CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Chevy 350

do i have to break in my engine if im using the same cam if so please give tips and type of oil thanks,
everythings new except the cam and rockers

A new camshaft is around $125. Do you want to risk it? There’s an old analogy about ruining a good soup with one lousy ingredient …

Naturally, there are more parts that require break in than just the camshaft.

I’d consider getting a new cam–you can likely do a lot better than the stock cam that came with the engine. It was a truck engine, right? You can probably find a cam that will give you better performance and economy than the stock one.

Yes, if you reuse the old cam, you will still have to break in the engine. The engine is bored .60 over and you have new bearings, rings, etc, right? So a lot of new parts have to wear in.

Are you using a new set of lifters? If so, it’s generally recommended that a flat tappet cam and lifters be installed as a set.

The reason is because the face of the new lifters is actually a dome and the cam lobes on a new cam are not actually perfectly level across the top of the lobe. It has a minute bevel to it and this is done to cause rotation in the valve train.
Using a set of dished lifters on a new cam or vice versa will become a problem at some point and there’s also the issue of microscopic cam lobe pitting or any wear crease on the ramps of each cam lobe.