About Engine Break-In
 

Recently I changed oil&filter at 300mi on new engine. I need to make a 700mi round trip and I'm wondering about running at a constant highway speeds(70-80). The first 350mi will end in an engine cool-down of a few hours and the return 350mi ends with a complete cool down. So far, I've varied the rpm up to 4k. Should I wait to get it higher on occasions. I don't want to baby this thing, but I also want to break it in properly. Advice? Thanks

i got two questions ...

1. over 4,000 rpm? why?
- On a good day, my cars rarely hit those revolutions. usual is between 2,000 and 3,500 and that is on serious driving.
- WOT, pushing the pedal to the metal, is another story.
-At 80mph your car should be doing just under 3,000 rpm .. if all is as it should.


2. what is the new engine? a rem? a pull out? a rebuild? stock? modified?
I cant invision a 1987 new engine being kept for 20 yrs.

BTW, if i remember correctly, the old "break-in" was more about piston rings than anything else.
IF the engine is new, meaning new pistons, rings, cylinders, bearings, I probably be tempted to vary whatever speed I'm driving + / - 10mph. I would also be changing the oil, 1st time, at maybe 1,000 miles.

lets see what others have to say.





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Way too anal!!! First of all this new engine should have never been taken to 4000 RPM. This engine in any operation will never see that RPM. Second, driving 700 miles wont harm a thing. Vary the road speed like stealth says and just drive it. This concern comes from old engine technology from the 60's. I sell new cars with new engines and I only mention to go easy on the brakes to seat or break them in, never anytthing about engine break in.

Geez, from one guy I get symantics and from another psychologized....thanks

Running engine to 4k while driving wont hurt engine, free reving is another story. It's best if engine has over 500 mi. minimum before taking trip. You can speed up break in by driving in second if you live in a urban setting where there is alot of stop and go traffic, you should be ok under 50 mph.

it is not semantics .. a overhauled old engine with new installation of rings and/or cyl sleeves and/or crank bearings would be broken in different than a GM issued NEW engine which does not need a so called break-in.


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