• Welcome to Mustang7G!

    If you're joining us from Mustang6G, then you may already have an account here!

    As long as you were registered on Mustang6G as of March 10, 2021 or earlier, then you can simply login here with the same username and password!

Break in period RPM?

robvas

Well-Known Member
Joined
Mar 7, 2024
Threads
7
Messages
1,287
Reaction score
1,029
Location
MI
Vehicle(s)
2011 Mustang
Different situation. This was a comparison of differing wear in two identical standard engines.
Not sure I'd really compare a Honda motorcycle engine to a Coyote. Too many differences.
Sponsored

 
OP
OP

hoodscoops

Well-Known Member
Joined
Apr 28, 2025
Threads
12
Messages
62
Reaction score
9
Location
NY
Vehicle(s)
DH, Sti
There's always lots of heated debate about hard break in on bike forums.
One channel tested the theory on two new CB250 engines. They ran them in, one by the book, the other run hard, and then stripped and miked the components.
Wear on bearings etc was the same on both, as were pistons. The hard run engine had twice as much piston ring end gap, which they wrote off as not important.
Except, that extra gap meant that engine will lose compression and start using oil well before the other. Increased ring gap indicates premature wear and loss of ring tension.
Which is why I do it by the book. Sunsequent owners will thank me.
What is the recommend RPMs then?
 
 








Top