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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Lousy ineffecient heater !

Last winter I installed an old Bosch heater in my TF It is round, has two doors, it is the same type that was installed by german MG dealers. I had the core cleansed and pressure tested before installing it. Hot water comes from the outlet on the LH side just above the thermostat, and is fed back into the Y pipe.

The heater has been a huge disappointment. It does deliver lukewarm air, but only after 15-20 miles driving. In cold weather, when I need the heat, the lukewarm air is more like chilly, so that it is better to turn the heater off. I Believe I have managed to remove trapped air from the heater by having done something like 2.000 miles this summer, with the water circulating through the heater

Has any one else had a similar experience? Or is this the way heaters used to not) work in the fifties?

regards,

Jan
Jan Kristoffersen

...although not 'hot'... i get enough heat to keep the 'chill' off in cold weather... I can put my hand a few inches away to warm it up. Again...it doesn't heat up the interior by any means, but does take the chill off on 'cool' nights...

I have the same connections....pick up water at the thermostat ... put it through the heater and empty into the lower rad hose pipe....

The nice thing is it takes the water before the thermostat so it warms up fairly quickly....
gblawson(gordon- TD27667)

Jan, You say the hot water comes from the left side ABOVE the thermostat! It should come from under the thermostat. Here's a photo of my 1500 with the heater port and temp gage port. PJ




Paul sr

Check the temperature of the plumbing as it goes from the engine to the heater core. You can use your hand (be careful) or better one of the IR point/shoot thermometers. Start at the housing, and move toward the heater. I would think it should be about 180 degrees or so with the engine hot, and just a little temp. drop. The water exiting the core should be a little cooler. This will tell you if there is adequate circulation, etc. If it is coming off from above the thermostat like Paul pointed out, you may have very little flow, as the thermostat may just be cracked open on a really cold day. George
George Butz

Jan,
I have a round Smiths heater in My TD and after installing it, it was necessary to make a positive bleed of the air in the heater to get proper circulation.

Take the hose that goes to the Rad return water hose off - run the engine from cold with your finger over the return port to prevent water/antifreeze being lost out of the lower connection and let the hose from the heater dispense into a large plastic bottle/bowl. It will help to have someone refilling the rad header tank until a good flow of water is coming out of the heater hose. it won't take long to get this if it is only an air lock stopping the flow.

IF you don't get any flow to speak of after a few mins, - look to the input hose and see if you are getting good flow there.

If the rad was cleaned and tested there should be no problem but you never, know sh*t happens :) With good flow in and nothing out - I'd look there next.

Hope this helps It sure solved my heater issue. Thing runs toasty warm and up here in New England, you need a heater in winter. Sometimes summer as well :)

Rod
R D Jones

You might start by installing a hotter thermostat. You could try and heat the system up by placing a piece of cardboard in front of the grill. I did that to the TD last winter instead of changing the thermostat. The Arnolt heater in my TF keeps the frost off my right foot. The modern Mojave heater in the TD will keep the entire cabin quite toasty even at sub zero (Farenhite) temps.
L E D LaVerne

Thank you for quick responses! I got it a bit wrong, the water outlet is of course below the thermostat, as in Pauls photo. What I did to get out air bubbles from the heater when installing was to hold the hoses ( I use hoses, not pipes) high while filling from one side, the lowering the other end until I had a seemingly free flow. But it is probably worth trying to bleed at the heater itself by the power og the running engine/water pump. I have a fresh thermostat in the car and a digital temp probe in the rad hose just over the thermostat confirming that it opens up at 73 degrees Celcius.

On my shelf I have a six vane water pump bought from "The frame up". Is it worth the effort to swap the water pump for better flow??

The amount of experienced advice one has access to on this BBS is amazing. The downside unfortunately seems to be that both some members and even their offspring inevitably will pass away, as we have witnessed on the BBS this week. My condolences goes to you who have been bereaved of your loved ones or friends.

regards,

Jan
Jan Kristoffersen

Jan,

I would think that "better flow" would result in cooler temperatures, not warmer.

Gene
Gene Gillam

Gene,
My concern is that the amount of water circulating through the heater is insufficient, and that a w/pump with higher capapcity would put more water through the heater hoses. But that might of course not be so.

regards,

Jan
Jan Kristoffersen

LaVerne,

Is the Mojave heater really so superior? That might be the answer then?

