Hi guys,
So here's the deal. I want to move the temp switch for my thermo's from the radiator to the manifold. The manifold already has a hole tapped in it so I was wanting to make use of that, I think it is 3/4 BSPT but I'm not sure. Anyway, naturally all the temp switches have metric threads, and pirtek don't have any adapters from imperial to metric thread around these sizes. So my too options are tap out the hole to metric or find an imperial threaded temp switch. I want to avoid the first option as much as I can because its just a pain in the rear end so I was thinking I could get in a temp switch from the states.
Does anyone know a supplier or a site that will handle this stuff I'm after, I've got no idea where to start looking? Or does someone have a better idea of how to fix the problem, something I havn't thought of.
Any help would be great,
Cheers,
Sourcing temp switch
Started by
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, May 01 2007 01:57 PM
24 replies to this topic
#2
LXCHEV
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Posted 01 May 2007 - 02:43 PM
I think you're already on the right track by thinking of yankee stuff.
Eg. All autometer gauges come with sender units, and these will all be imperial thread. And I'm sure the sender units would be readily available individually. That's the way I'd be going for sure! You just need to find out which sender unit you need!
I have an Autometer temp gauge fitted to my car.... and I put my sender unit into the intake manifold (coolant passage near the front). (Edelbrock manifold, yankee too).
Looks like half my car is American.
Eg. All autometer gauges come with sender units, and these will all be imperial thread. And I'm sure the sender units would be readily available individually. That's the way I'd be going for sure! You just need to find out which sender unit you need!
I have an Autometer temp gauge fitted to my car.... and I put my sender unit into the intake manifold (coolant passage near the front). (Edelbrock manifold, yankee too).
Looks like half my car is American.
#3
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Posted 01 May 2007 - 03:28 PM
Yeah, thats what got me thinking that way, cos all my guages are autometer and the water and trans temp are obviously imperial and slotted straight into the holes. Like you I've got the water temp sender in the intake manifold and I was wanting to add the temp switch for the thermos there too.
Did some tests with one of those thermal infra-red temp reading guns or whatever they are. We were getting between 30 and 50 degrees F difference between the manifold coolant temp and radiator coolant temp - no wonder the fans weren't on when they were supposed to be! It was 190 df in the manifold but the fans wouldn't come on because it was only 140 df in the rad at the switch!
Did some tests with one of those thermal infra-red temp reading guns or whatever they are. We were getting between 30 and 50 degrees F difference between the manifold coolant temp and radiator coolant temp - no wonder the fans weren't on when they were supposed to be! It was 190 df in the manifold but the fans wouldn't come on because it was only 140 df in the rad at the switch!
#4
davelh
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Posted 01 May 2007 - 04:42 PM
make life easy, and just cut a metric thread into the hole you have
iven if you need to go the next size up, it is only alloy
or, make your own imperial to metric adaptor using similar methods
cheers
dave
iven if you need to go the next size up, it is only alloy
or, make your own imperial to metric adaptor using similar methods
cheers
dave
#5
Dr Terry
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Posted 01 May 2007 - 05:07 PM
Hi Guys.
The hole in the manifold is 1/2" NPT which is an SAE thread (not Imperial) and you probably won't find a metric switch bigger than that to cut a larger thread to match. What I've done many times in the past, is to get a normal Holden temp gauge sender, which if you look closely is usually a brass adaptor with an 1/8" NPT thread in its centre to accept the small sender. Just unscrew & throw the sender away, enlarge the hole & cut a metric thread to match your thermo switch. The adaptor is made of brass, so the thread cuts easily and you're not destroying an original Holden manifold, it will screw straight in.
'Hey Presto', you've made your own Metric to SAE adaptor.
Dr Terry.
The hole in the manifold is 1/2" NPT which is an SAE thread (not Imperial) and you probably won't find a metric switch bigger than that to cut a larger thread to match. What I've done many times in the past, is to get a normal Holden temp gauge sender, which if you look closely is usually a brass adaptor with an 1/8" NPT thread in its centre to accept the small sender. Just unscrew & throw the sender away, enlarge the hole & cut a metric thread to match your thermo switch. The adaptor is made of brass, so the thread cuts easily and you're not destroying an original Holden manifold, it will screw straight in.
'Hey Presto', you've made your own Metric to SAE adaptor.
Dr Terry.
