AC Owners Club Forum
AC Owners Club Forum => Ace, Aceca & Greyhound Forum => Topic started by: ivs on November 09, 2014, 13:45:19
-
Looking for one Otter in line switch for the AC engine. This is the termo switch in front of the engine on the water pump which activates the auxiliary carburetor. Should you have one please contact me. Thanks for looking on those parts boxes in the garage!
Ivs
-
I do not believe the exact bi-metal switch is not now available as Otter stopped manufacture some years ago, but a similar type switch is used on Austin Healey BN4 through BN7 which is a cylindrical unit with a flange, so you might consider this & modify the aluminium housing to accommodate it, unfortunately they are quite expensive for what they are but if you contact your local Healey specialist in USA or if needed one of the specialists in the UK they might give some advice. I think they are approx. $113 in USA
They are used in the same way for control of the enrichment solenoid on SU carburettors.
Otter manufacture many types of bi-metal switches.
Robin
-
Have found the part number for the Otter switch for Austin Healey & other cars fitted with SU carburettors it is an SU Part AUD3936, so if you Google it you might find local sources at a better cost! you will still need to modify your housing though!
Robin
-
Robin,
Thanks for the info. I'm familiar with the Jaguar/healey version of the otter switch. I'll use that solution as the last option. Still confident that someone will have a used one languishing in the garage[:)]
-
Have sent details of the Otter Thermostat to Otter who hopefully will be able to suggest a current part which could be adapted to fit the housing, we will see! I am sure more owners might need them!
Robin
-
If you have a photo of the part, I could have a look around the Autojumble at the NEC this weekend!
-
Can send a picture to your Email Address if you let me have it!
Robin
-
Here are Robin`s photos:
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/ACEngineSUOtterThermostatAssemblyNovember2014038_zps84c35256.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/ACEngineSUOtterThermostatAssemblyNovember2014038_zps84c35256.jpg.html")
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/ACEngineSUOtterThermostatAssemblyNovember2014037_zps0b2578e0.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/ACEngineSUOtterThermostatAssemblyNovember2014037_zps0b2578e0.jpg.html")
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/ACEngineSUOtterThermostatAssemblyNovember2014036_zpsbcd682e6.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/ACEngineSUOtterThermostatAssemblyNovember2014036_zpsbcd682e6.jpg.html")
I`ll keep my eyes peeled at the weekend.
-
Nik
Thanks for getting the pictures on the forum.
Robin
-
Please have a look for me as well! If you can get some, I'd take 2 or 3 of theese missing parts - never found an alternative - even with Healeys or Jaguar XKs.
Thanks a lot,
Chris
-
Oh boy... I hope this isn`t going the same way as the filler caps saga!!!!
-
Nik
I will help to determine if Otter can assist & there response suggests that one of there current designs could be adapted to suit, I am certainly not going to get into the filler cap saga, I have enough to do with the Weller engines & the tens of thousands I have spent on that project.
As with the PVT stub axles I will ask the Club to take it over & invest as I am sure the requirement for these small but important parts will be required to keep the valuable AC cars working as intended, at the moment I do not anticipate major costs but what is important is the support of the owners of these cars to make some commitments.
My interest is in the PVT AC cars which do not have this sophistication I am pleased to say, as with Stub Axles I will initiate then expect the other Club members & the Club to take over!!
-
Fingers crossed we can meet demand from the N.O.S market!!!
-
I am well on the way to a solution using a new Otter/ modified thermostat, I will have a sample thermostat for mounting in a cover plate which will be made to fit the switch housing this would then be a replacement assembly, however I am only prepared to have these made if sufficient owners are willing to invest, so please indicate who will do so!
Robin
-
As there has been minimal interest in a solution for an Otter thermostat replacement in spite of a potential solution, it will be uneconomic to proceed beyond making a prototype, which I will complete, I anticipate the initial cost of parts with minimum order values will not be recoverable let alone my time!
-
.
Robin.
Don't throw your toys out of the Pram............
It is only the select few ACOC Members who use the Forum, many have still to master time travel and enter the 21st Century.
So let's buy a couple of months and advertise in the next issue of ACtion and see response [;)]..........No, No!! not another Fuel Filler Cap SAGA...[B)]..
Seriously, It is one of those items required by many but not readily available, May I suggest that you continue with your prototype and hopefully a small batch run will be viable and appreciated by many..ACOC members and AC Enthusiasts[:)]
If a positive response then I will put the project forward at suitable ACOC Council meeting..to help financially..[:)]
In the meantime I will speak to Terry Webb regards letter and pictures in ACtion .....Good Luck with the prototype..[^]
Keith...[:)]
-
Keith
I am afraid my pram was disposed of many years ago probably to make Spitfires!
I will complete what I have started in respect to making a sample Thermostat, so we will see!
There is one issue, my thermostat is open & makes contact (closes) @ temperature which appears not to conform to the ACE handbook description of the operation, it would help if somebody would confirm if the switch should be normally open or closed!