Jan Kristoffersen

Jan,
I put a Mohave heater in my TD 3 years ago and I love it.
I also take the water off just below the thermostat to the heater and return it to the Y pipe.

It may be overkill but I put a diverter valve in the return line to prevent flow to the heater in the summer. Others accomplish this by other means.

The plumbing you describe sounds fine. If the pump was inadequate you would probably be having engine overheating problems. It sounds like an ineffective heater.
Mort


Mort Resnicoff (50 TD-Mobius)

Jan,

Considering you have a "new" thermostat, you should blank off the bypass via a gasket at the housing, or, as some prefer, restrict it with just a tiny hole in the gasket.

When the thermostat is closed, part of the flow goes right back into the engine via the bypass, when it should be running 100% to the heater.

On the other hand, when it is up to temp and the thermostat is open, the sleeve is supposed to block the bypass. Without the sleeve, some hot coolant short circuits right back into the block, and can contribute to overheating in hot weather.

We have an Arnolt heater, and within about 5 minutes, the heater core is pretty hot to the touch. When fully warmed up at 190F, our core is too hot to hold onto.

HOWEVER, even with the heater blowing hot air, the interior never really gets warm, even with a hardtop and side curtains. Still, it sure is an improvement over the days when I rode motorcycles in cold weather!

JIM
JIM NORTHRUP SR

Over the years I have had several set ups that got air in the system and did not function well. My solution was to install a shut off with a bleeder valve at highest point in system. my old Volvo 164 had a constant battle going on in the summer between air conditioner and heater. This allow me to stop the flow in the summer to the heater core.


David Sheward TF1500 #7427

Jan I think both heaters are making about the same amount of heat at the cores. The difference is the Mojave heater has a squirel cage fan and pushes a lot more air through the core.
L E D LaVerne

Jan, is there any chance that one of your hoses is kinked thereby reducing the amount of coolant flow? Since you had the core cleaned, somehow the flow is restricted. My TD has been modified to take the hot coolant from just below the thermostat like your TF and the cockpit temperature sometimes is too much! I have just a regular water pump but I use copper tubing, not rubber hoses.


Jim Merz

By most automotive standards 73C (about 160F) is not very hot. I would go with a 180F thermostat. I put a 180F thermo in my TD and still barely get 70c on the gauge with sending unit in the radiator tank.
John Quilter (TD8986)

I see that Moss lists three thermostat options for the TF;

74 degrees Celcius summer, 82 degrees standard, 88 degrees winter.

I have sorted my cooing issues with clean cooling system, MGB seven blade fan and an auxiliary 10 inch pusher electric fan in font of the rad that is only used on long steep ascents or in traffic jams.

Would my cooling issues come back if I go for an 88? Perhaps he standard 82 degrees Celcis thermostat is the way to go?

Below is a picture of my Y pipe, which a list member was so kind to pass on to me. By blowing air through the shut off valve did not seem to obstruct flow when fully open, but maybe water behaves differently than a mouthful of air?

regards

Jan


Jan Kristoffersen

88C/190F would work fine all year long, especially if your TF has a pressurized system.

I stuck in what would be 85C/185F in our TD as that was sitting on the self and fit with little modification, and the TDs usually aren't pressurized.

If there's a problem and it is going to overheat, a low temp thermostat won't make any difference.

Before recoring the radiator, ours could hit a steady 110C/230F on a very hot summer day (supercharged boost at 80mph), and a 50/50 water/antifreeze solution boils right there without pressurization! That's with a 6 blade stainless steel fan and the heater trying to help cool it down, too! It didn't really bother me since I am a "steamfitter."
JIM NORTHRUP SR

Jan, you mentioned that you use a hose to feed the hot water from the elbow towards the heater. Just thinking: is that hose leveled low enough so to keep the waterlevel under its radiator level?
The other thing I would check is if the heaters fan can take enough free input of air. Good luck, Huib
Huib Bruijstens

As Rod Jones has suggested, You probably have air in the upper portion of the heater core. If this is true in your case, it will definitely have an effect on flow through the heater and heat transfer. I am curious to know the solution when you find it. PJ
Paul sr

One more thought- as the engine is just warming up, feel the radiator tank and determine if your thermostat is sealing decently or if coolant is leaking past.

