'Running in' a motor and its longevity

Submitted: Sunday, Apr 18, 2004 at 18:04
ThreadID: 12162 Views:1717 Replies:7 FollowUps:8
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Surely the way in which a motor is initially run in plays a massive role in the longevity and reliability of that motor. Allowing all moving parts to smoothly and gently seat and wear into position must be critical as is the flushing of newly contaminated oil.
When helping a friend buy a new car recently we test drove a honda civic. The salesman drove us out into the street and down the road for a test drive - the car was cold and brand new. After nearly 1km we hit the freeway and the salesman floored the car to show us what it had. He passed redline in 2nd gear and took it further to show us how the rev limiter cuts in - holding it there so we could feel it. I took my friend elsewhere to shop.
Hands up wo would buy a new car knowing it had been treated like that! That experience really had me wondering how many brand new cars had been treated, and perhaps a clue as to why 'lemons' exist.
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Reply By: Bonz (Vic) - Sunday, Apr 18, 2004 at 18:41

Sunday, Apr 18, 2004 at 18:41
Most cars these days come already "run-in" I have been told. Theres not the need to go thru a exhaustive slow fast faster type of process like a 1970 Falcon/Holden. That being said, there is still some caution regarding revs during the first 1000km and I reckon this guy's just blown that caution out the door.

As to the wisdom of running in, my uncle always would "drive 'em like you intend to drive 'em from day 1 me boy!" and he had car after car that went like the clappers, he rolled them over at 100000, miles or km's and he reckoned that was the best way. Who knows?
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AnswerID: 54841

Reply By: flashnick - Sunday, Apr 18, 2004 at 18:50

Sunday, Apr 18, 2004 at 18:50
Sometimes a solid wear in like that is ok (within reason)
I know 2 mechanics that run in new motors under load ie pulling trailers and implements (tractors) - just use common sense (that rare commodity)
Nick
AnswerID: 54845

Follow Up By: The Horse - Sunday, Apr 18, 2004 at 19:08

Sunday, Apr 18, 2004 at 19:08
When testing a new Toyota, shortly after the honda, the salesman was very strict when it came to revs etc, asking us not to take it over 4500 (redline 6500ish) and said not to do so for some km afterwards. I checked on the net (googled 'running in') and there was a heap of info re: driving/running in a new car, many mechanics considering it to be critical.
also - if cars are pre run in, why do they usually perform so much better (power and consumption wise) after 10 to 20k. I agree that tolerances are tighter within a motor these days, so perhaps less running in req.
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Reply By: sean - Sunday, Apr 18, 2004 at 21:04

Sunday, Apr 18, 2004 at 21:04
And I am not so sure that an easy run ins are good for a motor. I cerainly use to think so but these days motors outlast the car and there are mechanics who say that motors needs revs to preoperly seat the rings.

Sean

AnswerID: 54873

Reply By: Member Eric - Sunday, Apr 18, 2004 at 21:12

Sunday, Apr 18, 2004 at 21:12
After all rebuilds, I always ran the motor for 15 min at around 2500 RPM , and then shut it down till the next day . The way i was taught as a Apprentise. The reson behind this , was to get the metals at a high tempreture , and then alowed to cool down . A smal hardenning prosedure . After the initial run , I would frive then around town for a week .. Genera rule was not to do stints of over 30 Kms at a time fir the first week . We also have them a little stick , but nothing over the top .

saying this , the dealer does the initial run in , then the vehicle will do small runs , as in test , then driven onto a Truck , then the pre delivery ect . So they usualy are run in before you get them . Also the oil used on run in is very fine . Metals eg, rings / bearings & camshafts these days , are a far superior metal to what was used in the days of XY's & HQ's . I wouldn't stress to much about it .
AnswerID: 54878

Follow Up By: The Horse - Sunday, Apr 18, 2004 at 22:47

Sunday, Apr 18, 2004 at 22:47
Eric,
thanks for the reply. I have a funny feeling you know what you're talking about!
Horse
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Reply By: Member - StevenL - Sunday, Apr 18, 2004 at 23:00

Sunday, Apr 18, 2004 at 23:00
I am picking up my new Turbo-Diesel Prado next week. Given what I have read on this thread and on a few others I will just drive it as normal from day one. Seems the only thing is not to sit on a contant cruising rev for too long on the open road during the first few thousand k's.

Steven
AnswerID: 54901

Follow Up By: The Horse - Sunday, Apr 18, 2004 at 23:16

Sunday, Apr 18, 2004 at 23:16
folks,
what happens if you sit on the same revs for too long anyway??
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FollowupID: 316581

Follow Up By: Mad Dog (Victoria) - Sunday, Apr 18, 2004 at 23:27

Sunday, Apr 18, 2004 at 23:27
Apparently this is a good way to end up with a nice polish on the cylinder walls...Glazed, then the rings don't seal too well
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FollowupID: 316584

Follow Up By: Member - Bruce (San Diego) - Monday, Apr 19, 2004 at 03:01

Monday, Apr 19, 2004 at 03:01
I remember in my farming days in Oz we had a White tractor with a 3208 Cat motor which glazed the walls and needed to be rebuilt at 1500 hours, and a Louisville truck with the same motor which went like a charm, the mechanic said it was the constant rev's on the tractor which glazed the walls, 5-6 hours constant work at the same rev's.

Bruce
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Reply By: The Horse - Sunday, Apr 18, 2004 at 23:39

Sunday, Apr 18, 2004 at 23:39
can a glazed piston be fixed some how...additives etc??
AnswerID: 54905

Follow Up By: The Horse - Sunday, Apr 18, 2004 at 23:56

Sunday, Apr 18, 2004 at 23:56
...sorry..i meant cylinder walls. but can the pistons become glazed too?
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FollowupID: 316587

Follow Up By: madcow - Monday, Apr 19, 2004 at 10:13

Monday, Apr 19, 2004 at 10:13
With modern machining most engines are "blueprinted" straight off the floor and the need to "run in" whilst still needs to be followed it is not as critical. I am still a believer that it needs to be done in a variety of conditions, highway, city and towing etc for the first 1,000kms at least.
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Follow Up By: The Horse - Monday, Apr 19, 2004 at 11:24

Monday, Apr 19, 2004 at 11:24
Thats pretty much what I have always followed. keep it varied.
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FollowupID: 316622

Reply By: Member - Eskimo - Monday, Apr 19, 2004 at 14:51

Monday, Apr 19, 2004 at 14:51
The only reason we have to "run in" automobile engines is because of poor? machining processess.

Everheard of refrigeration compressors or other properly machined rotating equipement having to be "run in"?

These things are designed to be put under full load conditions from the moment they are started.....and yes we do have variable speed drives!

AnswerID: 54973

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