Breaking in a new motor.


Sep 8, 2012
I just got done building a new 4.1, and am wondering what's the best way to break it in? Also is it common for a double roller cam with hydraulic lifters to be a little tickie?

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Motor is fully assembled, setup and primed? If so, start it up, check for leaks, after reaching operating temp hit it with boost a few times to seat the rings...this procedure assumes full roller motor. Depending on engine builder you may or may not need to change oil. Cut open oil filter and check for the bad stuff. Install new filter, maybe new oil too.
I agree on the boost but not 20 psi...5 to 10 psi at part throttle and making sure your AFR's are good.
Yea it's fully built and it's running. I put amsoil break in oil. I did have a problem with cam bearings the shop put factory bearings in it but fixed that problem.

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Roller lifters will be a little noisy because of the link bars moving around. Short travel lifters like Comp 885's will be a lot noisy.
My 885 are not any more noisy than the others.

Roller cam has no break in.
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Good to know cause mine is noisy and it's scary cause I just blew up my old motor. So I'm all paranoid. Lol

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Just completed one.
Primed, started, cam run in. Cooled down, cut the filter, OK. New filter,out to the road. Drove several miles, checked for leaks, etc. GTG.
Put some mild boost to it, {10-14#}, 3-4 times, drove another 10 mi.
While still hot, dropped the oil, filter cut, all looks GTG.
Drive it.
Not sure where the 500 mi, no power driving comes from, other than 25 yrs ago, before ring technology improved to where it is, today.
When we have dyno access, it's a 20 min run in at 10% load, varying rpm.
Cool down, check it out, cut the filter.
A couple short pulls, then it's hammer time! If the rings haven't seated by then, 500-1000 mi won't do it, either.
1 other item I do: If the exh has been ceramic coated, I wipe it down w/ denatured alcohol, to get grease, fingerprints, off. I also run a fan in ft of the bumper, to force air over the headers. This pretty much cures the fresh coating.
Since we're here I have a 4.1 .30 over 80 lbs inj, small cam double roller, 66 turbo, front mount, meth, looking for 20 for boost. What do you all think I should run for fuel pressure?

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So I have another question about the fuel pressure. When I pull the line off the adj fuel regulator it does not change fuel pressure. Any ideas?

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Does anyone know were I can find a video of a double roller cam motor with hydraulics lifters so I can see if my sounds not normal. Cause it's very tickie and gets louder as I drive and rpms increase.

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