#6
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Posted 01 May 2007 - 11:06 PM
1. I think Dr Terry has come through with the goods there Sam!!!! Fantastic advice!
2. That is amazing with such a difference in temps between your intake manifold and radiator!!! No wonder you used to complain about the car's temp gauge running hotter than what you'd like!!! Sounds like once you've relocated the sender, you'll be laughing.
2. That is amazing with such a difference in temps between your intake manifold and radiator!!! No wonder you used to complain about the car's temp gauge running hotter than what you'd like!!! Sounds like once you've relocated the sender, you'll be laughing.
#7
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Posted 01 May 2007 - 11:42 PM
Would be a problem if you are using a 70C thermostat, but if using a standard 82 deg thermostat cant see that you have a problem. What happens when the temps get hotter? like 220F in the manifold?Did some tests with one of those thermal infra-red temp reading guns or whatever they are. We were getting between 30 and 50 degrees F difference between the manifold coolant temp and radiator coolant temp - no wonder the fans weren't on when they were supposed to be! It was 190 df in the manifold but the fans wouldn't come on because it was only 140 df in the rad at the switch!
#8
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Posted 02 May 2007 - 06:59 PM
Don't quite understand what you're saying DA. I want my fans to come on according to the manifold temp so that there is a closer relation with guage and fans. Fans coming on earlier will hopefully help short circuit heating issues and they will stay on longer than they previously did. My thermostat is 70c
Manifold is not stock holden item but Harrop for VN heads. I had the bolt that plugs up the hole checked and it was definately BSPT, but i can't quite remember the size
, pretty sure it was 3/4. The switches I was wanting to put in are around the 16-22mm mark.
Cheers,
Manifold is not stock holden item but Harrop for VN heads. I had the bolt that plugs up the hole checked and it was definately BSPT, but i can't quite remember the size
, pretty sure it was 3/4. The switches I was wanting to put in are around the 16-22mm mark.Cheers,
#9
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Posted 02 May 2007 - 10:52 PM
The point I was hoping to make is that if the manifold is only just above thermostat temperature then you dont need the fans to come on, and that the temperature difference you have between manifold and radiator might be due to the thermostat being slightly closed( which if it were an 82-88C thermostat would be possible) and/or poor circulation.
Seeing as you have a 70C thermostat might not be the case. How does the temp at the thermostat cover compare with manifold and top tank of the radiator when in overheat/hot mode?
Seeing as you have a 70C thermostat might not be the case. How does the temp at the thermostat cover compare with manifold and top tank of the radiator when in overheat/hot mode?
#10
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Posted 03 May 2007 - 10:06 AM
What is your temp on/off of your fan switch?Wouldnt of thought you would get 50F drop from manifolds to rad unless t/stat was almost or completely shut,or cycling between.
Iv never found those infra red guns to be real acurate, and difficult to pin point a exact temp,some people have had better luck with them.
Iv never found those infra red guns to be real acurate, and difficult to pin point a exact temp,some people have had better luck with them.
#11
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Posted 03 May 2007 - 11:52 AM
Didn't test the temp of the thermostat cover so can't say how it compares to radiator and manifold.
On/off temps for the fan switch are something like 85 on 79 off.
The 50df reading was taken after shutoff, the other lower ones during running.
Whether the guns totally accurate or not it gives an indication of the heat difference and is enough for me to want to move the switch to the manifold.
On/off temps for the fan switch are something like 85 on 79 off.
The 50df reading was taken after shutoff, the other lower ones during running.
Whether the guns totally accurate or not it gives an indication of the heat difference and is enough for me to want to move the switch to the manifold.
#12
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Posted 03 May 2007 - 12:49 PM
Good luck, nothing wrong with having it triggered from the manifold......just think youd be better off with it triggering around 95-100C, since that appears to be your hottest point......otherwise your fans could be "chasing their tails" trying to remove heat from a basically luke warm radiator.
#13
Dr Terry
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Posted 04 May 2007 - 08:13 AM
Hi Guys.
Liam said :- �I had the bolt that plugs up the hole checked and it was definately BSPT, but i can't quite remember the size , pretty sure it was 3/4."
