Upgrading a Dolomite heater?

[new to this]

Steve

Im hoping i can still get away using the original water pump,i know there not the best but im changing so much just to try and get this EFI to work one less thing is a bonus

Dave

[sprint95m]

thats a better way of plumming it, but you will need some sort of by pass ,other wise if ive got this right if you turn the heater off the car would over heat,and i take it you just block off the original supply from the inlet manifold
I would like one of those mangolet manifold but there dear, and then ive still got to drill holes in it for the injector bungs

dave[/color]

Dave, the heater plumbing is an additional circuit running in parallel to the cooling circuit.
If you forget to set the heater to hot when filling the system, your car will come to temperature normally
but the heater won't work (because it is airlocked)

The pipework in a Stromberg or SU inlet manifold is required for heating said manifold,
which has nothing to do with the operation of the heater as such,
it is for convenience that Triumph used it to supply the heater on Dolomites.
On 2000s they used the cylinder head for the heater feed.


On a standard water pump cover all three connections are inputs to the pump.
If you are making your own inlet manifold Dave, I take it you are going to have an external radiator bypass
rather than the troublesome little tube Triumph employed?
You can simplify things for the manifold design if you use a header tank and remote thermostat
but of course you have to then make up bespoke hoses.


The cooling plumbing I am using is a tried and tested system (car makers have been using it for 4 decades).
I did learn about this the hard way having made the extremely stupid mistake of buying Davis, Craig products...
http://sideways-technologies.co.uk/foru ... ment-96217
There is a drawing I did explaining the cooling circuit when coolant is flowing through the radiator
and a photograph of a Land Rover remote thermostat.

If you don't have one already, I suggest you get a Car Builder Solutions catalogue,
there is a lot of useful explanations in it. They also have videos on YouTube.



Ian.

[dollyman]

Just to add, if you are not getting enough flow through the heater Ian? Mercedes used to have a pump for the heater as standard on some models, i think in was the early 230E? From memory just a simple in line jobby fitted as new from the factory.

Tony.

[new to this]

This is where im up to,but run in to problems on thermostat














Ian

could you post a picture of the under side of your mangolits manifold,does it plug in to the top of the water pump cover

Dave

[sprint95m]

You are coming at and not that far away Dave.









Dave, the standard bypass tube is more trouble than it is worth so I don't use one.
I block both of the holes for it with core plugs.
Furthermore for the EFI I don't use a Dolomite thermostat or it's housing indeed,
instead I have a remote thermostat and a header tank.

If you were to employ a remote thermostat it will simplify your installation absolutely enormously
because you can simply require to have a 32mm pipe from the cylinder head coolant outlet joined to a hose to the thermostat.
It will be necessary to also fit a header tank (to fill the cooling system easily) and to plumb the radiator bypass into the bottom hose.


It is also simpler to have the heater input from the cylinder head. That way you don't need the H-pipework you made,
the heater return can be cut from a length of 13mm silicone hose and connected to either the water pump cover
or into the bottom hose.
If you wish to keep your H-pipework, you can of course fit a spout into the coolant pipe I suggested making.

You will need two temperature senders, I suggest you locate them in the cylinder head water transfer plate.
The one for the EFI is definitely better there rather than at the front of the engine.


Ian.

[new to this]

Ian

Ive made an alloy header tank to fit on drivers side suspension turret ,i fitted it there as it makes the pipe work smaller and easier runs

I wanted to have a oil/water gauge fitted , was planing to fit the capillary tube in the back of the head in the water transfer plate ,again so im not running the capillary pipe right across the engine ,and for the EFI set up i fitted a boss in the thermostat housing for the sensor

This bypass thing has been my biggest problem

Im a bit confused you said your not using the thermostat in the housing , its already there why not use it , i was trying to copy the original manifold setup ,at the base of the thermostat theres a foot , i was trying to incorporate that as well,but its been a real pain,

How would i plum/fit a remote thermostat housing

P.S Sorry ive hijacked your thread but its all sort of related

Dave

[sprint95m]

This bypass thing has been my biggest problem

Im a bit confused you said your not using the thermostat in the housing , its already there why not use it , i was trying to copy the original manifold setup ,at the base of the thermostat theres a foot , i was trying to incorporate that as well,but its been a real pain,

How would i plum/fit a remote thermostat housing

You are correct Dave, I could use a thermostat in the manifold and a bypass hose from there.
However the remote thermostat I use allows for the bypass to be a 32mm hose, the same size as the radiator hose.
This gives a better flow than using the 16mm bore standard bypass tube.
(16mm bore has a cross section of 201 sq.mm, whereas 32 bore is 806 sq.mm).
Having done this before I know the car drives better, the result is akin to fitting a lighter flywheel.

Trying to fit a 32mm hose tail the manifold is not impossible, but for me my choice is easier and less expensive too.



