Final Thoughts Before Engine Break-In

[OK-944]

Getting very close (within a few days) of turning the key, and still a bit confused about what might be best for my (87NA) engine…break-in wise.

Having finished rebuilding the engine last fall, and letting it sit until now…I’m thinking that even though I was pretty generous with the assembly lube, I should probably pull out the OPRV to re-lube its O-ring, especially as I seem to recall that I’d only oiled this O-ring instead of applying assembly lube to it.

As for the actual break in process…I’ve read various articles by all kinds of “experts,” and opinions are all over the map. Some say not to let a flat tappet engine idle at all after initial startup, but just go right out and set the rings. Others say give it 15-20 minutes at 2000rpm, then drain and refill the oil, then go out and seat the rings with a few bursts of the gas pedal…then refill again and drive 500 miles, then refill once more and consider it done.

As for the oil itself…some say to use straight, single-weight (30 weight) conventional (non synthetic) oil for setting the rings, then multi-grade conventional for a couple hundred miles, then go to the oil of choice (like a synthetic multigrade). Others say to use a conventional multi-grade to set rings, but with some ZDDP (zinc) additive to protect the flat tappets, then conventional multi-grade for 500 miles, then go to oil of choice (Mobil-1 10/40 in my case).

Still others say the extra ZDDP is really only needed for brand new engines, because on a rebuilt engine the cam lobes and tappets have already had time to “harden” and so need no such oil additives.

And this is just the very tip of a huge iceberg!

Sometimes I think I should just start with a multigrade conventional oil (no ZDDP additives), start the car and allow it to idle for 15 minutes (at 1500-2000rpm), drain the oil, then refill once more with multigrade conventional oil (perhaps with some ZDDP added), and drive with a few ring-setting bursts…then drain the oil - then fill once more with conventional multigrade (no ZDDP) and drive normally for 500 miles, then go to my favorite Mobil-1 10/40.

Heck…sometimes I think I should just fill her up with a conventional multi, hit the gas a few times, drain the oil and refill with Mobil-1, and and call it a day!

Oh...and one more thing - what about "priming the oil system" prior to initial startup?

At any rate…I know I’ve picked your brains on this awhile ago…but I’m suddenly feeling the need to pick a little more. Thanks!

[jjeffries]

Said with kindness and respect, I promise: just start the bloody thing!

Either of the ways listed should be fine. I agree idling is to be avoided, and use mineral oil for the first fill, but otherwise just have at it.

“You can do this”, as the kids say nowadays.

John.

[jjeffries]

And leave the OPRV alone. Nothing's changed or deteriorated since you installed it.

[OK-944]

Thanks John J...sounds like a plan!

...but I do think I'll let it idle just a bit - enough for a walk-around, paying special attention to the new fuel line connections...especially those from hard to soft lines just before they enter the engine bay (left the plastic wheel well liner off just for this purpose) - because it would be downright embarrassing to go out in flames on my first run!

[jjeffries]

All good. What I meant is no idling for minutes on end.

Having Mrs OK-944 or your neighbor, Vern, on hand with a fire extinguisher might be prudent but otherwise, have at it.

John

[guru944]

OK-944;

Use a proper Engine Break in Oil SAE 30 weight. Do not use any oil Addatives or Multi-viscocity oil because Rings must seat and Valve guides need heat cycling. Otherwise compersssion will not be spec and vacuum will be off and eventually motor will burn oil prematurely. Recommend min 500 miles but no more than 1000miles will due.
PM Me for more details, Later...

[OK-944]

Hmmm...I think I'll just go "up the middle" on this - and give Royal Purple's Break In Oil a try. This is a 10W30 non synthetic, and while it does have a bit of extra ZDDP added, it has a bit less than some of the other "break in" formulas/additives.

At any rate...here is my plan: that I'll do just a few minutes of high idle after startup, just enough to make sure that things are circulating properly (with good pressure), and that the car is not puking gas and/or oil, fully aware that coolant is another issue and will require regular bleeding for awhile after this.

(Edit: after giving more consideration to the fact that I did a DIY Sunnen AN-30 (silicon paste) cylinder hone as part of my rebuild, I will allow the initial high idle to go for 15 minutes (perhaps 20), then go ahead and drain the oil. Reason? In addition to the above, I want to give the engine a chance to rid itself of as much rebuild residue as possible - particularly any left over silicon paste - while still in a "no load" state).

AAARRRGGGHH...scratch that edit! Looks like my original plan is best, because a long (20 min) 2K rpm idle could cause the cylinder walls to become prematurely glazed, thus preventing the rings from ever bedding in properly. I just hope that there's not too much leftover silicon paste residue...having its way with my crank and rod journals!

Then I'll take the car out and for a bit of ring-setting (maybe a dozen rapid but not overly aggressive accelerations/decelerations), and drive for another 30 miles or so, varying rpm's as much as possible. (will also get car state-inspected, hoping I don't get pulled over before this!)

Then I'll drain the oil and examine it.

