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Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 12:05 am
by 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

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 12:24 am
by 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

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 12:33 am
by 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 !

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 12:37 am
by 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 ?

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 1:01 am
by Simon.Gardiner
Dave.Thomas wrote: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

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 1:55 am
by 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

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 7:32 am
by Mick D
Hi

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

Regards Mick

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 8:54 am
by 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

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 12:53 pm
by brenton.roy
Can you get an ezi out into it Dave?

Re: Oil pressure regulator thread size

Posted: Sat Jun 22, 2019 1:00 pm
by 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