sheared flywheel key

pignoliracing69

pignoliracing69

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So one of my flatheads sheared a flywheel key ... took it out had a 3 , I only found a 4 to put back in is this okay ? It does run but sounds like valves tap ?
Only ran on ground not on track..
 
Could be that the flywheel is not centered on the taper of the crank now (burr) and possibly has the coil legs dragging? Just a thought.
Changing from a 3 to 4 key should not make any difference in sound.

Ignition timing should not cause a valve to tap. Not sure what the noise is you are hearing - might be normal valve clatter, spark plug not properly indexed and thus intake valve collision, too soft of springs allowing the valves to hit the head, spring coil bind, piston hitting some head gasket material, head gasket burnt/blown out at #7 head bolt, LOTS of things it "could" be.


Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Chassis
Vector Cuts
(25 years full time serving the karting industry)
www.CarlsonMotorsports.com
215 N. High St.
Linden, IN 47955
765-339-4407
bcarlson@CarlsonMotorsports.com
 
One thing for sure is you need to lap the flywheel into the crank real well, so it doesn't slip and shear another key. It's the taper that locks the flywheel to the crank and not a key that holds it anyway, most of us don't even use a key. if you use an oil base lapping compound , clean both parts up real well with alky or MEK before torqueing the flywheel on. Jon
 
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