What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

IO-540 Break-in

rvanstory

Well Known Member
8 hours into Phase 1 flight testing. Engine temps were pretty high to start (350-395), but have seemed to really settle down on yesterday's 1 1/2 hour flight. I've been flying at 75% & 65% power. Yesterday at 65% power, the CHT's were 325-358 degrees. I have only used 1/2 qt oil in those 8 hours.

Here's my question, when can I start using this engine as I would "normally" and consider "break-in" complete? Want to do more touch and go's and leaning without fear of hurting the engine.
 
Your CHT are now in the normal range but it would not hurt to go another hour at hight power to confirm the break-in is good.

Michel
 
You are done pretty much, just keep it going hard for an hour or two more, change the oil and enjoy!
 
Usually the temp drop indicates that the primary ring seating is done. Break in is not fully complete, but the risk of ring flutter is mostly gone at this point. You can drop the restriction on low power descents and pattern work.

It would still be wise to keep as much time at >65% as possible, as the complete break in/ring seating is likely not finished.

Larry
 
Back
Top