Lotus Elan

Spigot thread size?

PostPost by: The Veg » Wed May 17, 2017 1:08 am

Anybody know the size of the straight-cut thread on this spigot from the water pump housing, to which the heater hose connects?
Attachments
img_20170516_205513.jpg and
1969/70 Elan Plus 2 (not S) 50/2036
"It just wouldn't be a complete day if I didn't forget something!" -Me
User avatar
The Veg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1522
Joined: 16 Nov 2015
Location: Atlanta 'burbs (southeast USA)

PostPost by: ericbushby » Wed May 17, 2017 9:06 am

Apparently, if it is on the block it will be NPT (national pipe thread) because it is a Ford design but pipe threads on the cylinder head are BSP (british standard pipe) because it is a Lotus design and therefore british.
Remember that with pipe threads that the number is the bore of the pipe not the size of the thread.
I would have called that a 1/2" NPT hose tailpiece.
Cheers
Eric in Burnley
ericbushby
Fourth Gear
Fourth Gear
 
Posts: 840
Joined: 13 Jun 2011
Location: east lancashire

PostPost by: Craven » Wed May 17, 2017 10:43 am

Front cover is Lotus so BSP
Craven
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1092
Joined: 14 Sep 2013
Location: south coast uk

PostPost by: rgh0 » Wed May 17, 2017 11:47 am

Yes Lotus designed, cast aluminum parts are BSP - e.g. head, front cover, diff housing
Ford sourced cast iron parts are NTP - e.g. block , gearbox
Weber carbs are metric :lol:

cheers
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7513
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: The Veg » Wed May 17, 2017 4:46 pm

Thanks gents. The reason I asked is because the spigot on the heater is 5/8" and this spigot is 1/2" for some strange reason. A PO just clamped the snot out of the 5/8" hose on it, but I'd rather have the same size spigot at both ends instead of re-bodging it.
1969/70 Elan Plus 2 (not S) 50/2036
"It just wouldn't be a complete day if I didn't forget something!" -Me
User avatar
The Veg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1522
Joined: 16 Nov 2015
Location: Atlanta 'burbs (southeast USA)

PostPost by: mbell » Wed May 17, 2017 6:42 pm

It's standard to have 1/2" spigot and 5/8" pipe! The factory did the same over clamping.

I cheated with mine when fitting New hoses and fitted a length of 1/2" inner 5/8" outer pvc hose. Then inserted the heater house over that. Plenty of silicon grease to aid fitment and has been fine so far.

Did the same at the thermostat housing end too.
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
mbell
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1674
Joined: 07 Jun 2013
Location: Austin, TX (UK Ex-pat)

PostPost by: The Veg » Wed May 17, 2017 8:50 pm

Mine is 5/8" everywhere except this spigot, so if I can find a 5/8 spigot with that thread then life will be simpler, especially since that hose runs through nothing but difficult-to-access places where fitting a reducer and a short bit of 1/2" hose could be tricky.
1969/70 Elan Plus 2 (not S) 50/2036
"It just wouldn't be a complete day if I didn't forget something!" -Me
User avatar
The Veg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1522
Joined: 16 Nov 2015
Location: Atlanta 'burbs (southeast USA)

PostPost by: mbell » Wed May 17, 2017 10:07 pm

I just put the hose directly over the spigot and used a single length of 5/8" heater hose.

Getting the spigot may be tricky on this side of the pond...
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
mbell
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1674
Joined: 07 Jun 2013
Location: Austin, TX (UK Ex-pat)

PostPost by: mbell » Thu May 18, 2017 12:41 am

Adding a photo of the thermostat housing outlet to better sure what I did..
Attachments
20161213_203749.jpg and
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
mbell
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1674
Joined: 07 Jun 2013
Location: Austin, TX (UK Ex-pat)

PostPost by: CBUEB1771 » Thu May 18, 2017 6:28 pm

The Veg wrote:so if I can find a 5/8 spigot with that thread then life will be simpler


I searched for something like this for a very long time, this is a very common fitting for a 1/2" bore hose but not for 5/8". Finally Lotus Marques in Australia started machining their own hose adapters with the nipple end for a 5/8" bore hose. The threaded end is BSPP, I just can't remember the size right now and I am away from the garage. I think it is 3/8" BSPP which should have a thread major diameter of 0.656" (1/4 and 1/2 BSPP are 0.518" and 0.825" major diameter, respectively). I just looked at the Lotus Marques web site and the hose adapters are still listed but the photos make them look like they have tapered pipe threads which would be wrong. Try shooting them an email and enquire if they are still machining their own hose adapters. Don't worry about ordering from the US, I have bought quite a few bits from Lotus Marques, all high quality and they are pleasant to work with. The proprietor used to work in the US for one of the now-defunct computer hardware companies, Wang Laboratories if I recall correctly.
Russ Newton
Elan +2S (1971)
Elite S2 (1962)
User avatar
CBUEB1771
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1684
Joined: 09 Nov 2006
Location: Boston, Massachusetts USA

PostPost by: The Veg » Thu May 18, 2017 10:11 pm

Wang? No kidding? Haven't heard that name in ages! Back in the late '90s I worked in an office that was still using an old green-screen Wang IT system.

Thanks for the tip; will get in touch with LM.
1969/70 Elan Plus 2 (not S) 50/2036
"It just wouldn't be a complete day if I didn't forget something!" -Me
User avatar
The Veg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1522
Joined: 16 Nov 2015
Location: Atlanta 'burbs (southeast USA)

PostPost by: CBUEB1771 » Fri May 19, 2017 3:12 pm

Here is a photograph of the 5/8 hose X 3/8-19 BSPP hose barbs from Lotus Marques. A 3/8 Dowty washer is shown along side. When I looked at it again last night I realized that my memory must have failed me about Steve at Lotus Marques having these barbs specially made. There are stamped markings on the flats of the hex that make me realize this must be a commercially available item. However I must have looked at more than 30 on-line catalogues for hose and hydraulics suppliers in the US, Canada and UK and found only versions for 1/2 inch bore hose with a 3/8 BSPP thread. There was a comment about Lotus also clamping the daylights out of a 5/8 hose on the 1/2 inch barb. This is not what happened at Lotus. The original heater hose for the inlet side of the engine on a +2 (050P6006) is formed and has two diameters, 5/8" bore at the heater end and 1/2" bore at the front cover end.
Attachments
img_0467.jpg and
Russ Newton
Elan +2S (1971)
Elite S2 (1962)
User avatar
CBUEB1771
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1684
Joined: 09 Nov 2006
Location: Boston, Massachusetts USA

PostPost by: RichardHawkins » Fri May 26, 2017 7:52 pm

I have just checked mine, 3/8 BSP.

As you are inthe USA I would think the answer would be to get a local machine shop to make what you need from hexagonal brass bar.

Richard Hawkins
RichardHawkins
Fourth Gear
Fourth Gear
 
Posts: 772
Joined: 05 Jul 2008
Location: Lincolnshire U.K.

PostPost by: rgh0 » Sat May 27, 2017 6:03 am

Another way would be to get 5/8 to 1/2 hose joiner and use two sections of hose to match the 1/2 inch connection you can get for the front cover and 5/8 connection for the heater.

There are people who make custom silicone hoses these days so you could probably get the hose needed made if no no one stocks anything suitable

cheers
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7513
Joined: 22 Sep 2003
Location: Melbourne, Australia

Total Online:

Users browsing this forum: Quattro123 and 10 guests