[DeTomaso] Why do Camshafts Fail ?

[STEVEN BLUM]

I just plled my engine apart and found 2 cam lobs worn out and several lifters worn concave. When discussung the problem with my engin rebuilder he said flat tappet cams  have been going because of the change in motor oil. Several manufactures have found excessive wear to the cam and lifters because of the lack of zinc in the oil. Everyone should be using either the zinc additive or racing oil with the zinc in it.


If anyone is interest in 4V iron  heads from a 74 Cleveland let me know. I just replace mine with aluminum.


Steve



 
> From: charlesmccall at gmail.com
> To: dtpantera at gmail.com; detomaso at realbig.com
> Date: Tue, 24 Nov 2009 20:36:34 +0100
> Subject: Re: [DeTomaso] Why do Camshafts Fail ?
> 
> Thanks Don, that answered at least one of my questions - what is the failure
> mode of a cam (besides violent failure - ie breaking in half)
> 
> Assuming it survives break-in, I wondered if there is a hardened layer like
> a human tooth, and that once you wear through this outside layer and reach
> the softer inner portion of the lobe, the wear is much faster until you wipe
> the entire lobe? From what I see, the entire lobe is hardened so wear should
> be even throughout the life of the cam. 
> 
> So what happens during the 100,000 miles of your cam, if you are lucky? Does
> it gradually wear down a little each year so that your lift is reduced? Does
> a 50,000 mile cam have a much different profile from a new cam, assuming
> somewhat aggressive valve springs? I assume that they eventually just wear
> away
> 
> Charles McCall
> 1985 DeTomaso Pantera GT5-S #9375
> "Raising Pantera Awareness Across Europe"
> http://www.poca.com/index.php/gallery/?g2_itemId=2323
> 
> -----Mensaje original-----
> De: detomaso-bounces at realbig.com [mailto:detomaso-bounces at realbig.com] En
> nombre de Don Thomas
> Enviado el: martes, 24 de noviembre de 2009 19:15
> Para: DeTomaso List
> Asunto: [DeTomaso] Why do Camshafts Fail ?
> 
> I came across this... and just found this interesting enought to pass
> along...
> 
> http://www.summitracing.com/expertadvice/professoroverdrive/?techQuestion=10
> 4
> 
> -- 
> Best regards,
> -dt
> Don Thomas
> _______________________________________________
> 
> Detomaso Forum Managed by POCA
> 
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
> 
> DeTomaso mailing list
> DeTomaso at list.realbig.com
> http://list.realbig.com/mailman/listinfo/detomaso
> 
> _______________________________________________
> 
> Detomaso Forum Managed by POCA
> 
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
> 
> DeTomaso mailing list
> DeTomaso at list.realbig.com
> http://list.realbig.com/mailman/listinfo/detomaso