My first venture into installing a later model thermostat looked pretty good, an O-ring and snapring, but the rough casting let coolant weep past and it took forever to warm up. It took a just a dab of silicone seal to stop the leakage and the heater gets a good flow and heats quickly.

Report back on your bypass circuit.... how did you deal with blocking that off?
JIM NORTHRUP SR

My TF came with a KL Heater but in the "box of bits". It is certainly original since it is painted the exact metalic sand colour. The tappings for the feed/return pipes are from the Y pipe and from the plate to the rear of the cylinder head. Can someone, though, please post a photo of how the heater fits under the dash. There doesn't appear to be room to mount it with the mesh front vertical. Is it possible this should face downwards? Also where does the rehostat for the fan fit?

Thanks for the anticipated help

Jan T
J Targosz

jan, i have a different heater..a round Smith's unit. different from yours, but i assume close enough in size a weight that this maybe of some help. i mounted to a 3/8" piece of plywood painted black. i then used Adel clamps to hang the plywood from the scuttle support tube. that location with that heater works well as it sit forward of the gearbox dip stick access port and aft of the shift lever. i originally installed a rheostat to an "L" shaped bracket at the bottom of the dash. i later decided that a simple push "on", push "off" single pole switch was all i needed. i removed the rheostat and positioned the on off switch on the back of the instrument panel. it is completely hidden from view. one push on, one push for off. i did use an inline fuse on the hot wire.
i also tap off the back of the head. another poster here on the forum, mr northrup provided coolant temperature readings taken at different locations in the cooling system. the tap off the back of the engine was only 7 degrees cooler than a modified thermostat housing tap. 7 degrees hotter coolant was not sufficient enough difference for me to modify and run a longer line to my heater so i stayed with the rear engine location. i have more than enough heat for my use of the car. as with so many projects there is no one "right way".

regards, tom
tom peterson

This has been overwhelming! So many views and so much support within 24 hours...
My T is a 54 TF 1500. I dont think it has a bypass, but it surely has a pressurized cooling system, 4 psi I believe.

I have decided to work along these lines:

Check for restriction in Y pipe shutoff valve.
Fit a hotter thermostat, carefully siliconized in to position to avoid any bypass when thermostat is closed.
Bleed the heater core after checking that my tubes have no high points (above water level in rad)

If this doesnt work: Order a Mojave heater?

Regards,

Jan
Jan Kristoffersen

Jan,
You posted a picture of your Y pipe with the valve attached.

The bypass is the other branch on the side that has the hose running up just under your thermostat.

Check that the fitting/gasket attached to the thermostat housing blocks off that old water passage, or a large % of your water will take a sortcut right back into the engine, starving your heater. That alone can account for a "lousy inefficient heater!"

Anyone have a shot of the TF thermostat housing? I've only got TDs to go by.

That reminds me that the Arnolt heater was supplied with a fitting, tubes and hoses that replaced the bypass hose, and routed that water to AND from the heater; really easy to install! I'm uploading a photo of the Arnolt parts now, and will subsequently attach an image of the assembly, like it isn't obvious.

As Dave Braun always says- "WARMLY,"

JIM


JIM NORTHRUP SR

Arnolt heater fittings and lines, assembled...


JIM NORTHRUP SR

Those were my thoughts as well Jim. I'm thinking the coolant is taking the easiest path..back to the pump instead of through the heater. My original plumbing was fairly simple. Coming off the bypass ..to the heater and then back to the bypass.


L E D LaVerne

It's still doing the same thing but with a lot more complication with the addition of the blower.


L E D LaVerne

The finished product. It's a real maze but it gets the job done...just don't ask me to change a hose.


L E D LaVerne

The Arnolt fitting is blanked off between the two heater branches with a small hole in between for a small bypass when the heater valve is shut off.

If the heater is getting full pump flow, it should bleed the air out by itself in no time.

LaVerne, adding the blower at your altitude makes your engine "normally aspirated" finally. Sortof reminds me of all the oldtimers tricks to start diesel engines at high altitude.


JIM NORTHRUP SR

Jim, Here's a couple shots of a 55 1500 thermo housing during tear down and Y pipe connection.



