Overheating issues with remanufactured 360

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Travis72dart

Travis72dart

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Hey guys its been a while since I've been on the forum. I have a 72 Dart Swinger and when i bought it it had a 318 and it blew so i bought a re manufactured 360 from O'reileys.
We've been having overheating issues with it for a while and are trying to troubleshoot it.

The engine has:

Big Thumper hydrolic cam with a Duration: 283/303 Lift: 513/498
Dual core aluminum radiator with custom fan shroud with 2 high puller 10" fans
We've had the heads redone several times they are stock 360 heads (were on the 318)
It also has a stall converter3400


we were thinking of maybe putting the stock torque converter in it and putting a milder cam to see if that helps at all.

If you have any other questions i can answer them, i would love to find out the problem if anyone has some input.

Thanks,
Travis
 
has it ever ran normal? overheating from the get go? first thing to check in a pot of boiling water is the thermostat.
 
FIRST thing to do is determine where the timing is and what the distributor curve is

SECOND thing to do is investigate the cooling system. Did it cool the 318 OK? Any "overhead" with it?

Thermostat? try a good name brand stat, 180

If none of that works degree the cam. You can "get into" the engine good enough to see how "close" it might be without tearing the engine clear down.
 
first thing I would do is check the thermostat if this problem has just crept up and has NOT been an issue from the beginning
 
Are you 100% sure it's really running hot, or is the gauge just reading hot? The first thing to do in my mind's eye is to verify 100% that it is really running hot first. Infrared guns are really cheap at Harbor Freight.
 
RustyRatRod said:
Are you 100% sure it's really running hot, or is the gauge just reading hot? The first thing to do in my mind's eye is to verify 100% that it is really running hot first. Infrared guns are really cheap at Harbor Freight.
Click to expand...


........And that too..........
 
what is the rating of the electric fans?
i've read you need at least 3000 cfm
is it overheating in traffic or at speed?
 
Let's see your cooling fan set up and radiator, what kind of fans are you using and does the shroud cover the radiator? Converter and cam are not the issue IMO, My 340 in my dart has a 3800 converter and 480/235 @50 solid cam with 28x19 summit universal radiator, I use a chevy HHR electric fan with shroud and have no cooling problems.
 
Thanks for all of the responses!

It has overheated since we put the engine in, we start it and it slowly creeps up if you leave it idleing, or drive it.

We replaced the thermostat twice i believe with 180's.
Someone was saying to just run it without it, is that recommended?

My dad and i have been working on this car for a while and hes getting frustrated because hes a Chevy guy. We always had a project car growing up we have a SS 396 Chevelle, several Novas, a factory slant 6 diesel Dart (forget the year), etc. I personally like Mopar and i bought this to be a father son project when i was 17 or 18. Ran fine with the 318 but a hose popped off the manifold and it got too hot too quick and blew, we decided to get the 360 and have been trying to find the overheating problem for a little over a year. Waiting to do body work and get it polished.

Here's some pics of the engine and cooling system







 
I believe your fan shroud is the culprit. It's is blocking more radiator area than the fans are allowed to draw air through.
 
RustyRatRod said:
I believe your fan shroud is the culprit. It's is blocking more radiator area than the fans are allowed to draw air through.
Click to expand...

It was overheating before we put it on, that's why we had it made. It is attached to the top of the radiator and covers the back and then attaches to the bottom.'

Before we installed it, it seemed to overheat faster now we can go about 3 miles without it getting too hot.
 
Is the coolant circulating through that radiator properly. Water pump?
 
WHEN does it overheat? Does it ever cool back down any?
 
i see this a lot.Like RRR mentioned,how can any air get through that flat aluminum and what is the rating of those fans?
 
ir3333 said:
i see this a lot.Like RRR mentioned,how can any air get through that flat aluminum and what is the rating of those fans?
Click to expand...

Don't remember the exact rating but they were the highest rated for their size. We have them set to where they come on when we turn the key.

We have changed the water pump.

As I said we had problems before we had the shroud and fans.
 
Those fans are way to small. I have two 10 inch fans like those in front of my condenser pushing air when the AC is pulling the interior temp down. They do not have enough CFM to cool the motor.
The shroud is to restrictive, no air can free flow when cruising. Put a belt driven fan with a thermal clutch on the front with the fan 1/2 way in the shroud.
 
Does your idle speed change at all after it gets hot?

Have you done a leakdown test?
 
Why is there so little clearance between the engine and radiator ? Seems like no room for a good clutch fan . Is the engine mounted in the right place ?
I run a 30 over 11.3 :1 340 and it never overheats , factory rad clutch fan and shroud . This weekend took a 100 mile cruise and it was 93 degrees , no problems , not even sitting in standing traffic for 1 hour . I was melting , car was fine .
 
a solid factory 6 blade will cool better than a clutch fan.
a clutch fan is designed to slip and use less hp so turns less than crank speed.However they are adequate for some builds.
 
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