Rebuilt engine break in-oil recommendations

[lurch85]

Straight 350 gas with reverser

I went the whole way, and had my engine completely rebuilt by Baril Engine in Green Bay...
Filled it up with Fleet Farm Farm-Rated 10-30 for break in...
A quick look at my manual and I don't see a break in procedure (I got it running, but I need to go to bed for work tomorrow)
How many hours, should I go with this in it, and then recommendations?
Thinking about going a synthetic 10-30, 10-40, or 15-40... It will see occasional use as both bulldozer in summer and skidder/forwarder (has a gafner clam loader) in the fall/winter.
Anything else you guys have to add, i'm listening,,,
yes, i replaced the front reverser seal...

[Lavoy]

15W-40 is a diesel oil, and while it won't likely hurt it, there are some differences, and from what I have heard or read, don't do it, no real reason to. I would run a good quality 10W-30, or, once you have some hours on the conventional oil, I would switch to Mobil 1 or some other synthetic.
Lavoy

[Stan Disbrow]

Hi,

I would use 10w30 and change it and the filter after about 25 hours. Look for a large number of particles in the drain pan, and slicing the can off the filter would be a good idea as well. There will be some, but if there is a lot that will tell you something is not right.

Also, vary the speed of the engine often during those early hours. That helps most of all to break in.

Stan

[lurch85]

Thanks guys , the only reason I thought using diesel oil it's because it was built so much like a diesel. But no problem using those other synthetics either .. will do and thank you

[CuttingEdge]

I am not sure I would break in an engine with synthetic oil. I did on my snowmobile since it came with Mobil 1 (4 stroke Yamaha), but it took 750 miles to do it! I would go with regular oil first, then switch to a full synthetic after the break in period was over.

That is what I would do if it was my machine.

[Lavoy]

I still don't break in on synthetic, but now that so many new cars and pickups come from the factory with synthetic oil, I wonder if I am being overly paranoid.
Lavoy

[Stan Disbrow]

Hi,

The difference between synthetic and conventional base stock is really only the uniformity of the molecule chain.

Conventional is separated from a bunch of different size molecule chains. So, while it is mostly uniform, on the order of 98 percent, there will be some which are lighter and heavier than the desired size.

Synthetic is made up from the smallest chain, methane, so in the end you get all the same chains.

Keep in mind that base stock only makes up half of the oil you buy. The other half is all additives. One to keep it from thinning too much when hot. One to keep it from thickening too much when cold. Several to grab up dirt and combustion byproducts (aka detergent). One to absorb moisture. One to reduce oil oxidation. One to prevent rust. One to keep a film on the parts when the engine is not running. Etcetera.

So, when it comes to break in, just buy the lower cost oil. You will be changing it early anyway, so there is no point in buying the higher performance additives which they save for synthetic and why it costs more than conventional.

Stan

[lurch85]

no.. using a cheaper conventional for the break in... After that was the question.

[Stan Disbrow]

Hi,

It really does not matter in this application. These are not high revving, high heat engines. That is where one gains an advantage with synthetic.

I would (and am) more concerned with the mix of additives than with the base stock when it comes to application. So, I would pick based on lubricant formulation for the machine.

That leads me to something touted as being made for the machine. There are several choices, but I chose to just use what Deere sells long ago. In this case, Deere Torq-Gard.

Remember, the additives are half of what is in the bottle, and at the very least we know that Deere engineers picked what they add in based on testing in their own machines.

Stan