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Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Radiator
Posted by: Dave Underhill
Date: July 01, 2019 07:51AM

I have a 72 GT with a 2.8 5 speed out of a 83 Firebird.
Would a new MGB rad be enough to cool it properly? I have an older rad in there now and it doesn't seem to be enough.


ex-tyke
Graham Creswick
Chatham, Ontario, Canada
(1083 posts)

Registered:
10/25/2007 11:17AM

Main British Car:
1976 MGB Ford 302

authors avatar
Re: Radiator
Posted by: ex-tyke
Date: July 01, 2019 09:23AM

The older MG rads up to '76 were tube and fin construction - not very good from a heat transfer perspective.
Later RB rads from 1977 had a more modern serpentine construction. I would recommend a later rad with a suitable shrouded puller type fan. Don't be afraid to move the rad about 6" forward to the RB location.


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 02, 2019 07:19AM

Thanks Graham, I'm just an hour or so up the road from you. In the Aylmer area south east of London.


MGBV8
Carl Floyd
Kingsport, TN
(3780 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB, Buick 215

authors avatar
Re: Radiator
Posted by: MGBV8
Date: July 02, 2019 08:44AM

A number of 3.4L V6 swaps have utilized the late stock radiator. I use a repop GT V8 radiator on my Buick 215.


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 02, 2019 12:00PM

Thanks Carl, I will give that a try.


jjohanski
James Johanski

(35 posts)

Registered:
11/15/2017 08:57AM

Main British Car:


Re: Radiator
Posted by: jjohanski
Date: July 16, 2019 07:40AM

I have a both an aluminum V8 rad of Chinese origin and a V8 brass repop and both work fine. I also have an expensive English made aluminum repop which is superior to both of these (superbly made and welded) which works even better but at twice the cost. Both of the first two are available from me. PM with any interest.


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 17, 2019 07:32AM

Thanks Johan, I ordered and received a Chinese 3 row aluminum rad. Put it in yesterday and took it for a drive last night.
It runs noticeably cooler at road speed but still gets pretty warm in town. It's a crossflow rad.



rficalora
Rob Ficalora
Willis, TX
(2632 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: Radiator
Posted by: rficalora
Date: July 17, 2019 01:47PM

If it's cooling sufficiently at road speeds but not in town or when idling, you probably have an air flow issue now. What fan are you running? Is the radiator shrouded?

Note, other issues can cause overheating too...
* Air in the cooling system
* Running lean
* Retarded timing


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 18, 2019 06:10AM

I have a 10 inch pusher fan on the front of the rad. No room on the back for a fan and a shroud. Could go to a bigger fan.
Timing is advanced form what the manual calls for. It's not pinging so I might try and advance it more. Don't know how I can richen it, it was running lean but not as much since I made a cold air intake for it.


rficalora
Rob Ficalora
Willis, TX
(2632 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: Radiator
Posted by: rficalora
Date: July 18, 2019 09:40AM

Can't say for sure, but the fan is probably a bit small.

Lean/rich - I'm guessing you have a carburetor. Should be able to change jets in the carb. Google/read up on how to tune your carb or have it done.

No room for puller fan/shrouding - you're effectively using the 10" diameter portion of the radiator for cooling when moving slow or stopped. Can you move the radiator forward? Or, post a picture of the engine bay so we can see what you're dealing with?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5820 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Radiator
Posted by: BlownMGB-V8
Date: July 19, 2019 10:00AM

Moving the radiator forward and using a puller fan would be a good first step. Volvo fans are quite good, readily available, have a very good relay, and are about the largest diameter you can fit. They also may come with a shroud that can be cut down to fit. Their dual temp sensor is available in the right ratings as well and does a good job. It's either a 16 or 18mm thread, taps that size are available for around $20 or so.

Jim


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 19, 2019 05:42PM

image.jpeg
image.jpeg
Here are a couple pics . I have room for a larger fan. The most I could move the rad forward would be 2".
Still not enough room for a fan and shroud on the back side.
I would have room for a 14" fan on the front.



Edited 1 time(s). Last edit at 07/19/2019 06:34PM by Dave Underhill.


ex-tyke
Graham Creswick
Chatham, Ontario, Canada
(1083 posts)

Registered:
10/25/2007 11:17AM

Main British Car:
1976 MGB Ford 302

authors avatar
Re: Radiator
Posted by: ex-tyke
Date: July 19, 2019 09:14PM

Quote:
The most I could move the rad forward would be 2"
The difference in factory rad position between your '72 and a '77 - '80 'RB is about 6" forward. Are you sure that 2" is all you can get?
Water pump mounted fan not an option?
Temps rising when idling,as Rob has pointed out, are typically due to low airflow and/or no recirc protection. Your front mounted pusher is contributing to a grossly underperforming rad - your rad is capable- just need to maximize its potential.
Feel free to stop by Chatham any time and we can go over a cooling diagnosis and strategy.


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 19, 2019 09:22PM

If I cut out anymore forward I will be cutting out a reincorcement piece. Might not matter though.


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 19, 2019 10:38PM

I might make a trip down Graham. Your about two hours from me.



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5820 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Radiator
Posted by: BlownMGB-V8
Date: July 20, 2019 01:43PM

That piece you are referring to doesn't add much and is almost routinely removed. The stiffness of the front crossmember far outweighs it. On my car and the Roadmaster we not only removed that and the panel it is attached to, we cut off the frame stubs and welded in 2" x 1/16" wall square tubing that follows the taper to the outer edge of the grille opening, allowing us to install a 32" wide crossflow radiator, all with no ill effects. We modified the bumper brackets to match.

You don't have to worry about it. If you are concerned, a lower radiator guard can be built which adds back some at least of that stiffness plus protects the bottom of the radiator. I'm a big fan of those, but recommend you not build it heavier than it needs to be to protect the radiator. It can also be incorporated into the air dam (spoiler). With those changes the radiator can be moved all the way out to the grille and even tilted, giving you plenty of room for a puller type fan.

Jim


Dave Underhill
Dave Underhill

(11 posts)

Registered:
09/05/2017 07:30AM

Main British Car:
1972 MGB GT 2.8 Chevy

Re: Radiator
Posted by: Dave Underhill
Date: July 21, 2019 08:36AM

Thanks Jim, I will have to decide how much work I want to go to.


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