The Triumph Dolomite Club - Discussion Forum

Mahesh wrote: So a 5 is too hot, and a 7 too cold, a 6 should be just right, (couldn't help it)

Saying that my car seems to prefer NGK BPR6EFIX10 Iridiums over standard.

Avoid the R. These have 5 KOhm internal resistance I believe. Your 123 has also a 5 KOhm in the rotorarm. Using resistant less leads you will be ok but when they are of the carbon core type you can end up too much.

Jeroen

soe8m wrote: ↑Mon Jul 09, 2018 8:23 pm

Mahesh wrote: So a 5 is too hot, and a 7 too cold, a 6 should be just right, (couldn't help it)

Saying that my car seems to prefer NGK BPR6EFIX10 Iridiums over standard.

Avoid the R. These have 5 KOhm internal resistance I believe. Your 123 has also a 5 KOhm in the rotorarm. Using resistant less leads you will be ok but when they are of the carbon core type you can end up too much.

Jeroen

Magnacor leads ?

Mahesh wrote:

soe8m wrote: ↑Mon Jul 09, 2018 8:23 pm

Mahesh wrote: So a 5 is too hot, and a 7 too cold, a 6 should be just right, (couldn't help it)

Saying that my car seems to prefer NGK BPR6EFIX10 Iridiums over standard.

Avoid the R. These have 5 KOhm internal resistance I believe. Your 123 has also a 5 KOhm in the rotorarm. Using resistant less leads you will be ok but when they are of the carbon core type you can end up too much.

Jeroen

Magnacor leads ?

Depends on type. They have different type of leads, resistance and non resistance. Then there can be a resistor in the cap.

Jeroen

James467 wrote: ↑Sun Jul 08, 2018 12:58 pm So back to the heat! It's around 33 degs so I ran the car down the M3 and back, about 25-30 miles or so in the traffic at various speeds up to a good 80 or so.

Temperature gauge was well under 3/4 and the car felt happier and the heater was off.

So given the temperature I would expect some expect needle movement and this is now acceptable to me.

Coming off the motorway onto 50/60 mph roads and the needle dropped to just over half way, quickly as well.

I'm happy with that.

I am unconvinced that the problem is solved.
My thinking, based on my experience, is that I would expect no needle movement given that this was relatively easy driving.
It does sound to me James that your car won't be capable of a long climb?


If it was me, I would be trying fitting a header tank. Previously we disagreed on where to locate one,
but I will stubbornly stand by my opinion on this because I tested the positioning using coolant as the level indicator.






Ian.

James467 wrote: ↑Mon Jul 09, 2018 10:15 am Thanks Steve!

Alun has mentioned that hes not too happy with the temp readings given the size of the new rad. This morning I tested the voltage stabalizer and it reads a solid 9.8 volts output. I have sourced a NOS Smiths one which I will test for comparison.

As for the temperature sender, it is a new one from Robsport. I have also been able to source a new old stock correct Smiths one from eBay (for NWL actually!) so when it arrives will be able to do a comparison.

Tony will have to tell me how to do that!!

Hi James, I have updated my original thread on Original temperature senders.
viewtopic.php?f=6&t=29903&p=280196#p280196

The item I did for the mag; all those years ( as we talked about ) is a big file at about 1Mb . I'll see if I can shrink the images or use multiple PMs.

Tony.

I am unconvinced that the problem is solved.

I haven't tried the old temp sender yet and tested the temp gauge so one step at a time.

If it was me, I would be trying fitting a header tank. Previously we disagreed on where to locate one,
but I will stubbornly stand by my opinion on this because I tested the positioning using coolant as the level indicator.

Trouble is Ian, not trying to be belligerent but I don't see how a header tank would help with cooling issues. The temp doesn't rise past 3/4, Tony runs Evans and he has the same temp reading, a header tank would only help in a situation of coolant loss, which I have none. Yes it's a good mod but in this case it should run fine as standard.

Magnacor leads ?

Yep, and they are blue!!

James, next time you have the car warmed up and the electric fan on,
put your hand in front of the temp sender and you will see what I was writing about on my thread, intense heat from the radiator forced by the electric fan.

I know my temp gauge reads just over because of it.

So in theory, if you could make a shroud for the temp sensor it would give a more accurate reading?

Tony.

dollyman wrote: So in theory, if you could make a shroud for the temp sensor it would give a more accurate reading?

Tony.

I have a watercooled temp sensor. Will post a pic sometime.

Jeroen

soe8m wrote: ↑Tue Jul 10, 2018 10:25 pm

dollyman wrote: So in theory, if you could make a shroud for the temp sensor it would give a more accurate reading?

Tony.

