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Bolt Crank Pulley Heavy Duty Allen Head W/washer

Bolt Crank Pulley Heavy Duty Allen Head W/washer

Bolt Crank Pulley Heavy Duty Allen Head W/washer
Part No: C-AHT147
Fits the following:
Classic Mini
Sprite & MG Midget
It is not uncommon for the front damper/pulley assembly to work loose on highly stressed engines, even if thread lock is used. The source of the problem is the bolt -- it's simply too short with not enough threads engaging the crankshaft. This uprated bolt is a super high-tensile socket head bolt that is used with a thick EN16 washer. It is of sufficient length for twice the recommended thread engagement.
Torque to 80 lb ft. Thread locking liquid can be used for race applications.
Consistent and effective crank damper retention has long been a problem on the A-series engines. The standard crank damper/pulley retaining bolts are desperately ineffective, even in standard applications. The damper/pulley manages to work itself loose, despite all efforts made to counter this. The situation is highlighted further in performance use - either road or race. Source of the problem is the bolt - it’s simply too short, insufficient threads engaged in the crank. Even a hefty dollop of thread lock compound doesn’t help. The solution used by notable A-series engine specialists is to use a flywheel bolt cut down by 3/8”. Fine if you’ve got an abundance of flywheel bolts laying around - strangely becoming quite rare! New ones are quite expensive. And there’s standard/preferred replacement bolt available because of the (typically) weird thread type. The solution is now available from Mini Spares Centre. C-AHT147 consists of a super high tensile (12.9 grade) socket cap head bolt and a thick EN16T steel washer. The bolt’s cut with the correct thread type, and sufficient length to ensure twice the recommended engineering thread engagement. This also means pulleys can be spaced further out where required for clearance without fear of the bolt coming undone. It is recommended that a quality thread locking compound is used as no lock washer is applicable. Standard torque settings (65lb ft) are maintained.
I need a longer pulley bolt for a B-series (MGB) engine. It is 5/8" diameter with a 16 tpi thread-count. The original is 7/8" long. I need it more like 1.5" long. Any chance your C-AHT147 is the same diameter and thread-count? Many thanks! Allen Bachelder
Yes these are 5/8-16tpi but I am not sure about the total length, they are about twice the standard length.

Spridget Mania Tech Team

The Spridget Parts and Accessories Experts

Related Technical Articles:
Classic Mini Cooper Engine Pulleys & Fan Belts page 38
Created: January 10, 2019
Crankshaft pulley with vibration dampers, water pump pulleys, fan pulleys are all itemized on this page, stock and high performance versions. Fan belt listings are also shown.