Will doing this damage the Babbitt bearings? Ive been lucky, upon disassembly of my engine I found the bearings in perfect condition, very surprising.
In the MTFCA engine manual it says to take the bare block to a transmission shop and have it cleaned in their equipment if the Babbitt is good because the trans cleaning equipment wont damage the bearings. I plan on doing that but for the caps and connecting rods, what to soak them in to not damage the Babbitt?
Iíve used gasoline with no bad side effects.
Mineral spirits won't bother babbit.
Good news on disassembling your engine and finding out the babbitt is good! Don't know if this engine was rebabbited since you've had it but whatever the case that's a positive to be sure.
A good degreaser that's not caustic wont hurt the Babbitt. Soaking an engine in a hot tank in some engine shops might hurt the Babbitt if its left to long. Some use a mildly caustic solution to clean blocks that probably would damage it.
For the home mechanic gasoline or mineral spirits works fine.
My parts washer is full of mineral spirits and I have been using it to clean T parts for over 40 years. The MSDS for Safety Kleen Parts cleaner indicates that it is mineral spirits with a little green die in it. That is what most professional auto shops use. What you don't want to clean babbit with is a caustic like lye.
(Message edited by paulmikeska on October 21, 2017)
If you use gas, don't use gas with Ethanol, unless you want to burn up.