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Engine break-in period

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L

lbcfan

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I've been bad.

My "new" 1275 has transformed my bugeye. I tried to take it easy at first- keep it under 45- no flooring the accelerator. That only lasted two hundred miles or so. Tonight I realized I was beating the heck out of it.

Do these engines really need 500 miles below 45 mph, like the workshop manual says? It's hard holding back.

Someone tell me it'll be ok...
 
Different schools of thought w/ break in. Some say 2K for 20 minutes is all you need. Some say top gear full throttle from 20-30 mPH up to 70 then coast back down a few times. some say drive it easy for the first 500...or 1000....or 1500. From what I've seen, all agree not everyone agrees. Don't worry about it. IMO break in lube and an initial oil change at 100-500 miles (or both) is more important than a little beating on it.

I do a good over all break-in at various speeds and loads. Hap will be able to give you a better idea on school of thought for A series.
 
Depends. In the old days, machine work could be iffy....depending on how far back, WAS iffy.
Tight wrist pins, not quite perfect crank grinds, rough pistons, cheap rings.
The last half dozen engines I've done they are right on the money, no scuffing, no shavings, no real hot spots.
New cars back before, oh, 1960? you had to do the break-in, but not any more.
Oil change, yeah, but nobody does the varying speed bit any more.
I still tend to take it easy......if you really want to do an old-fashioned break in like we used to, start out with 20W Non Detergent oil so nothing stays in suspension, and first oil change it all comes out the bottom of the sump when you pull the plug, and the thin oil finds it's way into tight spots, like wrist pin bushings.

Now, if I was buying a "rebuilt" or "remanufactured" engine from one of the many outfits around, I'd be doing a careful break-in. Seen too many issues...plus the cheap cast rings, the thin sleeved valve guides.

The camshaft break-in on initial startup IS the important bit.
Dave
 
TOC said:
Oil change, yeah, but nobody does the varying speed bit any more.

The camshaft break-in on initial startup IS the important bit.
Dave
Click to expand...


Nobody??? That musta been your name choice for me but Mom shot it down :jester:


LBC, the cam break in reffered to is the 2K for 20 minutes part. I agree with Dad that cam break in is most crucial, especially with todays crappy parts and oil.


I like the speed variation 30-70 full load then coast break in as I want to make sure the rings are seated for all loads and speeds. Makes sense when you think about it. Dad doesn't like it when I do that, especially in the driveway. :driving: :jester:
 
Nobody as in new car recommended, at least not since they quit importing Yugos.
When I was in The Navy, one the the fu....errr.....nukes did big MoPars. He claimed 90 in second, shut it off, and pump the snot out of the gas until it dragged down to 20, do it again, and a third time, and the rings were broke in. Every time he rebuilt it in the 3-1/2 years I was on the boat he did that. My flatmotor I rebuilt at the same time was rebuilt again 300,000 miles later, so guess which option worked best.
 
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