Page 16 R & D Marine Engine drive plates, mountings & couplings Engine mountings Flywheel drive plates Flexible shaft couplings Style A B C H S Full Load (mm) (mm) (mm) (mm) Thread Rating, Kg C-Type 102 13 72 56 5⁄8” UNF 86, 136 Sheer, small 102 13 56 56 5⁄8” UNF 42, 78 Sheer, medium 102 13 70 78 5⁄8” or ¾” 80, 105, 156, 255, 309 Sheer, long 127-140 13 70 78 5⁄8” or ¾” 81, 106, 187, 256, 310 Style A B C H S Full Load (mm) (mm) (mm) (mm) Thread Rating, Kg Sheer, large 102 13 92 71 ¾” UNF 345 Double-acting 102-140 13 70 78 5⁄8” or ¾” 190, 305 Yanmar Y50 128 12.5 60 100 M16 60 Yanmar Y70-Y200 175 12.5 60 100 M16 60, 73, 109, 146 Sheer Sheer Double-acting Yanmar Drive Plate Selection If replacing an existing R & D drive plate, look for its code number (something like “15M2”) stamped close to the edge if the plate on the gearbox side. Otherwise, do the following:- 1. Identify the spline of your gearbox from the table below. 2. Chose element. Select High Def for 3 or 4-cyl engines and for 6-cyl with light flywheels like Cummins and Perkins, as these are best at eliminating gearbox rattle. Hammer Head can be used if there is not enough space for the High Def element though rattle absorption is not as good. Loop elements can be used on 6-cylinder engines like Ford and Gardner with heavier flywheels where rattle is not a major problem. 3. Measure your flywheel in both Imperial and Metric units, as most common flywheels are drilled in Imperial, fractional dimensions. If the flywheel is recessed to take the drive plate, order “M/C O.D”. Almost any size plate can be supplied and can be drilled on any P .C.D. that is more than about ½” (13mm) bigger than the ZZ dimension of the element. Engine and gearbox weight is often split 40/60 front/rear. Full load of selected mount should be about twice the weight of the corner of the engine it is supporting. Element details Torque Code Rotation XX YY WW ZZ HP/100RPM (mm) (mm) (mm) (mm) HIGH DEF 1.9 AM Anti-clockwise 25.4 32 0 127 3.8 AN Anti-clockwise 25.4 35 5 182 5.7 AL Anti-clockwise 26.4 34 12.5 194 9.5 AD Anti-clockwise 29 36 6 235 13.3 AE Anti-clockwise 31.8 39 0 302 HAMMER HEAD 1.9 W Either 25.4 32 2.3 127 3.0 D Either 25.4 35 5 175 4.8 Y Either 28.7 35 5 182 5.7 AJ Either 29.5 36 8.1 150 5.9 L Either 25.4 35 5 175 6.7 U Either 28.7 35 5 182 10.5 R Either 28.7 35 5 182 Element details Torque Code Rotation XX YY WW ZZ HP/100RPM (mm) (mm) (mm) (mm) LOOP 1.1 A Either 25.4 32 0 127 1.9 B Either 25.4 32 0 127 3.4 E Either 25.4 35 5 207 3.8 F Either 29.5 36 8.1 158 4.8 G Either 25.4 35 5 207 5.1 H Either 29.5 36 5 183 5.7 J Either 29.5 36 8.1 158 6.3 K Either 28.7 35 5 207 7.6 M Either 25.4 35 5 207 8.6 H Either 29.5 36 5 183 8.6 V Either 28.7 35 5 207 10.5 P Either 28.7 35 5 207 14.3 S Either 31.8 35 5 207 22.9 Z Anti-clockwise 44.2 57.2 0 330 Gearbox Spline Sizes Diameter No. of gearbox models (mm) splines 19.7 17 PRM Delta 22.6 20 Volvo MS, Yanmar SD 25.4 10 PRM100-280, Volvo 100 Z-drive 28.6 10 PRM 175-265, 310 28.84 17 PRM 301-750 29 10 PRM 60-90, 120-150, ZF 5-15, B/W 500, TMC30-60 35.4 26 B/W 71-73, 5000, 6000, PRM C, Paragon, TMP1200, Twin Disc 5010, 502, TM 93-880, Volvo MS3-5, SD 110, 250-280 drive, ZF 25-220, 38.1 10 Parsons 40.5 18 PRM 601, 1000 41.3 10 SCG MRF350 44.8 20 PRM 1500, 1750 52.3 32 SCG MRF350HD Gearbox Number Size Pitch Register Thicknesses Ratings Flange Type of Holes S Circ P R T (mm) HP/100RPM 4” standard 4 10mm 3¼” 2½” 32.5, 32.5, 35.6 3, 5, 8 4” Volvo 4 10mm 80mm 60mm 32.5, 32.5, 35.6 3, 5, 8 5” Standard 4 7⁄16” 4¼” 2½” 32.5, 32.5, 35.6 8, 13, 20 4” Yanmar 4 10mm 78mm 60mm 45, 45, 52.4 3, 5, 8 5” Yanmar 4 10mm 100mm 65mm 45 10 5¾” Twin Disc 6 5⁄8” 4¾” 3” 47.5, 49.8, 55.4 20, 28, 37 6” Standard 6 ½” 4¾” 3” 47.5, 49.8 20, 28 In order to select an appropriate coupling, first identify the diameter of the output flange of the gearbox. Then take the full HP rating of the engine, multiply it by the gear ratio of the gearbox and divide it by the full RPM of the engine, in hundreds. For example, with a 120HP , 2500RPM engine and a 2.9:1 gearbox, this would be 120 times 2.9 divided by 25 which is 13.93 HP/100RPM on the propeller shaft. So a coupling should be selected that is a little more than this figure