TSRM/MK3 Supra/Repair Manual
Repair ManualWiring Diagrams
p.081
EM/Engine Mechanical82 / 98
p.083
BORING OF CYLINDERS — MK3 Supra Engine Mechanical, page 82
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BORING OF CYLINDERS HINT: • Bore all six cylinders for the oversized piston outside diameter. • Replace the piston rings with ones to match the oversized pistons. 1. SELECT OVERSIZED PISTON Oversized piston diameter: O/S 0.50 7M-GE 83.40 — 83.45 mm (3.2835 — 3.2854 in.) 7M-GTE 83.41 — 83.46 mm (3.2839 — 3.2858 in.) 2. CALCULATE AMOUNT TO BORE CYLINDER (a) Using a micrometer, measure the piston diameter at a right angle to the piston pin hole center line, 22 mm (0.87 in.) from the piston head. (b) Calculate the amount each cylinder is to be rebored as follows: Rebore amount = P + C — H P = Piston diameter C = Piston clearance 7M-GE 0.08 — 0.10 mm (0.0020 — 0.0028 in.) 7M-GTE 0.07 — 0.09 mm (0.0028 — 0.0035 in.) H = Allowance for honing 0.02 mm (0.0008 in.) or less 3. BORE AND HONE CYLINDERS TO CALCULATED DIMENSIONS Maximum honing: 0.02 mm (0.0008 in.) NOTICE: Excess honing will destroy the finished roundness.