Petcocks to drain the engine block of coolant?

[MrTruck805]

Hey All,

I drained my engine block of coolant the other day. I noticed the drivers side plug was pretty busted up so I figured I'd just throw a petcock on there instead.

What I'm wondering is if anyone has ever done this to the passenger side? It's not quite as straight forward because the knock sensor is attached to passenger side plug.

Thanks in advance.

 

[MrTruck805]

Sorry, should have specified it's an 1989 350 TBI.

 

[4X4HIGH]

While I haven't done it to a late model block that utilizes a knock sensor I have done it with earlier blocks and to be honest it's not worth it because all the sediment builds up from the bottom of the block and usually just opening the petcock won't allow the coolant to come out because of said sediment blocking the opening.

 

[ryoken]

you can just run an NPT tee if you want...

Mercruiser runs a fancy 45 degree one with these plugs in em..

i can't seem to find a pic of the fitting.... if i get a few minutes i'll see about getting the merc part # tomorrow if you want... it's a one piece, bronze male npt into the block, 45 degree body with a npt for the knock sensor.. than that straight thread blue plug on the bottom..

 

[xpndbl3]

unscrew the knock sensor to drain the block, but i'm not sure why you need a petcock in there, usually a marine application for winter, you could just run coolant...?

 

[ryoken]

oh, and as Scott mentioned, they usually get sediment.. one of my basic winterizing tools this time of yr is a wire tie, to poke em clear!

 

[MrTruck805]

Thanks for the replies. That Mercruiser part sounds pretty cool, but I couldn't seem to find it either. The plug on the passenger side is still in good condition, so I'll just stick with that. I'll go with a petcock on the other side and hope it's worth the trouble in the long run.

Thanks!

 

[British Slave]

Go buy a brass plug at the local hardware store.