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Swapping my 78 radiator for a 68 version

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magnum Silver Member Daryl Wade
Athens, Ontario, Canada   CAN
One of my biggest and expensive issues I have with the 78 Bee is the radiator and thermostat housing.(cracked the head from overheating when the coolant level wasn't properly filled)

I really think the design is poor in that it was made to accommodate larger engines by moving the radiator support forward.

I have a 68 donor car and was wondering if anyone retrofitted the older radiator support bracket closer to the engine to allow use of the older style radiator (and much easier to service IMHO) with the cap on the top?

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Peter-Sherman Avatar
Peter-Sherman Peter Sherman
Melbourne, Australia   AUS
The earlier radiator has less capacity than the 78. The 78 was the V8 radiator albeit with the hose inlet/outlets swapped around. It would work however, same motor.
Moving your radiator back could be done. But hardly worth the effort as you can see from this photo
You would would need to buy and weld in the captive nut panel parts that the radiator surround attaches to. Big job.

You might prefer to block off the radiator thermo switch hole and fit a screw in switch. Just pick one that is cheap and available that operates at about 92 Celsius. , or use a radiator hose adapter on the bottom hose (87 degree switch for that)
http://www.ebay.com/bhp/radiator-hose-adapter


Attachments:
MGB Radiator 001.JPG    58.2 KB
MGB Radiator 001.JPG

magnum Avatar
magnum Silver Member Daryl Wade
Athens, Ontario, Canada   CAN
Peter:

Much appreciated.

My 78 is running quite well and the temps are all fine, it is just time to renew the antifreeze and I know what a pain it was getting all the air out of the system as it is.

I think I will take your advice and keep the existing set up.

Regards

Daryl Wade
Athens ON
Canada

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Gerry Avatar
Gerry Gold Member Gerry Masterman
Prairieville, Louisiana, USA   USA
I have never had any issues getting the air out the cooling system on my 78B. For me it has always be straight forward and easy. I fill the cold system nearly full through the plug on top of the thermostat housing then thread in a piece of pipe 8" long into the housing. I crank and run the engine until it reaches normal operating temp, top off the the level while the air burps out into the pipe. When there is no more burping, I shut the engine down, let it cool then remove the pipe and install the plug.

mgv8glen Avatar
mgv8glen Glenn Towery
Dover, Delaware, USA   USA
For years, with my GT V8 I used the 77-80 MGB 4 cyl. rad. with the tubes going to & from the rad. changed for the Rover V8 & I had no fill plug??? I took the top rad. hose off at the thermostat & filled the cooling system from the hose, clamped the back in place, fill the overflow tank & squeeze the top hose till I got no air out into the overflow tank, put the rad. pressure cap on & go. I have seen the early 62-67 rad. put in place of the 77-80 rad. with a man. switch to turn the electric fans on. The rad. cap might hit the hood with the 68-76 rad. with the holes in the newer rad. support, but drilling new holes in the rad. plate will fix that.

geezer Avatar
geezer Silver Member charles durning
Magee, Mississippi, USA   USA
1958 MG Magnette ZB "Chick Magnette"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
I just drill a 1/8" hole into the thermostat flange. That will burp out the air while filling. Just be patient.



Give an Englishman a car and he'll make it leak

barry s Avatar
barry s Silver Member Barry Stoll
Alexandria, VA, USA   USA
1972 MG MGB GT
1974 MG MGB
1976 Triumph TR6
1980 MG MGB
If a hole is drilled into the thermostat cover, coolant will escape under pressure. If the thermostat cover is OE for an RBB it will have a screw in plug. OE was stock, subject to stripping. Brass replacement is available.

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geezer Avatar
geezer Silver Member charles durning
Magee, Mississippi, USA   USA
1958 MG Magnette ZB "Chick Magnette"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
I wouldn't drill into the thermostat cover (water outlet), no need to. Taking out the brass fill plug would suffice.

The 1/8" hole is drilled into the thermostat flange.



Give an Englishman a car and he'll make it leak

lewisrn Avatar
lewisrn Gold Member Bob L
Danville, Indiana, USA   USA
1980 MG MGB "The "B"
In reply to # 3494857 by mgv8glen I took the top rad. hose off at the thermostat & filled the cooling system from the hose, clamped the back in place, fill the overflow tank & squeeze the top hose till I got no air out into the overflow tank, put the rad. pressure cap on & go.

X2. I've done it many times without issue. Pretty quick and easy after you get the hang of it.



"Trying to get through to some people is like listening to the smell of the color nine."
Herb & Jamaal

It's how you react that matters. There's not a pill for maturity.

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barry s Avatar
barry s Silver Member Barry Stoll
Alexandria, VA, USA   USA
1972 MG MGB GT
1974 MG MGB
1976 Triumph TR6
1980 MG MGB
Charles - If the hole, wherever it is drilled, is to allow air to exit from the cooling system, coolant can escape as well.

geezer Avatar
geezer Silver Member charles durning
Magee, Mississippi, USA   USA
1958 MG Magnette ZB "Chick Magnette"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
No coolant will escape.

In reply to # 3494898 by barry s Charles - If the hole, wherever it is drilled, is to allow air to exit from the cooling system, coolant can escape as well.



Give an Englishman a car and he'll make it leak

geezer Avatar
geezer Silver Member charles durning
Magee, Mississippi, USA   USA
1958 MG Magnette ZB "Chick Magnette"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
I you don't want to drill a hole get a thermostat with a jiggle pin in the flange. That will do the same thing.



Give an Englishman a car and he'll make it leak


Attachments:
therm 1.jpg    24.9 KB
therm 1.jpg

barry s Avatar
barry s Silver Member Barry Stoll
Alexandria, VA, USA   USA
1972 MG MGB GT
1974 MG MGB
1976 Triumph TR6
1980 MG MGB
Charles - I now understand that you mean to drill a small bypass hole into the actual thermostat flange. I was thinking of the cover.

Gerry Avatar
Gerry Gold Member Gerry Masterman
Prairieville, Louisiana, USA   USA
If my memory is correct there is already a bypass cast in the head to allow some flow to bypass the thermostat. I'd have to check my spare head to be sure but seems like it is on the drivers side of the thermostat opening

geezer Avatar
geezer Silver Member charles durning
Magee, Mississippi, USA   USA
1958 MG Magnette ZB "Chick Magnette"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT
The bypass cast into the head recirculates the water back into the block. It does not bypass the therm.



Give an Englishman a car and he'll make it leak

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