Improving a car heater.....

[Sprint95m]

Has anyone tried improving the output from their car heater?
Is it viable?

 

I have a Dolomite Sprint (stripped to just a shell) and would like to have a better heater.

A bit of history....
Three decades ago I went from a T2500S to a Dolomite Sprint
and soon noticed that the heater output was much poorer.
After first trying flushing out the heater matrix ( a lot of sludge did appear)
I went on and fitted another heater from a 1500HL, this was okay for clearing the front screen
so I just put up with it.
In 2007 I acquired an early 1850 which had a dreadful heater. Flushing it made no different but
I reeted at it and adjusted the controls to effect some small improvement, 
but still wasn't happy so I looked at other options.....

Just like a 2500S, TR7s have their heater supply from the cylinder head so
I bought a TR7 transfer housing only to discover it won't fit an early 1850 (but will fit the later 1850HL).

However, being an early 1850, my car had a blanking plug in the transfer housing
so I bought a suitable hose tail and very very carefully fitted it. Bingo,
a much better heater but alas heater performance fell away when it was needed most.
A strange quirk of Dolomites is that they run at 1/2 on the temp gauge during summer and 1/4 in winter.
Next I fitted in place of the 82 version, an 88 degree thermostat which gave a running temp at 1/2 all year
and a heater that produced heat! (An early 1850 should have an 88 thermostat anyway.)

 

Which brings me round to today.
The heater is goosed on my Sprint so I am going to have to do something about it.
A secondhand replacement is the easy option but I am wondering if I can sort and improve the knackered one?
To this end I have been looking online for a .replacement heater matrix.

The Sprint matrix is 270x130x50 with 1/2" bore connections.
Interestingly I found that a lot of current cars actually have a smaller and narrower matrix but 16mm connections
so I am thinking flowrate is the key?
I have managed to find one to try from a Peugeot 605 which is bigger than the Dolomite matrix and has 16mm connections
(I am assuming it has bigger matrix tubes too?).

What I would like to do as well is run ducting to the back footwells.
I am going to enlarge the aperture in the plastic windscreen duct.
Preferably I will keep the existing controls.

 

 Any thoughts please?

 

thanks,

Ian

 

PS I will be using a Stewart EMP coolant pump which produces a flowrate many times greater than a standard Sprint pump.
 

 

[Nick Jones]

Don't remember having issues with the heaters in my 1850 or Sprint.  The 1850 certainly got used extensively through a winter, the Sprint, not so much.

The Vitesse heater (Smiths) was always shite.  Damn-all blow (likened to the dying breaths of a very old lady) and not much heat either.  The Delaney Galley (sp?) one in my Herald was excellent though.

The blow problem was "solved" with a Golf Mk2 blower motor (it's only moderately pathetic now) but the heat problem persisted through flushing, heater valve replacement, various plumbing changes and even removing the non-feed end to rod it out (was actually pretty clear anyway).  Only later when I took the other end off to change the orientation of the stubs I realised the problem was that there is supposed to be an internal partition to make water flow through the matrix - and it was gone - so the flow largely bypassed it.  It does produce heat now but it's still moderately crap overall.

Might be worth poking around on here

https://www.t7design.co.uk/products/heating/ducted-heaters.html

[Escadrille Ecosse]

Ian. Similar problem with my Scimitar SE6a when I got it. No blow and no heat. Cleaning out the matrix helped a bit but not much.

Blow issue was addressed by replacing the blowers. There are two on the SE6 which makes is a bit bloody expensive. However that made things significantly louder and a somewhat more blowy. Adequate at least.

Next was sorting the various air leaks on the cold inlet side and around the air vents and this made a big difference to heat. if only by getting rid of the cold draughts.

Finally I decided to replace the matrix. An in doing so discovered what was the main issue with the Scimitar. Older cars like the Spitfire, Vitesse control heat by adjusting the amount of hot water coming into the matrix. Nowadays heaters are air-mix type. Hot water always flows through the matrix and the temperature is controlled by varying how much cold air goes over the matrix and how much just bypasses it. On the Scimitar all the internal seals had perished so the air just took the easiest route and what little actually went to the hot side largely went round the sides of the matrix.

Sorting that was a vast improvement!

If the Dolly has an air mix heater then maybe worth looking there.

 

[Sprint95m]

Thanks guys.

