Ok, now that I managed to "break" the valves [img]style_emoticons/<#EMO_DIR#>/rolleyes.gif[/img] , how do I break in the new ones ? I hear new valves require some time to settle in just right ( I'll have new lifters and new guides as well ) so for the first 100 or more miles the speed at which I'm driving should vary as much as possible and that I should even put a bit of stress on the rpms from time to time, but absolutely not go over a 5krpm level... is this correct, or is there a commonly accepted wisdom for what exactly it is that I should do ?
Guidance is appreciated !
avoid high rpms (above 5000) for first fifty-100 miles or so, but vary rpms, not a straight 50 miles at 60mph. that should be about 250,000 to 500,000 cycles...more than enough. They are not as sensitive as rings....
then change the oil.
"break them in on the track" - that's what we always said
or was it "break them into pieces on the track"?
i can never get that one straight
<!--quoteo(post=73539:date=Jun 8 2009, 05:20 PM:name=xrad)-->QUOTE (xrad @ Jun 8 2009, 05:20 PM)
<{POST_SNAPBACK}><!--quotec-->then change the oil.<!--QuoteEnd--><!--QuoteEEnd-->
Why ? ( BTW, I have fairly new oil in there now )
What xrad suggested is more for seating piston rings and bearings in a fresh engine. Typically a cam & lifters break-in after 20-30 minutes of operation. I 2nd changing the oil after ~1000-1500 miles...
re: oil cahnge; with any newly machined parts, there's always the chance of metal particles, which is rather undesirable for obvious reasons. Also if assembly lube was used when installing the lifters [I hope they use it], it's best to get that out too.
<!--quoteo(post=73554:date=Jun 8 2009, 07:18 PM:name=S_Cal968)-->QUOTE (S_Cal968 @ Jun 8 2009, 07:18 PM)
<{POST_SNAPBACK}><!--quotec-->re: oil cahnge; with any newly machined parts, there's always the chance of metal particles, which is rather undesirable for obvious reasons. Also if assembly lube was used when installing the lifters [I hope they use it], it's best to get that out too.<!--QuoteEnd--><!--QuoteEEnd-->
noted. will change the oil as indicated.
The above is what I tell anyone else to do for break-in. For my engines personal rebuilds, I tend to run them in hard over the full rpm range after 20 miles with at least 2 oil changes before 100 miles. I like to start with non-synth for older engines and synth for newer. I have inspected the cylinders and valves on several of these engines and they were in excellent shape.
After measuring tolerances and making everything as clean as possible, I have not had any problems