MED ALLOY WATER PUMP PULLEY

Description
Two larger pulley sizes (4.220" and 4.720") are available, designed to slow the water moving through the radiator to allow it time to cool - an important factor on any high-RPM race engine.
For reference, the original stock pulley measured 3.875".
Please note - on installation you must first check for clearance between the pulley and cylinder head, especially where the head has been heavily skimmed.
Frequently Asked Questions
Which size pulley would you recommend?

For most fast road engines we would suggest the 4.220" option, as the largest pulley is best suited to engines with sustained high RPM levels.
Will I need to run a different size fan belt?

Possibly, yes, but this also depends on the crankshaft pulley and alternator/dynamo pulley diameters. We keep two fan belts that will suit - 825mm, for use with an MED S-pulley, standard alternator and 4.220" water pump pulley, and 838mm, for MED S-pulley, large alternator pulley and/or 4.770" water pump pulley.
Which engines do these water pump pulleys suit?

Any A-Series engine apart from the very last MPi Minis.
Will these fit all A-Series water pumps?

Yes, whether you have one of our MED-5701-WP race water pumps, or a standard-fitment item.
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