I have a watercooled temp sensor. Will post a pic sometime.

Jeroen

I have seen one of those before somewhere

Tony.

I'm in the middle of recomissioning Richphy's Sprint at the moment, it's all running but the Kenlowe is not fitted yet and so there is no fan at all. During warmup, even before the stat has opened, the area of the (Weber) inlet manifold around the temp sender becomes untouchably hot. I'm not convinced that some sort of heatshield to protect it from fan air will do much! The stat opens just a gnats below normal temp on the guage as reported by the new (Fitchetts supplied) sender. whereupon the temp drops a degree or two then starts to climb again. Once it gets past centre, i switch it off as I have no intention of even remotely cooking the motor! But the Kenlowe should go on tomorrow and all should then be OK.

Steve

James467 wrote: ↑Tue Jul 10, 2018 8:11 pm

I am unconvinced that the problem is solved.

I haven't tried the old temp sender yet and tested the temp gauge so one step at a time.

If it was me, I would be trying fitting a header tank. Previously we disagreed on where to locate one,
but I will stubbornly stand by my opinion on this because I tested the positioning using coolant as the level indicator.

Trouble is Ian, not trying to be belligerent but I don't see how a header tank would help with cooling issues. The temp doesn't rise past 3/4, Tony runs Evans and he has the same temp reading, a header tank would only help in a situation of coolant loss, which I have none. Yes it's a good mod but in this case it should run fine as standard.

Not intending to be clever, but I did suggest starting with the sender some time back.


Re. header tanks, these have been used since the 70s including by BL. To begin with these were largely plumbed into
the top of the radiator but this method was soon revised to the now standard plumbing into the bottom hose/bottom of radiator.
The purpose of the header tank is to prevent cavitation by ensuring that the water pump has a constant uninterrupted supply.
Avoiding cavitation ensures that the coolant is in contact with all the surface of the engine, thereby making heat transfer efficient.

Slant four engines are prone to cavitation at the back (hence their inclination to blow head gaskets between cylinders three and four).
Triumph twice revised water pump impeller design and Saab offer a fourth variation and both went for a header tank (TR7).
(Saab completely redesigned the water pump twice, the second of these being a long lasting effective external design 900).

In order for a header tank to be it's most effective it should be located as high as possible.





Re. Tony's experience with Evans coolant, he is using Classic Cool 180.
This is not suitable for Dolomites. It should be Power Cool 180.
Tony contacted Evans and they confirmed this.


I used PC180 in my old Dolomite 1850. It ran at halfway on the gauge all year round using an 88 degree thermostat,
which is the same reading as when I was using water/antifreeze.
Evans Coolant has a lower heat transfer coefficient than water but this is offset by EC staying in contact with all surfaces.


The so called expansion tank that Triumph employed is the weakest link within the cooling system.
Jod Clark wrote an article for Dolly Mixture describing how he cured an overheating 1500SE by replacing it's tank.
Using Evans Coolant will mask this weakness because it doesn't pressurise the cooling system.


If I could only make one change it would be to fit a header tank.
Evans coolant would be my second change.



Hope this clarifies things.



Ian.

The stat opens just a gnats below normal temp on the guage as reported by the new (Fitchetts supplied) sender. whereupon the temp drops a degree or two then starts to climb again.

That's exactly what mine does Steve, driving around this morning the fan cuts in and out nicely and the temp is around 1/2 way. Once I have tested the gauge and new sender I'll set the fan to come in hotter.

I am not worried about it any more, it uses no water or oil. I'd like to test the sender and gauge as per Tony's instructions just to entertain myself.

soe8m wrote: ↑Tue Jul 10, 2018 10:25 pm

dollyman wrote: So in theory, if you could make a shroud for the temp sensor it would give a more accurate reading?

Tony.

I have a watercooled temp sensor. Will post a pic sometime.

Jeroen

I have some different temperature senders to try.

One from Robsport, one from LD Parts and a NOS Original.

The Voltage stabiliser is reading a constant 9.7 Volts. I have taken a resistance reading of them all, Tony is this the right way to do it?

First is the one from LD Parts.





Second is the one from Robsport



Third is an original old one I had



Fourth is the one off the car of unknown origin (I thought it was Robsport but could be Rimmers)



The NOS ones haven't arrived yet, when they do I'll test them.

I have fitted the LD Parts one, temp rises happily under a fast idle to the calibration marks, stat opens, temp falls a tad then rises to a shade under 3/4 then the fan cuts in. This was all done with the bonnet closed and idling in the sun on the drive at around 28 degs ambient for 30 mins to simulate traffic.

I set the fan to cut in earlier and it will maintain a lower temperature if I want it to.

I just need to test it on the motorway.