Got this from and old timer here on the board (I forget who :frown
but I've been doing this for the past 5 years I am very happy with the results everytime.
"Well here is my way of detailing your engine:
step #1 with engine cold spray the entire engine as well as fire wall and inner fenders with WD40 and don;t be cheap with it.
step #2 take a 5 gallon pail of hot water and tide laundry soap and start washing everything down with an old wash mitt. Or pull an old work sock over your hands and arms and start to dig in.
step #3 Now rinse off everything.
step #4 spray the entire fire wall and engine again with WD40, using an old tooth brush you can get into the hard to get spots. Wipe everything down with a clean rag or two.
step #4 start engine after removing covering from alternator be it a bag or rag or even an old towel. After engine is warm and dry NOT HOT shut it off.
step#5 spray everything under the hood and I mean everything with armorall let sit for 1 hour and then wipe the entire compartment down with clean rags.
IT WILL LOOK SHOW ROOM NEW AND IS SUPER EASY TO KEEP CLEAN. THE WD40 LUBRICATES AND PREVENTS RUST AND THE ARMORALL PROTECTS ALL THE RUBBERS. I HAVE DONE THIS FOR OVER 25 YEARS AND NEVER HAD A COMPLAINT FROM ANY ONE. YOU CAN THANK ME LATER WHEN IT IS ALL DONE."