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I'd not worry too much about your car being a bitsa. The Mk2 has always been subject to modifications and swaps by the factory and racers in the 1960s and by the restorers and upgraders of more recent times. The main limitation (in my view), apart from doing the mod well, is to stay in the spirit of the car and consider what would William Lyons and Bill Heynes say. A second aspect is what's allowed by the local vehicle licensing authority.
I just want to pass a comment on the much maligned SU Thermo carb system. My car with 90.000 miles on the clock when restored still has its original red Genuine Otter brand switch fitted (Manufacturing date mid 1965 displayed on it) and has had the AED refurbished (more cosmetically than anything else). The car starts at first push of the button & behaves perfectly cold. While the system is of aged design it can work perfectly. 90% of hard starting & poor cold running is caused by the needle in the AED not being properly set for your local ambient conditions & ideal enrichment. The system can thus be reliable & work well.
I understand people wishing to fit a switch or slider for greater control but the system can work perfectly & for a very long time without one & as designed. I do admit to always having a spare Otter switch in stock in case of trouble but just wanted to comment that the system can be reliable over a very long period with the AED needle set up correctly for your conditions. Set up that needle. No 10 in diagram.
I will now be prepared to be shot down in flames with many stories.
Last edited by Glyn M Ruck; 09-01-2022 at 12:02 PM.
Glyn. No rat a tat a tat from me.
The Thermo carb works fine.
My beef is with the Otter switch.
I don't know how many times I have found a failed Otter switch. A simple check with an ohm meter when cold should show a complete circuit.
Unfortunately all too often it is open circuit. (possibly points burnt/decayed due to 1 amp. switching ?)
This has resulted in exercising the option of reverting the system to "manual control" with a swich somewhere around the dash panel
A bit of background
When I first started reviving/restoring Jaguars in the 1980s the Australian Jaguar dealers were not interested in supporting older cars like the MK1/MK2. Anything earlier than an XJ6 Series 1 was effectively
ignored. Consequently, we lived on second hand parts and whatever else we could scrounge or modify..
With the introduction of the internet in the 1990s our eyes were opened to alternate sources and I still have a hard copy of the SNG Barrat no4 catalogue from roughly around the year 2000.
But we still have an Aussie mindset of "make and mend". So, I don't see a mad rush to buy new Otter switches which will cost over A$100 after paying the exorbitant postal/carrier fees from England.
It is much cheaper to buy a $5 switch and the leftover from $100 will buy two slabs of beer.
Cheers
No more Otter switch reliability issues ~ not that common.
Amazing isn't it and my original still works fine. I presume you are aware that you can move out of the dark ages & bring the Otter switch reliability right up to modern vehicle standards.
See reliable electronic switch for electrical control of the solenoid coil of the starter carburettor. The original switch works with a bimetal (Invar) spring device and switches off at about 27-30 ° C water temperature. The modern electronic switch opens reliably and precisely at 32 ° C. It replaces the original switch for all vehicles with SU HD 6 and HD8 Thermo carburettors. Available at most common outlets like SC Parts for GBP 60 which I am more than prepared to pay for the sake of reliability should mine ever fail. This is my spare. The same price that Barratts charge for their standard Otter switch give or take a few pounds. So being parsimonious does not come into the equation.
Last edited by Glyn M Ruck; 09-02-2022 at 06:38 AM.
What can be simpler or more reliable than a bimetallic strip? Even in the 1980s, they'd done around 20 years service and in quite an arduous environment. What would I do to improve them? Use them at a lower current load to operate a relay. A mechanical relay may well be no more reliable, but much easier to replace. In practice, I'd settle for Bill's switch. Incidentally, mine failed closed; I guess the contacts welded themselves together?
I was just giving a Sensible alternative to the Standard Barratts item that most buy at a similar price now ~ (the clip above was the 2013 price). One that I was happy to pay for. Horses for courses. Of course as long as I keep a spare I won't have a failure & I like modernising things. There is nothing wrong with Bill's switch as long as you remember to turn it off & find a place to hide it ~ both easy ~ the hisser is somewhat obvious. I expected to be criticised on this post. I'll take it on the chin. And I'll stand by my comments in post No 23. A post people liked, your goodself included.
