Freeze, Frost Plugs sizes for 248 engine please.

[Guest 1937RHDNZ]

One of my frost plugs has rusted out, its one of the 3 below the manifolds. I haven't taken it out just yet, but have measured the size to be 1 31/32, which is uncannily close to 50.0mm. I am sure that the hole will be an imperial size not metric. Can somebody please inform me of the size that I need to purchase. I wish to purchase locally to keep things simple. Undoubtedly won't be referenced in any book here!

Regards Neil

[Mark Shaw]

You probably need a 2" plug when measured at the outer lip. The rounded end should be slightly tapered. When you press it into the block it should compress to fit the hole to make it seal.

If a metric size is a bit too big, you can always sand or machine it a little until it fits. This might be better than waiting for one to ship from the USA.

My 2 cents...

[Guest elmo39]

Neil go to a local engine reconditioner they will have what you need , i would suggest you get them in brass , you will never have any problems with them again in your life time , they are or should be readily available i never had any problems getting them for my DeSoto

[Brian_Heil]

If one is leaking the others are ready and waiting and all they need to do is watch the first plug to learn how to fail!

Purchase a couple of the rubber expandable type plugs that you insert and then draw up with a center nut and bolt. Available at every auto parts store. Good insurance.

Better yet, replace the rest of the plugs and do it right as my father would say!

[Guest 1937RHDNZ]

Thanks guys,

I can now inform you that the 3 freeze plugs below the manifolds are in fact 1 15/16ths for this engine. I will of course be fitting brass and replacing all three, the other freeze plugs are not so accessible, so will be on the "if & when" list.

[Guest]

While you have the core plugs out be sure to clean out the water jackets.