Nick, I think the Dolomite's heater blower is adequate but as this is housed remotely under the bonnet 
I can always change it after the car is reassembled.
That is an interesting website. Ideally, I wish to retain the original appearance of the heater on the dash 
but if necessary will change it.
I well mind the little 12V heater blowers (hair dryers I called them) that were dash mounted for demisting the front screen.
The Dolomite Club sells remade front screens but won't commission a version with a heater element, sadly.
(You can get heated screens for a Morris Minor nowadays!!!)

Escadrille, the Dolomite heater is the coolant flow type. 
It is funny that you mentioned the Scimitar, given that the SE5a used a Dolomite heater assembly but with a bigger matrix
(270x140x58mm as opposed to 270x130x50). I did find a price for having one made, £114+VAT & delivery and that is without the inline valve.
The Peugeot one is £33 delivered.  In addition an inline valve, operating cable and assorted plumbing will likely cost in the region of £50 I expect.

I am looking at this just now because the car is stripped completely, so if I have make holes in the bulkhead to reroute plumbing and or fit fit cabling,
now is the time to do it!
When I get the Sprint on the road (hopefully this year, but who knows how long lockdown will last?) I won't know how my heater compares
directly to a standard Sprint heater because I am also changing other things that influence heater performance, namely the coolant pump, thermostat
and heater supply.

 

thanks,
Ian.

[Mark]

I had to narrow a Smiths heater box and matrix on my Vitesse to allow room to move the engine back. I cut off two rows from the matrix. The two end tanks where half filled with crud as hard a cement which needed to be chiseled out. I don't think any amount of flushing would have removed it. I assume most old vehicles will have a similar build up, so think the only option would be to find a NOS matrix or a modified modern alternative.

Despite now having slightly less volume my heater is hotter than before  but nothing like a modern car.

[Escadrille Ecosse]

Good luck Ian. Now is the time to do that job.

I remember having to deal with the leaking heater in my Hillman Avenger. 1974 car disintegrating by the time I got it in 1979. Dreadful job. A friend commented that they way they built cars in those days was to start by hanging the heater unit from a bit of rope and then assembling the entire car around it. Not far off.

I have always found the heater in Spitfires to be excellent unlike a lot of other Triumphs and other makes of similar vintage. Very much better than the wife's 8 year old Ford Fiesta for sure.

[Sprint95m]

Take one has not really worked out.
I bought a new Peugeot 605 matrix for a little over £30,
but pipes for through the bulkhead are not included and they are "sir you should sit down" money
(they are included with other older Peugeots).

I thought about trying to make suitable push in pipes but then decided to look again at matrix options
and found (on ebay) a VW one that I hadn't seen before, which looks suitable so have went for it.
Probably arrive next week.

 

The local motor factors and breakers being closed by the restrictions in place to combat covid-19 is a pain.
Understandable and in fact something I support, but still a pain nonetheless.

 

Ian.

 

[Nick Jones]

30 minutes ago, Sprint95m said:

they are "sir you should sit down" money

 That made me laugh.  Your phrasing that is, not the unreasonable expense.  What do the holes in the matrix look like?

Anything like this random photo (205 heater I think)

[Sprint95m]

Yeah just like that 205 arrangement Nick.

However on a 605  the pipes are joined to the retaining plate and
the whole lot is held in place by only one screw.

My experience (admittedly rather limited experience) of French cars makes me wary of chopping and changing parts
from one model to another because there doesn't seem to be much interchangeability.
When my brother had a Renault 19 I was advised by the storeman at the local dealership to, if possible,
take the old part(s) along to do a comparison before buying.
For some reason this R19 had R21 Savannah back brakes, as in backplates, springs, shoes everything!
I still have parts that were supposed to fit that car but didn't.

 

Ian.

[Sprint95m]

Today the Royal Mail delivered the VW heater matrix.

It has overall dimensions a bit bigger than the Dolomite one but the tubes are huge by comparison
and each has fitted inside what looks like an Arcamedes screw,
(obviously to ensure the coolant flows against the surface of each tube).

Out of interest I thought I would measure their capacities,
well the Sprint matrix held so little that it didn't reach the first mark on my measuring jug (100 ml)
whereas the VW one is over 350ml I think.
If I can find a suitable measuring cylinder I will try this again to get  more accurate measurements.

 

 

Ian.