Flat tappet cam life

[zrayr]

Originally Posted by 4pipes

Ray, synthetics are not recommended for FE's with flat tappet cams. It's a separate problem than ring sealing. Crane cams states on their website that synthetics may be too slippery for the lifters to rotate adequately in their guides (not enough friction between the lifter and the cam), and that if the cars are not started regularly, the oil will drain off the cam faster than conventional oils.

Facts are in short supply in this discussion. Without comprehensive scientific research they always will be. What we are left with is direct real life experience, and hear-say. Neither of which is a broad proof of fact.

No cam manufacturer, no oil company, and no engine builder are going to admit fault. They will point elsewhere, to the other factors, as Crane does with "maybes" and other vague references. With flat tappet engines declining in numbers, the importance of this issue to be scientifically researched is also on the wane. We are left to determine what works on a case by case basis. There will never be a scientifically proven, definitive yes or no on the use of synthetic oil in flat tappet engines of differing designs. All one can do is observe what works for them, and make decisions accordingly.

I have experience with Ford small block, and the FE series of engines that have used synthetic oils in racing and street applications, over a period of years, without the problems others have encountered. So using a oil with superior wear characteristics make sense for me. If others have had a negative experience when using synthetic oils, they may decide the problem was causes by a lubrication issue, and go back to a conventional oil.

Cams and lifters have been failing for years before synthetic oil were introduced. So it seems unlikely that all current failures can be ascribed to the use of synthetic oil.

Z. Ray