Thread: Oil Plug question

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Another challenge! There's what appears to be an oil gallery at the driver's rear of the early 283 I'm rebuilding and when the machine shop cleaned my block they pulled the old plug out. Thinking it was threaded, I got a 1/2 inch plug...but apparently the hole is not threaded.

Here we go again, just like the crank bolt issue, no threads and I need to plug this hole or I'm going to have a major puddle (and no oil pressure) on start-up!

I was test fitting a cylinder head when I saw it, and the machine shop doesn't have a small plug I could drive in with a punch. Am I going to have to cut threads on this? I have a pic of the spot but no easy way to hang a pic here without using a photo-sharing site.

Hoping the picture shows up here.

It's been a long time since i worked on an early sbc and if I remember correctly that is a small style freeze plug.
On your crank, if it's early, they're pressed on and thin in diameter compared to late 283's. I used to emery cloth the snout and the inside of the harmonic dampner, apply some wheel bearing grease and pound it on with a 2x4 and a BFH.

Thanks Ken, I'll look for a freeze plug for that! It would explain the raised ridge just inside the opening, to stop the disc and hold it flat inside.

Originally Posted by IowaTom

Thanks Ken, I'll look for a freeze plug for that! It would explain the raised ridge just inside the opening, to stop the disc and hold it flat inside.

You're welcome, do check and make sure there aren't others as well. Does the block have a provision for a road draft tube?

I think it was Dorman Products that made all the Welch Plugs in various sizes. A quick google search just verified this for me. Any good auto parts house should have it.

Thanks for the help! I've ordered the plugs.
Speaking of which, there is a hole under the bolt holes, on the passenger side of where I mount the water pump. I see on my pump it allows coolant to flow thru to the radiator. A pipe plug that fits the hole came with the pump. Hmmm... no instructions on whether or not to use it. Both of the gaskets for the pump have a third hole. Do I use that plug? Can't imagine why I would.

That water hole is to allow some low flow before the thermostat opens so the coolant flows enough to evenly come up to heat-

On the oil gally back on drivers side-----------there is a plug that is inserted there to cause the oil to flow thru the filter and then back to the main gallies after being filtered------

Thanks, Jerry! I leave that plug out of the water hole.

Originally Posted by IowaTom

Thanks for the help! I've ordered the plugs.
Speaking of which, there is a hole under the bolt holes, on the passenger side of where I mount the water pump. I see on my pump it allows coolant to flow thru to the radiator. A pipe plug that fits the hole came with the pump. Hmmm... no instructions on whether or not to use it. Both of the gaskets for the pump have a third hole. Do I use that plug? Can't imagine why I would.

Glad I / We could help.
Yes on the coolant bypass to the radiator. If no coolant was allowed to move at all, the engine would overheat before the thermostat could open. So this small flow allows the rising temperature to reach the thermostat which allows the hot coolant to leave the engine and obviously maintain an even temperature in the engine. So toss that plug in the junk drawer for another day.