Engine: V8 Engine Break-in

[NMJack]

Can't find Jim Pepper's post about breaking in a new V8 engine. Anyone have it handy? Thanks.

[StudeRich]

Several people have posted logical methods here on how to do that, all pretty much the same.
To start off, you could have Seven Qts. on hand of a High ZDDP Oil like Valvoline VR1 Racing or "other" break-in Oil.

6 Qts. with filter, and a spare for the trunk.

[DieselJim]

With the engine at temperature, run full throttle from 40 to 60 ten times. That burns the oil off the cylinder walls and seats the rings. Then 50 to 70 ten times. After engine cool down, check valve adjustment, Change the oil and filter after 500 miles. Been doing this for over 50 years.

[Mike Van Veghten]

What Rich (oil) and DieselJim (driving practice) said...
"Except", I'd change the oil after the first 150 or so miles.

No sense in circulating all of the breakin, metal sluff (partials), thought the engine for 500 miles!

Mike

[DieselJim]

Good po[nt.

[JoeHall]

I break Stude rebuilds in the same way I used to with Harley shovel and pan heads: Keep steady RPM low, below 2000 or so for the first 5 minutes; below 3000 or so for the first half hour, then occasionally rev to 4000 or so during the first 1-2 hour run in, in the shop. Then, on the road, (with OD locked out) keep speeds to 50 or less for the first 50 miles, then 60 or less the next 500 miles, then ad lib. Never had a problem with cam / lifter break-in by doing it this way, and usually do first oil change in 500 miles. As for ring break-in, usually only 500 miles or so for moly; 1000 or so for cast iron, and 3000 or so for chrome rings. But ring break-in rate also depends heavily on final hone grit: 360-400 for moly; 320 or so for cast iron, and 220 or so for chrome. Moly and iron rings aren't too particular, but if you don't use a coarse hone for chrome rings they may never fully break-in.

[JoeHall]

I also avoid lengthy, steady road speeds the first 500 miles, instead vary with occasional pedal to the metal followed by lengthy foot of pedal till slowed way down.