Paul sr

another




Paul sr

Another



Paul sr

One more




Paul sr

OK, I now understand what the bypass is, and I can clearly see that it has to restricted somehow. But is it an option to block it completely? Is the bypass really needed?

regards,

Jan
Jan Kristoffersen

Hi Jan,
lots of good advice here, but please remember two differences between heaters then and heaters now.
1 heaters were not all that effective in the 1950s,
2 heaters for Uk climate were never all that effective in Scandinavian climate.
Best regards
Sven
SO Sven

The bypass job is to allow the thermostat to be informed about the actual temperature of the hot engine parts. The water kind of takes the temperature of the engine and the (tiny but ok) flow through the bypass "informs" the thermostat pretty inmeadiatly about this temperature.
Blocking this would imply that the watertemperature in the engine's hottest parts would keep raising and it would take a very long time (heat transfer through a not-flowing tube of water) before it knows and before it can open its door to the big radiator for cooling down. Hope this helps, Huib
Huib Bruijstens

I agree with John and others who've mentioned the low temperature thermostat.

I notice when driving my truck on a cold day that while it's blowing some heat as it passes 160f it's not really hot until it gets to 195f/90c or at the thermostat setting. It actually peaks at 210 and then cools dramatically when the slug of cold water from the radiator runs through, finally settling at 90c.

When I was assembling my TF engine I grabbed the only thermostat I had on the shelf, a 190f/88c. It behaves the same way, getting to 210/99 before opening and settling at 88.

I follow all heater threads as I have one to install. All this information is helpful.
J E Carroll

Is there something I am missing? The water going through the bypass will bee cool, having passed through the radiator, and would contribute to keeping the thermostat closed even when the engine is hot enough too wish the thermostat to be open? Or does the water circulate the other way around? And are we really sure at all of how the water is circulating in the xpag/xpeg cooling system? Or am I just stupid ?

hoping for enlightenment!

Jan
Jan Kristoffersen

Jan, see http://www.ttalk.info/XPAG_Cooling_System.htm for Gene Gillams analysis. Bud
Bud Krueger

Hi Kris,
until the thermostat opens the water does not go near the radiator.It is shunted round the front of the block/cylinder head until up to temperature at which time the stat opens.
There is circulation through the heater before the stat opens. I know this because my heater starts to work even before the temp gauge starts to rise.
I know we do not get the low temperatures you get in Norway but my heater is very efficient as long as I make sure the draughts (drafts?) are cured,
Ray TF 2884
Ray Lee

If you block the bypass, you can drill a small hole in the thermostat so that a little flow of coolant is allowed through. Then the thermostat will be correctly 'informed' about the temperature?
Willem van der Veer

Just for fun, attached is a picture of the fitting instructions of a K-L '54' universal heater to M.G. TD.


Willem van der Veer

and page 2


Willem van der Veer

and 'special hints for cars with thermo siphon cooled engines'

Even if the XPAG has a waterpump the hints are useful.


Willem van der Veer

Jan
Just a thought.....my TF has an old GM seat heater under the dash that works very well. But, after I first got the car it did not. I found that if the water pipe that goes to the lower radiator hose is hanging low (a dependent loop) then the system does not work well. Once I secured that rubber pipe to side wall and kept it elevated, it worked and heated fine. The water pump may not be strong enough to pump through the heater core AND bring the water up at the end of the flow.
Take a look at yours and see if a simple positioning adjustment changes things.

Tom
'54 TF
T Norby

You don't need any by- pass if your heater always has water flow. It circulates through the heater when thermo is closed. My heater didn't work until I blocked the bypass hose and put in a thermostat. I used a 190 o thermo which is a little high for an un- pressurized system. But the heater works great!
Chuck
Listen to LaVern!
cj schmit

This thread has developed into what would now be the best available for heater installation! Thank you everyone for sharing your knowledge.

I had a dream tonight, along the lines of Chucks proposal of blocking the bypass and always let the water flow through the heater. What if one installed a three way shut off valve on the bypass pipe bypass branch, so that water could either be shunted through the bypass or the heater, but never both places at the same time? Does that sound like a feasible way ahead?

regards

Jan



PS: LaVerne; I would suspect that several more TF owner than I are eagerly looking forward to your detailed and illustrated report on installing, tuning and driving with a T Lange supercharger. I really do hope that you will enlighten us on the perils, pitfalls and excitement of TF supercharging!

