Hi All,
It has been hot around here (in the high 90's) and my 66 Dart is feeling the effects...while stop and start driving in town the mechanical temp guage is staying around 200-210 degrees. Once I get on the highway and drive a short distance the temp comes down to normal operating temp-around 180-185 degrees.
Should I be concerned about the higher operating temps around town? Am I in danger of ruining my engine? Radiator flows well and the cooling system has been flushed recently. Also has a new 180 degree thermostat and the water pump was replaced recently. Any input appreciated!
Thanks
Todd

Low-speed heatup = lack of airflow through the radiator. A fan shroud helps, but they're hard to find for the '65-'66 cars. A better fan (w/more blades and larger diameter, preferably with a clutch) helps. A properly sized and selected electric fan helps a lot.

The big question is whether you can spare the room at the front of the engine bay! Fortunately the engine bay of the '66 Dart is about the longest of all the early A-bodies. Clutch fans have been done, and I'm pretty sure electric ones have, too.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

It's a small thing, but check for dirt/leaves/bugs/stuff clogging the radiator fins, as well as for bent fins.
If you have an AC condenser in front of the radiator, check both and the space between as well.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

I use a 5 blade fan and clutch from a f-j-m body slant car with air.

Works in my 69 dart.

Greg

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http://www.youtube.com/hyperpack

I use a 16" pusher from a Mercedes to keep mine cool.

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Of course ours is a little unique cause it's in open air, but we stay deadlocked around 190-200.

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Linder Tech.com
Bubba's Trailer Park

I'd be interested in an answer to the original question -what is too hot?

My temp gauge needle (71 Dart) wants to sit around 3/4 to 7/8ths of the "operating range" on the gauge -is this unusual? Is there a way to know exactly how hot it is?

I'm suspicious because I know the radiator is non-original... don't know if it's smaller than stock or not.

see:

http://www.slantsix.org/forum/viewtopic ... ture+gauge

http://www.slantsix.org/forum/viewtopic ... ght=#77514

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

On my now-departed Corveette, the fan did not come on until it hit 220. This is shown by the instrumentation in the Vette. The second one came on at 225. If you can trust your gauge, then yu are not in danger of damaging your engine. The carb doesn;t work as well, or at least the same, when it gets that much hotter, so you might want to put an aluminum shield under the carb to deflect the heat coming off the engine. A slant six is way stronger than a Chevy small block, and that is a fact even Chevy guys concede!

If you are worried about it, put a pusher electric fan on the front. This is guaranteed to keep your temp down. However, studies have proven that engines wear less when they are hotter, not more, as long as you don;t blow your coolant out. That is one of the reasons why modern engines run so hot, and tend to have a longer service life than cars had when I was a kid.

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Thank you. I have to say that my Dart is running about 220 on average based on that TSB diagram. I think something is up.

Hmmm, is this a fan that would be activated with a switch?

By the way, your Dart looks killer, Sam. Wow.

A manual switch or
A temperature switch

and the AC compressor if you have AC......

Use a relay (and diodes for multiple on modes).

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

have you ever see the guts of a temp/ oil pressure/ fuel gage? they're 2 stinking pieces of lightweight steel with one rivet and a .0000something wire wrapped around one of the arms. The accuracy of the needle relies on that tiny wire heating up the piece of metal and moving the needle. They suck but they suck bad. In fact, I can't recall another car maker wich such good products as mopar having "el cheapo" instruments as they did. Really not dependable. I'd say if you're really concerned about your engine's operating temp, get a real sender and a real gage (chinese $#!+ will even cut it, they're far more reliable then mopar gages) and see what's up. My car did the same apparent overheating and as it turns out, I was having a faulty sender/gage. Car was 180º all the time and the gage was almost pegged (no shorts anywhere, just bad sender and or gage and you're just about to worry over nothing)

I run a combination of a small lightweight flexfan (5 blades 13" diam) and 2 small pushers from a renault 18. They're set up to start at 92ºC (sometimes during the summer motor gets hot especially idling in transit)
the electrofan/small fan combo it's working nice for me. The flex fan weights less than 1/4 of the original big steel fan, it looks way cooler, costed me $20 on summit, and the electro twin fans give me the peaceof mind to stomp the gas peddle everytime I feel like go wild (I Know it's gonna cool of later)

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

If you get a flex fan be sure it has a steel, not aluminum center hub. The aluminum hubs are known to crack and sometimes fail with spectacular results.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

Thanks for the nice comments Brooklyn! If you have been following my poor mournful thread about no spark, then you know this car isn't running now. Comments such as yours help keep me from wanting to sell it. I know myself well enough to be in touch with my fairly intense feelings about such things, but also to know that they are passing.
Sam

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