Hi:
Road & Track used to list piston speed as part of their testing data. All of the
XPAG-XPEG engines have the same stroke so the RPM @ 2500 ft/min would be the
same. These engines all have a 3.54 inch stroke. This data came from one
article about T series MGs.
The same should have been true for all of the B series engines, but notice the
slight difference in calculations for each different article.
The stroke listed for these engines is 3.50 inches
The Midgett III stroke is listed as 76.0 mm
Blake
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TC , 5.12 rear axle, 4.50 x 19 tyres:
Mph/1000 rpm ................. 15.5
Engine revs/mile ............. 3870
Piston travel, ft/mile ....... 2280
Rpm @ 2500 ft/min ............ 4230
equivalent mph ............. 65.6
R&T wear index ............... 88.2
TD, 5.12 rear axle, 5.50 x 15 tyres:
Mph per 1000 rpm ............. 14.9
Engine revs/mile ............. 4030
Piston tavel, ft/mile ........ 2380
Rpm @ 2500 ft/min ............ 4230
equivalent mph ............. 63.0
TF 1500, 4.88 rear axle, 5.50 x 15 tyres:
Mph per 1000 rpm .............. 15.6
Engine revs/mile .............. 3840
Piston travel, ft/mile ........ 2265
Rpm @ 2500 ft/min ............. 4230
Equivalent mph ............... 66.2
R&T wear index ................ 87.0
MGA, 4.30 rear axle, 5.60 15 tyres:
Mph per 1000 rpm .............. 17.0
MPH @ 2500 fpm piston speed ... 73.0
MGA, twin cam, 4.30 rear axle, 5.90 x 15 tyres:
Mph/1000 rpm .................. 17.6
Engine Revs/mile .............. 3400
Piston travel, ft/mile ........ 1985
Rpm @ 2500 ft/min ............. 4280
equivalent mph .............. 75.5
R&T wear index ................ 67.5
MGA 1600, 4.3 rear axle, 5.60 x 15 tyres:
Mph/1000 rpm .................. 17.2
Engine Revs/mile .............. 3480
Piston travel, ft/mile ........ 2030
Rpm @ 2500 ft/mon ............. 4285
equivalent mph .............. 73.8
R&T wear index ................ 70.7
MGA MKII, 4.10 rear axle, 5.60 x 15 tyres:
Mph/1000 rpm .................. 18.1
Engine Revs/mile .............. 3320
Piston travel, ft/mile ........ 1935
Rpm @ 2500 ft/min ............. 4290
equivalent mph ............... 77.5
R&T wear index ................ 64.2
MGB 1800, 3.91 rear axle, 5.60 x 14 tyres:
Nph/1000 rpm .................. 17.9
Engine revs/mile .............. 3340
Piston travel, ft/mile ........ 1950
Rpm @ 2500 ft/min ............. 4290
equivalent mph .............. 77.0
R&T wear index ................ 65.1
MG Midget III, 4.22 rear axle, tyre size ?:
Mph/1000 rpm .................. 15.4
Engine revs/mile .............. 3900
Piston travel, ft/mi .......... 2080
Rpm @ 2500 ft/min ............. 4690
R&T wear index ................ 81.0
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