Engine Break-In Tech!

[pvt.tadpolxj]

Hey you guy's, I have a question i have never asked anybody. With a remanufactured engine. What kind of oil should i use on break in time and for how long? And what's the scoop on going to a good synthetic for full time use?:confused:

[4x4Dalton]

I would go with Royal Purple Break In oil,plus if it was me I would let motor break in for at least 500 miles, then for a Synthetic oil to use after I would go with Mobil 1. Hope this helps ya some.

[4.3LXJ]

One thing to watch in todays oil market is the phosphorus content of the oil. Many synthetics do not have it or a very low content. The 4.0 is an old school flat tappet engine that requires those types of additives. Most lifters on the newer engines, like 90 and newer have roller cams/lifters in them and don't require those additives. The break in oils have extra amounts of it in them to help break in the camshafts, which on a flat tappet engine have to be work hardened to keep from wearing out prematurely.

[LizardRunner]

I usually break in for 1000 miles. I'm a castrol syntec user (sponsors sometimes count) but most of the top quality oils are close to each other. I also dump in some extra additives.

[uberxj92]

for what it's worth here's my 2 cents... i help run a family owned machine shop we rebuild engines...first 500 miles stay under 55-65. then change the oil & put in synthetic for 1000 to 1500 miles & you should be good after one more oil change . it doesnt hurt to check your timing at this point & check the valves.