Joshua, yes I have seen the radiator shutters on old cars, and yes, I agree to the remark that some of these modifications may solve nonexisting problems, and I can even expand on that: This entire project is really overkill! As someone mentioned in an earlier thread, lots of engines have been trotting along for almost a century without even a waterpump, just self circulation, so I guess the slansix can take most of what we throw at it. But like most of you, I just cannot stop trying to improve on things!

The diodes and lamps(LEDs) have been added to the worksheet!

Olaf

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Aspenized

Remember that the thermostat opens at the rated temperature. The coolant will be at that temperature or higher when the engine is hot and running under load. On a hot summer day coolant entering the radiator can easily reach 220F. The airflow through the radiator when the vehicle is moving over ~10 mph (air speed, not ground speed) is greater than what the fan can produce. (averaged airflow through the entire radiator, not just concentrated at the fan) Use a single sensor, in the radiator outlet tank. There's no reason to power the fan if the vehicle is moving.

Ken

I've seen a prewar car with thermostatic shutters in front of the radiator. My father used to put cardboard in front of the radiator during in very cold Michigan winters on his '73 /6 Dart - but experienced overheating when he forgot to remove it in the spring. He had a ~6x6" square hole cut in the cardboard and held in in place with wire.

i have a piece of paneling cut to fit bottom 3/4 of rad....need to use in winter to get heat in cab

Just do the electric fan mod and forget about blocking the heater core. Most of the time my electric fan never comes on and I get lots of heat in the cab.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Ken, yes, having just one sensor in the lower tank or hose was my first conclusion, rather than having it in the top tank where all the radiator producers make fittings for sensors. My only concern was about slow going traffic uphill or with heavy load and little air movement. My water temp climbes very high with the radiator I have now in such situations. Having the sensor in the top tank would maybe start the fan a little earlier in such a situation, but I don't know if it is significant. But then again, my rad is full of old rust and goo (no, not from oil) and have started some small leaks, which after all is why I'm replacing it! I think I'll do the full package with two sensors just to find out, and it also just dawned on me (SBS-slow brain syndrom!) that setting it up right with override switches gives me a possibility to use just one at the time, and then switch between top, bottom or both to see what the sensor locations means in practical use.

Ted, my main concern was the balance of having the optimal intake temperature for the engine, while still having enough heated air in the winter, but after all the heater inlet hose is at the water outlet from the engine, to give you the hottest water available needed for heating. If I'm remembering correct, you have a large, heavy duty radiator, but that radiator may almost be too efficient for the liking of the engine under normal operation. The fact that your fan almost never turns, even with a sensor placed in the top tank, indicate a very efficient use of fuel - I know you get very high milage - and it also means your radiator is very effective. Even so, a water inlet temperature on the low side doesn't exactly mean your engine will die on you, and your feet will not suffer either! You have a modified engine that may require a big radiator when driven hard, but perhaps not for daily use. Please don't get me wrong, I mean this seen from the engine's point of view!

People with stock engines giving no problems should run a stock radiator.

As for the blocking off air to the core or the idea of shutters; as some of you point out - in very low temperatures you just need to do that. As far as I know - and correct me if I am wrong, the equipment used in cars for 'main markets' is set to function normal above -20 C (-4 F), and 10-15 degrees lower than that may start giving serious problems with heating.

Mopars from the mid/late seventies (maybe earlier too- I just don't know), had something installed to prevent overheating at idle in cars with A/C or heavy duty cooling; the TIC-valve, or Thermal Ignition Control Valve. I presume this thing is a child of the start of the emission equipment era, but good thinking anyway, at least when it works! The valve is fed by both ported and manifold vacum, and has a hose to the distributor that normally is given ported vacum. If water temp at idle reaches 225 F, the valve opens for manifold vacum to the vacum advance on the distributor, thereby increasing the starving engine's idle speed to help lowering the temperature. It is also part of the Lean Burn system's electronics.

But it all leads me back to my original question: What is the ideal inlet water temperature for the ENGINE?
Olaf

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Aspenized

Olaf,
I went out and measured my radiator core. It is stock, a little over 18 by 18". The V8 and air-conditioned cars got the 22" wide radiators. You can tell in my pictures that there is a larger bracket on the left side to make up for the smaller core.

Yes, the system is very efficient with the parts I used. When we are in the 30 to 45 degree temps the fan never comes on for days. I think running the heater pretty much keeps everything balanced. If I put the 205 degree stat in, then I can get it to come on now and then at lights and after shut-off, but my feet are cooking inside! A 195 is perfect and the 180 stat works great in the 100+ degree summer temps.

I am running a bone stock 1980 225 at the moment while my good engine is out getting a few upgrades. Since this engine has never been rebuilt and the water passages are full of junk I am running the 180 stat with good results temp wise and mileage. I do miss my rebuilt motor though........it has allot more power!

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Temps from my daughter's "Bone stock" 65 Dart, 56k miles, 225 with 19 inch radiator, 195 thermostat, & mechanical fan after a 70 mph expressway run with ambient temps at 75F:
Thermostat housing shell 198F
Top hose outer skin 175F
Bottom hose outer skin 146F

I'm going to use the 30F difference between the top & bottom hose as my starting point in setting a top hose adjustable thermostatic fan control & a bottom hose adjustable thermostatic fan control in my 65 Dart with electric fan.

