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Discussion Starter · #1 ·
Just curious what the real racers out there do to break in thier new motors. For mine I just broke in the cam, took it out and seated the rings.
With about 20 miles on it flogged it at the auto-x (put the fan through the radiator).
I drove it about 20 more miles, hit another auto-x event, 7 grand no problem.
Then drove about 30 miles before the drag race event where I floated the valves just over 7000rpm.
The next event was about 60 miles later and I was pulling 8 grand.

I can't really drive the car on the streets much, and I'm not really too concerned about a short longevity motor... If all I use the car for is 10 auto-x events and 5 road coarses a year I don't think I will really wear anything out, I'll probably just continue to break parts here and there. I'm guessing my tranny and rear end won't hold up to the abuse for too long, but when they go I'll upgrade.
 

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Assuming you built the engine to competition specifications, that is, looser tolerances, then the cam break-in is pretty much all you need. On the racing engines I've built, I will run the engine for 20 minutes at 2000-3000 rpms to break in the cam and lifters. I will then recheck the ignition timing and get the jetting in the ballpark. Another 20-25 minutes of running time varying rpms from 2000-4000 rpms (never keep it at one rpm level). Finally, a valve lash adjustment, recheck timing, change oil and filter, and it's ready for the dyno. At this point, full load 8000+ rpms pulls are fine, the engine is broken in.

Bob
 

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Discussion Starter · #3 ·
Good, looks like I'm doing OK, I did change the oil/filter after seating the rings. The mains and rods are on the loose end of spec and it was bored to the spec given by Venolia (can't remember exactly). I had to adjust the valve lash pretty much the same time the oil was changed too, they were making some noise after the cam and lifters mated.

I wish I had a dyno to play with =(
 
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