Chevy 350

Hi All,
Can anyone tell me what these things are and what their purpose is ?
there is one each side of the block just above the top of the oil pan.
They have a wing nut type set up, should they be done up tight or back off ?

Cheers,
Mike.

 

That's a drain cock. Open it a couple of turns to drain the cooling water out of the block to winterize.

 

Can you confirm if the drain cocks are to be left tight and loosened to drain from time to time or left open all the time ?

Thanks,
Mike

 

Keep closed tight.

Only open to drain the water out of the block. Sometimes you have to poke a paperclip in if water doesn't come out well. Rust scale will lodge up against it.

 

They're called petcocks and as described drain out the water jackets, so the block can be winterized. I usually just pull them out and install a plug, on the odd block they still live on. It's just one more part that can fail or get knocked off during engine installation (been there), so I just whack them out and install a plug.

 

so the block can be winterized,

What does winterized when ?

Thanks,
Mike

 

Sorry, winterization is what's done in northern states where people put their boats in in the summer and haul them out to store them over the winter.
Winterization is getting water out of anywhere it would freeze and crack something. It's also keeping corrosion down. It was common here to have 350s and 454s pump raw water thru the engine for cooling. That petcock is used to drain water out of the block. There are also freeze plugs on the manifolds that you screw out to let water out. Then you replace them and fill it with antifreeze for winter storage. The antifreeze also has an anti-corrosion part that keeps the rust at bay. The other part of winterization is checking everything, fogging the cylinders with fogging spray and the carb, and stabilizing the fuel. Changing oil is good too.

 

Ok cool thanks for that,
As the weather is good all year round and boating all year round I don't need to use these.
Just leave them closed

 

Marvelous, coming from a country where not winterizing meant ruining your engine with certainty, I have to restrain myself every autumn when the urge comes to drain and spray and fog. Once I even bought a large can of antifreeze, then I remembered the seawater never drops below 12 C / 53 F.

 

they seal when wound out, CCW.

 

That's tricky, one would assume that to seal them you would wind them all the way in ?
I'm I correct in understanding they are closed when they are wind all the way out ?

 

yes assuming they are the original ones