Cooling 3.9L V8

[donfaber]

For better summer cooling - is there an alternate water pump or thermostat to consider? Im also considering re-coreing my MGB stock radiator. Things are fine until temp runs above 80 degF

[mgb260]

Don, What fan do you have? 180 thermostat would be good. Have you looked at a 65 Mustang radiator?

[MGBV8]

As Jim suggested, better radiator & better fan.

[donfaber]

Guys - I have what looks like a 12" Corrpeggio (about 10 years old) pulling fan installed on the engine side of the radiator, I don;t know the capacity and am looking for a better one.  Thanks for the tip on the 180 deg thermostat.

[donfaber]

is the 65 Mustang radiator a good fit (close)?

[mgb260]

Don, It is longer and you may have to trim brackets and redrill. The V8 one has both inlet and outlets on passenger side. 6 cylinder has top inlet on passenger side and bottom outlet on driver side. Can't beat the Volvo fan.

https://www.ebay.com/sch/i.html?_from=R40&_nkw=65+mustang+radiator&_sacat=0

https://www.therangerstation.com/tech/volvo-electric-cooling-fan/

[donfaber]

Jim - I need to see your car(s)! My son lives in University Place - we come out 1 or 2 times a year!

[mgb260]

My cars are basket cases. Life keeps getting in the way. Glad to help others though!

[MGBV8]

We certainly appreciate your help over the years.  You are a walking hot rod encyclopedia of gearhead knowledge!

Aren't you planning to retire before long?

[mgb260]

Carl, been retired for 4 years but working on home improvement projects and a few health issues for both the wife and I. Helping the grandson on the MGB restoration and haven't even started on the Sunbeam.

[MGBV8]

Ah, time flies.  I thought you were still working out of town.

After my dad had been retired for awhile, he said that he didn't know how he found time to work.  

[DiDueColpi]

Hey Don,
The engine bay on the B's are tiny and once you get it filled with a big V8, headers, filters, hoses, accessories etc. It becomes really tight.
All that air that comes through the rad has nowhere to exit.
With that in mind , an air dam or spoiler will help to give a low pressure area under the engine compartment. Hood vents will help, but they need to be well forward of the high pressure area in front of the windshield. Wheel well vents help as well. These will also pull heat away from the exhaust making the cockpit more comfortable. You get the idea, port and polish the engine compartment.

Live like you mean it
Fred

[turbodave]

I have a 3/4" thick single row radiator from a 1999 Nissan Maxima in my Rover and never have cooling issues. I am using the stock Nissan fans as well - I find that OEM fans / shrouds are almost always superior to anything else available.
That said - I agree that it's all about airflow thru the radiator, especially in a B

If you want the best cooling system, take a look at the CWA200 brushless electric pump, using the TinyCWA PWM controller from Tecomotive. This is a brilliant setup that uses an automotive OEM pump, and the controller will control the motor to achieve the desired operating temp. It also has settings such as fan output, and a "cool down" to slowly circulate the coolant an turn the fan on/off as needed to avoid heat soak.

[donfaber]

Lots of good info - thanks!

[MGBV8]

Another option for removing heat from the engine compartment if not using fenderwell exit headers (RV8 style) is the method used by Kurt Schley.  He cut an opening in the fenderwell by the header.

Not a very good pic, but hopefully you can see the wire mesh he used to cover the hole.  Works due to the wheel well being a low pressure area.

[BlownMGB-V8]

I still favor the "use a a bigger radiator" approach and probably always will after seeing how it handles the output of the 455 and the 340. You can easily make the radiator too small but can't make it too big.

The MGB will accommodate a surprisingly large radiator without all that much effort and without compromising the structural integrity of the front of the car and the bumper supports. This is more than can be said for the "notch the frame" approach, something that creates a weak crumple zone at the radiator and can lead to destruction of an otherwise repairable car after the cost of new fenders and pulling the tub straight plus a new radiator is taken into account, damage that might have been avoided with a stronger frame section.

The approach is a simple one. Using 1/16 wall x 2" square tube and telescoping 1-7/8 square tube for the bumper stubs, the frame extension is laid below and along the line of the inner fender flare outwards to the margins of the grille opening, tied into the inner fender with extensions up and down followed by a lower crossbar to tie the two sides together. I find that 1 x 2 rectangular tubing works quite well here, up to 1/8" wall thickness depending on your desire for more or less substantial radiator protection.

This allows the use of up to a 17" x 32" generic (Summit) crossflow radiator and a late Camaro dual 2 speed fan assembly, cost for both around $250. 16x32 would be an easier fit of course. The slam panel may need some modification but making it removable is not difficult. I've had replacements made in polished stainless bent by the local sheet metal shop based on a bent wire pattern that I provided and been quite pleased with the result as it dresses up the engine compartment nicely.

For the bumper you simply include parallel forward pointing stubs, weld the telescoping pieces to the bumper support brackets, trim off the excess, plug those in and use a cross-bolt to secure them. A bolt tube is a good idea to prevent collapse of the square tube but this can just as easily be a flat piece welded inside the telescoping section. I like to weld a nut on the opposite side for the bolt to thread into as well just to make bumper removal and install easy.

The result is a strong front structure that protects the radiator from curb damage and an end to overheating concerns. As always with these cars, strong consideration should be given to the use of a surge tank to remove air pockets from the system. I recommend a 1 gallon capacity tank located on the passenger's side shelf with vents to the system high points and a drain to the pump inlet. Heater return can also go to this tank.

It's the ultimate solution for any high powered MGB. We've been running this system on the Roadmaster and my roadster for over a dozen years now and overheating is simply not a concern no matter the conditions. The RM has AC and barely hits midrange on the gage.

Jim