Old Merc Alky stuck with castor oil
I acquired an old Mark 50 alky modified powerhead that sat for years with castor oil and is thoroughly stuck. It's a really trick block and worth restoring. Anyone out there that can tell me what will soak thru and cut this stuff without beating the poor thing to death??:eek::confused:
I'm going to try some MEK on it today - -
might not be all a castor problem
If the engine was not run on gasoline and oil prior to storage, the problems may not be all "castor stuck". As is common knowledge, alky will attract moisture right out of the air, and if humidity was high where the motor was stored, rust and/or corrosion could also be a problem. I have never used the Kroil product myself, but have heard very good things about it, especially from gunsmiths to free up rusted firearms. If you do get it freed up, might not be a bad idea to check the rod and main bearings before trying to run it to see if they do have some rust on them. If so they would not last very long and could cause more damage to an otherwise salvageable engine if not taken care of before attempting to start. It would not take that long to drop a rod cap to see if the bearings and/or bearing surface is rust free. If not, you can pretty much figure on rust throughout, requiring rebuild. In addition, if moisture was present, rings could be rusted to the liners, possibly making hitting piston tops with anything harmful.
I heard of several engines in this condition brought back to rotating condition by soaking in a 55 gal drum with enough automatic transmission fluid to cover the powerhead, but with the price of fluid these days, that would not be cheap.
There is a person who posts as Mark 40-H or similar on HR who seems to have much experience with rebuilding older engines. Perhaps he could be of some help. I think he posts on BRF also but don't remember what he uses for a name here.
Good Luck