MRL 360 Coolant Temp 210+

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TRWRacing

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About 600 miles on the engine. Running stock cooling system for 1973 Dodge Dart Sport 340 with what I believe the original radiator 26" with stock shroud and 18" 7-blade fan with thermal fan clutch 13lb cap and has A/C but not working at the moment. System has been flushed once during heater core replacement last year. Engine was installed late 2016. Timing is initial 12" with about 32" total. A/F set via drop rpm method with the highest vacuum 14". Idles at about 800-830 rpm and runs good otherwise, but seems to run hot in Sunday morning minimal traffic, 85-90 degrees. Seems to idle for 30 min. in driveway at about 205*
Here are the specs per my MRL build sheet:
Edelbrock 1406 600 CFM carb with step 23 setup
Airgap type dual plane intake
2.02 Intake valves
1.60 Exhaust valves
Iron stock heads
Stock 340 Exhaust Manifolds
FBO Ignition System with limiter plate and spring kit
Summit K50062 CAM 285/218 .480 lift 118 LSA 108ICL
Summit Racing® Cam Kits SUM-K50062
SBM Mopar water pump 58-184 6-blade 6 vanes
180* Mildon high flow thermostat
Turbo Action Torque Converter 17501 11" 2500 stall
Flex plate for external balance
3:23 Rear Gears
Coolant is 50/50 conventional green
Hood to radiator support seal is installed
Radiator hoses are new gates, but lower one does not have a spring in it.

Used ifrared temp reader and temp is about 13* difference from top of raditor by hose inlet to outlet.

This seems to run hot y/n? What are my options? Water Wetter?
Thanks.

Added Autometer electric gauge with it's own sender to work in conjunction with the stock gauge

temp2.jpg
 
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It seems a little hot to me, My only thoughts are, is the fan clearances correct, and maybe a good aluminum radiator and shroud.
 
Fan is about 2/3 inside the shroud. If I need to go to aluminum radiator, what are the recommends of type/how many cores and what vendor? I want to use the stock fan clutch setup.

Thanks,
Eric
 
If it cools good at high speed then your radiator is capable of cooling the engine. If that's is true then getting hot at low speed should mean that you're no getting enough air. Does it stay cool at 65 MPH??

Treblig
 
My mine is faulty, I think that the clearance are 3/4" from the radiator to fan, and 3/4 to 1" around the fan shroud.

As for aluminum radiator there are many, Be Cool, Phoenix, Griffin, Champion. I have used Griffin and Phoenix with good luck. They all make a stock style radiator. I like a 4 row, myself, but each has their own favorite.
 
I have a 03 Dodge Ram with a 408 with 180º thermostat.
I have gauges installed in the truck that tell me the exact temp rather than cold and hot like the stock gauge. My gauge sits right on 210º or slightly under all the time in stop and go traffic.
Now when I had the old engine.. 5.9.. it would stay around the same temp.
What I'm trying to say is the 210º is most likely normal temp in stop and go traffic.
If it got any higher I would start being concerned.
When I get out on the open road with air flowing the temps goes down to 185º.
 
I have not had it up to 65 mph for any length of time cause of needing a front end rebuild, which is getting worked on next week. I am not comfortable to do that for safety until that is done.

For the most part. The stock gauge seems to read lower than the autometer.
 
Isn't that the newer cars run hotter than the older ones?
My 408 runs around 180 to 190 on a hot day. Or maybe we are just splitting hairs here. I guess it is all preferences as to what you are looking for.
 
With driving creeps up past to 210 without any traffic. I am not sure what to expect since it is not a stock engine and with a 50 year radiator. I guess, my real question is this normal or do I need a better radiator for my application? If I do, just want something that works with current fan/clutch/shroud.

Or is this normal? I have not driven a vintage car of this type in 25 years - thanks.

Running NGK GR4 plugs
 
13* is no where enuff temp loss, go shoot the same fittings on your daily driver, it's prob close to 40 - 50* drop from inlet to outlet. The rads not shedding heat. Use the temp gun across the rad. You'll likely find cold areas, those cold areas are plugged tubes not passing hot coolant. If so, I'd take the rad to a rad shop, have it rodded out if possible. I still run my original 69/340 with goodies, the original re-cored Dart rad, original clutch fan, 180* stat, it never goes over 185*, just like when I bought it new, - with NO electric fans.
Cheers
 
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I will try that the next time I have it out. Thanks. My assumption is the radiator is plugged at some tubes. I am seeing some white corrosion on the outside at the bottom of some tubes.
 
Just curious anyone know if OER radiators any good? 4 row match the original 26”
Compared to an aluminum? Website says made in USA.
 
At least put a spring in the lower hose and hook up a vacuum advance.
12° advance at idle is not what an engine likes.
 
Yea, I agree with inertia. It's running too hot. My 360 runs at about 185. Had my radiator re-cored a while back it'd a three row.
 
Steven190 said:
Isn't that the newer cars run hotter than the older ones?
My 408 runs around 180 to 190 on a hot day. Or maybe we are just splitting hairs here. I guess it is all preferences as to what you are looking for.
Click to expand...

