wuzak
Captain
The oil coolers were in the front of the nacelle for all production P-38s.
Allison V-1710 Installation in P-38
P-38 limited to 420mph
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The oil coolers were in the front of the nacelle for all production P-38s.
Allison V-1710 Installation in P-38
GregP
Major
No way. The P-38F was the first combat-ready P-38, and it was very definitely a production machine.
wuzak
Captain
The holes in the front of the engine nacelles, below the spinners, are for the oil coolers.
The little flap lowered ahead of the landing gear is the outlet for the oil cooling ducts.
wuzak
Captain
In the J and L the centre duct is for the core type intercooler, the two outer ducts are for the oil coolers.
Old Wizard
2nd Lieutenant
GregP
Major
Sorry, I said "Oill Coolers," and was thinking "Intercoolers." Duuhhhh .... the Intercoolers would only support 1050 HP and you were and ARE correct on oil coolers. The oil coolers are the same on the P-38, P-39, P-40, and P-40. There are two circular cross section coolers with hexagonal honeycomb fins. The center intake on the F was the carburetor intake.
Gotta' READ this stuff before I post it!
The P-38J moved the INTERTCOOLER from wing leading edge to chin intake. If I am not mistaken (never!), there is still ONE P-38 flying with operational turbochargers (I have heard that, along with ONE P-47 with one working). The rest have configured the outside intakes of the J and L to be oil cooler intakes, the center intake to be carburetor air, and have blocked off the original carb intake down alongside the trailing edges of the wing.
Cheers, Wayne. Sorry for the mis-post above. I plead stupidity and beg to be made to get drunk. In fact, the F model is Glacier Girl, pic taken at Planes of Fame, right in front of Steve Hinton's Fighter Rebuilders hangar.
Gotta' READ this stuff before I post it!
The P-38J moved the INTERTCOOLER from wing leading edge to chin intake. If I am not mistaken (never!), there is still ONE P-38 flying with operational turbochargers (I have heard that, along with ONE P-47 with one working). The rest have configured the outside intakes of the J and L to be oil cooler intakes, the center intake to be carburetor air, and have blocked off the original carb intake down alongside the trailing edges of the wing.
Cheers, Wayne. Sorry for the mis-post above. I plead stupidity and beg to be made to get drunk. In fact, the F model is Glacier Girl, pic taken at Planes of Fame, right in front of Steve Hinton's Fighter Rebuilders hangar.
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The level of misinformations in this tiny thread is amazing, and that for the P-38!!
Two P-40s, since one is not enough.
That is before mentioning that Allison-engined P-40 actually featured one oil coller per aircraft, so did the P-51. Center intake of what F?
Nah, dont do that.
(my bold)
The bolded part will need a whole salt factory for people to swallow (me included), since the grain of salt won'd do it.
Two P-40s, since one is not enough.
That is before mentioning that Allison-engined P-40 actually featured one oil coller per aircraft, so did the P-51. Center intake of what F?
Nah, dont do that.
(my bold)
The bolded part will need a whole salt factory for people to swallow (me included), since the grain of salt won'd do it.
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Shortround6
Major General
This picture doesn't prove anything one way or another since it is of a plane in 1947 but I thought it interesting anyway.
Modified P-38J. Note exhaust pipe.
Red Bull, at least at one time, used a top carb inlet.
Without under cowl pictures of the duct work it is impossible to say what stock appearing current flying aircraft are doing.
Is aircraft was a wreck but shows (I think?) where some of the ducts are.
redish/orange scoop is the normal carb intake. Curved aluminum duct coming up from under the engine to the top rear would be (?) the intercooler to carb duct. It might not take a lot of sheet metal work to adapt the intercooler intake and space to this duct vs the work needed to route the air from the redish/orange scoop to the carb inlet?
I am not sure if there was an inlet inside the wheel well for dirty conditions? but this would might not work well once the gear was up and would provide zero ram effect.
Modified P-38J. Note exhaust pipe.
Red Bull, at least at one time, used a top carb inlet.
Without under cowl pictures of the duct work it is impossible to say what stock appearing current flying aircraft are doing.
Is aircraft was a wreck but shows (I think?) where some of the ducts are.
redish/orange scoop is the normal carb intake. Curved aluminum duct coming up from under the engine to the top rear would be (?) the intercooler to carb duct. It might not take a lot of sheet metal work to adapt the intercooler intake and space to this duct vs the work needed to route the air from the redish/orange scoop to the carb inlet?