Then I'll refill with the same break in oil, and drive another hundred miles or so.

Then I'll drain the oil and examine it.

Then I'll refill with a standard (not break in) non-synthetic 10/40, and drive 500 miles or so, prior to moving to Mobil 1 10/40.

The above basically represents my own distillation of the tremendous range of suggested approaches I've come across in researching this over the past months, and now I just need to do this!

[walfreyydo]

I think this is easy to overthink. If it were me I would do:

1) add cheap oil (10W40?), hook up oil pressure gauge, pull dme relay and crank until you get good oil pressure
2) startup, let idle for 20 minutes, turn off, drain oil
3) change filter, refill oil, drive for 50 miles, staying under 3k rpm, drain oil
4) change filter, refill oil, drive for 250 miles, staying under 4k rpm, drain oil
5) change filter, refill oil, drive for 500 miles, no rpm limit, drain oil
6) change filter, refill oil, drive as normal, drain oil at normal intervals

Although my only full rebuild is on a subaru ej251 engine, this was the process I followed and the engine has been running strong for almost 100k miles now. I think the most important step is that first/second oil change to get those metal shavings out, which happens with all rebuilds as the rings seat, etc. Might want to go with a cheaper filter for those first few changes as well.

[OK-944]

Yup (the plot thickens!)...I'm gonna add that 20 minute initial high idle back in. I'd rather risk a bit of early ring glazing in exchange for removing as many particulates as possible prior to placing my engine under load.

Just purchased 15 quarts of Valvoline "Premium" 10/40 conventional oil on closeout for 39.00, and will run half of this (a little less than half actually) for that first idle, then load it up to set rings with Royal Purple Break-In oil for 50 (ish) miles, then back to the Valvoline dino for about 250 miles...then onto Mobil-1 10/40. Oh...and four filters - three being the less expensive Hengst, and the fourth a Mahle.

[Rasta Monsta]

I don't get the high idle part. Start it and prevent it from idling while you check for leaks, then drive it fairly hard for a couple hundred miles.

Drain, fill, and enjoy your new motor.

Less thinking, more flogging!


Rasta

PS Royal P break in oil? I am uncomfortable having their products in my neighbor's garage, just saying.

[OK-944]

Idle part is to make sure everything is working ok...and that there are no leaks (new gas lines, rebuilt PS rack, radiator which had been dry for 20 months). Also will hopefully give the lifters a chance to even out, keeping in mind that these lifters have been inactive for 20 months. Also a chance to get rid of some rebuild residue (especially any AN-30 silicon paste) before I load things up.

At any rate...this is how I roll and I'm good with it.

[Fast Freddy 944]

Originally Posted by OK-944

Getting very close (within a few days) of turning the key, and still a bit confused about what might be best for my (87NA) engine…break-in wise.

Having finished rebuilding the engine last fall, and letting it sit until now…I’m thinking that even though I was pretty generous with the assembly lube, I should probably pull out the OPRV to re-lube its O-ring, especially as I seem to recall that I’d only oiled this O-ring instead of applying assembly lube to it.

As for the actual break in process…I’ve read various articles by all kinds of “experts,” and opinions are all over the map. Some say not to let a flat tappet engine idle at all after initial startup, but just go right out and set the rings. Others say give it 15-20 minutes at 2000rpm, then drain and refill the oil, then go out and seat the rings with a few bursts of the gas pedal…then refill again and drive 500 miles, then refill once more and consider it done.

As for the oil itself…some say to use straight, single-weight (30 weight) conventional (non synthetic) oil for setting the rings, then multi-grade conventional for a couple hundred miles, then go to the oil of choice (like a synthetic multigrade). Others say to use a conventional multi-grade to set rings, but with some ZDDP (zinc) additive to protect the flat tappets, then conventional multi-grade for 500 miles, then go to oil of choice (Mobil-1 10/40 in my case).

Still others say the extra ZDDP is really only needed for brand new engines, because on a rebuilt engine the cam lobes and tappets have already had time to “harden” and so need no such oil additives.

And this is just the very tip of a huge iceberg!

Sometimes I think I should just start with a multigrade conventional oil (no ZDDP additives), start the car and allow it to idle for 15 minutes (at 1500-2000rpm), drain the oil, then refill once more with multigrade conventional oil (perhaps with some ZDDP added), and drive with a few ring-setting bursts…then drain the oil - then fill once more with conventional multigrade (no ZDDP) and drive normally for 500 miles, then go to my favorite Mobil-1 10/40.

Heck…sometimes I think I should just fill her up with a conventional multi, hit the gas a few times, drain the oil and refill with Mobil-1, and and call it a day!

Oh...and one more thing - what about "priming the oil system" prior to initial startup?

At any rate…I know I’ve picked your brains on this awhile ago…but I’m suddenly feeling the need to pick a little more. Thanks!

Yes zddp, take it out and drive it normal, no hot rodding. let it cool, cycle and repeat a couple more times, or a couple hundred miles, then give it hell...