Synthetic oil

Turtle n Peeps wrote:

ScottG wrote:

RAS43 wrote:

Passin Thru wrote:

Flows easily, therefore not recommend for use on high mileage engines; nor do I recommend using it in new engines during the break-in period because it is so slippery and dramatically limits the wearing of new mating parts within the engine. This initial wearing of parts is what makes for proper engine break-in, sealing of piston rings, mating of camshafts and lifters, etc.

You do know that more and more manufacturers are using synthetics in their engines today without issues don't you? One example is Corvette and their engines are doing great. Just saying.

Yes, this is old wives tale stuff. Engines can break in just fine with syn. oil and most exotics come with it from the factory.

Do what you want, but this is no wives tale.

Here is what Crane Cams has to say about the subject:

Crane Cams wrote:
Crane Cams does not recommend the use of synthetic oils during the initial break-in period for a new camshaft. Use a good quality grade of naturally formulated motor oil during this period. If you choose to use synthetic oil after the engine has been broken in, change the oil filter and follow the oil manufacturer's instructions.

Last Comp Cam I put in had the same warning.

Comp Cams wrote:
Flat Tappet Break-In
All flat tappet cams will require special attention during the break-in process. Due to recent changes in motor oil formulas, a switch to a diesel or non-synthetic racing motor oil in combination with COMP Cams® #159 Camshaft Break In Lube is mandatory in order to avoid camshaft failure during break in. Cams requiring dual valve springs during normal operation will also require that the inner valve spring be removed during break in so that critical lifter rotation can be established. The appropriate COMP Cams® lifters, and correct valve springs, rocker arms, and pushrods are also absolutely essential to ensure long camshaft life. Please refer to the instructions in your cam box for complete procedures or page for our tech bulletin on the topic If ever in doubt, please call the COMP Cams® CAM HELP® line at 1-800-999-0853.

Another site that recommends to break in an engine on dino oil.

Most of the newer cars are now running roller cams, and 4 valves per cylinder. Flat tappet cams are old school.

Nowadays, you can't switch out or modify cams due to pollution control requirements, either by state or by National DOT standards. So Crane cams is a non issue, except on a closed course competition car.