M-train

iTrader: (3)

The reason I ask is that most hot rodders have had many camshaft failures using flat tappet lifters.

The zinc additive has cut those failures down over the years.

Now, the VQ engines don't have lifters, but they do use a flat "cup" on which the cam lobe runs across much like a conventional flat tappet lifter.

So, I was wondering if anyone has experienced cam failure without using any zinc additive?

gabez33

iTrader: (7)

Nope not all, I pretty sure the resounding answer is no here in general too. Cam failure is very rare with the VQ, the cam shaft design is nothing like the lifters in say an LS motor where stuck or cracked lifters are issues

M-train

iTrader: (3)

Thanks.

It problem with the old pushrod engines was the cam lobes failure. Todays oil is different than years ago. Most motor oils back years ago were made high in zinc.

Here this will explain it better than I can.

http://www.cranecams.com/pdf-tech-ti...failure811.pdf

bealljk

iTrader: (13)

I thought this was a pretty good episode - I believe they touch on break-in oils.

http://carcastblog.adamcarolla.com/2...ed-jr-audi-r8/