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Adger Smith · 06-18-2009, 06:28 PM

I need to add a few more things about camshaft failure... Sorry I left this out of my last oil/ cam article. :~) .
There will be instances when you do everything as right as you possibly can and still flatten a hydraulic or solid flat tappet cam. I think the primary reason is the failure of the lifter to keep spinning. There can be several reasons for that, but the most common are lifter bore(s) too tight and grab a lifter…or a piece of grit migrates “out of hiding” and gets between the lifter and the bore….it still goes up and down but doesn’t spin….cam flat. Some of these particles get magnetized and all the washing with hot soapy water will not dislodge them….BUT….continually flush them with hot oil and……Guess where they go & what is the results.
Every engine I do gets a Sunnen precision Hone run through the lifter bores with a #13 stone in it. Ball hones & Brake Cyl hones will not do what the Sunnen hone does, make the lifter bore straight & round... The same hone I use when doing lifter bore bushings, different stone.
Crate Camaro,
Where in the world did you get the information about the Comp Additive being taken off the market? I was ordering a couple of cams & lifters today from Comp and ask about the validity of your comment. My buddy Tim Cole responded:

COMP Cams is definitely NOT going to discontinue the 159 oil additive.

I just ran out today & I order it by the case. Good stuff!
Crate Camaro,
You were on to something with the moly lube on the cam lobes. There is a less abrasive type of moly than the ARP bolt moly.
Oh, just one other point. Wash the cam & lifters and check each lifter for the proper curvature. I've found some lifters that customers get a deal on that are almost flat. When they are put on a very active came lobe they grab & don't spin. It is the curvature of the lifter plus the degree of angle/taper ground on the lobe that makes a lifter spin. The taper is also what keeps the timing gear pulld back against the front of the block. Have you ever seen a block that has had the timing gear eat into it? You can bet it was a cam lobe. problem that most likely caused it.

Ben,
Thanks for the kind words. Good luck with your re build.

06-18-2009, 06:28 PM	#23
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Camshaft failure I need to add a few more things about camshaft failure... Sorry I left this out of my last oil/ cam article. :~) . There will be instances when you do everything as right as you possibly can and still flatten a hydraulic or solid flat tappet cam. I think the primary reason is the failure of the lifter to keep spinning. There can be several reasons for that, but the most common are lifter bore(s) too tight and grab a lifter…or a piece of grit migrates “out of hiding” and gets between the lifter and the bore….it still goes up and down but doesn’t spin….cam flat. Some of these particles get magnetized and all the washing with hot soapy water will not dislodge them….BUT….continually flush them with hot oil and……Guess where they go & what is the results. Every engine I do gets a Sunnen precision Hone run through the lifter bores with a #13 stone in it. Ball hones & Brake Cyl hones will not do what the Sunnen hone does, make the lifter bore straight & round... The same hone I use when doing lifter bore bushings, different stone. Crate Camaro, Where in the world did you get the information about the Comp Additive being taken off the market? I was ordering a couple of cams & lifters today from Comp and ask about the validity of your comment. My buddy Tim Cole responded: COMP Cams is definitely NOT going to discontinue the 159 oil additive. I just ran out today & I order it by the case. Good stuff! Crate Camaro, You were on to something with the moly lube on the cam lobes. There is a less abrasive type of moly than the ARP bolt moly. Oh, just one other point. Wash the cam & lifters and check each lifter for the proper curvature. I've found some lifters that customers get a deal on that are almost flat. When they are put on a very active came lobe they grab & don't spin. It is the curvature of the lifter plus the degree of angle/taper ground on the lobe that makes a lifter spin. The taper is also what keeps the timing gear pulld back against the front of the block. Have you ever seen a block that has had the timing gear eat into it? You can bet it was a cam lobe. problem that most likely caused it. Ben, Thanks for the kind words. Good luck with your re build. __________________ Adger Smith (Former SS)