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FE Power Forums => FE Technical Forum => Topic started by: fekbmax on May 12, 2016, 02:40:42 PM

Title: Cam gears
Post by: fekbmax on May 12, 2016, 02:40:42 PM
I have done it and I imagine at least one or two f you have as well, dbl pinned the cam gear. Have always wandered though why dbl keying the crank gear wouldn't be even more important.
I guess I'm just asking for you guys thoughts on this. I have seen way back in the day where some guys ha put a couple tacks on the crank gear. Not recommended I sure.. LoL
Title: Re: Cam gears
Post by: jayb on May 12, 2016, 02:56:10 PM
The theory is that the pin in the cam gear and keyway in the crank gear are primarily for alignment, and that torquing the bolts on the crank and the cam to the correct specifications will apply force to the gears and keep them fixed on the crank and cam.  Of course, that would be for a stock engine, and as soon as you start running a lot of valve spring pressure, the bolt torque may not be enough.  I exceed the factory bolt torque spec on the crank just to make sure there is a whole bunch of pressure holding that gear to the crank, but sometimes even that is not enough as I discovered last summer after my SOHC swallowed an air cleaner stud.  People double pin the cams for the same reason, and there isn't a thing wrong with doing that, but usually it isn't necessary, at least in my experience...
Title: Re: Cam gears
Post by: blykins on May 12, 2016, 03:03:56 PM
I double pin cam gears when I get to about 750-800 lbs open pressure.  Maybe it's unnecessary but it makes me feel good.  LOL  A 5/8" bolt torqued at 100-125 lb-ft is a little more substantial than a 7/16" bolt torqued at 65...that's how I justify it.  :)