The remote thermostat is plumbed into the top radiator hose.
The bypass is made up is straight hoses and a 90 degree elbow into a T in the bottom hose.
In the link I posted a couple of posts back, there is a photograph of the remote housing I installed on an 1850.
Having a longer top hose, there is a bit more space on a Sprint.

This is the type I use
https://www.ebay.co.uk/itm/Land-Rover-T ... e959caf564
In the photograph:
the top left is connected to the inlet manifold,
top right to the bypass hose
and the bottom to the radiator.


Ian.

[sprint95m]

I'd never considered the Dolomite heater inadequate, till I went on the RBRR in Mahesh's Sprint in 2018.

Steve, I have learned some more about the causes of poor heater performance
and more particularly why it can vary from car to car. (This is from people who repair heaters.)

The causes being clogging and internal corrosion.

Inevitably the silt from the engine will gather in the heater matrix.
This will set like concrete in time and the useable volume within the matrix is reduced.....
and no amount of back flushing will shift it.
Another problem is corrosion of the divider plate, once it becomes holed, coolant will pass from inlet
to outlet without going through the matrix at all. As the hole enlarges less coolant goes through the matrix....



Ian.

[James467]

The causes being clogging and internal corrosion.

I'm pretty sure that was what was said on page 1!

[sprint95m]

Some progress after a setback.

I have found a suitable matrix.

This is for a VW transporter, I don't know which model, I found the matrix by size and only know it's part number.

This is the second choice matrix, the first was Peugeot 605 but alas
these come without any pipework attached, you have to buy that separately.
Normally, this would be a minor problem because there are probably half a dozen places within 15 mins walk
that will have something suitable by way of a solution but I cannot visit any because of the current lockdown.
(I have had to buy a lot of stuff online including paint because of the lockdown restrictions ).

So I took a look on ebay but then casually decided to try for a different matrix which is where I found this VW one.
It took a while to find it's dimensions on Google (the Carcooling UK site doesn't show it),but
as you can see is close in size to the Dolomite one, being roughly the same length and width but 15mm taller.
(It has 19mm hose tails but I am going to stick with my original plan of employing 16mm hoses because that is what the new valve size is.)
Obviously, being plastic, the internal divider between the inlet and outlet can't corrode.
This matrix cost £24 including VAT and delivery.

The striking thing about the VW matrix is how large the diameter of the tubes is, it is almost like comparing rone pipes to garden hose.
They pipes have what resembles an arcamedes screw inside (obviously to ensure the coolant is circulated onto the wall of the tube)

Out of interest I tried comparing the capacities
the Dolomite holds so little it didn't actually reach the first mark on my measuring jug (100ml), whereas
the VW matrix is fully 350ml,
or to put it another way, less than three club nips compared to a 1/2 bottle .


Next I will have to clean up the heater box (which is in quite a state),
then decide where to put the heater valve?


thanks,
Ian.

[sprint95m]

Have got the VW heater matrix installed to see if it will work.
The existing heater controls function as before, albeit employing a Bowden cable to operate the heater valve.
Once I install it I will bore new holes for the pipes through the bulkhead.


Hopefully I can get the Sprint on the road this year and then see how it does.


thanks
Ian



PS
As an aside,
now that I know how heater performance is improved I am wondering if it is possible to fit
a smaller heater than the VW one, entirely within the Dolomite heater box, yet still improve on a Dolomite one and,
also have no modifications to the heater box and for the pipes exit through the existing bulkhead holes?
There are quite a few possible candidates, eg
https://www.ebay.co.uk/itm/FORD-FIESTA- ... SwPkheEyHv
but most seen to be for small cars so this may be an idea not worth pursuing?

Using Google I can find easily the ratings for heat output from universal car heaters but none of the car manufacturers ones.

[RichardHyde]

Ian, did you fit and test your VW heater ?
Thanks, Richard

[naskeet]

Hi Ian, when i had a minor 1000 the heater was bad, so upgraded it to an Austin Metro matrix.... Warm as toast after that, even with the single speed blower Bit of a squeeze getting it in though.

Tony.

During my early-childhood in the late-1950s & early-1960s, when we lived in Dundee, Scotland (not to be confused with Dundee, South Africa, where it's relatively warm!), my father's then Morris 8 Series E, didn't have any heating, demisting or defrosting system at all. It was quite chilly travelling the 420 miles from Dundee to London during the Chrismas holidays to visit my grandparents. Oh for the luxury of a Triumph Toledo 1300 "HL Special" heating, demisting & defrosting system.

[naskeet]

Hi Ian, I think the basic problem here is the use of EWC as the coolant.
Just to recap on what I wrote for the mag some time ago I deduced EWC was based on Propylene Glycol.
When used as a vehicle coolant its physical properties have 3 problems.

1. The specific heat is much lower than that of water.
Water = 4.18 J / g / K.
EWC = 2.51 J / g / K.
So for a given heat input EWC will run hotter.

