Forgot is not quite accurate. I planned to. Had the new cam, new heads, and a host of other new stuff. Put high zinc oil in it. I did my best guess on timing, best guess on carb adjustment. Fired it up and it barely ran. It was just little stuff that had to be deal with, timing off, carb adjustments, ect before I could even get it to run at 2000 rpms. Long story short the car ran for about 10 mins at idle before I could even get to a place to break it in. So now what? Is this a ticking timebomb waiting for a lobe to go flat? It is a comp cam and I've heard the new process they use makes cam break not quite as crucial as it was before.
trouble with idling initially is that the crank isn't spinning fast enough to fling much oil onto the cam. that is the biggest reason for the 2ooo rpms to fling oil on the cam so things are lubed... with that said, in the 80's when I was a mechanic we put cams and lifters in and sent the cars home with their owners without any break in. but parts and oil were different back then. good luck...
I put a Comp Cams Thumpr flat tapper hydraulic cam in a W motor this past year. I took the inner springs out and followed all their oil recommendations and ran it for several heat cycles up to about 6 hours of run time. I pulled the intake back off just to look everything over, wear patterns and such. It all looked good so I reinstalled the inner springs and ran it several more hours. So far so good.
Double valve springs. I took the inner ones out for break in. Still not completely clear when I reinstall those. Comp not recommends the 10-10-10 break in. 10 mins at 2000 rpms, 10 mins turn off, 10 more mins running. Run it 50 miles, then change the oil. It isn't clear when you put the inner springs back in.
Once you got it running correctly, you were able to complete the 20 minutes run time at 2000 rpm ? Solid or Hydraulic cam ? If you got the break in done, go back and check valve clearance/ lifter pre-load and run some more and see if any noises from valve train occurs. Worry about inners once you're sure no damage done.
The break in on my yblock did not go as planned, 5 attempts, start and ramp up then shut down due to m***ive oil leaks caused by ****py old spin on filter adapter and ****py new gasket, probably a total of 10 minutes or so running at speed, sorta. After getting that all sorted out I did a 20 minute run in, springs were old originals . Seven years on and some 10 thousand miles later it was just fine, had me ****ting a brick at the time though, fwiw ***embly lube on journals and white moly on the lobes
Springs back in after the 20 mins. As others have said the 2000rpm is to give good oil feed (and also with very lumpy cams to give a smoother running) the 20 mins is to give sufficient time to work harden the surfaces. You've got it this far, I'm sure it'll be fine.
My 283 died about 5-10 minutes into my initial break in run. I just let it cool, then fired it up and ran it again for 20 minutes at 2000ish rpm. Has run great ever since.
With actual dedicated break in oil, you should be just fine to do the 10-10-10. Then put the inner springs in for the ring seating session. My method for flat tappet break in is 10 minutes, let it cool down as much as I can physically bear to wai, fix the little things like coolant leaks, make a sammich, stop fuel drips etc., then do the other 10 minutes. Make your own sammich. If the Mrs's makes it for you, the mill wont have cooled enough. Clean the crumbs off the counter, put the mayo back in the fridge. After cam break in, I'd either find a ch***is dyno (or even better an engine dyno) and really put the load to it for the best ring seal you can get. Loading the rings hard initially can be the difference between a decent running engine and a great one, without a bunch of blow-by. If no dyno available, dont run the motor after break in until the car is ready to hit the streets and load the rings the old fashion way. It's hard to not want to hear her run, but ring seal is up to you. -rick
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