Help with oil plug B&S 31P777

[Bange]

Hey guys!
As some already know, I am repairing a Murray 42" with B&S 31P777 and one of the problems is the oil plug that came with a water valve (don't laugh).
I need to know the measures of such a plug to make an appropriate one, because here it is either very expensive or it is very difficult to get original parts.
I need the following measures:
What is the external measure of the plug thread?
How many threads per inch? I believe it is 20 ... is that correct?

Wrong valve...?

 

[Rivets]

More than likely a 3/8” pipe thread.

 

[Scrubcadet10]

More than likely a 3/8” pipe thread.

Ditto,
Tractor supply sells 3/8 pipe, male thread on both ends, then a cap on one end.

 

[Bange]

There's something different ...
The hole in the housing is 9/16 = 0.563 "
The tube as quoted from 3/8 = 0.375 "
Did they widen the casing hole?


The thread of the water valve is quite different and what was sealed was the excess of teflon tape.

 

[bertsmobile1]

No
Pipe threads are named by the size of the hole that the liquid flows through
So a 3/8 pipe thread is around 9/16 outside diameter
And to make things more confusing it will be a tapered thread so it locks into itself air tight

 

[Bange]

I understand ... but I waste time or money looking for a representative ... the best thing is to do it.
But do you say that the thread is tapered (not parallel)?
This complicates a little without knowing the angle.
Do you know the standard (BSP, NPT)?

 

[bertsmobile1]

No
I use BSPT taps & dies or NPT taps & dies

 

[Scrubcadet10]

Most likely it's npt. I'll use the model # and see if i can confirm...

 

[Bange]

Okay, being NPT, I already saw that the thread tooth angle is 60 ° and the taper can be 2 °.
But I also saw that every NPT / BSP female is parallel, so the male can be at standard NPT angle (1 ° 45 ' to 2 °) or parallel.
I believe that the fact that bertsmobile1 uses both NPT and BSP in "taps & dies", is due to aluminum fluff in the housing, as it will be compliant for both 55 ° (BSP) and 60 ° (NPT) teeth.
I also saw that all thread material in tubes, for the 3/8 tube, the thread has 18 wires per inch ... if confirmed, this information is enough for me to make the thread in an aluminum or bronze tube, I don't know yet .

 

[Scrubcadet10]

I don't mean to sound condescending but i think you're over thinking it some....go to your hardware store. Buy a 3/8 NPT tube, male thread on both ends and buy a cap or valve to fit on one end.
Teflonsealing tape on both ends. Install it. You're done.
Or you can call Briggs And Stratton and ask them what size thread the 31p777 engine sump drain plug is.