Proper brake in procedure on rebuilt engine

[jon laing]

What oil, oil change, speed, etc. is proper on 1939==85hp rebuilt engine. Jon Laing

[Scott H in Wheaton]

I haven't broken in a rebuilt flathead before, but I've done dozens of small block 289 v8's.
This is what I do:

10w30 oil

start engine, calmly bring it up to 2000 rpm

run it for 20 minutes, keeping an eye on oil pressure, temperature, leaks, and rpm...the rpm will gradually increase as the motor loosens up so I adjust the rpm down to keep it right around 1900-2000

After 20 minutes shut down, change oil and filter.

Next time I run it I dial in the carb mixture settings, timing, and rpm

the purpose of running 2k rpm for 20 minutes is to work-harden the camshaft lobes

The purpose of the oil change is to get the micro particles of metal and assembly fluids out of the system

[El Rat]

I use heavier oil and retorque heads as many times as necessary. g

[hardtimes]

Originally Posted by jon laing

What oil, oil change, speed, etc. is proper on 1939==85hp rebuilt engine. Jon Laing

Hey jon,
IMO, main purposes of 'proper' procedure is to seat rings and break in cam ..as stated. However, the written procedures , that guys have stated, in threads like this, is so varied ...so as to keep me interested in reading answers to this quiry.
It isn't as varied as asking about what oil to use, but tooo varied to have one settled/firm idea of what best do to. I'd like to hear what Walt has to say on this subject.

[Walt Dupont--Me.]

There's no since of me typing in a long procedure. There all OK. I don't care what you use for oil. I pressure the oil system before I start it. The idea is, start it, check oil pressure, if engine sounds good run it up 1500 or so for like 15min. You can rev it every now and then to change the rpm, keep an eye on the temp. By then you can idle it down to adjust the carb or carbs, check timing ect for a couple if min. Now you can shut it off, retorque the heads, If aluminum heads let it cool off and then retorque. The idea is don't let a new engine idle for a long time. Don't start it every time a friend come into shop just to show them the engine for a min. and do that for a year before your ready to road test the car. I like a test stand to start a new engine just to catch a little problem like carb don't run right or some other little problem that I can fix before giving the engine to the owner. This is longer than I wanted it to be. My 2 fingers are worn out. lol Walt

[Charlie Stephens]

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Ask the person that rebuilt the engine if you intend to go back to him if there are problems. What he says will probably match what has been posted.

Charlie Stephens

[Ross F-1]

This is the best procedure I've found, from people who know:
http://www.hastingsmfg.com/ServiceTi..._procedure.htm