Originally posted by CleviteKid:
Well Britannic,
Are you ready to sell that Duramax now that your CUCV is running so well ?
I spent last Friday at Crane Cams in Daytona Beach on one of my consulting projects (I know, its tough work, but someone has to do it) and the tech guys there acknowledge the benefits of gear drives for the cam and injection pump on a diesel, but have had a few annecdotes of problems in high RPM gas engines (above 8000 rpm, I think). They are speculating that the torsional vibrations at the end of the crankshaft are transmitted via the gear drive to the valve train and setting up harmful resonant conditions in the inner valve spring, causing valve spring fatigue failures. The slack in a chain isolates the valve springs from this resonance, they think.
I have not heard of any valve spring failures among those of us using the gear drive on our diesels, so I still recommend gears as the way to go. Sounds like The Brit is a big believer now, too ! ! !
Dr. Lee