PB-50 is the same as WD-40 and it says it can be used on engines and spark plugs. Its by blaster and the website is blasterproducts.com. Im wondering if I can use this as after run oil in my engine since it lubricates and displaces and repels moisture?

The ingredients are:
Medium Aliphatic Solvent Naphtha
Heavy Petroleum Distillate
Hydrotreated Light Distillate
Barium alkylnaphthalenesulfonate
Carbon Dioxide

Here is the ingredients even though they make no sense to me lol

No wd-40 has a chemical in it bad on the crank if it's filled and overall the oil in wd-40 is not ment for this application aro is cheap just get the real stuff and all it takes is a few drops so it last a long time.

Does marvel mystery work? I have to order aro and i dont want to

Im not positive but IMF you have a engine with a silicone filled crank it can destroy it wd-40 will for sure make it expand. It's not worth the risk. If you use sidewinder you don't have to worry about aro as its in the fuel and works I've tested it year ago with team strike. If not leave it with all fuel out if engine it won't hurt to leave it dry once just get all fuel out.

Go to the pharmacy/drug store and buy some castor oil. It's probably cheaper than brand name ARO.

nitro express is 100% correct , pharmacy grade castor oil if you feel the need otherwise just quite literally dump the fuel out of your tank at the end of raceday and you're golden