Projects Flathead break in miles.

Hi guys.
As of today I am driving my ‘36 on a regular basis. My engine is all new inside. A 1950 8BA with only about 60 miles on it. It’s running great and has 50lbs oil pressure at start up and 20+ at hot idle on a 90 degree day after running for a while. How many miles do I need to drive the car at varied RPM to consider it safe to drive at 50-55 MPH at a constant speed. I have been told not to run at constant speed for a long time at first. There is a car show about 70 miles away from my home next month that I want to attend. The drive is a mix of highway and rural two lane touring.
Has anyone had experience with this ? Any advice would be great.

Thanks!!


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Waiting for this answer also, good question.

 

I took it pretty easy for the first 100 miles. I did few short trips up and down the rpm's. Changed oil and filter and put another 500 miles with a little harder pounding. Cranked a little more timing and changed jets in both carbs. Changed oil again and now right at 1000 miles and drive it however I choose. Really started coming around about 600 miles. Have fun!

 

Pretty much what Walter did.

 

What!? Flathead engine "break in" is different than OHV engine break in? Depending on the type of rings and final hone on the cylinder walls... break in is almost immediate. Right?! Moly coated rings......Chrome rings(anybody use those any more?) take longer. Just wondering............
6sally6

 

DRIVE IT LIKE U STOLE IT

 

Never broke one in
The last one we burped it and drove it 450 miles on its first trip.
Watching the headers glow at night cruising down the interstate was fun
Hammer down

 

A frequent error with flatheads is to think you need special cam lube additives and or
synthetic oil...both of which will prevent your cast rings from properly seating. I prefer
driving in urban traffic / stop and go up to 50mph / with numerous on-off cycles of
cool downs and full temp runs. If your oil turns BLACK at 500 miles don't panic...it's usually the
black-zinc phosphate "parkerizing" from cam and other components wearing off. Very common oil pressure on new flathead engines should be 40lbs cold and 20lbs at hot idle.
...and be sure to drive it with a grin.

 

The instructions that came from Isky for my MAX-1 cam said to run it at 2,500 RPM for 15-20 minutes at first start up with Brad Penn SAE 30 break-in oil. That's what I'm trying to do now that the motor's back in the car. Had some oil and water leaks that have prevented running it that long so far though.

 

I wouldn't worry about a 70 mile jaunt to a rod trot as long as you didn't do the whole distance at a steady speed on the freeway. Hell it is 48 miles to the next town if I turn right at the end of the driveway and 35.7 miles to where we stop for coffee when we head in that direction.
You might plan in a breakfast stop to let the car cool down a bit half way and give it the once over and go again rather than doing the whole trip at one shot.

 

I don't think there's any one way to do it, the only caveat being don't drive at constant speed for a long time. So really just a "what not to do" thing.

That said, I like to drive it like I stole it, gently... Don't baby it, but not necessarily balls out. Always worked out for me. Change the oil at about 4-500 miles the first time.

 

I have cast rings in my flathead. The old rule of thumb was 500 mile break in but with cast rings my machine shop jokes that they are seated while cranking it over, he was making a joke.

I took my car out today, new 276” motor and ran it around town for an hour, put about 20 miles on it, stop and go and thru the gears. I’m going for the 100 miles and change the oil before I crank on it but I don’t hold out hope there as it’s going to be a nice week with a show coming up Saturday about 40 miles away.

That being said, no smoke, full of coolant, oil like new. 180 degrees on the gauge and 60 lbs cruising at 2500 rpm and almost 40 lbs hot idle.

Cliff Ramsdell

 

Good feeling to get to the point that you can let her rip and feel confident enough that the motor isn't gonna explode.

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How to properly break in an engine
1. ***emble properly
2. Press the pedal on the right
3. Change oil
4. Repeat step 2

 

Just drive it. You should "break it in" the way you intend on driving it. So just go out and enjoy!

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Thanks so much guys for all of the advice. I have been driving all over town and having fun!!


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