Hello
Please consider the following engine.
The engine has been rebuilt with a complete new valve train. This includes new: cam, lifters, pushrods, valves, valve seats, guides, and springs.
My question is:
How many miles does it take to wear-in the new valve train ?
Thank you.
Full Version: Valve train wear-in
Cam and lifter break in happens in about the first 20 minutes of running.
The rest of the components like valves and valve seats will get to know each other better in a couple hundred miles.
The rest of the components like valves and valve seats will get to know each other better in a couple hundred miles.
Usually, you do the following to initially seat rings and break in the valve train:
1 Break in oil
2) Crank but don't fire and make sure you have oil pressure building.
3)Start it and bring it up to about 2K RPM's (Time it if possible or get it close)
4) Hold that position for about 20 minutes....
5) Monitor oil pressure during the entire event and watch for leaks, smokes, noises etc....
Shut it down and let it cool.
Once you are through that, you an break in as normal.
1 Break in oil
2) Crank but don't fire and make sure you have oil pressure building.
3)Start it and bring it up to about 2K RPM's (Time it if possible or get it close)
4) Hold that position for about 20 minutes....
5) Monitor oil pressure during the entire event and watch for leaks, smokes, noises etc....
Shut it down and let it cool.
Once you are through that, you an break in as normal.
QUOTE(Robarabian @ Jan 15 2023, 09:32 AM) 
Usually, you do the following to initially seat rings and break in the valve train:
1 Break in oil
2) Crank but don't fire and make sure you have oil pressure building.
3)Start it and bring it up to about 2K RPM's (Time it if possible or get it close)
4) Hold that position for about 20 minutes....
5) Monitor oil pressure during the entire event and watch for leaks, smokes, noises etc....
Shut it down and let it cool.
Once you are through that, you an break in as normal.
I agree with this
But add to change the oil after that initial 20 minutes
Then more break in oil after checking the valves.
Another oil change after a few hundred miles
DUH, I forgot to put that.. yes, immediate oil change to get the metal out... thanks for catching that!I would do 500 miles easy and then change it to the normal oil. That's just me.
Usually, you do the following to initially seat rings and break in the valve train:
1 Break in oil
2) Crank but don't fire and make sure you have oil pressure building.
3)Start it and bring it up to about 2K RPM's (Time it if possible or get it close)
4) Hold that position for about 20 minutes....
5) Monitor oil pressure during the entire event and watch for leaks, smokes, noises etc....
Shut it down and let it cool.
Once you are through that, you an break in as normal.
I agree with this
But add to change the oil after that initial 20 minutes
Then more break in oil after checking the valves.
Another oil change after a few hundred miles
QUOTE(brant @ Jan 15 2023, 11:06 AM)
QUOTE(Robarabian @ Jan 15 2023, 09:32 AM)
Usually, you do the following to initially seat rings and break in the valve train:
1 Break in oil
2) Crank but don't fire and make sure you have oil pressure building.
3)Start it and bring it up to about 2K RPM's (Time it if possible or get it close)
4) Hold that position for about 20 minutes....
5) Monitor oil pressure during the entire event and watch for leaks, smokes, noises etc....
Shut it down and let it cool.
Once you are through that, you an break in as normal.
I agree with this
But add to change the oil after that initial 20 minutes
Then more break in oil after checking the valves.
Another oil change after a few hundred miles
And for break-in oil, get something with high zinc content. Or get a zinc additive.
And don't stop the engine during that 20 minute break-in period. 
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