GM Patents Twin-Charged, Variable Dynamic Compression, Hybrid Engine

[solarite_guy]

Originally Posted by solarite_guy

...Before I forget, there were some 2 stage supercharger arrangements where an "auxiliary" supercharger was the second supercharge. Off the top of my head right now, I couldn't say which engine and which aircraft got these.

It's too late here. I'm not typing straight. Need to add "Other than the P63..."

[Chopped]

Too much mathematics going on in here, my brain hurts.

[XByoot]

Originally Posted by solarite_guy

Just for clarification, the turbo superchargers were not used in turbo compound arrangements.

The PRTs on the 3350s were a more advanced form of turbo compounding than seen on the 1710 in the picture I put up. This arrangement added direct power to the engine crankshaft and supercharger.

BTW the engine I posted was originally meant for Miss Bardhal before the era of the jet turbine powered Hydroplanes.

Before I forget, there were some 2 stage supercharger arrangements where an "auxiliary" supercharger was the second supercharge. Off the top of my head right now, I couldn't say which engine and which aircraft got these.

Thanks Dave...looking at the schematic of the Allison it shows an auxiliary or pre charger arrangement driven by the turbine then the gearbox to the engine?

[solarite_guy]

Yes Steve, that is correct, I had the order of the superchargers wrong. That's what I get for staying up way past bed time...

Also, while away from this topic, I did a little research to get some first hand information.

The engine shown is an Allison, but was not from an aircraft. It was a NACA test development engine.

I found the actual NACA paper on the calculations they came up with using that test mule. Pretty interesting reading if you have the time.

http://www.missbardahl.com/engine/te...%20efficen.pdf

I also, found the web page with some more details about the Unlimited Hydro Miss Bardahl.

To complicate matter that team was actually using a Merlin where everyone else was using Allisons. I remember as a kid watching the races on tv all everyone talked about was the Allisons. The dominant boat in the early and mid 60s was Merlin powered.

To complicate things even more yet, those guy were actually going to use the exhaust turbine from a GE type B turbo supercharger as an RTC in a turbo-compound arrangement driving the auxiliary and main superchargers and the crank. I don't know if anyone ever put something like that in a hydro, regardless of power plant?

Here is a little bit of information about that.

http://www.missbardahl.com/engine/te...hancements.htm