Hi All,
I have a Raceline Water Rail on my silvertop, it come with 2x threaded holes for sensors and takeoffs etc.

I need to know the thread size for both to allow me to get sensors (or adapters) to suit.

One is much larger than the other, the larger I believe is 1/8NPT maybe? it currently fitted with a one wire sender that feeds a TIM dash gauge.

The smaller one I have no idea about, it is currently blanked off with a torx headed bung.

Any ideas what the threads are as standard? as i need to find a location for a GM type sender for megasquirt.

I will see if i can get a picture in a bit.

3/8 npt

Photos:

quote:

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Originally posted by big_wasa
3/8 npt

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larger, the smaller one is 1/8 as you say.

Ahhh I see... Thanks

So it seems I can fit the GM sender into the currently occupied spot and then either use an adapter for the other hole or alternatively use one of those inline hose fitting things. Ebay here I come...

big_wasa, are you sure it's npt? The gasket surface on the fitted sender suggest a parallel BSP thread.

Raceline instruction manul might seem the obvious place to look:

http://www.raceline.co.uk/products/part_section.asp?SectionID=35&CategoryID=2

LIST OF COMPONENTS
1 x Raceline cast alloy water rail
1 x gasket
1 x M8 x 40 caphead screw
2 x M8 x 25 caphead screws
1 x M10 x 40 caphead screw
1 x M10 plain washer
2 x 1/8in NPT tapered plugs
1 x 90deg heater elbow (optional) or blanking plug

In addition, if the thermostat fitting kit has been supplied, you should have:
1 x thermostat housing
1 x thermostat
1 x gasket
2 x M8 x 25 caphead screws
1 x pressure cap

[Edited on 12/3/12 by loggyboy]

I did look at the website but it suggests that the two points are the same (1/8 npt) which on mine they are different. It's does not look modified afterwards to my eyes.

Looking at the photos of other rails, some seem to have a 90degree pipe conected to the larger hole. So it must be the '1 x 90deg heater elbow (optional) or blanking plug' which typically doesnt list a thread. Maybe an email to raceline might confirm.

The silver top sensor and the heater elbow that fit the hole are both 38 npt.

You can see in the photo it's been re sealed using ptfe on it's threads.

Race line updated the rail with extra ports for sensors as well as the option of the heater elbow.

Just spoke to Raceline.

They say they come with 2x 1/8 NPT as standard, but it is normal for people to drill and tap them to other sizes.

I now know I have 1x 1/8 NPT and an unknown atm, which is probably a 3/8 NPT.

I'm going to get a standard GM sensor (which is 3/8 NPT) and try it. If its does not I'll get an hose adaptor for it.

Cheers all!