Sump plug

[Chillidoggy]

Does anyone here know what thread diameter/type the sump plug is on the S4/S4s engine? I believe it might be 1/2" BSP, but confirmation woudl be great.

TIA.

[EXCEL V8]

The Excel sump plug is certainly 1/2" BSP - not sure why an Esprit would be any different.

Pete

[Chillidoggy]

Thanks Pete. I took a flyer and ordered one, so TBC.

[Chillidoggy]

The S4s sump plug is NOT 1/2" BSP, that is too large to fit.

There was a change in 1993, correct S4s thread size TBC.

[fjmuurling]

On my SE the plug has a flange for a copper washer (I use a bonded seal) so most likely (almost sure from memory) the thread is not conical but straight.

[Chillidoggy]

Yes, it’s a straight thread.

I suspect it’s the same brass plug for the sump as for the cam housing bolt access holes.

[Escape]

That does ring a bell. Aren't they the same part number?

[Chillidoggy]

17 minutes ago, Escape said:

That does ring a bell. Aren't they the same part number?

Yes, but the thread size isn’t shown. I have a different adaptor on its way, so I’ll soon know what it is (or what is isn’t).

[Escape]

I just checked, it is the same part number and my parts manual lists the cam housing plugs as M20.

[Chillidoggy]

1 hour ago, Escape said:

I just checked, it is the same part number and my parts manual lists the cam housing plugs as M20.

M20 x ?

[Escape]

It doesn't say... Standard M20 would be 2.5mm pitch, but I seem to recall it's finer. I'll see if I can get one out easily to measure the thread.

[Chillidoggy]

1 minute ago, Escape said:

It doesn't say... Standard M20 would be 2.5mm pitch, but I seem to recall it's finer. I'll see if I can get one out easily to measure the thread.

 

I measured the thread as a touch below 20mm, with a 1.5 pitch. As I said, I have one on the way so will see what happens when it gets here.

[Chillidoggy]

And it’s just arrived. Report to follow.

[Chillidoggy]

Now confirmed, sump plug for the S4s is M20 x 1.5.

Looks like there was a change around 1993.