They do.... I'm guessing newer vehicles do this for emission control... or something.
 
Purely emission. They want/'need' all the fuel to be burned completely in the exhaust so everything needs to be scorching hot.
There no need for an older car to have an engine running this hot. It leaves hardly no room for error or something like a coolant leak.
The moment the system-pressure goes away you will have instant boiling going on.
 
Maybe the clutch fan,at slow speeds they slip and don't even turn at crank speed.I have solved
minor heat problems by getting the proper fixed blade fan.
 
Some things to also look for and know would be a lean running engine &/or the distributor to far advanced. If your engine is octane sensitive, that could be a problem as well.

I’m also fighting high temps on a new build. These are my next target areas to fiddle with since it is a fresh rebuild and not yet dialed in.

I also have a new radiator, 50/50 mixed coolant, new shroud, viscous cooling unit with the fan 3/4’s into the shroud.

It was OK until the temps reached the mid ‘80’s. Now the temp goes up to 210+ a tad more.

I’ll be looking into the distributors timing at idle and at full vacuum. The I’ll get into the carb. I believe I’m running a little lean. I want to also change to
A 190* from a 180* Thermoquad stat.

Also as a note, the swap from 3.23 to 3.55 added some heat which is I am sure is due to the extra revs.
 
Does not sound like there is any one huge problem, but that radiator sure isn't working very well.
You don't need an aluminum radiator. Brass actually transfers heat better. A good brass 3 or 4 row radiator is what you need, unless weight is big issue.
Sounds like the fan might be a little close. 1/3 inside the shroud is what you really want.
You could probably advance the timing to 35°-36° total. Retarded timing will often make them run hotter.
 
TRWRacing said:
About 600 miles on the engine. Running stock cooling system for 1973 Dodge Dart Sport 340 with what I believe the original radiator 26" with stock shroud and 18" 7-blade fan with thermal fan clutch 13lb cap and has A/C but not working at the moment. System has been flushed once during heater core replacement last year. Engine was installed late 2016. Timing is initial 12" with about 32" total. A/F set via drop rpm method with the highest vacuum 14". Idles at about 800-830 rpm and runs good otherwise, but seems to run hot in Sunday morning minimal traffic, 85-90 degrees. Seems to idle for 30 min. in driveway at about 205*
Here are the specs per my MRL build sheet:
Edelbrock 1406 600 CFM carb with step 23 setup
Airgap type dual plane intake
2.02 Intake valves
1.60 Exhaust valves
Iron stock heads
Stock 340 Exhaust Manifolds
FBO Ignition System with limiter plate and spring kit
Summit K50062 CAM 285/218 .480 lift 118 LSA 108ICL
Summit Racing® Cam Kits SUM-K50062
SBM Mopar water pump 58-184 6-blade 6 vanes
180* Mildon high flow thermostat
Turbo Action Torque Converter 17501 11" 2500 stall
Flex plate for external balance
3:23 Rear Gears
Coolant is 50/50 conventional green
Hood to radiator support seal is installed
Radiator hoses are new gates, but lower one does not have a spring in it.

Used ifrared temp reader and temp is about 13* difference from top of raditor by hose inlet to outlet.

This seems to run hot y/n? What are my options? Water Wetter?
Thanks.

Added Autometer electric gauge with it's own sender to work in conjunction with the stock gauge

View attachment 1715188402
Click to expand...
If you think it's running a little bit hot you can change the diameter of the water pump pulley
 
I would FIRST confirm the aftermarket gauge's temp by pointing a laser temp-gauge at the waterpump, t-stathousing and hoses.
I have a SunPro temp gauge in another car that decided to add 20°F to the original temp one day. But the engine is also still running hot because of a partly clogged radiator, so all this didn't help matters when you're driving around and you notice the gauge at 230-240 on the highway.
 
69_340_GTS said:
Does not sound like there is any one huge problem, but that radiator sure isn't working very well.
You don't need an aluminum radiator. Brass actually transfers heat better. A good brass 3 or 4 row radiator is what you need, unless weight is big issue.
Sounds like the fan might be a little close. 1/3 inside the shroud is what you really want.
You could probably advance the timing to 35°-36° total. Retarded timing will often make them run hotter.
Click to expand...
Or to much timing!
 
A rad guy told me yesterday fan should be sticking approx 1/2 in and 1/2 out of shroud.
With my temp gun my stock 273 ac 3 core rad gives me 207* at sensor 176 upper rad hose 126 lower rad hose. 16 psi cap. Can't remember tstat but I think 190.
So a 50* drop at rad. Pretty good no??
Also rad guy said make sure coolant is NOT OAT technology NO TO PRESTONE. Google "OAT coolant"
TRWRacing said:
Fan is about 2/3 inside the shroud. If I need to go to aluminum radiator, what are the recommends of type/how many cores and what vendor? I want to use the stock fan clutch setup.

Thanks,
Eric
Click to expand...
 
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