I am not sure if there was an inlet inside the wheel well for dirty conditions? but this would might not work well once the gear was up and would provide zero ram effect.
wuzak
Captain
This picture doesn't prove anything one way or another since it is of a plane in 1947 but I thought it interesting anyway.
Modified P-38J. Note exhaust pipe.
Good thing they pointed the exhaust downwards - otherwise it may have added some warmth to the radiators....
GregP
Major
Thanks for the compliments above Tomo. I guess I'm not on your short list. I'll get over it.
I was talking about the F-model P-38 with two oil coolers per side, same as the J and L model P-38s. American airplanes shared a lot of parts. The P-38, P-39, P-40, P-47, and P-51 all shared some parts for many models and oil coolers are among them. They tended to share starters as well and, to an extent, carburetors. I didn't say the P-40 had 2 oil coolers above. But it DOES have one that is the same unit as used in the P-38. It even has the same part number. The P-38, P-39, and p-40 also share the same Cuno filter, so you only need one type of spare oil screen.
The P-38J/L cowling has an opening under the spinner that divides into 3 sections. The two outer sections each feed one oil cooler. The center section feeds the turbo intercooler in stock form. On the outboard side of each engine boom, just below the trailing edge of the wing, there is a small duct that originally was the fresh air intake for the turbocharger and ultimately fed the carburetors when the air was compressed by the turbos. All the flying P-38s today, except for one (to my knowledge) have had the turbochargers disabled, the fresh air intakes have been plugged, and the center intake that used to feed the intercooler has been made into the fresh air inlet for the carb.
The radiators are in the side bumps that stick out from the booms on both sides aft of the wing trailing edge. The aft portion of these radiators is a door that opens and closes, controlling radiator airflow.
Hopefull that straightens out the intent above, even for Tomo.
Great pics above. The top one is obviously quite modified and also rather obviously has the turbochagers disabled. Otherwise, there would not be an exhaust pipe exit. Another clue is the scoop at the top of the cowling that would otherwise not be needed at all.
The Red Bull unit was originally modified by Lefty Gardner, and was reworked when Red Bull restored Lefty's P-38L after his son, Ladd, put it into a field on the belly after an engine failure. Lefty's plane was then sent to Ezell Aviation in Breckenridge, Texas and was nearly complete when a tornado came through and damaged several aircraft, including the P-38. Red Bull acquired it sometime after and restored it. Lefty's plane had P-38F cowlings fitted to the P-38L airframe because Lefty wanted it that way.
Without some study, it would be hard to say whether or not the F cowlings are stock or modified, and I am talking strictly the shape of the cowling. The shape of the curve, to be specific. You can't change the placement of the cowling mounting points because they have to connect to the airframe in the stock locations. I am under the distinct impression the turbochargers are still disabled, but don't know for sure. They might be functional. Lefty flew it both ways, according to people who knew him well, but I never asked whether or not the turbos were working when Lefty quit flying it. In any case, the two openings at the bottom of the cowling each feed oil coolers. There is no other place to mount them except the stock locations as the interior of the engine booms is very crowded and getting new air ducts to different areas would be almost impossible in any practical sense. That particular plane's booms are even MORE crowded since F-model cowlings are smaller than L-model cowlings to start with. The only reason to change their location would be to use the space for something more important than oil coolers. On an Allison bird, oil is used to partially cool the engine, and the oil coolers are vital to keep the engines running. To the pilot, the engines are more important than any other system!
The exhaust also isn't pointed downwards; it goes into a collector pipe and feeds the turbocharger wheel, exiting straight up. The turbo is mounted with the axis of rotation in the vertical plane. The turbine wheel spins horizontally on the shaft and the exhaust goes straight up out of the turbine wheel. That's why the P-38 seems so quiet on the ground ... all the exhaust noise is aimed straight up, and the long exhaust collector acts sort of like a muffler and drops the volume level by the time it exits the airframe.
I have a pic made of the turbo air intake for Tomo. Hopefully it loads. Photobucket seems awfully slow today.
I was talking about the F-model P-38 with two oil coolers per side, same as the J and L model P-38s. American airplanes shared a lot of parts. The P-38, P-39, P-40, P-47, and P-51 all shared some parts for many models and oil coolers are among them. They tended to share starters as well and, to an extent, carburetors. I didn't say the P-40 had 2 oil coolers above. But it DOES have one that is the same unit as used in the P-38. It even has the same part number. The P-38, P-39, and p-40 also share the same Cuno filter, so you only need one type of spare oil screen.