Using the same measuring locations & same measuring instrument on my 65 Dart I will initially adjust the fan controls until I get the same temps without the electric fan turning on. Then I will let the engine increase it's thermostatic shell temps to 210 & insure the fan comes on(cutting one switch out at a time) and monitor temps at the other location as my starting point for evaluation.

ps: I found 25F changes in temps across the top radiator tank .....this might suggest that the closer the top thermostatic control is to the thermostat housing the more accurate the engine temp measurement would be?

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

Ted, I had the impression you had a larger radiator, sorry about that. I wonder, does your Dart have different setups of the heater, depending on if it has AC or not? On my Aspen with nothing other than a heater, the hot water circulates through the heater core at all times, and heat inside the car is regulated only with the volume of air passing over the heater core. It is not exactly helping in keeping the car cool in the summer, to have hot water circulating inside the car, with the heat only dampened by a plastic cover! I have seen that the Diplomats with AC has a water shutoff/bypass valve in the heater hose, but I am a bit reluctant to install one like that when considering sediments settling in a heater core without circulation. Any comments on that?

DonPal, that was very interesting reading. I've got to get me one of those IR thermometers! The difference between top and bottom is vital information, and I see you think more or less along the same path as me with two sensors to find the balance. The difference in temperature that you measured across the top tank makes one wonder how exact any calculations that includes the radiator's cooling area can be. I guess that the temperatures across the surface a radiator with inlet and outlet at the same side will always be biased toward that side, it would have been interesting to know the differences in temperature across the top tank in a radiator with water in- and outlet on opposite sides. From that aspect, there must be quite large variations when comparing old and new radiators as well. Sedimentation would surely have a different pattern, and a slantsix radiator should in theory clog up sooner than a V8 radiator with water inlet on the other side. It would be interesting to hear if anyone has been able to compare that. My own radiator has been picking up on the leaking in the last few days, but I will try to get some temperature readings. I have a new radiator underway, so I'll be able to publish any differences in temperatures between old and new in a short while. It will be interesting to compare some numbers in the months to come!

A small dilemma: I'm dying to cut open the old radiator to see the inside, re-soldering a 33 year old radiator is out of the question for me. On the other hand, I have to remove the thermostat and use a radiator cleaner to flush out any old crud from the engine block before attaching a new radiator, and that will clean the old radiator before I have a chance to see the inside! Anyone with a bright idea?
Olaf

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Aspenized

True about the hot water inside the heater car at all times. My 72 Imperial has the water shut off on the inlet hose like you describe. That is one way of keeping it cooler inside, but where I live I want the heat and even more heat.....so I run a 205 stat in the winter. I don't see why you can't plumb a shut off. If your worried about accumulations, just install a filter screen in the system.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Ted, I told you I get these attacks of SBS (slow brain syndrom)! Filter is of course a very good idea. I also know that the large hauling rigs often circulate the coolant through specially made filters for concistent cooling and to prolong the cooling components' life.
Olaf

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Aspenized

Installed & operating in my 65 Dart 225 (195 F thermostat) are top & bottom electric fan thermostats in parallel with a manual override switch:
With engine idling after a warm up run I set the upper thermostat first to click on when the thermostat housing hit 200F. Respective measurements:
Hottest part of radiator tank-202F
Top hose outer temp-188F
Lower hose outer temp-148F
Temp guage on dash near mid position

Lower thermostat was then set after disconnecting upper thermostat to come on at 150F outer lower hose temp which gives similiar tank, hose, and thermostat housing temps.

I'm starting at these low temps and will monitor engine response, temp readings, & gas mileage as I increase settings.

I hope to settle on final readings after hot & cold season testing to determine the best settings for my stock Dart except for the oversize U.S. Radiator 17 1/2 x 22 x 1 1/4 core

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/

Hi DanPal, what kind of adjustable thermostatic fan control do you intend to use, are they connected to temperature sensors in the tank/hose, or do you use external sensors in the radiator cooling ribs?
Olaf.

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Aspenized

External sensors press against the radiator cooling ribs & are positioned immediately above lower hose & just below the upper hose at the tank to core connection.

My 65 Dart has an added radiator overflow tank to insure the upper tank is always full.

Note the thermostatic housing reading and top tank immediately at the upper hose connection have matched temps of 200 F at the initial settings.

I found the thermostatic housing would not heat up over 200 F with the engine at an idle for the 65 F ambient day......perhaps the large core radiator barely needs air movement for that ambient temp.

Since your question was what was a PERFECT inlet temp I'm planning on plotting the ambient versus inlet temp while maintaining a constant temp at the outlet.....I expect a delta temp(lower versus upper) of 35 to 70 F degrees for an ambient range of 40 to 100 F for my stock engine.

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1965 Dart 110k, 225, Carter BBD Super Six, 2 1/4 single exh., sbp manual scarebird front disc, 7 1/4 rear 2.94 sure grip, 14 x 4.5 OEM wheels, 833 OD with hyd. throwout bearing, HEI, electric fan, ram air/heated air, Accusump. http://plymouthcarclub.com/