1987 Supra Comp - 351w block drain plugs

[Lou22]

Hi, All;

First post from a long time reader in Toronto, Ontario. Winterizing my Comp for the second time, with a small twist from 183671836818369last year.

Just wondering if anyone can tell me: is the small threaded hole above the starter on the pic a drain hole for the water jackets? I bought the boat last fall, and drained water through 7 locations - including this one. About a half cup of water came out last year, but it’s bone dry this year. Tried to clean around to look for a blockage with an angled pick..nothing.

Bit of background: found a small crack in the water jacket this spring behind the flywheel, same side as the starter (had been there for a long time) when replacing the damper plate. Repaired with proper cleaning and epoxy, has held up perfectly. Knowing that this crack existed along with the fact that the freeze plug directly above the hole in question has been RTV’ back in...someone obviously didn’t winterized this engine one year, and it froze solid.

Wondering: I think there may be a hairline crack in the block that released water last year down into this hole, but not this year. No water in the oil, no leaks of any kind, engine runs beautifully.

Opinions?

[Jetlink]

There are only five plugs total on the 351W to pull, I just did mine last night. Two on the side of the block, two (one on each manifold at the rear) and one on the "J-tube" bottom prior to the impeller.

[Lou22]

Thanks. Actually, I stand corrected - there were 8 locations total for draining the water from the engine and related components, including this one. They are:

2 at the Block (one starboard front, one port rear)
2 at the manifolds
1 at the J-tube
1 at the trans cooler
1 at the raw water pump

And..the 1 in question. I don’t think this one is meant for drainage. Just want to verify what it’s actually for. Again, I think there may be a hairline crack that allowed water into this threaded hole last year..no idea why it’s not wet this year.