1/4" NPTF Oil Gallery Plugs

[ort]

Malcolm
just go to your local air or hydraulic supplier they will have them for a few pence. you might not get NPTF but you will certainly get NPT which will be OK with sealant.
Iain

[rgh0]

Malcom
Dont worry I spent all of Saturday in the garden and had a BBQ with the family and a few to many nice beers and a very good bottle of red wine

I am just embarrassed that the first time i measured the plugs I pulled some of the cleaner ones out of the box to measure the threads on a couple and all the clean ones where BSP and all screwed into blocks OK, It was not until I measured some of the old dirty ones under a magnifying glass after seeing the blue print that I got it right and discovered all the originals were NPT. Even with a thread gauge you need to hold it up to the light and use a magnifying glass to see the slight offset in teeth pitch over the 7 threads on the plug.

cheers
Rohan

[AHM]

Well I'll eat my hat... and some humble pile.

The only excuse I can offer is that I measured with a tap, which I had assumed was 1/4 BSPT- The markings have been ground off - It was 2nd hand. I just checked against a 5/8 UNF tap (18 tpi) and it matches, so not BSPT (19 tpi)


Ort,
Are you able to identify which threads in the head/block are BSP and which NPT/F? There doesn't appear to be any consistency.

[englishmaninwales]

Update.
I obtained brass 1/4 NTP plugs this morning from a local hydraulic company.
They fit correctly.
It is clear now that the originally supplied plugs are far looser in the threaded oil way until they tighten up. As described before, they tighten well below the surface of the block and partly into Nos 1 and 5 drillings.
The taper (0.4mm) and thread appears the same for both plugs, but measure up differently (approx.):
New plug tapers 13.4mm to 13.0mm
Originally supplied plug tapers 13.2mm to 12.8mm
I'll try and locate some steel plugs to finally fit to the engine.
New front cover, backplate, pump and associated hardware that arrived this morning now awaiting to be fitted.

Malcolm

[oldchieft]

Please post when you build up the Burton timing chest.

I have a set of those parts on my wish list for a tall block build.

Jon the Chief

[englishmaninwales]

Correct steel 1/4 NPTF plugs now installed ok.

[2cams70]

Hooray! The original OEM 1/4" NPT plugs are still available new from Ford. Part number is 87837-ES2.