Hi all, I've performed a search and read up on everything I could find regarding engine break-in. Still one question though. I understand to take it easy on the engine for the first 1,000 miles and to "vary the engine speed often." Ok, two questions, I lied. First, by "vary the speed," does that mean RPM's or MPH? I've been keeping her at or under 2K RPM's, but should I try to vary the RPM's from low all the way up to "redline" often, or just vary the speed in MPH? I thought you're supposed to keep the RPM's as low as possible during break-in. Secondly, is it ok or even recommended to go fast (ie. 70 plus) for short distances? I've read that you should keep it under 55 when breaking-in. I've got about 200 miles on her now and so far I've really been babying her. Under 2000 RPM, 55MPH or lower, Texaco 87 Octane, and no jack-rabbit starts or quick stops. Is this what I should be doing? Thanks for the advice!

[This message has been edited by Bear (edited 09-11-1999).]

 

Bear,

Great question, of course I don't know the answer. My truck has 5k now and no problems. My break in consisted of not driving the hell out it. My MPH's and RPM's were all over but again I didn't abuse the motor. My .02.

I too would like to see what everyone suggests.

Whats really scary is how people might have test drove the truck. I know I have opened up vechicles I have test drove.

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99 4x4 XLT supercab 5.4L Flareside, Deep Wedgewood Blue/Med. Graphite w/ CAPTAIN CHAIRS "the ones seacrow wants", Pioneer DEP-4000, Tint, K&N, Bedliner, 3" Catback w/3 Chamber Flowmaster, 285/75/16 BFG A/T on American Racing Python wheels



[This message has been edited by Loser1 (edited 09-12-1999).]

 

I wouldn't redline it just yet. At least not often.

Just drive it normally in a mix of situations. i.e., surface streets, freeways, short and long drives. At around 2,000 miles, start having some fun.

 

Think of "break-in" as a honing or lapping process. The 2 surfaces has to remove the high points(on a microscopic scale) from each other. This process produces heat, so let it take place at a slower speed than the maximum allowed. This goes for all contact surfaces, bearings, brakes, clutches, gears...

Seating/honing/lapping/break-in should take place at different speeds and loads, to ensure a good fit and proper operation when the engine experiences those conditions (different speeds and loads) when "break-in" is over, ie: usefull life starts. So, I did not exceed 2500 rpm before 1000 miles, 3000 before 1500 miles, and 4000 before 2000 miles.

Changing the oil at an interval shorter than the recommended during this "break-in" time, is probably wise, as small particles might actually be removed from a mating surface.

I changed oil at:
30 miles(to get rid of junk that might have been left in the passages during assembly, and then plugged the filter),
1000 miles,
3000 miles and
6000 miles.

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99 Black Lightning
Rhino liner
Superchip

 

Damn! BlackLight, you win! To think my freinds thought I was **** about the initial care and drivng of my new truck! Well, they drive chevys, so they have nothing to lose! I'm glad you told us, but I hope you don't tell everybody about that. Ever since Clinton Valley closed, who knows where you'd end up!

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98 F150 SC XLT 2WD 4.6, 3.55 LS Tow Pkg. CHIP K&N Airbox mod. Mobil One Oil "Moonlight Blue"
Lund Fastback/spoiler, Lighted visor, Runninng Boards, Crome Taillight covers, Smoked Bug and Rain guards, Shelf-it, Carpet dash cover, Red Wings license plate in front, Red Wings license plate frame in back, Little Detroit Viper hanging from mirror, Oh yeah, and one "Blacked-out" grill
LOOK-OUT! Can't jump curbs anymore RB's make it look lowered! http://www.fortunecity.com/silverstone/daytona/843/