I have been having problems with my radiator (1979 210 stock) getting very hot from driving only 11-15 miles! Sometimes the coolant actually boils and know the coolant is good because I just changed it. Yesterday I refitted a new motorad thermostat (180 degree), hoping that would fix the problem but so far it hasnt made much of a difference. I have been told it could have something to do with the timing. I do have a new weber 32/36 fitted as well. Would that have anything to do with it? I also live in Phoenix and it's been getting to about 105 degrees F lately.Any ideas?

It' time to have it take to the radiator shop and have it rodded out!

Save your head gasket...

I've blown so many head gaskets when the weather warms up and cars mysteriously run hot, but only if you try to go somewhere on the highway, never around town...

true you could be having problems from timing or running way lean, but i'd make sure the radiator radiates properly...

flush and reverse flush that beast, make sure it radiates

flushes aren't worth doing when a proper rod out is so cheap.

Please forgive my ignorance, but what is a rod out and how much does this usually cost?

The radiator core is made of many tubes, usually oval shaped, that transfer coolant from the top tank down to the botom tank. Because these tubes are small the radiator actually serves as a fairly efficient filter by traping lumps of crud that are liberated from the block.

This crud slowly but surely blocks the small tubes in the radiator & reduces its ability to shed heat by restricting coolant flow.

Rodding the radiator refers to a process where the top & bottom tanks are removed from the radiator, usually by a radiator specialist, & a small rod is pushed along the tubes in the opposite direction to coolant flow in an attempt to restore flow in the radiator core.

If the core is badly corroded, or damaged, or too solidly blocked to clear, then replacement is the fix. If a heavy duty core is available, then it is often a good idea to spend the few extra sheckles & have it fitted. I use a cheezecloth condom kind of coolant filter in the top tank of my new radiator & this has captured much more crud than I had believed it would. Now my 1200 runs right on the money even when cruising at highway speeds during even the hottest days.

Spend what it takes to fix it now rather than wait untill your engine is damaged when you need to pay to fix both the radiator AND the engine.

here a rod out is about 60 -80 $ a flush is 30 -40$

Personally... I don't flush, just run proper coolant, and every 10 years get the rad rodded, it's a great time to put in a better core too.

Where can I find a core?

Have you asked your radiator shop?
They sell & fit cores at radiator shops.

any radiator shop worth it's solder can recore a radiator or upgrade it to a 3 row or whatever.

I ask them to do odd things like put the bung from a sunny radiator in for the electric fan switch.

If they can't find a core find another shop.