Thread identifiation

[dat260]

Hi,

Anybody know what thread early 74Z have? Is it S.A.E, Metric or NPT? I need to install Auto Meter guages; water temp sensor and oil sender.

Cheers,

[zKars]

None of the above. Primarily BSPT. BSPT to NPT adapters are your friends.

Others, me included, have cheated and run NPT taps into those threads and gotten away with it (close, but not exact, 1/8 bspt is 28 tpi while NPT is 27tpi), but if you can find adaptors (McMaster Carr has them in the US, but don't like selling to CDN's... ) then go with them

With an adapter in the water temp sender location, (that hole is ~ 1/4NPT) it may space the new sender out quite far. If your sensor is 3/8NPT, then you'll have to bore that hole out anyway, and re-thread. Carefull, those housings crack.

[dat260]

None of the above. Primarily BSPT. BSPT to NPT adapters are your friends.

Others, me included, have cheated and run NPT taps into those threads and gotten away with it (close, but not exact, 1/8 bspt is 28 tpi while NPT is 27tpi), but if you can find adaptors (McMaster Carr has them in the US, but don't like selling to CDN's... ) then go with them

With an adapter in the water temp sender location, (that hole is ~ 1/4NPT) it may space the new sender out quite far. If your sensor is 3/8NPT, then you'll have to bore that hole out anyway, and re-thread. Carefull, those housings crack.

Thank you for the reply. Anybody like McMaster Carr in Canada? What if I use the original sender and sensor would it work?

[dat260]

I found this guy here in Canada, he's expensive.

British Standard Pipe Tapered Threaded BSPT Adapters from Cole-Parmer Canada

Edited May 19, 2014 by dat260

[zKars]

stock sensors will likely not work. Ohm readings hot/cold hi/low pressure won't match the new auto meter ones, at least very very unlikely, would have to compare.

Good find on the canadian supplier. Stainless is the reason for the cost. Call them and ask for brass equivalents

[dat260]

Thank you zKars for your help. Is this what I need?

Lot of 2 x Brass Adaptor Fitting 1 8 BSP Male to 1 8 NPT Female | eBay

[dat260]

Are all the threaded holes on the engine block and head BSPT threads?

Edited May 23, 2014 by dat260

[zKars]

Sorry for the delay there.

The ebay fittings you link to are close but not correct. Those have parallel threads (straight) not tapered. you need BSPT not BSPP.

Regarding the other question, only the pipe/sensor fittings are BSPT. I'm assuming you don't mean the various bolts that hold things together. THey are standard metric stuff, 6x1, 8x1.25, 10x1.5.

This one looks more right. BSPT Male to NPT female.

http://www.ebay.com/itm/Auto-Meter-2269-1-8-NPT-to-1-8-BSPT-Oil-Pressure-Metric-Adapter-/201055603779?pt=Race_Car_Parts&hash=item2ecfd90c43&vxp=mtr

I just searched 1/8 BSPT adaptor, got lots of hits.

Autometer makes one. http://www.autometer.com/cat_accessorieslist.aspx?pid=11

Try your local speed shop.

Edited May 23, 2014 by zKars

[dat260]

Thank you for those links. So basically all entry/exit holes that are use for liquid under pressure are bspt threads (water and oil). Everything else is metric.

Appreciate your time.

[Jarvo2]

Attached below is a great Datsun torque spec guide that I have come across, this should also help with your original question.

General-Datsun Torque Specifications.pdf

[dat260]

Thank you for that booklet