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MG MGB Technical - HEATER

Just a thought as anybody tired or fitted the 4 kw heater mattrix in to there mgb I would be instrested in the results and O and at what cost many thanks Paul
Paul Midgley

What 4 kW heater matrix is that? Where have you seen it advertised?

Mike
Mike Howlett

The 4.5 kw heater is sold by moss
Its a direct replacment for the original i think
Shall be fitting 1 myself after the cars respray is finished
David

oops
should have said its 105 quid and has a 2 stage fan
David

An electric heater? And lose the extra cooling capacity needed on sunny days? Not likely :o)

The B heater is pitiful though... surely someone, somewhere has a drop-in replacement (water-based) matrix and fan that actually pumps vast quantities of hot air into the car.

ttfn,
--
Olly
Oliver Stephenson

If your system is clean, there is no problem mine gives plenty of heat if I want it.

Clive
Clive Skelhorn

Mine is clean for sure, but is still nothing when compared to modern cars (which should have no advantage, our old engines have just as much heat rejection as new ones...). Perhaps I need a Bob Munchausen valve...

ttfn,
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Olly
Oliver Stephenson

the 4.5 kw is water based
David

Here is a start:

Heater cores: aftermarket larger units that allow for extra heating capacity. Sold by one of the vendors here or over there, not sure..
OR
Blow through the stock unit and clean the 20 to 40 years worth of sludge buildup out with hot water and compressed air or radiator flush the whole system.

Heater valves: All the replacement units around do not open all the way. Check the archieves, you will probably find the fix for this. Basically, you are only recieving about 60% of the total flow you should.

Thermostat: make sure your is the correct unit for the weather we are in. These are EASY to remove and replace compared to ANY modern car. Place a 180 degree unit in there for late season drivning

Wear driving gloves and a tweed hat: Doesn't everyone over there do that anyways?
I am joking! Take that as such.

Hoses: Make sure they are in good condition, no kinks, bends, cracks, soft spots or fittings to slow down water flow. (radiator flush Tees are a source of water slow down- minor, but still there)

Blower motor fans: Thes usually do not run as fast as modern replacements, but should run faster then what yours is probably running. Cures- rebuild/replace fan motor or replace w/ modern unit.
Add a relay, this will increase voltage going through to it, best to do on the high setting since the lower settings are slowed down anyways. Check grounds and all fittings as these can be corroded and lead to a lessoned fan speed.

Scwirl cage: Clean the dust off this and make sure its straight.

Ducts and air passageways: CLEAN THESE UP, then reseal the bottom of the heater box, and all other sealing surfaces. You are probably not getting full heat due to leakage in and out. Also, remove the heater core and blow out the outside of the fins with compressed air or water- again, probably pulled.

On some cars with air ducts like the MG A, midget and a number of others, I highly reccomend making sure these ductworks are in place because it triples the strength of the air moving through the system.

Make sure automobile is at correct operating tempurature, pre warm the motor as this will promote motor longevity and warmer driver/ passenger. A little money spent in petrol (even at Euro-prices) is alot cheaper then rebuilding a motor in the long run.

If you bring your vehicle back to the standards it was built to, you will find it a very nice vehicle to drive and not as much need for improvements. Once you have everything to stock conformation and clean, then proceed with the oversize heater core and fan installed in the original fans location or the relay addition.

-BMC.
BMC Brian McCullough

Brian, great advice for all there.

Beg pardon to Paul and David, I just assumed that something rated in kW would be electric. I'm not quite sure how you would calculate the exact power output of a heat exchanger, as it will vary depending on the temperature of the outside air.

I think I'll take my valve apart :o)

Any recommendations on sources for fan motors? I don't fancy the price of the MGOC's 'uprated' one. If there's a scrapheap alternative then I'm up for a bit of forraging.

Cheers,
--
Olly S
Oliver Stephenson

The roadster heater has burnt my feet in the past and the V8 is more than adequate even in freezing weather, but maybe I'm just 'ard. I've checked my air temps against Bob's and get about the same.
Paul Hunt

Original mgb roadsters heater is rated at 1kw i think Oliver
David

I have been using my B here in The Netherlands over this cold but almost snowless winter. I have made several mods to the cooling system which has helped to warm up the engine quicker. First of all change the thermostat to a winter one...about 88F? I have installed an electric cooling fan. I managed to find a cheap one from a Peugeot Van (Five UK pounds from a scrappy) then used a horrible Kenlowe switch!
The other thing I have done to improve the heating was to use the improvements suggested on the following web site.
http://members.aol.com/bobmunch/HTRVlsHT.htm
There is an alternative suggested on this page but you need to change the original one for something nonstandard!
http://hometown.aol.com/akamrmg/index.html
Cecil Kimber

I agree with Brian except on one note: pre-warming the car is not a good idea, unless he's talking about such devices as external tank heaters and other appliances commonly found on cars from the frozen north (and necessary: I spent ten of the longest years of my life in Mn.) Most automotive experts agree that excessive idling is one of the worst things you can do to an engine. It will come to operating temp much more quickly while driving. Warming up the car by prolonged idling causes raw fuel to enter the cylinders, reducing lubrication.
BTW, MGA's could be bought with an optional retactable oil cooler shield for cold weather driving. Would be easy to fabricate one.
R. L Carleen

What would be perfect for quick warming-up is a cable and handle so you could back the timing off 10 degrees on a cold start. Granted, you've got much less power, but the engine reaches full temp much quicker. Obviously by this point you've gotta have the timing back to normal otherwise it'll boil. It wouldn't even be that hard to rig up with our disis... just slacken the clamp bolts and rig up a heater-valve style cable to turn it round.

All modern cars do this, except they don't have nasty distributors to cope with... it's all done in software.

Thank you all for your comments about the standard system. Mine probably isn't the worst out there, but it's not the best either and you've given me some ideas to work with.

ttfn,
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Olly
Oliver Stephenson

R.L.,
I guess I could agree with you that excessive idling could be problematic. Even more so on carbureted motors that are not setup almost perfectly and do allow more fuel on the walls of the Cyl.'s then a fuel injected motor.
Numerous items such as alternators, power steering, air conditioning, automatic transmissions, crankcase bearings and such have a tendency to go out in cold weather, but a slight warm up can allow these items to at least have a chance of survival.
On all standard classic MGs (to at leasst 1980) when they quit sending these cars to the North American market, they had carbon throw out bushings rather then bearings. When trying to start a vehicle with the clutch depressed, you will find in cold weather that the motor does not even turn over fast enough to start and has a terrible time staying runing. My thought is a five minute warm up time... Make sure your fast idle and enrichment mixture is correct for winter driving, allow for plenty of fast idle (not too fast!) so you are not excessivly putting unneeded (expensive) gasoline on the cylinder walls. Yes, R.L., I think on an old MG with carbs, warming up completely may have been an overstatement, but (I think) its not all that bad. Ok, now 'm way off the initial subject. Hope that clears up the idle issue..

R.L. has a great idea of covering the oil cooler. In cold weather, this should always be covered if you do not have the thermostat placed in the oil cooler system. Here in MN, we cover the radiators on our cars.. Depends on the size of the system, the general outside temp and so on, but about 40% covered in an MG in 0 degree Celcius weather probably wouldn't hurt, though it will not fix your origianl problem and you will need to keep an eye on the temp gauge.

Hope I have cleared things up a bit.
Good Luck,
-BMC.
BMC Brian McCullough

This thread was discussed between 20/02/2003 and 23/02/2003

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