Oil pressure regulator thread size

[Dave.Thomas]

Just managed to break the oil pressure reg bolt clean off, it’s the pre 41 type. I’ve found another in an old timing cover, but want the tread confirming please. I’m getting approx .435” x 26 tpi which equates to 11/32, does that sound correct ? I want to obtain the correct tap so I have it ready to clean up depending on how the remainder comes out

[nevhunter]

A "new" tap (if you can get it) may not be a good fit for the original. You often find that if you wind a tap through threads you will have a loose fit that will just strip easily. You won't know what you are left with till you get the remaining piece out. If it comes out easily you won't need a tap. If you have to drill it out in aluminium you have a problem, anyhow. Hard to do that successfully. I would try to avoid it. Remove it in one piece without expanding it. Nev

[Dave.Thomas]

Thanks Nev, I get your drift. I know I can’t afford to touch the old thread but thought I’d better have a tap ready in case I do.
These things are sent to test us !

[Dave.Thomas]

The oil pump had fine lockwire neatly looped over it and across the slots on the plugs underneath. Is that an Ariel thing or a cautious previous owner ?

[Simon.Gardiner]

The oil pump had fine lockwire neatly looped over it and across the slots on the plugs underneath. Is that an Ariel thing or a cautious previous owner ?

I'm guessing it's an Ariel thing as I've had at least one like that too.

SG

[nevhunter]

Yes to the wire. but wayback. I've had more trouble with the squares being rounded off and can't get them out. They don't HAVE to be ridiculously tight and the early and later ones are different. with different springs. Big cause of pump failure. Early ones have tapered springs. Real trap for the unwary. Nev

[Mick D]

Hi

Isn't 0.435" more likely to be 7/16", (0.437")?

Regards Mick

[Dave.Thomas]

Hi mick, thanks, you’re correct. I must’ve looked at .345 not .435 ! I’m sure I have a 26 tpi 7/16 tap too , if required. Well spotted

[brenton.roy]

Can you get an ezi out into it Dave?

[Dave.Thomas]

I gingerly tried an easi out, but I’m terrified of it snapping in situ. I shall probably take it off and warm it a little in the oven