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TEMPERATURE CREEP AT SPEED

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toolmanxiii View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote toolmanxiii Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2015 at 9:25am
Originally posted by mcjarv mcjarv wrote:

One of the last of my problems (so far) is coolant temperature rise at highway speed, went out yesterday for a test ride to see just how high it would go.

Hot humid day 95 degrees, 68 mph at 3100 rpm with A/C on it climbed to 220F and seemed to level out.

EVERYTHING is new,,,,3 core radiator from APD, Edelbrock water pump, 3700 cfm electric fans and a $8 Summit high flow 180 degree thermostat. I would think I have enough radiator but ?????

What gets me is that in town it holds 180 degrees no problem, only creeps at speed, if I slow down it will come back down.

I ordered one of those high dollar Robert Shaw thermostats yesterday just out of curiosity but I have my doubts.

 The other thought is that it might be running lean and I have not pulled a plug along side the highway yet although I plan to have it dyno tuned in the near future,,,the 650 Holley has 67 primary and 73 secondary jets in it from Willy's Carb & Dyno Shop.

Thoughts

Thanks, Mike


I see this as a problem from the get go . TSM calls for 195 for a reason . I can go into the whole sepal about how the cooling system works but will have many say : my brothers friends uncle told me :    Air flow through the rad cools the coolant . but if the coolant never stops flowing long enough to cool it will just keep heating . A thermostat is designed to allow for a minimum running temp . not how hot it can get . 
Also total Ign time will affect heat production at crusing speed . retarded time will create more heat than the best cooling system can handle .


Edited by toolmanxiii - Apr/17/2015 at 9:35am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mcjarv Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2015 at 9:29am
Its fixed, problem solved, works great and is far from TSM stock.

Thanks, Mike

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Buzzman72 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2015 at 9:43am
So how did you fix it?
Buzzman72...void where prohibited, your mileage may vary, objects in mirror may be closer than they appear, and alcohol may intensify any side effects.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote specter57 Quote  Post ReplyReply Direct Link To This Post Posted: Apr/17/2015 at 2:17pm
i would like to know about ignition timing since i changed from the standard distrbutor and spark box and coil to a HEI distibutor....so is retarded timing when it fires before TDC? what is a good degree to be on for a stock motor? and what rpm to check this at? and does the vacuum hose have to be on it or not?...dont knock me for not being a auto mechanic but i can fix it if i know what to do....since i have everything for my coolant system new and i cant get it down in the hot summer...but if its cold out or cool it doesnt even get close to 200...thanks again
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mcjarv Quote  Post ReplyReply Direct Link To This Post Posted: Apr/18/2015 at 7:22am
Originally posted by Buzzman72 Buzzman72 wrote:

So how did you fix it?

See page 6.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote toolmanxiii Quote  Post ReplyReply Direct Link To This Post Posted: Apr/20/2015 at 6:11am
Originally posted by specter57 specter57 wrote:

i would like to know about ignition timing since i changed from the standard distrbutor and spark box and coil to a HEI distibutor....so is retarded timing when it fires before TDC? what is a good degree to be on for a stock motor? and what rpm to check this at? and does the vacuum hose have to be on it or not?...dont knock me for not being a auto mechanic but i can fix it if i know what to do....since i have everything for my coolant system new and i cant get it down in the hot summer...but if its cold out or cool it doesnt even get close to 200...thanks again


Can one of the mod's point this in the right direction ? I tried the search and came up empty although I know it has been discussed here many times.
 
Timing advance. is DEG Before TDC.  retarded is not necessarily After TDC but in that direction . rather just later than it should be .
 A lot depends on what engine . what Mods have been done . different cam's/intakes/heads  need different advance curves. dirfferent total advance . more mechanical ,less mechanical. more or less Vac advance .
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Post Options Post Options   Thanks (0) Thanks(0)   Quote uncljohn Quote  Post ReplyReply Direct Link To This Post Posted: Apr/20/2015 at 11:27am
Timing of the engine, that is the number identified with how or what it is set at does not depend on the distributor.
If you used 8 degrees before top dead center before you changed distributor, 8 degrees before top dead center now is still a good number.
A specific engine may or may not be happier with a different number but that was not your question.
Changing the distributor does not change the number used.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote specter57 Quote  Post ReplyReply Direct Link To This Post Posted: May/01/2015 at 2:21pm
thanks and was curious about the timing setting...i have mine set close to the 7/ 8 degree BTDC range....i moved it to where it would just run about a degree or two ATDC to see if it made a difference in the temperature of the motor but it didnt....with the thermostat in and it opening at the degree it suppose to, can the coolant still flow faster than it needs to cool it off in the radiator and cause the high temperature?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote uncljohn Quote  Post ReplyReply Direct Link To This Post Posted: May/01/2015 at 3:08pm
Late timing, After Top Dead Center give more time for exhaust heat to be dissipated into the cooling system. How that actually affects running temperature is going to be a function of how efficient or inefficient your cooling system is and how it is measured is going to depend on how accurate your gauge is and where the sensor is located. It is also going to depend on how hard the car is going to be driven too.
Most of the data that says speed of water through the radiator is a major factor is urban legend based on stories on older cars with either poorly designed cooling systems or for the most part plugged radiators.
I have yet to purchase an AMC car that did not have a partially plugged radiator or to be honest a used car with any age or miles on it.
A flow Kooler water pump improves cooling by pumping water faster via eliminating the cavitation of the impeller thus pumping water back into the engine rather than foam and all those air bubbles.
It is going to be 100 degrees today, I do not expect to see any of my cars over heating. But then I know that they are tuned correctly and have good radiators in them.

Keeping the water from boiling by using a heavy duty cap helps eliminate cavitation and the forming of air bubbles that get trapped in poor flowing spots.

It makes no sense to arbitrarily detune your car by retarding the timing unless there is some objective you are trying to reach. I like a little bit of advance on the timing setting, that is my preference. But the factory recommended point is there for a reason. Retarding the timing will decrease the power available and tend towards running hotter. How far it goes is a function of other things then. And you as the tuner are in charge to them.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote toolmanxiii Quote  Post ReplyReply Direct Link To This Post Posted: May/01/2015 at 5:53pm
retard the timing will eat gas and overheat the exhaust valves and manifolds . good way to kill an engine

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