what kind of oil to use on new rebuilt engine

[chargerman68]

just wondering trying to start it

[Chryco Psycho]

I would use Shell Rotella 15-40 & use either GM EOS or Comp cams additive to replace the needed zinc & phosphate 
Don`t use a fram filter either

[chargerman68]

why is that

have cheap filter and castro 10w30 sin

[Chryco Psycho]

no prob add the additive so the cam lives & buy another filter if you have a fram on there or you could be rebuilding again

[chargerman68]

stock filter
thanks for the help

[firefighter3931]

why is that

have cheap filter and castro 10w30 sin

You don't want to use a synthetic oil for breakin or for the first few thousand miles. This is important because the rings will not seat properly with a full synthetic oil.

I agree with Cryco....the Rotella 15/40 Diesel oil with GM EOS (engine oil supplement) is ideal for breakin. As soon as the cam is broken in ; drain the oil and change it along with a new filter....then repeat at 500 miles. Normal intervals after the 2nd oil change. 



Ron

[Challenger340]

I've been adding a can of high pressure hypoid gear supplement to the standard "dinosauer" Oil.
It is pure zinc, etc.

Been very successful in no lost Cams.

[dave571]

Synthetic is generally NOT recomended for break in, by any cam or engine builder.

[Challenger340]

Synthetic is generally NOT recomended for break in, by any cam or engine builder.

LOL !
Dave you would be amazed how many people take their "primed and ready to fire engine" , Home, and then promptly drain the dinosauer Oil out, refill with synthetic, fire-up, and later, wonder why their rings won't seal !

SAD, but true.

DO NOT USE SYNTHETIC OIL FOR BREAK-IN !