P-38 Question

[J.SMITH]

In My Warbird Digest (Jan/Feb 2008) It states that Ruff Stuff is the only flying P-38 with operating tubo-superchargers. Is this a true statement.

[JET1]

very possible

In My Warbird Digest (Jan/Feb 2008) It states that Ruff Stuff is the only flying P-38 with operating tubo-superchargers. Is this a true statement.

the turbo driven superchargers were very problematic according to Lefty. too many moving parts.

[steve D]

Re: P-38 Question

Glacier Girl has them and so does POF Porky, whether or not they are "operational" or not I'm not sure but the exhaust still runs through them. Why run the risk of a turbo fire and the added maintenance on an operational turbo when nobody goes up to 30k anymore(except J. Roush in his Mustangs recently)

[Coyote Chris]

Re: P-38 Question

I was told the same thing at Oshkosh where Ruff Stuff has been the last two years. Here is what Wikipedia says about the P-38 turbo problems (of course, the other current flying P-38 Allisons still have the single stage internal super charger)

"The P-38 would be the only fighter to make it into combat during World War II with turbosupercharged V-1710 engines. The operating conditions of the Western European air war - flying for long hours in intensely cold weather at 30,000 feet (9,100 m) - unmasked several severe problems with the P-38's turbosupercharged V-1710. The V-1710 engines in these P-38s had a poor manifold fuel-air distribution and poor temperature regulation of the turbosupercharger air, which resulted in frequent engine failures (detonation occurred in certain cylinders as the result of persistent uneven fuel-air mixture across the cylinders caused by the poor manifold design). The turbosupercharger had additional problems with getting stuck in the freezing air in either high or low boost mode; the high boost mode could cause detonation in the engine, while the low boost mode would be manifested as power loss in one engine, resulting in sudden fishtailing in mid-flight. Specific details of the failure patterns of the P-38's turbosupercharged V-1710 were spelled out in a report by General Doolittle to General Spatz in January 1944 [p.188-189, Ludwig. "P-51 Mustang: Development of the Long Range Escort Fighter"]. It was too late to correct these problems in the production lines of Allison or GE, and so the P-38s were steadily withdrawn from Europe until they were all gone by October 1944."

[dj51d]

Re: P-38 Question

Glacier Girl has them and so does POF Porky, whether or not they are "operational" or not I'm not sure but the exhaust still runs through them.

It is my understanding that on most currently flying P-38s, the exhaust runs through the empty turbo housings. I asked Kevin Eldridge about the turbos the year he flew Ruff Stuff to Oshkosh, and he said at the altitudes they typically operate at the only real difference the turbos make is in the sound. I'm not sure why they chose to go with operational turbos given the often associated difficulties, but having seen all 3 fly, I can say the Ruff Stuff certainly sounds different than Glacier Girl or Porky.

[440_Magnum]

Re: P-38 Question

In My Warbird Digest (Jan/Feb 2008) It states that Ruff Stuff is the only flying P-38 with operating tubo-superchargers. Is this a true statement.

I think most of the B-17s and B-24s still flying don't actually use their turbos any longer either. When I recently walked around the Collings Foundation birds, I noticed that a couple of turbos didn't even have their wastegate butterflies installed although the turbos themselves were all present. Without the wastegate butterfly valves the turbos won't ever build any boost, even though they'll spin a bit and a small fraction of the exhaust will flow through them. The valve has to be able to close off the downstream exhaust and force all the flow to go through the turbine in order to build boost.