I think my radiator is too big.....?

[tony g]

Geoff I just read yours after I posted the previous. Thats a good point about setting the target high. Im going to try that first

Tony

[sprint95m]

On the DC website instructions it gets a little confusing re the stats

It specifically mentions BMWs and Rovers (Triumph being grouped under this banner) with use the bypass tube system.
The instruction is to remove the thermostat and also remove the bypass and fit blanking plugs (22mm core plugs in our case).

I spent quite a bit of time researching this.
Australian forum member Stag76 has posted his successful set up (on a TR7 Sprint) and given lots of advice.

From that it would seem sensible during colder ambient temperatures to have the set temperature at the high end, maybe 95 or even 100 and experiment with that.

Yes that is the way I was thinking because I wondered if the default of 85 degrees was based on the requirements for an Australian climate?

The fact that Tony with his smaller capacity (but similar surface area) Fiesta radiator has experienced the same problem confirms
what Jeroen stated, the bigger than standard capacity radiator is not the problem.



thanks,


Ian.

[shaunroche]

..... took a thermostat and cut the guts out of it to leave just the ring, to act as a flow restrictor.....restricting the flow out of the engine (stat housing or top hose) seems in theory what we need......
Tony

This is what I have done...



We'll see how this goes when it's started, though I'm not sure if a Sprint engine requires more heat dissipation due to it being a bit meatier than an 1850?

[tony g]

Thats what i did. In practice the water can only pass through that gap anyway with an open stat so cant see a problem doing that.

Tony

[sprint95m]

From that it would seem sensible during colder ambient temperatures to have the set temperature at the high end, maybe 95 or even 100 and experiment with that.

Geoff, I tried the highest setting on the controller (95 degrees) and guess what.............



no difference ,
as it was when I first posted the question, the ambient temperature here is still less than 5 degrees Celsius.

I'll leave it as is time being and see if increased ambient temp improves matters.
The longterm BBC forecast for next week suggests a jump in ambient temperature to over 10 degrees .




From all this I have learned that I do have the wrong Saab radiator. I ordered the 32mm version but never thought to check
what I had actually received.
My choice was made by looking at what the Triumph engined Saab 99 used, the 9-3 radiator I ordered is basically the same
save for a different top LH spout orientation (9-3 is the same as a Dolomite).

This, discovering that I have a thicker radiator than intended, also answers a question that puzzled me about how others using 9-3 radiators
have more space between the bottom pulley and radiator than I have on my car.


I have bought one of they cheap IR surface thermometers to play with, it might be informative to compare readings?





thanks,

Ian.

[soe8m]

I was not planning to use ever such kind of setup but out of interest I did read the instructions. When you remove the thermostat and have an always open circuit the engine will never warm up properly I think. To warm up the ewp should not be pumping at all. Then you have the problem of no heater circulation. This setup and how it's supposed to work with the controller will never work ok in our climate. The engine has to run around 85 degrees water temperature for normal use. On a track I can imagen you will notice a difference but I have to say that cooling with the std water pump was also never a problem on two race cars for about 10 years. I can only see disadvantages over advantages. The thought of a radiator too big is thinking the wrong way. The temp normally controlled by the thermostat is engine temp. Does it becomes too hot you enlarge the surface by opening the thermostat. Your radiator does not control your engine temp. The size of the radiator only determines how fast and how much excessive heat can be lost. The ewp setup at your car is wrong. Not the radiator.

Jeroen

[Karlos]

Just a few thoughts of my own...

The over cooling is caused by the permanently open circuit through the radiator and the fact that the pump is on all the time ('on' as in continually pulsing at 10/30s or whatever it was).
I don't think you can have a radiator that is 'too big' or 'too efficient', it is there to do one thing: remove heat from the coolant. If you had a radiator big enough you would never need any sort of fan to increase the rate of heat exchange. The reason why 1300 and 1500 engines don't have the same radiator as a Sprint is that a smaller one is good enough -any larger is a wasted cost in the price of a larger radiator and filling it with extra anitfreeze. If you put a Sprint radiator in a 1300 Dolly the engine would get to the same working temperature as before in the same amount of time. The only difference is that the thermostat would have to open less often for the engine to remain at the same temperature.

It seems to me that the EWP controller is not regulating the frequency of flow correctly for ambient temperatures below 20 Celcius and the removal of the thermostat has also altered the coolant flow path around the engine. There seems to be no control over the diversion of the coolant flow from "round the block" to "round the block + through the rad" so the coolant is getting over-cooled.
Using a smaller radiator is back-tracking on the improvement in cooling efficiency you are looking to achieve.

Is there a way to control the flow rate? That is, to reduce the run time to say 5/30s. Reducing the flow rate/frequency of the EWP run time would contribute to a higher running temperature, but you would keep the efficiency of the larger radiator available to you for those 'hotter' days.

[soe8m]

And that is the problem. It should be not pumping below normal operating temp if you want the ewp working as an thermostat. But then the heater is non functional. In other words your heater will work fine when it's a very hot day when the ewp spins around and in the winter it will freeze inside the car forever while driving. This ewp setup without a thermostat and plumbed in in the lower rad hose cannot work.

Jeroen

[tony g]

Just been out in mine with controller set to 90. Fully warmed up and fan in and out. Guess what? , it started cooling on a mile straight in overdrive at 60 mph until the 75 light was flashing. Heater went cooler. Im now thinking of running a thermostat as well and keep a bypass from heater outlet to water pump cover. Worth a shot?

Tony

[sprint95m]

Just been out in mine with controller set to 90. Fully warmed up and fan in and out. Guess what? , it started cooling on a mile straight in overdrive at 60 mph until the 75 light was flashing. Heater went cooler. Im now thinking of running a thermostat as well and keep a bypass from heater outlet to water pump cover. Worth a shot?

Tony

No that won't work Tony,
to have circulation the return needs to be plumbed in before the EWP, not after.

I have emailed Davies, Craig and await their reply.




Ian.

[tony g]

Ian, if the return is plumbed before the ewp and its not running will there be no flow anyway?

Tony

[sprint95m]

Yes that is right, there is only flow while the EWP is running.


Which controller do you have?
The (LED display) 8020 I have was discontinued last year when the (LCD) 8000 was introduced.





Ian.

[tony g]

Led for me too. I have 2 of them in fact and both behave the same. Does yours do a 2 minute fan run after starting for the first time? Really annoying

Tony

[gmsclassics]

Ian / Tony

Have either of you done a recent run with a radiator blind covering half or more of the radiator surface area?

I'm still concerned you might do something that compromises the benefits on a hot day in summer - which obviously is some way off!

Geoff

[tony g]

I haven't Geoff but maybe worth a go in the short term.

Tony