laurieonthego

Hi All and Happy New Year!

I am flushing the radiator in my 74 BB 454. I have drained the radiator and removed the two engine drain plugs. Two questions:

What is the torque to re-install the two block drain plugs (cannot find the torque spec in the service manual)
Do I need to use regular thread sealant or lock-tite on these bolts?

Thank you!
L

TimAT

Regular thread sealer. They are NPT pipe thread. No clue on an official "torque" but since it's a taper thread, just enough to not leak is good.

laurieonthego

Yahoo!!! Here I go! Thanks so much, TimAT! You are a rockstar! Laurie

HeadsU.P.

The Thread Sealant that Tim mentions is made by Permatex, comes in a white (toothpaste) tube and is compatable with glycol (anti-freeze). Maybe check Autozone or O Riellys. Another version comes in a metal can with an application brush for doing bolt threads.

Bikespace

Would standard white teflon pipe tape work? If the OP is anything like me, she might have a half dozen rolls sprinkled around the house and garage. It seems like it should work (it's teflon), but a quick google search shows that only the yellow or pink teflon should be used for glycol pressure applications.

I have white teflon on my radiator drain plug. I'm not going to change it.

TimAT

IT's a taper thread. You could put Crisco on it and be fine----until you went to remove it. I've got a couple rolls of Teflon tape around too. I'll use it when I don't have anything else. Kind of like a rubber fuel line on the pressure side of the fuel pump. I'm not a fan of it.

HeadsU.P.

This is how bubba-ism starts. Well, I don't want to drive to the store and get the correct stuff. Or teflon tape is 50 cents cheaper than thread sealant. Or I'm not going to keep the car very long anyway . . . . .

Do it right. When you cut-corners, the corners will cut you.

TimAT

Exactly why I keep darn near everything. I bet I have 10 cans of various anti-seize compounds, tubes of RTV, composite epoxies, greases and things like that. All technically expired for aircraft use, but it sure works fine for automotive stuff.

noonie

Contrary to popular belief, pipe threads are made to seal unto themselves, no pipe dope or tape is necessary for sealing. The dope or tape is for lubrication only, to assure the threads are tight enough. You can confirm with SAE specs.

The best to use in this case is a hex headed brass pipe plug.

Bikespace

Thanks for the input! I'll pick up some PTFE pipe dope and keep Bubba at bay.

7T1vette

ANY pipe thread sealant will act as a lubricant when tightening it down. That means the plug will be fully engages with LESS torque than is spec'ed for a dry install. If you over-torque a pipe plug in a cast iron block, you can cause it to crack. With sealant on the plug, you just need to snug it down well. A thread sealant which hardens-up is better, as it will help retain the plug when sealant is cured.

HeadsU.P.

I disagree about sealant is for lubrication only. In this case the drain plug is subject to tremendous vibrations of the block and tempertures from 25 below zero to 250*. A sealant will also insure a leak free joint between the two different metals.