Re: TF ENGINE CRANK

[Bob Grunau]

Hi Rocky, Your machine shop is right, you need tolerances. These are: Connecting rods 45 mm -0.035 mm or 1.7703" -0.015 mm 1.7716" Mains 52 mm -0.035 mm or 2.0459" -0.015 mm 2.0466" Radius ( and this is IMPORTANT ) 2.5 mm +/- 0.15mm. Crankshaft breakage is greatly assisted by too sharp a radius. So make sure they understand you want the 2.5 mm radius. The above dimensions come from the MG Series Y Maintenance and Instruction Manual. This manual has way more data than the TD Workshop Manual. The dimensions are confirmed in my 1971 Vandervell bearing manual. Note the TD Manual rounds up the dimensions to 1.772" for the rods, 2.047" for the mains, not really precise enough. If the machine shop ( and you ) are really on the ball, you need similar dimensions for rod and main bearing housing diameters. The connecting rods should be re-sized to ensure the big ends are round and to the correct diameter. I'm copying the T-ABC list in case anyone there needs this information. Regards, Bob Bob Grunau 150 Pinewood Trail, Mississauga, Ontario, Canada, L5G-2L1 905-274-4136 -----Original Message----- From: owner-mg-t@autox.team.net [mailto:owner-mg-t@autox.team.net]On Behalf Of Krislynco.llc Sent: Wednesday, June 08, 2005 1:25 AM To: mg-t@autox.team.net Subject: TF ENGINE CRANK Hello folks can anyone tell me ..the machine shop that is rebuilding my xpag engine needs to machine/polish the crank and says that the crank connecting rod bearing diameter should have a plus or minus diameter of ???? when machined.. yet the MG T tech manuals only give a specific size without any tolerance which he indicated is impossible to do..any thoughts?? Thanks Rocky