The trick with pipe threads (BSPT and NPT) is that the quoted size i.e. �� BSPT is not the actually the outside diameter of the thread. A �� BSPT fitting is slightly over �� in real diameter. The reason for this is that a �� BSPT thread is the thread that is cut on the outside of a pipe that has a �� INSIDE diameter. �� BSPT is an imperial (English) thread, whereas �� NPT is an SAE (Society of Automotive Engineers) (US-based) thread, but they are very similar. They both have the same outside diameter and the same pitch (threads per inch), but their thread angle is different. A �� BSPT fitting is a tight fit in a �� NPT hole, but a �� NPT fitting will be a loose fit in a �� BSPT hole.
GM (Holden & Chev etc) have used �� NPT water fitting and sensors since the year dot. I find it difficult to believe that Ron Harrop would cut a �� BSPT hole to accept �� NPT genuine GM fittings and sensors.
Dr Terry.
Liam said :- �I had the bolt that plugs up the hole checked and it was definately BSPT, but i can't quite remember the size , pretty sure it was 3/4."
The trick with pipe threads (BSPT and NPT) is that the quoted size i.e. �� BSPT is not the actually the outside diameter of the thread. A �� BSPT fitting is slightly over �� in real diameter. The reason for this is that a �� BSPT thread is the thread that is cut on the outside of a pipe that has a �� INSIDE diameter. �� BSPT is an imperial (English) thread, whereas �� NPT is an SAE (Society of Automotive Engineers) (US-based) thread, but they are very similar. They both have the same outside diameter and the same pitch (threads per inch), but their thread angle is different. A �� BSPT fitting is a tight fit in a �� NPT hole, but a �� NPT fitting will be a loose fit in a �� BSPT hole.
GM (Holden & Chev etc) have used �� NPT water fitting and sensors since the year dot. I find it difficult to believe that Ron Harrop would cut a �� BSPT hole to accept �� NPT genuine GM fittings and sensors.
Dr Terry.
#14
makka
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Posted 04 May 2007 - 12:39 PM
I just went to repco and looked through their Tridon catalouge, hey presto, I found 1 that fits perfect!
#15
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Posted 04 May 2007 - 07:29 PM
Alright Dr. T, I concede. Sounds like the bloke who measured it for me made a bit of a boo boo, 1/2" NPT it is. Thanks very much for clearing that up, means I will actually get the right one now!!
makka, what type did you get, and with what on/offs? I've been to bursons and looked through the tridon cat. and most all of it was metric, I think the only imperial stuff was 3/8" gas, and the temps weren't what i wanted anyway.
I see your point DA about the fans working to remove heat from a rad that is not excessively hot, I'm going to have to think about it and get back to you on that one.
Cheers,
makka, what type did you get, and with what on/offs? I've been to bursons and looked through the tridon cat. and most all of it was metric, I think the only imperial stuff was 3/8" gas, and the temps weren't what i wanted anyway.
I see your point DA about the fans working to remove heat from a rad that is not excessively hot, I'm going to have to think about it and get back to you on that one.
Cheers,
#16
arrimar
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Posted 05 May 2007 - 07:02 AM
its a water pipe fitting........
go to a plumbing supplier.
go to a plumbing supplier.
#17
makka
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Posted 05 May 2007 - 07:44 PM
I think mine comes on a lil before 90 and off at 82, I will see if there are any part numbers on the outside of it
#19
rodomo
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Posted 07 May 2007 - 06:31 PM
Pirtek and Enzed are good for fittings too.its a water pipe fitting........
go to a plumbing supplier.
#20
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Posted 19 May 2007 - 05:44 PM
Hey makka did you end up finding any part numbers on that switch of yours?
#21
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Posted 19 May 2007 - 07:10 PM
shit, sorry. forgot all about it. will check tommorow
#22
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Posted 20 May 2007 - 06:07 PM
I Managed to find this
Tridon thermo fan switch catalogue
Cant seem to see anything that is 1/2"NPT Thread.
Tridon thermo fan switch catalogue
Cant seem to see anything that is 1/2"NPT Thread.
#23
makka
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Posted 20 May 2007 - 07:53 PM
mine is a TFS 110
#24
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Posted 21 May 2007 - 06:16 PM
Good find TUF, as I had originally thought from visiting Bursons the only imperial option is 3/8 gas, which is what yours is makka.
Back where I started, looking for 1/2 NPT from america or another foreign place.
Cheers,
Back where I started, looking for 1/2 NPT from america or another foreign place.
Cheers,
#25
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Posted 21 May 2007 - 07:20 PM
Hmmm, hey makka what mainfold you using? Is It a Edelbrock?
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