Best oil 350 rebuild

[zyl.3157]

Good day, I am rebuilding a 350 Chevy motor. What will the best grade of oil be for the run in. Regards Aj

[ZA Perana]

Good day, I am rebuilding a 350 Chevy motor. What will the best grade of oil be for the run in. Regards Aj

I am by no means an expert but are you running a brand new camshaft? If you are there are specific running in procedures. I would suggest finding an oil with a high zinc content.

[zyl.3157]

Hi, yes new cam, lifters ext. Not sure how true but someone suggested a straight 40 for the 1st 1000km. Regards

[Chev58]

Speak to the guys at the V8 Shoppe, they stock/sell the ZDDP additive required for the break in procedure - very important for breaking in a new flat tappet style cam, after break in procedures you can run a diesel motor type oil which still contain ZDDP (zink additives).
The ZDDP is mainly required for flat tappet cam/lifter lubrication.
A more modern approach would be a roller type cam with roller style lifters, then normal multi grade and synthetic oil are good.

[jevens]

Use Amtec running in oil available from RS performance

[RASSIE]

I only use Helix for all my motors.
Run motor at 2000 rpm after bled the oil pump. I do it by using a drill and a tool going in where the dist. is. Do this before installing the distributor and make sure all the rockers got oil before you start the engine.
Rassie.

[dom]

https://540ratblog.wordpress.com/2013/0 ... t-ranking/

Let me know when you read it. I haven't yet!

[Chev58]

Thanks Dom, this is a very interesting read/info indeed - an eye opener in fact.

[dom]

And then you get input like this:

"540Rat's results are flawed. He is testing new oil. He is testing film strength. He is not factoring in viscocity breakdown or ZDDP depletion. The facts are ZDDP levels drop up to 50% in 3000 miles likely more if the original level is reduced by 50%. The SM/SN rated oil that tests good when new with 600 PPM ZDDP may have inadequate protection @ 1000 miles when ZDDP levels have dropped to under 500 PPM. By the time you hit 3000 miles your trying to protect a flat tappet cam with 300 PPM ZDDP when the recommended level is 1000. Film strength is also a result of viscocity modifiers.

These are broken down as oil shear happens. A lot of conventional oils depend on high levels of Viscocity index improvers or "Viscocity modifiers" to turn single grade oil into a multi grade. These are very suceptable to oil shear. As this happens the film strength drops rapidly. Combined with dropping ZDDP levels this is a recipe for disaster, especially if your using a flat tappet cam with heavy spring pressures, high lift and fast ramps. True synthetic oils use little or no viscocity modifiers. This is one reason why many are considered extended drain interval oils.

The sheared VI improvers are contaminants. Do you really want your engine to be a guinea pig for a theory based on flawed conclusions using improper testing protocol, not factoring in the above obvious facts? Think about it. How much ZDDP is required to protect a flat tappet cam. Who knows. It varies with the application and severity of use. I would rather be safe than sorry. Use all the information available. There are plenty of oils on 540rat's film strenght list that also have 12-1400 ppm ZDDP and are synthetic based so have a more stable VI and reduced viscocity breakdown. His testing has merit but the conclusions drawn on new oil will not apply to the oil with 1000, 2000 3000 miles on it."