Robin
-
Robin,
Closed at ambient temperatures, open at elevated temperatures. So we need to know the trip out temperature ( it must be quite low, 30 or 35°C ?) There are other Otter switch patterns doing the same job - notably in Jaguars with the starting carburetter so maybe Otter would know ? As I understand the electrics the starting carburetter solenoid has 12v supply from the ignition loads and the Otter switch is in the earth connection. Thus, with a cold engine, there is a circuit and the starter carburetter is in operation as soon as the ignition is switched on - there is an audible click as the solenoid opens the starter carburetter feed. As the engine warms the Otter switch goes open circuit and the starter carburetter drops out. You will notice the obvious weakness in the system in that it is fail dangerous. See Ace and Aceca General Instructions page 22 and 23.
I would offer to check my switch to get an open circuit temperature, but as it is at least 60 years old there might be some variation from original specification.....
I would put a couple of spares on the shelf if that is any help.
-
Barrie
Thanks for the information, your description aligns with the Car Manuals & is basically a fail safe circuit so it does not run rich if a failure of the switch, I can get either type switches so is not a problem, the information I have is that the switch operates at 35 degrees centigrade with just over one Amp to operate the solenoid!
I do not know why my switch (the one in the picture) I have is open normally & closes on temperature!
Regards
Robin
-
Robin,
One explanation is car earthing polarity (ie positive earth changed to negative) may have been changed,but otter left the same?
Graham
-
Graham, nought out of ten for 'O' level Physics - polarity would make no odds to current flowing - the Otter switch opening would still break the circuit. I rather suspect the switch Robin has is far from well and is operating in reverse; they are temperamental things if dropped or tweaked. The failure mode of course depends whether or no the switch cooperates and opens at 35°C. If it fails to open then you run too rich, whilst if there is an electrical failure the starter carburetter drops out. There is a lot to be said for an on/off switch and a nice bright warning light - a solution often adopted in period. However an original solution is the best aim so well done Robin.
-
To compound the issue, I couldn`t find anything at the NEC autojumble, but a couple of helpful souls suggested contacting Burlen.
Must away to my pillow... it has been a loooooooooooooooooooong weekend!(But V enjoyable!!)
-
Have ordered a thermostat switch of each type, open normally also closed normally, so we can test either type, one point when cars are in high ambient conditions I would suggest that an over ride switch as indicated earlier would be needed, fortunately or unfortunately this is not normal in UK!
It will be a couple of weeks before I receive the sample thermostats & will then have some housings made to fit them into for testing, we then need a volunteer to test them as I do not have a car fitted with these enrichment devices!
Robin
-
I now have the sample Otter Thermostat which is set to 35 degrees Centigrade plus or minus two degrees, I also have designed & had made a few housing plates into which the thermostat will be fitted & held in with a shouldered screw, I will machine the cavity for the switch & fit the switch next week.
Ian Mahany has agreed to carry out a test on the thermostat for me & subject to that being successful will then get some costing's together, it should be realised that there are minimum charges to make special parts & some work time needed to machine & assemble the parts!
It might be best for the Club to take on the manufacture of a batch, I anticipate that at least thirty switches should be made due to minimum charges for parts, what is essential are how many will be required/ordered so it will shortly be up to you guys to make some commitments / recommendations on this matter, I will take some pictures of the final assembly & will arrange for a short article to be put in AC Action!
-
The sample Otter Switch is now made & will be tested by Ian Mahany for me shortly, Nik has been requested to put some pictures on the forum for me so you can see how it is, I anticipate the production types will be bonded into the housing as well as having the clamp screw to hold the thermostat into the plate.
It will be noticed that the wiring consists of wire tails so if you have them you will need to terminate them with a suitable connector!
-
The photos of Robin`s sample:
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/OtterThermostatReplacementDec1st2014045_zpscd99e026.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/OtterThermostatReplacementDec1st2014045_zpscd99e026.jpg.html")
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/OtterThermostatReplacementDec1st2014046_zps18df71a7.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/OtterThermostatReplacementDec1st2014046_zps18df71a7.jpg.html")
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/OtterThermostatReplacementDec1st2014044_zps4597b40e.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/OtterThermostatReplacementDec1st2014044_zps4597b40e.jpg.html")
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/OtterThermostatSwitchAssemblyDecember2014048_zpsb001e420.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/OtterThermostatSwitchAssemblyDecember2014048_zpsb001e420.jpg.html")
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/OtterThermostatSwitchAssemblyDecember2014050_zps4043983e.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/OtterThermostatSwitchAssemblyDecember2014050_zps4043983e.jpg.html")
(http://i134.photobucket.com/albums/q113/nikbj68/Otter%20thermostat/OtterThermostatSwitchAssemblyDecember2014049_zps165f9b17.jpg) (http://"http://s134.photobucket.com/user/nikbj68/media/Otter%20thermostat/OtterThermostatSwitchAssemblyDecember2014049_zps165f9b17.jpg.html")
-
I understand the new Otter Controls Thermostats are now available in AC Spares, these are the new design as described in the April issue of AC Action, these are very simple to fit as described & can be purchased from the Club Spares.
I hope this solves any problems for you.
Robin