The 'E' Type Forum

Folks, I have a freeze plug 1 5/8 (43mm) I was told it is for my 4.2 1967 engine,
it does not fit too big, hole measure is 40mm HELP what can I do, cannot find replacement
or I am just not hitting it hard enough, tried a 5lb hammer, no go. Thanks

1 5/8 is 41mm.........have another measure.....the usual suppliers should have what you need....SNGB etc...but core plugs are a common item you should be able to get locally.....a standard hammer and large socked should do the job easily.....Steve

mgcjag wrote: ↑

Tue Jan 03, 2023 1:59 pm

"karg sicked"

??

I know we are two peoples separated by a common language, but this has me stumped. I'm guessing it's either Welsh or a spell check gotcha.

..fingers not synched to brain....typo......was trying to give a quick reply whilst the poster was still on line.....Steve

Hi Steve, I have a 1 5/8 in my hand and it shows 41.275 in to be exact, so what size do
I try to find??? the size hole is 40 mm on my block, so does the 40mm fit to a 40mm hole??
or would I go a 41mm to make it tight, just want to be sure I order the rite parts. Thanks Mike.

There are 2 core plug sizes and these have part numbers C16268/2 and C16268/8 with the latter being the larger of the 2.

I don't know what the specific dimensions are, but if the item you have is more than 1mm bigger than the hole then it is obviously too big and will never fit.

I suggest you order the correct part and you should be able to fit it without any trouble just using a 1lb hammer and a socket that's as close a fit as possible to the diameter of the plug. Some people apply a little gasket sealer to the plug before fitting.

Make sure that everything is scrupulously clean and all scale and rust has been removed before attempting to fit the plug.

I'm not sure why you are replacing the plug but if the old one was rusty and leaking then it's likely that the others will be in a similar state.

Regards

Is your engine in the car or on the bench......in the car can be difficult to get to the core plugs......have you thoroughly cleaned up the hole.....they often have lots of scale build up or hardened sealer that needs scraping off....the plugs should be an interfearance fit and a good sealant used on them.........I suggest thoroughly cleaing the hole....almost everything on the E type is imperial sized..........your 1 5/8 plugs measure correct.....Steve

Alain can you put up a photo of the plug, and the hole in your block please?

Well, bought 40 mm freeze plugs, to fit in my 40 mm very clean hole, and guess what, too darn loose,
very frustrated, so 40 too losse and 42.275 (1 5/8) will not go in with big hammer, so now back to distributor
and hope he can get me 41 mm , getting to hate this engine, and yes it is out of car.

I thought I could help since I had some spares for my S1 3.8 but they are way out…

3.8 car 1 3/4in core plug.......why do we measure our "imperial" parts in metric then try to order a metric part to fit

Ohh, just because the guy was talking mm

Just order the factory part number and you should get the correct item. Maybe you'll have to pay more than from an auto store but it would have been fitted by now.

I never had anything like this trouble when I replaced the core plugs in my 1969 4.2 Sovereign.

Regards

autoalain wrote: ↑

Thu Jan 05, 2023 1:11 pm

so 40 too losse and 42.275 (1 5/8)

1 5/8" is 41.275mm

Again, a picture of your plug and hole might help. Is the block totally clean?

I'm thinking the engine is not the issue. Are you measuring the opening with calipers? As others have stated, the required plugs will be imperial measurement, so a nice round metric size is almost assured to be wrong. You need a plug that is only a few thousandth of an inch larger that the opening. 41mm will likely be too large.

Your 40mm measurement is very close (~.012") to a 1 9/16" plug, which is common enough to be found on Amazon, in the U.S. at least.

Finally found freeze plugs, 41.5 mm or 1.637 inches, success. thanks for all input Mike.

Im intersted in how you got a 41.5mm plug in a 40mm hole

Enthusiasm?