Breaking in new Cam and Rockers in an M20

[dude8383]

This may sound a bit silly... but if he pulled the head off etc and is essentially firing this motor up for the first time won't the coolant system need to be bled? How is he going to run the motor at 2500-3k for 20min without overheating... IF the system has air in it? Genuinely curious here!

[SkiFree]

Digger's pretty much nailed it.

[Earendil]

prime the oil

use moly lube on surfaces is good idea

you need to run the cam at about 2500rpm as soon as it starts for like 20min dont let it idle (idle is harder on the contact surfaces). its a good idea to vary it abit from 2000-3000rpm not keep it steady

you can use a proper breakin oil like one of the Brad Penn oils if you are worried

Thanks for the info! One clarification though; when you say "prime the oil" do you mean add an engine break-in additive, or does that mean something else?

[digger]

prime the oil

use moly lube on surfaces is good idea

you need to run the cam at about 2500rpm as soon as it starts for like 20min dont let it idle (idle is harder on the contact surfaces). its a good idea to vary it abit from 2000-3000rpm not keep it steady

you can use a proper breakin oil like one of the Brad Penn oils if you are worried

[Earendil]

I'm having a hard time finding info specific to the M20 break in processes for cams, because let's be honest, we don't put new cams in M20s very often :)

Two things worth considering in my particular break in processes

• The head gasket failed and my oil drained out looking like the sweetest milk chocolate you've ever seen.
• My E30 is not my DD, and is used mostly for weekend fun and a few track days a year. As such, I tend to stick to oil changes between every track day and just use dyno oil (I run synthetic in my E46).

My current plan is such:

1. Moly-Lube the new cam. I can't find info on whether an M20 needs this, but I don't think it can hurt...much.
2. Start with 10w-40 GTX, run car 0.5 miles around block, drain out. For whatever reason I have some sitting in the garage, and flushing the rest of the chocolate out of my system seems like a good use for it.
3. Replace bad oil with VR1 15w-50 regular oil. The ZDDP appears to be pretty high (1300).

Questions:

1. If I flush the system with the GTX, should I just keep running the VR1 until the next oil change, or should I replace it within a much shorter timeframe?
2. Should I add something to the oil to assist with breaking in the cam and rockers?

Thanks for reading!