2. The Thermal Conductivity is much lower.
Water = 0.606 W / m.K
EWC = 0.206 W / m.K

3. The viscosity is a lot higher than water.
Water = 0.5 Cp at 60 Deg C.
EWC = 8.4 Cp at 60 Deg C.
So to give a specified flow rate the pump pressure must be higher.
Or given a specific pump pressure, the flow rate is lower.

So, all other things being equal the engine will always run hotter with EWC.
And the heater will run cooler.

( The big advantages of the non-pressurisation , and non-corrosive properties are why I use it though. ).

So I did some maths around the heater matrix. See .pdf.

There are a number of assumptions but from Case 1 with an assumed flow rate of 100 gms /sec = 100cc sec or ~ 6L min and a heater inlet temp of 80 deg C and an outlet at room temp of 20 deg C the matrix is dissipating 25,080 Joules.

Case 2 is where the water is swapped for EWC and I assume the same inlet and outlet temps; and flow rate . So best case you will only liberate 15,060 Joules. BUT… EWC is more viscous so flow rate will be lower, and the thermal conductivity is lower which I haven't accounted for in this simple calc; But the inlet temp will be higher. Even so much less heat output.

Case 3 . Attempts to answer the question . How hot must the engine be with the same flow rate, and the same temp; drop to give the same heat output.
This comes out at nearly 120 Deg C. Far too hot for a slant 4.

So what are the solutions …

1. Let the engine temp rise. In Summer mine runs at 90 deg C

2. Yes, increase the matrix size.

3. Increase the flow rate, perhaps by use of the Davis-Craig mini motor-bike electric water pump controlled by the heater motor switch. Which is what I have on CWL.

HTH,
Tony.

I am not sure what EWC is, as it is not defined earlier in this topic thread, but I suspect that it might stand for "Evans Waterless Coolant"!?! So far as I am aware, the only advantage of using Propylene Glycol (or propane-1,2-diol, to give its proper IUPAC name) rather than Ethylene Glycol, is its low toxicity, but otherwise I know of no other advantages of using it as a heat-transfer fluid.

IUPAC = International Union of Pure and Applied Chemistry

In the case of NON-steady-state heat transfer, such as would be experienced in a heat exchanger, thermal diffusivity (a combination of thermal conductivity, divided by density & specific heat capacity) is the relevant parameter rather than thermal conductivity alone.

https://en.wikipedia.org/wiki/Thermal_diffusivity

What particularly influences the heat-transfer rate to the liquid-coolant, is the heat-transfer coefficient h [W/(m²K)], which varies with the degree of turbulence and the thickness of the fluid boundary layer.

https://www.engineeringtoolbox.com/heat ... %20rows%20

[Carledo]

I'd never considered the Dolomite heater inadequate, till I went on the RBRR in Mahesh's Sprint in 2018.

Steve, I have learned some more about the causes of poor heater performance
and more particularly why it can vary from car to car. (This is from people who repair heaters.)

The causes being clogging and internal corrosion.

Inevitably the silt from the engine will gather in the heater matrix.
This will set like concrete in time and the useable volume within the matrix is reduced.....
and no amount of back flushing will shift it.
Another problem is corrosion of the divider plate, once it becomes holed, coolant will pass from inlet
to outlet without going through the matrix at all. As the hole enlarges less coolant goes through the matrix....

Ian.

You may well be correct Ian, there does seem to be wide variation in Dolomite heater performance. I remember also, my days of running MkII Ford Zodiacs which had the heater matrix mouted higher than the radiator cap. These were a swine to keep working and had a pretty poor output for what was, in it's day, a luxury car. I took to keeping a spare assembly which was easy to change (4 easily accessible bolts and 2 hoses and job done) as turning it off for the summer meant the matrix was silted up when autumn rolled round and you needed it again.

Now I have the Dolomega on the road, I've been mightily impressed by the performance of it's heater. It only has the ordinary Sprint matrix and heater box, which I hosed through but otherwise took no special measures with. But the engine runs 16mm heater hoses that i've had to step down to 1/2", which, I think, helps a bit by putting the hot water through faster. It also had the moral equivalent of an H pipe which was too bulky to include so I fitted an early Sprint's short H pipe as part of the deal. This was a new stainless one from Chris Witor so obviously not corroded out. But finally and I think this may be the clincher, the engine in standard trim runs a 92 degree thermostat, which I have retained, so the water in the system probably averages around 10 degrees C warmer than most Sprints will attain in normal running. It's hot enough that I need to turn the heater DOWN within 5 miles of setting off on a cold morning. The only other 70s car heater i've ever met that performed this well, was in a Volvo 240! Whether this will translate into warmer rear footwells is still a bit of an unknown since I didn't get on the RBRR due to last minute family issues. but the signs are good, if I can get the front footwells too hot (rather than the normal "tolerably warm") in that short a timeframe, it's got to warm the whole interior better.

Steve