WWII Engine Power Enhancement

[Joseph G]

When I was in A & P School we had a couple of piston engines in the shop class that had a turbine/Turbo that had a shaft connected to a set of gears that we were told were use to assist in the rotation of the crankshaft to free up 300 HP on the dyno.

I also read about it some time later but can't find any information on it now.

What was this technology called, which engines utilized it and can anyone support the story we were told in class?

Thanks

 

[GregP]

It was called a turbo-compound engine. Exhaust was routed to the turbines (three for an R-3350) and the turbine was geared to the crankshaft to return some, but not all, of the power lost as exhaust heat. The most prolific of the turbo-compounds were the post-war R-3350s.

 

[pbehn]

There were many ideas

https://www.brighthubengineering.co...ts-came-before-turbochargers-and-jet-engines/

 

[swampyankee]

It's still being used, frequently on engines quite a bit more powerful than any of the piston engines with spark plugs.

 

[fastmongrel]

Napier Nomad
A turbo-compound Diesel engine

 

[J.A.W.]

Some graphs showing the effect of boost increases on speed.

Here is a Sabre-powered Tempest chart showing speed gain with boost upped from 9lbs to 12lbs.

http://www.wwiiaircraftperformance.org/tempest/hawker-12lbs.jpg

& below from 'Flight',
http://www.flightglobal.com/pdfarchive/view/1948/1948 - 1660.html

See the graph marked - - - - rising from the bottom right in the graph linked above,
it indicates a 'standard' Tempest F.6 ( with regular Sabre-type chin radiator) @ 17.25lbs.

 

[XBe02Drvr]

What was this technology called, which engines utilized it and can anyone support the story we were told in class?

When I was in the Nav there was an ELINT EC-121 based at our field that had turbo compound 3350s. It was parked out by the Flying Club, and whenever it wasn't flying it had one or more cowlings stripped off and mechs working on it. I never ceased to marvel at the plumber's nightmare that was revealed every time they opened a cowling.
Decades later you could still see on Google Earth the four stains on the pavement where that plane parked.
Cheers,
Wes

 

[BiffF15]

Decades later you could still see on Google Earth the four stains on the pavement where that plane parked.
Cheers,
Wes

Sounds like a MacAir ramp...