MG Sports Cars

Have a problem with cooling here in Tulsa when it passes 94 degrees. As you can see in the picture, water path from radiator to block is restricted. In the radiator design, is it normally possible to change outlet from right to left side on top, or do I need a new radiator? Or, perhaps a new "90" that bolts to the manifold (with a different orientation)?

From the looks of it you might be able to go over the heater hose to relieve some of the kink, but if i'm thinking right the upper hose wont collapse at high RPMs the lower hose will.
If you are getting hotter at idle the hot air might be recirculating from engine bay back through the radiator.

Try masking off the rad tank and sides to keep from recirculating hot air, it helped with mine!
Also I just noticed the zip ties holdind the electric fan to the core If you could get a shroud to pull all the air you can through the rad core and not just the circumference of the fan it helps quite a bit too!

My $0.02
Good luck!

Where have you got the rad fill/cap? In theory, it should be at the highest point of your cooling system...or am I missing something.
The heater return hose can be reconfigured easily or even use metal tubing as some have done. On my Olds conversion, I had it routed under the intake manifold. Check some of the typical hosing schemes and t-stat outlet orientations from conversions in the "photo galleries" section - I'm sure you'll see something that improves the hose routing. Eg, Typical routing as seen on Dave Burstyn's conversion........



Also make sure that the heater is plumbed correctly - coolant supply to the bottom port of the heater and return from the upper port - it's done this way to promote deaeration/venting.

Here's a few ideas.

In my 86 Mustang HO, the factory shipped the cars with a restrictor in the heater hose. Its purpose was to reduce the flow of coolant that bypassed the radiator. If your car does not have a valve on the heater hose that shuts off coolant flow when heat is not needed, you might consider using a restrictor.

I run Mobil 1 synthetic oil in my Mustang and the car runs cooler because of it.

Water carries more heat than glycol but glycol has a higher boiling point. 60/40 is the magic ratio.

I use a pressure-equalized thermostat from RobertShaw - 195 degrees.

The 'overflow' tank is actually a de-gas tank. Its purpose is to purge air from the system. It reduces oxidation of the coolant and engine coolant passages, and it prevents air pockets from forming.

Has anybody considered using iron Buick 300 heads on their aluminum engines? Cadillac did something like that. It probably makes the engine run cooler and gets better mileage.

A swiveling thermostat housing is available, which may help you eliminate the kink. Check with D&D - I'm not sure if they carry it, but they should know who does.

The nice thing about copper/brass radiators is that they're easy to modify. Any competent old-fashioned radiator shop can remove and relocate ports and blank off old openings. Removing and replacing radiator mounting brackets is especially easy. (They can be pop riveted on if you don't care to solder them.) This photo shows the early-MGB radiator that served me well for years... If you squint at it, you can probably see that the radiator was flipped 180 degrees from its original configuration. My local radiator shop took ports off a scrap radiator and used them because the original MGB radiator ports were smaller diameter.



You might want to visit a friendly auto parts store and select between the hoses they have in stock before you finalize port locations. Bent steel tubes are another option (as shown) - one advantage is that the suction-side will never collapse. (Note: I have an entirely different cooling system now.)

I think I recall someone saying that a good condition MG radiator would cool a stock 302. My MG radiator is NOT in good condition, but I was wandering if that's so!

Maybe in a perfect world. Radiator size is very much dependent on horsepower output, and never and I do mean never will you have a complaint about the radiator cooling too well. We went to extremes in the MGB-Roadmaster project and parking lot testing indicated very good results. I'm doing the same for my blown 340 SBB. But aside from examples such as these the MGB is size limited on radiator capacity even with a 4" extended core. I found a 5 row brass extended radiator with a high capacity core was good for about 300 hp from a blown 215, but Graham does quite well with a much thinner radiator in his 302 conversion so results can vary widely, even with careful attention to details. Happily, upgrades are available in most cases.

JB