My 3W 150 QSTS runs really good. I took the cowl off the other day and there is some black oily residue around the base gasket of the cylinders. It doesn't look like a bad leak, I just think the bolts need to be re-torqued. I called Cactus and AI and both of them told me that 3W does not give torque specs for the head bolts. Are there some engine experts out there that know what they should be torqued to? I have also read that you are suppose to warm the engine up and then torque them, but a good friend of mine that is a mechanic told me that that goes against all the automotive torquing procedures where you are suppose to warm it up and then cool it down before you are to torque it. Any help would be greatly appreciated. Thanks.

Big Bob

This has come up many times and it seems not many know about proper torque specs. I will post some info for you in a few hours. Perhaps the web owner here can place it for all to refer too. But yes, depending on the material. We Hot torque bolts on engine heads.At least in my Nuclear world. When the engine is run to normal temp. We shut the engine down. The bolts have stretched a bit,due to the heat. They are torqued. When they cool down, the bolts shrink a bit, providing an even tighter clamping of the head. I will post the info. when i gt to work today.
Forrest Gump

Ok, Here is the Nuclear grade info. On how Not to break a bolt.
Hope this helps.

TORQUE SPECS.doc

I never use a torque wrench on my plane engines. I just tighten until they "feel" right, pretty snug though. I have been playing with engines since I was a kid and just use my own judgment. So far so good.