Lazy JW]

This concept isn't quite as far-fetched as you might think, in fact it has sorta been done already on aircraft engines back in the 1940's-50's.

Just before jet (turbine) engines completely replaced high horsepower piston engines there was a lot of effort put into extracting maximum efficiency from the big radials. One type was the "compound" engine that was an enormous 4-row, 28 cylinder turbocharged radial that had the turbo shaft geared to the crankshaft output in order to recover some of the exhaust energy. The gearbox had some bodacious reduction ratio to make it all work, but work it did. At the time they were more efficient than a turbine, probably still would be but I doubt that very many are still operational due to the enormous complexity and resulting high maintenance costs.
Joe

 

[phoenix02]

http://www.barber-nichols.com/products/ ... efault.asp

Thanks for the feedback- it's been done, as seen above. Very complex gear reduction, but it works!


Okay then, we create a gear reduction box on the driveshaft or add a magnetic electrical generator to the tire hubs.... Hmm... I know this all has been done to death in the interest of electric cars, but I think there's a solution out there someone hasn't done or succeeded at yet...

-Michael

 

[Lazy JW]

Yowza! A 60,000 rpm alternator 8)

Take two, they're small
Joe

 

[80broncoman]

Okay then, we create a gear reduction box on the driveshaft or add a magnetic electrical generator to the tire hubs.... Hmm... I know this all has been done to death in the interest of electric cars, but I think there's a solution out there someone hasn't done or succeeded at yet...

-Michael

Simplest way to do it would be to take a smaller 4wd truck that has a bad tranfer case And just use a 2wd trans. Then install A generator where the front driveshaft ends.

 

[Lazy JW]

Okay then, we create a gear reduction box on the driveshaft or add a magnetic electrical generator to the tire hubs.... Hmm... I know this all has been done to death in the interest of electric cars, but I think there's a solution out there someone hasn't done or succeeded at yet...

-Michael

So are you still trying to drive the alternator for free?
Joe

 

[StrangeRanger]

Basic rule of engineering:
Every energy transfer has an efficiency loss associated with it. The more transfers which occur, the more the inefficiencies multiply. The more closely coupled parasitic losses (like alternators and water pumps) are to the prime mover (in this case the crankshaft) the fewer HP will be required to run them.

 

[Anonymous]

This concept isn't quite as far-fetched as you might think, in fact it has sorta been done already on aircraft engines back in the 1940's-50's.

Just before jet (turbine) engines completely replaced high horsepower piston engines there was a lot of effort put into extracting maximum efficiency from the big radials. One type was the "compound" engine that was an enormous 4-row, 28 cylinder turbocharged radial that had the turbo shaft geared to the crankshaft output in order to recover some of the exhaust energy. The gearbox had some bodacious reduction ratio to make it all work, but work it did. At the time they were more efficient than a turbine, probably still would be but I doubt that very many are still operational due to the enormous complexity and resulting high maintenance costs.
Joe

The engine you mentioned is the P&W R-4360, an 28 cyl/ 4 row radial. The Turbo-compound engine was produced by Wright - as the R-3350, an 18 cyl/ 2 row radial that powered the Lockheed Super Constellation. The exhaust turbine shaft was fed thru a reduction gearbox then to a torque converter that was geared to the crank. There were three of these on the back of the engine fed by 6 cyls. Also known as Power-recovery turbines. They extracted about 100hp each. Free horsepower! The problem today with these engines isn't parts so much as it is maint. costs and fuel! They don't make 115/145 octane (purple) Avgas any more.
I'd love to see someone try this with an automotive engine.

 

[rmt]

Hey Aerowrench, stick around!

 

[Anonymous]

They don't make 115/145 octane (purple) Avgas any more.

Only one place left in the USA where you CAN - the Commemorative Air Force (formerly known as confederate air force) Museum in Midland, TX.

About $9-$10 a gallon last I heard.

 

[matt1967]

I found an article using a school research database ( EBSCO HOST ) about british creating those turbo driven alternators. called them turboraters or somthing like that

 

[jamyers]

I'd think that if you really wanted to free up engine hp, a small efficient aux power unit (apu) would be the way to go. Something like a small Honda 4-stroke engine running the oil pump, water pump, p/s pump, and alternator - all at a constant speed.

Regarding extracting maximum energy, anybody remember Smokey Yunick's ceramic engine that used something like 90% of the heat energy?

If anybody comes up with a decent heat storage device, let me know.

 

[Anonymous]

Hmmm, I don't know about the oil pump. Kind of a critical component...

Alot of the hard core Drag racers use a friction drive for the alt. that basically slips at high rpm, along with an elec. water pump & fuel pump. All to save HP.

 

[wallaka]

Hmmm, I don't know about the oil pump. Kind of a critical component...

Alot of the hard core Drag racers use a friction drive for the alt. that basically slips at high rpm, along with an elec. water pump & fuel pump. All to save HP.

Most drag cars I've seen don't have an alt. The battery drives the electrics, and it's charged after every run.

 

[Anonymous]

Strange Ranger's right: no free power. A turbo section costs you something in pumping losses and back-pressure.

When I was smashing baggage at the airport right out of high school, Alaska airlines had one of those Super-Connies that they'd got cheap from TWA, which had happily replaced them with jets. The Alaska mechanics would work on that old bird for days, then fire it up and blow great thunderclouds of white smoke all over Sea-Tac airport. Shut 'er down, work a few more days, try again, more clouds of smoke. Eventually that poor old Connie went away; don't know if they finally fixed it or scrapped it. Alaska Airlines is a first-rate operation now, but in those days (Fifties and Sixties) they were the sad-sack of the industry. At the same time as the Connie they were operating a couple of cast-off Convair 880s which sounded like they had a bunch of bad bearings, but maybe that was just the charactoristic sound of those engines . . . Aerowrench??

 

[Anonymous]

Yeah, Radials have a character all their own.
A cold engine will make noise until warmed up. Clearances are pretty loose when cold. (air-cooled engine)
There's a joke in the aircraft industry, if a radial doesn't leak oil, it's out of oil!
The White smoke is from the bottom cylinders, (dry sump engine) Sometimes oil will drain back into the case and seep past the lower cylinders. Worse case is hydraulic lock of the piston and bent rods on start up. Ever see old WWII movies of guys rotating the prop backwards (2 revs)? They're checking for this.
Aircraft Piston Engines really reached their zenith in the mid 50's.

 

[jamyers]

Yeah, Radials have a character all their own...

Yup - a B-17, B-24, and B-25 were in town a week or so ago, I think it was called the "Wings of Freedom" tour. I took the kids out to the airport just to take a look, and while we were there they fired up the B-17 to take some paying folks for a ride.

Shivers down my spine hearing those great wonderful mechanical beasts come to life!