Question one comes here: Standard tune engine? and milage since last rebuild?



Jan Kristoffersen

Jan the super charger is old news. I rebuilt the engine (1250) basically stock but used the Moss forged crank shaft. I put a couple of thousand miles on it before I added the super charger and have put roughly another 20 thousand miles on it with the super charger over the last three years. I could go on but I'll leave that to another thread.


L E D LaVerne

LaVerne, I really look forward to that thread. Mine is a 1500 and a strong runner, but the thought of some more supercharger getup-and-go is tempting!

regards,

Jan
Jan Kristoffersen

Jan,
A 3 way valve would work.

Tanks to Paul Sr. I see there's no separate elbow attached to the housing, so there's no option for a gasket blocking the bypass. You might slip some slug into the bypass hose to block it, and optionally, drill a hole in it.

I experimented with the thermostat once, removing the loose air bleeder stem instead of drilling a hole, but found there was a significant flow of hot coolant to the radiator while the engine was trying to warm up. Eventually, I fabricated a separate fitting for the temperature gauge bulb and that gets a trickle of coolant constantly, acting as the bypass.

Personally, I feel the internal passages of the block would supply a bit of circulation avoiding hot spots before the thermostat opens; the bypass isn't essential in my opinion. Hot water will rise into the housing quick enough.
JIM NORTHRUP SR

Jan,
If you look at my post above you will see that I have a 3 way valve installed on my system. I call it a diverter valve. I use one position for the winter and the water flows through the heater. It takes water right from the engine so I get the maximum hot water in the shortest time (before the thermostat opens). I use the other position for the summer so that no hot water is circulating in the cab.
Mort
Mort Resnicoff (50 TD-Mobius)

...not sure the location of everyone who has posted...but believe me, you have to have a valve of some sort to shut off the heater in the summer...

I have a plain little on/off gas pipe valve just at the firewall...


gblawson(gordon- TD27667)

See http://www.ttalk.info/LawsonHeater.htm for a bit more on Gordon's installation. Bud
Bud Krueger

This seems like a good time to reactivate a posting of our late colleague, Bob Jeffers, from a couple of years ago. It really should be entitled "Rehabilitated Thermostat Housing". I'll reactivate the thread, but it's best seen at http://www.ttalk.info/JeffersHousing.html Great place to take off for a heater instead of a thermometer. Bud
Bud Krueger

This thread has inspired me to get my refurbished Arnolt out and figure out what I need to do to put it my car. I am missing the bottom mounting bracket. Anyone have one laying around or know where I can find one? It is something I can make pretty easy. If anyone has measurements or a blue print of it that would help. Moss used to stock it as you can see the PN on the pictures I have included. Also I would love to reproduce the original Arnolt decal on the front of my heater. Although I powder coated my heater black and I think it should be tan or bronze, I would like to make it look somewhat original. If anyone has pictures of a Arnolt heater with the decal or mounting hardware I would love to see what you have.

Thanks

The picture of the bronze heater attached has both brackets. I need the bottom bracket. The picture attached with the blck heter is mine sitting in place in my car.
Rich King TD 8732

Rich, see http://www.ttalk.info/Tech/Arnolt.htm At the moment mine is not installed. I could probably get some dimensions for you. Bud
Bud Krueger

Ok will so. For some reason my pictures did not post
Rich King TD 8732

Ben Cordsen restored this one. I'd try him for the decal.


L E D LaVerne

I don't have the measurements but it sounds like Bud can fix you up.


L E D LaVerne

The Arnolt heater can be mounted upside down and the doors can also be installed upside down to match.

With this configuration, I installed it as far forward and as high as possible. Leaves room for our cupholders. Heater keeps the coffee hot, too! (Yes, we have the 12V heated cups too, that plug into our cigaret lighter sockets)


JIM NORTHRUP SR

Here is an ad for the Key Leather (KL) heater from 1954



Chris Couper

Hi Chris,

I am desperate to see a photo' of a KL Heater fitted to a TF. I have a heater but have no idea how it fits into the car. I have asked for photos' a number of time but withour success.

Jan t
J Targosz

Jan. That tiny picture above is either a TD or TF. Cannot tell for sure which one it is.

