Motor Break-in

[blueskyracer]

Having read every post since we purchased this site the one thing I have notice is there seems to be a lot of variation in "break in" procedure for a new or rebuilt engine.. I know how I plan to do it but what works for you.. Maybe if we can keep a new person from doing it incorrect then they will have much better success which keeps them around longer.

So what has worked for you?

[ZUL8TR]

Here is a start

This from Jerry Wienandt for his 44xs race engine rebuilds

[Merc1]

Mike, How do you plan on doing it? Please share, we use Jerry's method.

[john527]

44 mod, place motor in test tank with pipes pointing toward your a##hole neighbor, let run at mid throttle for about 30 minutes and about every 2 minutes squirt some marvel mystery oil into the carbs, now your ready to rap on it for awhile, now your ready to place on boat and go like hell!

and here is what your neighbor will be doing

[raceright]

If you run a 4 cylinder Alky for 30 min. in a tank you now have 30 min of running time before you have to rebuild the crankshaft lololo

They are a little different.

[blueskyracer]

I plan to do the twenty minutes under light load on the beach with a small CSH prop and my bilge pump since I have a forced fed system.. Then go out and get up just on plane and vary the speed with no full throttle for at least two tank fulls.For me that is the hardest part.The brain keeps saying lets see what this sucker will do.. For me it is really hard.. I run my engines at a 8:1 mix and live by what Jerry says.."OIL IS CHEAPER THAN PARTS" I will also start out with the needles at 2 and a half turns and then slowly work them in and read the plugs after every run..

[blueskyracer]

If you run a 4 cylinder Alky for 30 min. in a tank you now have 30 min of running time before you have to rebuild the crankshaft lololo

They are a little different.

That would suck to use up half of the shelf life before getting on the water

[Merc1]

That sounds like a good plan!

[bill van steenwyk]

That would suck to use up half of the shelf life before getting on the water

That's why it is done differently with a PRO motor, or at least was when I raced. I used this process that was recommended by Harry ZAK for 30 years of active driving and then 5-6 more years of just owning equipment. Start with a 20/1 mix of Methanol with a good degummed castor oil like Blendzoll or equal and I NEVER had a problem I could trace to improper break in, but PRO motors are different in that you do not expect them to run for the same length of time that a gas burner does without some maintenance, and especially the Nikisil motors require different procedures. We used a cast iron L ring in my RB motor and changed it regularly every two or three races along with busting the cyl wall glaze with a ball hone, and did basically the same with the Konigs with non-chrome bores. You can't do that with Nikisil.

Finish up when done racing with an av gas or other high octane non-Ethanol gas-Blendzoll mix at 10-1 run on the bank to flush out all the methanol and any water and the average motor will last a long time. The same flush out process works well on a MOD or Stocker that uses a 10% Ethanol mix. Nothing will turn the bearings in a motor to junk quicker than sitting over time with water on the bearings and races/journals.

Also if a gas burning 40-44 cubic inch motor put out the same HP on the rod bearings that an alky motor does today, you would be doing the same rebuilding/maintenance as they do.

A dry fire on the bank to be sure it will run clean, then at most a tank of fuel at part throttle with short bursts at full throttle. The come in and check the plugs and it was ready to go till it needed rings again.

[dcrummett]

I plan to do the twenty minutes under light load on the beach with a small CSH prop and my bilge pump since I have a forced fed system.. Then go out and get up just on plane and vary the speed with no full throttle for at least two tank fulls.For me that is the hardest part.The brain keeps saying lets see what this sucker will do.. For me it is really hard.. I run my engines at a 8:1 mix and live by what Jerry says.."OIL IS CHEAPER THAN PARTS" I will also start out with the needles at 2 and a half turns and then slowly work them in and read the plugs after every run..

You're on the right track Mike... some depends on clearances you put the motor together with (to dangle a participle). The tighter you go, the more break-in you need.

Dan

[trident]

Break-in

This from Jerry Wienandt for his 44xs race engine rebuilds

Note key is to load it. No idling without a prop...

Jerry

[form-e one]

just built 44xs d-mod new pistons and rings,,, one dry fire,,, one 2min blast with prop on,,,, then race full tilt... still running,,, last weekend at lawrence.. as ron anderson use to say if its right it will last if not lets find out quick so we can fix it before the race,,,,

[blueskyracer]

just built 44xs d-mod new pistons and rings,,, one dry fire,,, one 2min blast with prop on,,,, then race full tilt... still running,,, last weekend at lawrence.. as ron anderson use to say if its right it will last if not lets find out quick so we can fix it before the race,,,,

Cheyney you sound like this guy: http://www.mototuneusa.com/break_in_secrets.htm

[ZUL8TR]

break in

My best break in with new rings and a fresh up hone and crank seals in a 2 cylindere Merc stocker was during the grapefruit circuit in the 70's. No time for test break in run had to work. Between race week ends I put the rings in and on the following week end set up to race, did a dry start on the beach for 5 secs, put in the water, at the 5 min gun off I went. Milled around and did some short bursts to 7000 and the race started, then full tilt. I think that worked because it was only rings and the pistons and block were already heat cycled many times from when the engine was new and raced many heats.

[blueskyracer]

Well all I can say is that Friday of Memorial Day weekend is going to be busy for me since I will probably have four brand new motors to season and a revamped boat to work the kinks out