Originally Posted by Archon
I agree. As the coolant is lighter than oil, those bearings likely have been surrounded by coolant for the entire year. The odds are not in your favor.
I am sure Dick meant to say that coolant was heavier than oil.
I have repaired more than a few cars with coolant in the oil and have found that over time, the emulsion that forms when the oil and coolant are mixed and circulating, slowly breaks down to re-form distinct layers of coolant and oil. After a car has been sitting for a month or more, the oil on the dipstick can look perfectly normal although a quart of coolant may be lying in the pan underneath it. When the oil drain plug is removed in this case, coolant, being heavier than oil, comes out first, then you see a mixture as the oil joins and finally, the stream changes to oil.
In such a case, you would expect the same to happen at the crank journals. That is, that the coolant would separate from the emulsion and drop to the low point against the bottom of the bearing shell and the low point of the journal.
The question is: Did the coolant damage the bearings? Sometimes it does, sometimes not. I think an important factor is how long the car was operated with an emulsion of oil and coolant. The lubricating properties of an emulsion compared to motor oil are so poor that bearing damage is likely to occur quickly. The type, condition and age of the coolant are important as well. Organic acid based coolants (like Dex) actually become corrosive as they age. And the chemical additives designed to prevent corrosion become depleted over time in all glycol coolants. So, old coolant against bearing metal, (aluminum, tin, lead) is much more likely to cause damage than fresh coolant.
I agree with Curt, that it is worth a try. I would go sparingly on the RTV silicone on the corner joints of the LIM, and use none on the rail pieces so that if the bearings are shot, the new parts can be transferred to the new donor engine.