Oil and Temp engine block thread size?

[Reddog929]

I have installed all new ultra light autometer guages and need to use the senders from the new guages. Im having a hard time with the thread sizes in the block and at the temp thermo location. Water temp looks like a pipe thread. I have the conversion adapters from Autometer but they are not the correct thread size. Has anyone used these guages and if so how did you get the senders to work? I could tap to make them fit but that is the last thing I want to do.

[ktm]

Oil pressure sender is 1/8 BSPT. Coolant may be 1/4 BSPT.

[Reddog929]

Bspt?

[m4xwellmurd3r]

British Standard Pipe Thread.

which is weird considering it's a Japanese car.

i figured they would be metric fittings.

[JimmyZ]

If you have a thread measuring tool which comes with tap sets here are some tell tale TPI's (Threads per inch) By measuring the old male thread vs the new male you can tell if it wil work. Be careful when screwing something unknown into the cast iron block. It is softer than the steel pickup bib and will strip/crossthread if you have got things wrong.

If you don't have a good answer I've got a spare block I can check for the thread info. You might also be able to find an adapter for NPT to BPT. (SPeed shop etc)

Tapered thread forms...

American NPT (National pipe thread)

27 TPI for 1/8"

18 TPI for 1/4-3/8

14 TPI for 1/2"

British Pipe threads

28 TPI for 1/8"

19TPI for 1/4 -3/8

14 TPI for 1/2"

Taken from Machinery's Handbook

2c

Jim

[JimmyZ]

I could tap to make them fit but that is the last thing I want to do.

Unless you have the block stripped and are able to clean the galleries tapping is a risky idea.

Here's the type of adapter to look for. Never did business with these people but I imagine this is what you need. The sender you have is probably 1/8 npt.

http://www.egauges.com/vdo_acce.asp?Subgroup=BSP_Adapter_Bushings