Cooling problem SOLVED

I don't post very often, but thought some of you folks might find my story interesting.

About 6 years or more ago I finished installing a 60 over warmed up 318 in my 66 dart vert. I had the core redone at a very competent local shop using a high efficiency 2 row core in the original radiator. I had the correct shroud and what I thought was the correct clutch fan and new clutch. It would not cool - 210F and more as you drove it, very spikey temperature peaks and valleys.

OK - I checked the robertshaw thermostat - confirmed it opened at 180 on the stove using a thermometer. Hmmmm. I swapped fans for a solid drive 7 blade fan. No dice, better but still too hot - it was running at around 210 and would not stay steady at idle or moving down the road for more than about 5 miles or so.

I decided to check the water pump - it was new when I assembled the motor, pulled it off - nothing suspect - 8 blade impeller matched with the correct pulleys on the crank and pump. I decided to install an anti-cavitation plate on the pump - just to boost water flow - Nope still runs hot and would continue to go up in temp as you drove - idled whatever.

Obviously I was not driving the car much - just little short runs to car shows a few miles away, nothing major. I also have another dart which is completely restoed that I will drive as well. Time as we all know has a way of getting out of your grasp...each summer I would mess with it and not get what I wanted. I figured the 60 over block was not helping matters either, hot spots thin walls - the usual stuff people theorize about...

I ended up buying a recored 69 dart radiator and shroud that boasted 3 rows off the internet that someone had used in their early A body w v8. Well that was better, but it would still rise in temp and not recover unless you stopped driving it.

3 years ago I installed an AL radiator and it was better maybe now around 200F, but it still was not there. It would rise in temp to stupid levels if you drove long enough. I decided to try making a shroud last year - which I completed, but never installed.

last year I went to the Nats and met up with the radiator folks from Wausaw WI - They guaranteed they could rebuild the oem radiator and make the thing cool. OK - I sent them the thing last fall and finally installed it about 2 weeks ago, this was with the correct shorud and a 7 blade solid drive fan. It was much better, but it would still rise in temp if you allowed it, it would get up to 205F and sit there, at least it was not spiking and continuing to rise as badly. Hmmmm.

I looked at the inlet and outlet temps on the radiator with an infrared thermometer. 205 outlet and 147F inlet - WHAT ??????? That is a huge temp difference - I concluded that the pump was inadequate. It made no sense to me with everything I had done over the time I had been working with this thing....

I researched the various high vol water pumps on the market. Last week while on a business trip - I visited the biggest nationally known speed parts dealer and physically compared stock, Brand M and Brand F water pumps for my application in the store. Brand M and stock are IDENTICAL, except for the price. I can say with ALL confidence that only one of these pumps that is truly high volume is brand F.

I bought a brand F and installed it on Saturday - A very interesting experience. When I got the old pump off the engine - I examined the impeller. Guess what - it spins like it is on bearings ! BUT - it does so without the fan side of the shaft turning. MEANING that the impeller was free wheeling - NOW, keep in mind this was a high quality NEW pump when I installed it, not from the cheapo chain parts stores. I guess even the "high quality new parts" are made outside the US. I wonder how long that impeller was going to stay on the shaft - it was like the end of the shaft was peened over enough to retain the impeller. It made no funky noises nothing, just as smooth as a bearing when rotating......Can you imagine the flight of foul language I used at that point, but also mixed with that I finally FOUND IT feeling ?

The best part of this whole thing ? NOW - The car never gets over 180 whether I flog the crap out of it or sit at traffic lights - or both !!!

It runs like it should have from the beginning. Thank God.