And yes there is nothing more simple than a bi metallic strip ~ but times move on. It's positively crude.
Cass has provided the most Elegant solution thus far by using a heated rear window switch & having a matching escutcheon made.
Last edited by Glyn M Ruck; 09-03-2022 at 06:08 AM.
As per Glyn's post this is my version of the choke switch using a second rear window demist switch with an escutcheon made to suit. Switches the choke on when needed and the light indicates that the choke is on.
60 GBP will almost make A$150 including postage so that will buy the $5 switch and 3 slabs of beer.
My favourite place for a manual choke is a pull on push off switch on the support panel for the bonnet release just above the release knob.
It is unobtrusive and. does not require holes in the woodwork or under dash panels.
Jag62
You are welcome to contact me by phone. We are about 80Ks apart according to RACQ trip planner.
Mobile 0418 647 981
We are all different Bill. I'm very happy with my spare sitting in it's box. And I don't drink beer to keep my weight under control. I'm diabetic. When I was traveling 230 days a year my weight went up to 138 Kgs living in hotels. I have now held it at 102 Kgs for 5 years. My latest diabetic medication is helping to get a few more Kgs off.
At the end of the day it's only money & my family are going to be left very well off right down to a house each, a pile of bucks & millions of air miles to travel. I lead a modest life so it keeps piling up. As long as I have my high end Audio System (love good music) & cars & live in a spectacular suburb with magnificent sea & mountain views I'm happy. Surrounded by a Nature Reserve so no more expansion can take place without demolition of an existing dwelling. Surfers paradise. The Malibu of Cape Town only better.
Last edited by Glyn M Ruck; 09-03-2022 at 07:44 AM.
Glyn, I didn't intend any criticism of you or particularly of the alternative to the otter switch, rather that, for what it does and where it's located, the old otter doesn't do too bad a job. And to mention that there's a fairly simple way that might protect it. Indeed, for any alternative apart from the switch, we have to wait 20 plus years to see if it does any better. Perhaps, it's something we should leave to the younger members?
It would be nice if UKGov copied the Chinese and arranged free postage on items for export. It would be a great help to small manufacturers making smaller items that are economic only when sold worldwide.
Glyn, I didn't intend any criticism of you or particularly of the alternative to the otter switch, rather that, for what it does and where it's located, the old otter doesn't do too bad a job. And to mention that there's a fairly simple way that might protect it. Indeed, for any alternative apart from the switch, we have to wait 20 plus years to see if it does any better. Perhaps, it's something we should leave to the younger members?
Understood Peter, & a relay is a good idea if the Otter switch is battling with current. Agree about the Chinese & it all arrives safe & sound.
Last edited by Glyn M Ruck; 09-02-2022 at 01:52 PM.
I'd really like to cut the switches open to see what's inside the electronic replacement and to see if the original are repairable. Incidentally, if engine/manifold/cylinder head surface temperature is good enough, companies like RS Components (Radio Spares for the less young) sell otter switches (30 deg off, 20 deg reset) for a fiver or so.
Bill wrote to me on e mail & said he would spend the 60 bucks and understood my thinking. I really appreciated that from him. A good man. We also discussed private matters that have nothing to do with Jaguars.
Last edited by Glyn M Ruck; 09-03-2022 at 03:34 PM.
So is that like the coolant temperature sensor in a modern fuel injected engine that tells the computer to leave the injectors opened longer when the engine is cold ?
Essentially the choke for a fuel injected engine.
So is that like the coolant temperature sensor in a modern fuel injected engine that tells the computer to leave the injectors opened longer when the engine is cold ?
Essentially the choke for a fuel injected engine.
No, it's just an on - off switch for the solenoid.
The temperature senders on EFI engines have a variable resistance with temperature and the ECU interprets the resistance and gradually reduces the enrichment based on temperature. The Jaguar system is just on off and shuts off the enrichment at 35 C. It doesn't have a tapering function to gradually reduce the amount of enrichment.
09-01-2022, 08:09 AM
And I don't drink beer to keep my weight under control. I'm diabetic. When I was traveling 230 days a year my weight went up to 138 Kgs living in hotels. I have now held it at 102 Kgs for 5 years. My latest diabetic medication is helping to get a few more Kgs off.
