New engine break in

[BNCHIEF]

After a engine is rebuilt how long does it take to break it in 100 miles or more vary the rpm up and down drive slower do not over rev the engine, drain oil and refill after 100 miles. Anything to add to this and also do you use an air filter? Thought this might be a good question to ask. Marvel mystery oil in the gas for upper cylinder lubrication. Also non ethanol premium gasoline.

[Captndan]

Yes to all of the above including the air filter. Premium is not necessary.

[Mitch]

From AER'S site

4. Do not idle engine to break in. This can cause loss of lubrication to cylinder walls and damage to engine.

Personally i would dump the oil twice in 100 miles

[BNCHIEF]

Definite no-no concur with you Mitch. Twice it will be I also run it thru a paint strainer and look for metal. Warm of course.

[tbirdtbird]

Miles was taught in resto college to run the engine in at 1/2 your max RPM for 30 min, all the while monitoring temps etc with IR gun etc. Stop at 15 min for a re-torque, then again at 30 min. You'll be surprised at how much you can take up. So, for an A, we set the throttle to 1200. This will give a basic seat to the cam/lifters. Rings will take 1K or more. Iron rings are suggested, not chrome or exotic coatings. He was taught to not baby the motor, get in it and drive it. The RPM will vary enough at stop signs, lights, etc. Accelerate through the gears, do not baby it, you want the dynamic compression of the higher rpms to force the rings against the walls to get a good, more rapid break-in. A slow baby-like approach will cause the rings and walls to glaze over and getting a good seat will be hard. You want a lot of wear in the beginning to avoid a lot of wear later on. Once the cross hatching is gone from the walls getting the rings to seat will be tough, so make it count. It is suggested to avoid synthetic oil for break-in, regarding the older alloys we are dealing with in a vintage vehicle, it is so slippery it can impair break-in. He uses straight 30 wt mineral oil, then you can switch to synthetic after 1K if so desired. We are with Mitch as far as 2 oil changes in 100. We actually dump the oil after that first 30 min run-in.
Agree with use of MMO. Since crap-a-hol arrived, we use it in all the vintage cars here for valve lube especially. 4oz per 10 gals. We stay away from max rpm until the first 1K, but are not afraid to run up to 1800-2000 rpm.

[BNCHIEF]

Absolutely right about synthetic good oil but not for break in.

[Rowdy]

I agree about not babying an engine during the break-in period. When we had our IH H tractor rebuilt many years ago the mechanic who did the rebuild recomended that we put a 2 bottom plow and plow with it for 4 hours for initial break-in, then change oil and retorque head. We followed his recomendation and it was a great tractor for a long time. It would pull the stack mover with two stacks of hay over a long steep hill in 3rd gear with moderate effort. Even our IH M would not make the hill in 3rd, had to have it in 2nd to make the same pull. Rod

[BILL WILLIAMSON]

I just drive them NORMALLY, if set up RIGHT, they'll just do what they're supposed to do!!
Chief always sed, "Break em in FAST & they'll always be a FAST car"! (NOT necessarily recommending that!)
Bill Nottoworry

[plyfor]

just did break in with 10 30 detergent; now at 60 miles, too early to use 15-40 Rotella? I also put a little ZDDP in oil .

[Mitch]

I wouldn't have a problem using it

[tbirdtbird]

If not already changed, I would be comfortable with draining out that 10-30, and going to the Rotella. They have decreased the zinc in Rotella, BTW. The manufacturers have to guarantee the cat to 120K, and they would rather deliver on that than on good lube qualities. Nothing wrong with adding some ZDDP if you like. I have an engine builders bible that suggests not just cam/tappets benefit from zinc, but all bearing and friction surfaces, contrary to popular belief. A. Graham Bell has written extensively on engine building, tuning, and oil. Yes we know there was no zinc in 1930. But why shun modern chemistry?

There are those that say any oil will do. I would love to see a scientific or professional reference to that. Maybe, maybe not. At the very least consider detergent oil. The more engines you work on, the more you will believe that. I am of the opinion that those that propose non-D have not taken apart very many engines....Maybe any oil will work, but since you just dropped 3500 for an overhaul, why not use the best you can?

Having said that once we get to 1K miles, we switch to a multiweight Mobil oil, and no longer consider zinc. For that first 1K, we use Valvoline Racing straight 30, which has about the highest zinc available.

As always your mileage may vary!

[BNCHIEF]

Tbird i am running an oil filter and changing oil more frequently than would be normal in a modern car I do like synthetics when engine is broken in but not sure about a model a. I know many say you do not need an air filter but I always say really than look at the air filter in your modern car. Renners did my carb and pressure balanced it.

[BNCHIEF]

I concur with everything said here I am running the rotella was only going to add the zddp after first oil change, was always taught to vary the rpm not wide open 1200 is a good rule of thumb let engine pull a little do not lug it. Good points on retorqueing, car has a new radiator and leakless water pump and no temp issues at all. I also pulls well and runs smoothly with no vibration not to me anyway but if you do not over rev it.

[plyfor]

thanks for the comments; had a little sludge in the pan bottom probably due to new babbitt which I assume is normal. The oil pump screen was cleanBTW, the Porsche Club of America did a research (published) study on zinc attributes with horiz opposed cyl. motors broken down and parts compared. Should be able to find it on-line.