I don't know what's in it, but I know it works. A guy i used to hang out with when I was younger had bought a '52 Chevy, 235 /'Glide. It had several stuck lifters from sitting for about 16 years before he had got it. We got it running (sorta) took off the rocker and lifter covers, and poured about 2/3s of a quart of Marvel on the rockers and lifters anf=d the rest in the tank. Well, I'll tell you what, after about 5-10 minuits all the lifters had freed up and it was running fairly well. I will admit, we took care of all the mosquitoes for at least the whole block with the smoke.
