The Ford Barn - View Single Post - James Rogers, Brent, Purdy, etc...question

MikeK · 09-29-2014, 08:44 PM

There seems to be an ASSUMPTION in this thread, and we all know what that leads to. The assumption is that all steel crank gears have the same pitch diameter, and they DO NOT. I have a number of used crank gears that have probably seen 100,000 miles grinding against dirt impregnated fiber gears. The pitch diameter has been severely reduced, and they would rattle like crazy against even a 0.005 over cam gear. One of them has so much tooth width worn away you could use it for a chain sprocket.

If this engine was put together with a well-worn crank gear that may be the problem, not the CL-CL distance.

09-29-2014, 08:44 PM	#15
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: James Rogers, Brent, Purdy, etc...question There seems to be an ASSUMPTION in this thread, and we all know what that leads to. The assumption is that all steel crank gears have the same pitch diameter, and they DO NOT. I have a number of used crank gears that have probably seen 100,000 miles grinding against dirt impregnated fiber gears. The pitch diameter has been severely reduced, and they would rattle like crazy against even a 0.005 over cam gear. One of them has so much tooth width worn away you could use it for a chain sprocket. If this engine was put together with a well-worn crank gear that may be the problem, not the CL-CL distance.