Your advise needed.

So I?ve just finished up overhauling a IHC 766. Looking to break in the engine. The problem I have is my dyno is not big enough to load this tractor to the 88 horse. It?s rated at 50 horse and intermittently 70 horse. The question is if I work the dyno between the 50 horse to the 70 will I load the engine enough to break it in? I?m thinking if I keep a close eye on the heat of the dyno I can run close to the 70 horse max for a while. I ran a 64 horse tractor a while and didn?t have any heat problems. Thanks for your time!

Put some Zinc additive in the oil and use like normal...

The key to breakin, in my 58 years of engine related employment and education is variability of load and RPM. With this in mind, I see no reason to load your Dyno to its max or beyond for extended time periods. 10 minute segments at differing RPM and Differing Loads is best practices. I think a program like this extended for 20 hours would provide an ample time to establish reliability. Jim

just use it normal with some variation in throttle and it'll break in fine. never heard of using a dyno to break in.

When I went to school we broke engines in on a dyno 5 hours the first couple at so much load and then increased it to full load for the last several the diesel instructor was a cat engine rebuild man in a previous career and the break instructions came from caterpillar. I put my 4020 on the dyno for 8 hours the first 5 following the instructions and the last 3 at full load a 112 hp at 540 rpm

Just use Zink or Deere break in oil. Do you think engines are broke in at the factory?

I've been told that you need to avoid constant speed and load during break in, but otherwise use it normally. I broke my 1030 in this spring plowing and discing my fields. It has 20 hours on it now and seems to be good. However, last year I did the same and it turned a bearing, so take my advice with a grain of salt. I've done other tractors tho, and had good luck putting them on the plow the first day.

Your Dyno will work fine. Just vary the load and use break-in oil. The new oils are too slick to break an engine in with most of them.

I Ran engines on a regular basis on my old M+W dyno not so much to break them in as to make sure everything was right. I would test the cooling system, oil pressure, and watch for any leaks. I always ran 5 min. or so at half throttle, medium load. Then a light load, then heavy at low RPMs. Then when everything was ok and up to temp I would run at full Rpms light load, medium load, then all out and pull it for all it had. You could see a HP difference between when you first started then when done. 20 -25 min. total. Never did anything fancy, or used any special oil or additive. After 35 years some of these engines have 10,000 hours and still smoking. I don't think its anything special, just apply a load at different RPMs and at different loads. If you have to wait for the dyno to cool off every so often ok. Best thing I have seen to break one in is a chisel plow or deep ripper. How many guys bought a new tractor back in the day to baby it? Most went to the field as soon as they were unloaded off the truck in the farm driveway. Most guys never were schooled how to break one in, just check the oil n water and go. If break in procedures were critical very few old tractors would be left alive. Al

How does the variable speed change anything? I've always heard it, but I can't imagine what changes that would have an effect on break in periods.

With new metal technology and bearing clearances, I don't think breakin is as critical or necessary as it once was.

I haven't rebuilt a tractor engine in years, but going back to when we were racing stock cars, on a fresh engine I'd get as much running time on it as I could before we went to a track. If I was working on something else in my shop, I'd fire the car up and let it run at a fast idle. Then, first time at a track, we'd take it a bit easy during the warmups and heat race. By feature time, we'd take the bridle off of her.

I can't say we ever had any engine problems.

just curious what your idea is of breaking in an engine? what are you expecting to take place?

I overhauled dads 4020 john deere several years ago.I finished late one night.I was planning on breaking it in the next morning. I got out of bed around 7 am and went to the shop to find the tractor missing.I found dad plowing in the back 40.He had 10 acres plowed before I got bed.It ran fine for years after that.He then traded it for a 4430 that had more problems than the 4020.

Hook it up to a plow and work her. Best way to seat everything so she don't slobber. She's a tractor, make it earn its keep.