Either way it looks like you either cut a hole in the underdash or just remove it completely.

I would think you would have to remove the underdash otherwise you are not going to get good circulation.
Chris Couper

Whoops. My mistake. The image in the ad above is for the K-L 360, not the Universal K-L 54. And the picture is of a TF.
Chris Couper

Hi Jan,
this is the heater mounting on mine.
The tape is only to protect the wiring and is hidden when tray is on.
Ray TF 2884


Ray Lee

The mounting brackets are integral with mine


Ray Lee

Return flow to "Y" piece




Ray Lee

Supply flow from thermostat housing, at one point I had it from the rear of the cyl head but I don't feel a great difference. As long as you keep the draughts down it can get quite warm.
Ray


Ray Lee

I forgot to say that the current drain was so high with the original motor that I did a mod.
I fitted a computer 12v cooling fan to the mounting hole of the old fan and blanked off the other holes in the upper case.
I also reversed the flow so that the air now blows down and not up into the scuttle area.
Now I can have headlights, wipers and heater all at the same without killing the battery.
Ray TF2884
Ray Lee

Per another poster..only 7 degrees difference between modified thermostat tap off and rear block tap off. Regards, Tom
tom peterson

Any idea how I can get in touch with Ben Cordsen?
Rich King TD 8732

Google his name. He has a design studio in Fort Collins, Colorado.
L E D LaVerne

Thanks Ray - exactly what I needed. You have confirmed what I suspected - the grille is horizontal.

Jan T
J Targosz

I have been absorbing this thread for some time while, very slowly, fitting a heater to my TD.

I now have a reconditioned Arnolt heater wired and plumbed in and a modified water outlet elbow with a take off that should (according to the thread) give me the hottest water. I have included a bleed valve at the highest point in the system in case air gets trapped.

As with many others, I am not yet getting heat.

I have the normal water pump (not the upgraded one which may help). Before I change the water pump I have decided to try putting an auxiliary water pump into the heater circuit. Following advice from a fellow owner at a show, I bought a VW Golf 12v inline pump and am ready to experiment with this.

I am not sure how best to wire it in. Do I need to use a relay? Where should I take the power from? Should I put an inline fuse in the circuit? Can I wire it into the same on/off switch I use for the heater itself (I didn't bother with a rheostat for reasons set out in the thread).

I think I am almost there, so any guidance would be much appreciated!

John Dennison
J M Dennison

John that's an interesting idea. I would use a relay then you could wire the switch into the switch you use for the heater. I was thinking about this idea and it seems feasible. I'm going to try an idea I talked about in earlier threads - using 5/8 ID plumbing instead of 1/2, which will increase water delivery to the heater by 50%... without adding electrical demand to the system.

if that does not work I'll consider a better pump (either the 6 vane pump or an aux pump like you are considering). Good luck in your project and I definitely think a relay and a fuse area a good idea.
Geoffrey M Baker

Thank you, Geoff. Most helpful.

Finding somewhere to position the Golf pump is not easy. There isn't a lot of empty space under the bonnet (hood). I think it will need to be on the return side. The picture attached shows the feed side almost done other than some braces needed to support the pipe work and keep it well away from the spark plugs.

Regarding your idea, I suspect the problem is not so much the diameter of the plumbing but with the lack of "oomph" in the standard water pump. I imagine that due to the low pressure, hot water coming out of the engine would naturally rise in the pipe work and flow through the almost 2" diameter thermostat housing rather than be diverted through a 90 degree branch off the housing.

I imagine that the more efficient water pump is the best option, and may end up doing thus myself, but of course would be keen to hear how you get on with either option.

John


J M Dennison

Thank you, Geoff. Most helpful.

Finding somewhere to position the Golf pump is not easy. There isn't a lot of empty space under the bonnet (hood). I think it will need to be on the return side. The picture attached shows the feed side almost done other than some braces needed to support the pipe work and keep it well away from the spark plugs.

Regarding your idea, I suspect the problem is not so much the diameter of the plumbing but with the lack of "oomph" in the standard water pump. I imagine that due to the low pressure, hot water coming out of the engine would naturally rise in the pipe work and flow through the almost 2" diameter thermostat housing rather than be diverted through a 90 degree branch off the housing.

