Ran search and read article on rebuilt run in. Did'nt go into specifics as far as when to change oil, and speed limits during engine break in. Read post where member suggested change oil after 500 mi's for first couple of oil changes, then changing over to synthetic. Wondered if best to run older engines on regular oil? Have need to use truck for hauling 8X10' enclosed trailor and thought perhaps should hold off until engine has some miles on it. Anyhow, any input, suggestions would be appreciated.

dave

 

dont exceed 60mph if you can help it for very long. varying rpms is important similar to breaking in a 2stroke. oil should be changed at the first 500 , then 1000 then 1500. use dyno oil during this time either a 10-40 or a 20-50. once you have gone about 10-15k miles you could switch over to synthetics of your choice if you want to. also dont use a fram filter.

 

Appreciate the input, purchased some 20-50 Castro brand oil, non synthetic, assume what you meant by 'dyno oil'. Read in the 'rebuilt run in' article advising to run engine at around 2000-2500 rpm (varying) for first 10-15min's to allow pistons, and other internal engine parts to seat. Intend to keep speed down to max. of 60 mph for the first few thousand miles. Thanks for the heads up on Fram filters. Read other threads by other members who rec. not using the filter.

dave

 

Petroleum oil is just fine. I use Castrol also, sort of a habit now, but all the big brands of motor oil are OK if they meet the latests specs of the car manufacturer. But then I believe in frequent oil changes and the only thing synthetics offer for a daily driver is longer change intervals. And they should for the prices. But I am just not comfortable with running oil more than about 5k mi.

 

synthetics also cut down on friction. if you were to run synthetics in everthing, diffs,tcase,tranny and motor they have proven a substantial gain in hp. that show trucks did the study using a dyno it was pretty cool.

 

Intend to look into using synthetic after putting some miles on the engine. Engine arrived today, to include couple sheets of literature 'pre-lubrication Procedure' and mentions immediately after starting engine, maintain 1800 RPM for about 15 min's while keeping watch on oil pressure. Hopefully, replacement engine gives a fraction of the amount of use/work the other 302 did.

dave

 

I have read those type of reports. I am supposing that those things only measure minute differences under the most extreme loads and maximum rpms before any difference shows up. As far as the gear oils are concerned, all those gear sets experience a lot of drag just because of the primitive type of oiling systems they have. I wonder, is there less drag using synthetics? If there were enough difference (in a daily driver,) to show less net energy being used that is, in a meaningful amount, like say, one mile per gallon, then I could be convinced to change my ways.

As to the "substantial gain in hp" are we talking about 5hp in a 500hp engine, or what? I am prepared to be educated.