The P-38J/L cowling has an opening under the spinner that divides into 3 sections. The two outer sections each feed one oil cooler. The center section feeds the turbo intercooler in stock form. On the outboard side of each engine boom, just below the trailing edge of the wing, there is a small duct that originally was the fresh air intake for the turbocharger and ultimately fed the carburetors when the air was compressed by the turbos. All the flying P-38s today, except for one (to my knowledge) have had the turbochargers disabled, the fresh air intakes have been plugged, and the center intake that used to feed the intercooler has been made into the fresh air inlet for the carb.
The radiators are in the side bumps that stick out from the booms on both sides aft of the wing trailing edge. The aft portion of these radiators is a door that opens and closes, controlling radiator airflow.
Hopefull that straightens out the intent above, even for Tomo.
Great pics above. The top one is obviously quite modified and also rather obviously has the turbochagers disabled. Otherwise, there would not be an exhaust pipe exit. Another clue is the scoop at the top of the cowling that would otherwise not be needed at all.
The Red Bull unit was originally modified by Lefty Gardner, and was reworked when Red Bull restored Lefty's P-38L after his son, Ladd, put it into a field on the belly after an engine failure. Lefty's plane was then sent to Ezell Aviation in Breckenridge, Texas and was nearly complete when a tornado came through and damaged several aircraft, including the P-38. Red Bull acquired it sometime after and restored it. Lefty's plane had P-38F cowlings fitted to the P-38L airframe because Lefty wanted it that way.
Without some study, it would be hard to say whether or not the F cowlings are stock or modified, and I am talking strictly the shape of the cowling. The shape of the curve, to be specific. You can't change the placement of the cowling mounting points because they have to connect to the airframe in the stock locations. I am under the distinct impression the turbochargers are still disabled, but don't know for sure. They might be functional. Lefty flew it both ways, according to people who knew him well, but I never asked whether or not the turbos were working when Lefty quit flying it. In any case, the two openings at the bottom of the cowling each feed oil coolers. There is no other place to mount them except the stock locations as the interior of the engine booms is very crowded and getting new air ducts to different areas would be almost impossible in any practical sense. That particular plane's booms are even MORE crowded since F-model cowlings are smaller than L-model cowlings to start with. The only reason to change their location would be to use the space for something more important than oil coolers. On an Allison bird, oil is used to partially cool the engine, and the oil coolers are vital to keep the engines running. To the pilot, the engines are more important than any other system!
The exhaust also isn't pointed downwards; it goes into a collector pipe and feeds the turbocharger wheel, exiting straight up. The turbo is mounted with the axis of rotation in the vertical plane. The turbine wheel spins horizontally on the shaft and the exhaust goes straight up out of the turbine wheel. That's why the P-38 seems so quiet on the ground ... all the exhaust noise is aimed straight up, and the long exhaust collector acts sort of like a muffler and drops the volume level by the time it exits the airframe.
I have a pic made of the turbo air intake for Tomo. Hopefully it loads. Photobucket seems awfully slow today.
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Shortround6
Major General
Top photo is supposed to be at the 1947 National air races. The Pilot, Chas. Walling had finished 2nd to Tony Levier in the 105mile SOHIO event for P-38s at 351.785mph average speed but dropped out on the 2nd lap of the Thompson race. Course was 15 miles per lap with four corners, two of about 80 degrees and two of about 100 degrees.
GregP
Major
Neat info, Shortround. They did a LOT of modifications to WWII planes to race immediately after WWII. But racing took a break after the fatal 1949 races and didn't resume again until 1964. WWII fighters were cheap (relatively) and spares were plentiful. The 1960s saw most of the heavily modified racers built. If you check out the pedigrees of all the currently-fastest planes, you'll see that their airframe were almost all cut up in the golden days of unlimited air racing.
Virtually none have been built from stock airframes for decades. Strega, Voodoo, and Rare Bear are ALL old racing airfames from the 1960s. The warbirds are getting too scarce some 70 years after the war, and the engines are, too.
So the purists out there who don't think we should be racing them are sort of barking up the wrong tree. The racers that still race aren't freshly-mutilated airframes at all. They are rebuilt from old racers that were already done. I know one P-51 that was built up from the wrecked airframes of six different P-51s! And it has a dataplate from an old crashed race plane!