I imagine that the more efficient water pump is the best option, and may end up doing this myself, but of course would be keen to hear how you get on with either option.

John


J M Dennison

John, where does your return connect?. If your pump was inefficient then you would overheat the engine. I would suspect the heater or the plumbing is at fault. I have a KL heater which is about the same output as the Arnolt and will cook with the heater on full.I don't know the layout of the Arnolt but the flow must go in the highest point and return from the lower.
Ray TF 2884
Ray Lee

John, I'll bet you can find a wide variety of 12v inline pumps which would work

http://www.ebay.com/itm/Mini-12V-Food-Grade-High-Temperature-100C-Water-Pump-47-5GPH-fr-Beer-Brewing-/121342056478?pt=LH_DefaultDomain_0&hash=item1c408cd81e

The biggest problem I think would be adding more pressure to a low pressure system. It would return it to the radiator at a pressure the radiator might have trouble handling...?

You definitely don't want to much pressure from your pump...
Geoffrey M Baker

Hi Ray

My return goes into the pipe that goes into the bottom of the radiator. I haven't taken the car for a run since fitting the pipe work but I have had it running for a while and the heater pipe work doesn't get more than lukewarm. I don't think water is flowing through it, hence the auxiliary pump. The water pump, by the way was replaced last year with another standard one. At the time I didn't know about the uprated one.

Geoff

The pump you pointed out is certainly a lot smaller and neater looking than the VW I have. I will check it out. Good point about the pressure! Thanks

John
J M Dennison

John,
The heater needs very little circulation, as the heater element gets very hot and the water returns to the engine almost as hot. If your heater element and lines are not getting hot, there's a fundamental problem somewhere.
Such as maybe there's no thermostat?
Some have tapped hot water at the front as you did, but they return it in the back of the head, which is the same pressure as the thermostat housing, thus no curculation.
I see your bleeder is at the top of the fee line, but that doesn't necessarily guarantee the heater core was bled, although, it shouldn't really need it.
Sometimes, bleeding a heating system can be frustrating. I'm a steamfitter, and after adding a new circuit on my hydronic system, the vertical head pressure of water standing on the one side was more than the pressure my simple CIRCULATING pump generates. It could not push the air down through the floor since there was approximately 10' of water holding it back on the other side. Reality check.
You might do like I've had to do in situations like this, take the return hose off the radiator return fitting, put your thumb over the branch so coolant doesn't all leak out, then suck on the hose!
If that doesn't work, stand the car on the back bumper until the air bubbles out!?!
Some are disappointed that their heaters don't make the interior toasty warm, but our cars are drafty, the elements aren't that large and the fans are pretty small. I'm just grateful there's a spot to warm up my hands, and ours has a nice, solid, well sealed figerglass top. The side curtains are a whole different story
JRN JIM

Looks to me like you have the air bleed on the wrong hose (line). The air bleed should be on the high point of the return line from the heater. Just put an Arnolt in my TD & no problem, but you need to bleed the line coming from the heater.

I ise a 180 degree thermostat with a small 1/16 bleed hole... you may find one with the bleed hole and a jiggler in the hole if you look through the books. Bleed hole... bleeds air from cavitation (sp??) from the impeller of the water pump (not really a pump...) when the thermostat is closed (as does the bypass). Standard on most modern cars.
fps111 Sisson

John Dennison, I really like the look of your small bleeder valve. Can you post a closeup of it? I'm wondering where I can find a similar item to install at the high point in my system.


Geoffrey M Baker

Can anybody else recommend a good bleed valve? I want to install one at the high point of my heater pipe system, and want it to be as small as possible. Can I just use something like a compressor bleed valve in 1/8 or 1/4? I want to avoid the "faucet" type of valve if possible. But I don't know if a compressor air fitting would be a good choice in a cooling system...
Here's one possibility...
Geoffrey M Baker

Sorry, here is the picture I wanted to post...


Geoffrey M Baker

There are always the brass radiator-style petcocks with the little winged handle, but I like the little schrader (tire) valve bleed valves you can buy at plumbing and hardware stores with an npt base, for bleeding air out of baseboard heating systems.



kylemorley

This thread was discussed between 13/11/2013 and 04/02/2015

MG TD TF 1500 index

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