RE: Cleaning glow engines
I'll second the ultrasonic. They are best if they have a heater built in. My choice for cleaning engines for function, not cosmetically, is glow fuel I put the engine parts in a glass beaker and put the beaker in the ultrasonic.. It doesn't do much for crash dirt though. That requires soapy water.
There are basically three types of curd that builds up on our engines. The worst looking but least troublesome is the baked on Castor Oil. Dawn Power cleaner will tackle it but it requires time and maybe three or four applications. Read the instructions and pay heed to the part about not using water until you are ready for the final cleanup.
The second type is the oil and wear curd the builds upIN the engine over time. Here, glow fuel does a great job of breaking it down and leaving a nice oily coat on everything when it is done.
The last is crash dirt. Sand, clay and what ever else you find in the pasture, requires some soap and water tor remove. Ithough I had the answer as one of our guys was polishing his engines and painting them, but wanted a method to clean the polish compound off. My suggestion was my Jewelery cleaning stuff that I've used for years. A little typo on the sample I sent him resulted in a very strong solution and it destroyed his polish on the aluminum parts. I'm not sure the standard mix wouldn't have done nearly the same, but in any case, if you are going to experiment with cleaners, be prepared for some discoloration.
I'm just finishing up an engine rebuild that I soaked for 24 hours in glow fuel and then through the ultrasonic for 15 minutes. The inside looked great. The fins still had a coating of red desert dust on them. A couple minutes with some Kurd buster and a tooth brush and things looked good as new. The glow fuel didn't touch the dirt though. Ithink it would be best to attack the engine with the Dawn first, soapy water to get the dirt second and then a bath in the glow fuel as a finishing touch to make sure the water is gone and every thing has at least some oil on it. Thenliberal after run oil on the assembly.