The fastest racer of them all was probably Dago Red. Last I heard that airframe was being completely disassembled and returned to stock condition! So, if correct, there's ONE seriously-modified airplane that will apparently be brought back to stock form. Last I heard it was owned by the Lockwoods. It should come out of the rebuild as a really nice bird.
Virtually none have been built from stock airframes for decades. Strega, Voodoo, and Rare Bear are ALL old racing airfames from the 1960s. The warbirds are getting too scarce some 70 years after the war, and the engines are, too.
So the purists out there who don't think we should be racing them are sort of barking up the wrong tree. The racers that still race aren't freshly-mutilated airframes at all. They are rebuilt from old racers that were already done. I know one P-51 that was built up from the wrecked airframes of six different P-51s! And it has a dataplate from an old crashed race plane!
The fastest racer of them all was probably Dago Red. Last I heard that airframe was being completely disassembled and returned to stock condition! So, if correct, there's ONE seriously-modified airplane that will apparently be brought back to stock form. Last I heard it was owned by the Lockwoods. It should come out of the rebuild as a really nice bird.
Conslaw
Senior Airman
I found this just after the first posting i did... LOL I sort of guessed part of the reason air racers didn't use the P-38 is two engines is a lot of extra work for privateers, even the USG seemed happier to make cheaper Mustangs in the end, i guess even the monster Tbolt is much cheaper to build.
Elvis
Chief Master Sergeant
Just a guess, but my first thought would be that the controls would have no effect at those speeds....thus the creation of the "flying tail", which I believe was pioneered on the Bell X-1.
It's my belief that N25Y had the turbos removed at the same time they backdated the cowlings (which required intercooler removal - why have the turbos without intercoolers). Of note is the first pic in post 28 of Charles Walling's race #14 which was registered N25Y and has side exhausts and the turbos pulled as well as the early cowls and no wingtips. If it became Lefty's White Lightning N25Y then Lefty likely never flew it with turbos. In place of the straight pipes that Lefty used (see pic in post 4) Red Bull have doghouses in which they've installed smoker systems.
Ascent
Senior Airman
In fact the first aircraft to use a "flying tail" was the Gloster E28/39 . There are pictures somewhere, I'll have to see if I can find one.
Elvis
Chief Master Sergeant
Thanks, I'd like to see those! =)
- Thread starter
- #38
Found this, don't know how much his words have been twisted but it looks valid ....Kelly Johnson, chief design engineer of P-38 (as well as F-104, T-33, U-2, TR-1 and SR-71) listed the following pros and cons of P-38s at a symposium in 1977,
GOOD POINTS OF THE P-38
1. Basic wing design – stall, lift, vol., etc.
2. Center line fire of guns – good armament.
3. Good forward visibility.
4. Counter-rotating propellers to counteract torque and improve stability.
5. Turbosupercharging.
BAD POINTS OF THE P-38
1. Engine problems – Backfiring – blew wing intercooler. Cooling – 3L – spark plugs (battle of San Fernando Valley – 9 engines). Solid fuel! – glass lines.
2. Wing intercooler – OK for 1000 hp, but not enough for higher power – waited too long to go to conventional intercooler.
3. Compressibility limit Mach 0.68 to 0.7 – wing thickness shape and induced fuselage nacelle flow field the cause.
4. Insufficient cockpit heat!
5. High aileron forces until power boost used.
The blending fillet on the wings to cockpit section was found to be extremely critical to air flow!
GOOD POINTS OF THE P-38
1. Basic wing design – stall, lift, vol., etc.
2. Center line fire of guns – good armament.
3. Good forward visibility.
4. Counter-rotating propellers to counteract torque and improve stability.
5. Turbosupercharging.
BAD POINTS OF THE P-38
1. Engine problems – Backfiring – blew wing intercooler. Cooling – 3L – spark plugs (battle of San Fernando Valley – 9 engines). Solid fuel! – glass lines.
2. Wing intercooler – OK for 1000 hp, but not enough for higher power – waited too long to go to conventional intercooler.
3. Compressibility limit Mach 0.68 to 0.7 – wing thickness shape and induced fuselage nacelle flow field the cause.
4. Insufficient cockpit heat!
5. High aileron forces until power boost used.
The blending fillet on the wings to cockpit section was found to be extremely critical to air flow!
