Elvis
Chief Master Sergeant
No worries, Colin. It was a fair comment. You asked, so I tried to clarify.
I think if a P-40 were to be re-engined with a Griffon, I suppose the F and L versions would be the best candidate, since mod's to use the Merlin would already be in place (and I'm thinking mostly about countering the greater weight. The Merlin's about 300-400 lbs. heavier than the Allison).
So lets start throwing some specs around.
Here's some for the Griff 58:
Model: Griffon 58
Original Application: Avro Shackleton reconnaissance plane
Engine Type: V-12 Piston Aero Engine, 60° "V" (angle between banks)
Material: Aluminum crankcase, cylinder banks and heads; Alloy pistons; Steel liners, rods, cranks, etc.
Bore x Stroke: 6.0" x 6.6"
Compression Ratio: 6.0:1
Supercharger Type: Two-speed, single-stage centrifugal 13.4" impeller
Supercharger Ratio: Medium Speed (MS) - 6.615:1, Full Speed (FS) 7.70:1
Boost Control: Automatic via Rolls-Royce auto boost regulator, w/increased boost when ADI active
Fuel System: Speed/Density type Fuel Injection (injected into eye of supercharger)
Weight: 2,000 lbs
Power: 2,450 HP takeoff at 2,750 RPM at SL with 25 psig boost using 115/145 PN fuel
Performance: 0.82 lbs/hp, 314 psi BMEP, 0.42 lbs fuel/hp/hr SFC
Max. Piston Speed: 3,025 ft/min
...and some interesting historical comments about why the engine came to be:
"Development of the Griffon Engine began at Derby, England 1939 when Harry Cantrill was assigned to develop a conventional V-12 scaled up from the 1650 cu-in Rolls-Royce Merlin. The engine was intended to produce more than 1,500 HP at low altitudes for naval torpedo bombers. For maximum utility, it was decided to keep the engine as compact as possible so it could replace the Merlin in some applications. The resulting design had approximately the same frontal area as the Merlin and was actually shorter. The bore and stroke was the same as the Rolls-Royce "R" Schneider Cup race engines of 1929 and 1931, which were direct ancestors to the Griffon, resulting in an displacement of 2,240 cubic inches.. The Merlin proportions of the Griffon were partially achieved by moving the camshaft drives and magneto to the front of the engine."
(quote and engine specs came from here)
Ok, Clay, you got me.
This is looking like an even easier re-fit than how I was imagining it a few days ago.
Sorry I doubted you.
So, I think I brought this up before, but aren't there any Mechanical Engineers in the house?....even "amatuer" ones?
I'd like to see some mock-up's (on paper is fine) of what one would look like, if you started with either the F or L version of the P-40.
Elvis
I think if a P-40 were to be re-engined with a Griffon, I suppose the F and L versions would be the best candidate, since mod's to use the Merlin would already be in place (and I'm thinking mostly about countering the greater weight. The Merlin's about 300-400 lbs. heavier than the Allison).
So lets start throwing some specs around.
Here's some for the Griff 58:
Model: Griffon 58
Original Application: Avro Shackleton reconnaissance plane
Engine Type: V-12 Piston Aero Engine, 60° "V" (angle between banks)
Material: Aluminum crankcase, cylinder banks and heads; Alloy pistons; Steel liners, rods, cranks, etc.
Bore x Stroke: 6.0" x 6.6"
Compression Ratio: 6.0:1
Supercharger Type: Two-speed, single-stage centrifugal 13.4" impeller
Supercharger Ratio: Medium Speed (MS) - 6.615:1, Full Speed (FS) 7.70:1
Boost Control: Automatic via Rolls-Royce auto boost regulator, w/increased boost when ADI active
Fuel System: Speed/Density type Fuel Injection (injected into eye of supercharger)
Weight: 2,000 lbs
Power: 2,450 HP takeoff at 2,750 RPM at SL with 25 psig boost using 115/145 PN fuel
Performance: 0.82 lbs/hp, 314 psi BMEP, 0.42 lbs fuel/hp/hr SFC
Max. Piston Speed: 3,025 ft/min
...and some interesting historical comments about why the engine came to be:
"Development of the Griffon Engine began at Derby, England 1939 when Harry Cantrill was assigned to develop a conventional V-12 scaled up from the 1650 cu-in Rolls-Royce Merlin. The engine was intended to produce more than 1,500 HP at low altitudes for naval torpedo bombers. For maximum utility, it was decided to keep the engine as compact as possible so it could replace the Merlin in some applications. The resulting design had approximately the same frontal area as the Merlin and was actually shorter. The bore and stroke was the same as the Rolls-Royce "R" Schneider Cup race engines of 1929 and 1931, which were direct ancestors to the Griffon, resulting in an displacement of 2,240 cubic inches.. The Merlin proportions of the Griffon were partially achieved by moving the camshaft drives and magneto to the front of the engine."
(quote and engine specs came from here)
Ok, Clay, you got me.
This is looking like an even easier re-fit than how I was imagining it a few days ago.
Sorry I doubted you.
So, I think I brought this up before, but aren't there any Mechanical Engineers in the house?....even "amatuer" ones?
I'd like to see some mock-up's (on paper is fine) of what one would look like, if you started with either the F or L version of the P-40.
Elvis
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