Jeep Wrangler Chevy Conversion Overheating Issues

Below is a transcript between a customer that installed a 1682-3C and our parts technician.  We sell Jeep engine conversion radiators on racewayparts.com in 3, 3HD and 4 Row versions.  Many customers often ask whether to go with the standard 3 row (which we do sell the most of) or to get into our HD cores and 4 cores.  This information is meant to give some conversion enthusiasts knowledge of questions and situations to be aware of when performing an engine conversion.  We hope that it may help you with your radiator choices.

OVER HEAT ISSUE:


1. The 350 is modified, bored, cam, full roller motor…

2. Flex fan is on it now, I have tried electric fans as well

3. I am not 100% sure of the CFM rating

4. Yes I have had a shroud made, and have run it both with and without

5. I had a 160 degree thermostat in it and have since removed it and it runs cooler, but still way above normal range

6. It has got a 15psi radiator cap on it

7. At idle, the temp will sky rocket quickly

8. The temp will rise at any speed

9. Temp will hold steady at higher speeds, but will not cool down much at all. The longer you have run it the less effect any variable has on the temperature, it just gets hot and stays that way.

ENGINEER RESPONSE:
 
After reading the specs that this 350 is modified I would have gone to a thicker radiator like the 1682-3CHD, 1682-4CHD. It is higher horsepower and higher compression so he really should have gone to more radiator in my opinion.


The radiator is a small part of the issue but there are other things going on. I would have gone to a 185 degree thermostat. A 160 is opening to soon and will not control the higher temps and no thermostat at all is asking for trouble.

The radiator does not generate heat. It get it from the engine. Even with this smaller core there should be some consistency in temps and I don't see any. The symptoms that are listed here point to lack of coolant flow or lack of air flow. The customer needs to get some temp readings using a thermal temp gun. Starting with the thermostat housing, then the top radiator hose connection and then the bottom hose connection. This will tell is what temps are coming off of the engine and going into the radiator and what is happening when the coolant leaves the radiator. With the thermal gun also look at cylinder temps to see if the cylinders are close in temp to make sure of circulation through the engine. The engine is holding a lot of heat and generating is quickly. Where is it coming from? Its not coming from the radiator so is the rear of the engine running considerably hotter than the rest?

This engine needs at least 2600cfm coming from the fan. It is also important to check the rotation of the fan. We also need to make certain that the coolant is flowing all the way through the system and by the description of what is going on one of the two if not both is part of this puzzle. A good starting point is the temp readings I mentioned. This will give a good baseline for comparison and start pointing out places to look for problems.

what type of coolant to put in a radiator

Choosing the right coolant.. we'll that should be easy right?  Match the color and pour away...!!?

Check out this article for some useful information if your looking to purchase anti-freeze to top off your system, or for a fresh install of a radiator express radiator.

http://www.popularmechanics.com/cars/how-to/products/1272436

HOW TO INSTALL A RADIATOR

Step One - Safety First


• Make absolutely sure that the engine is completely cold before you

begin removing and installing a radiator on a vehicle

• Turn the vehicle off and park it in an area that will allow sufficient working

space for the installation.

• Wear gloves and safety glasses when handling parts and working under

the hood

• Keep children away from the work area and keep all parts and tools off

to the side to avoid a tripping hazard

Step Two - Use the Right Tools

• Large drain pan or a bucket - to drain the old coolant

• Distilled water - 1 gallon

• 50/50 Antifreeze/Coolant – 2 gallons

• 2 straight blade screwdrivers - 1 long handle and 1 short handle

• Set of common open end wrenches - or an adjustable wrench

• Short angled pick - for breaking the seal on the hoses

• Ratchet -10mm, 1/4” or 3/8” sockets

• Hose Clamp Pliers – to remove clamps from hoses

• Hose Clamps – new hose clamps should be used for each installation

• Coolant Hoses - these should be replaced every 4 years.

• Quick Disconnect Tool – to remove quick disconnect fittings, if needed.

• Other Tools - as required to remove the cover, trim pieces and fan

shrouds

Step Three - Removing the Old Radiator

• Disconnect the negative battery cable from the battery.

• Locate the drain plug (also known as the pet cock), it is usually located

on either side on the bottom of the radiator.

• Remove the radiator cap to allow the coolant to more easily flow

through the system.

• Drain the coolant into the bucket. It may be necessary to raise the

vehicle for the bucket to fit underneath the radiator.

• Remove bottom hose clamp on radiator using a straight blade screw

driver or hose clamp pliers. If the hose will not come loose by hand, use

the short angled pick to break the seal between the hose and the hose

connection.

• Drain any remaining fluid from the hose and hose connection.

• Repeat this procedure for disconnecting and draining the top hose.

• Check coolant hoses to ensure they are functioning properly. After

removal of coolant hose, squeeze the hose to see if there are no cracks

and if the coolant hose returns to its original shape.

• If you have an automatic transmission, you will need to remove the

transmission oil cooler lines. Note: Many late model Ford and Chrysler

vehicles use quick disconnect fittings and a special tool is required,

while most import cars will use a hose and clamp.

• Carefully unscrew transmission oil cooler lines with an open end

wrench and be cautious not to bend the lines.

• If the vehicle has an engine driven fan, remove the fan shroud.

• Note: All fan shrouds attach differently. If the vehicle has an electric

fan, the fittings must be disconnected and some vehicles have sensors

that also must be removed.

• Locate the radiator mounting points. If the overflow tanks are located

on the left and right of the radiator, the mounting points will be at each

corner on the top tank. If the overflow tanks are located on the top

and bottom of the radiator, the mounting points will either be on each

corner and for imports on the top and for domestic vehicles running

vertical on the sides.

• Carefully lift the radiator from the engine compartment, avoiding contact

with the fan blades and not spilling any excess fluid.

Step Four - Installing the New Radiator

• Compare the new radiator to the old radiator and make sure it is the

correct part and all the connections are the same.

• Remove any fan assemblies or sensors from the old radiator and transfer

them to the new radiator.

• Check all hoses and hose clamps for damage or excessive wear and

replace these parts as necessary.

• The ground wire must be connected from the radiator to the support or

to the chassis.

• Check all screw-in lines (oil cooler & trans cooler) for proper seals and

start each by hand before tightening.

• After all connecting parts have been assembled to the new radiator,

reverse the above procedure for proper installation.

Step Five - Checking and Filling the Cooling System

• Once the installation of the radiator is complete, check and ensure all

the hose connections are tight.

• Check the vehicle owner’s manual for the correct type of coolant and

never mix different types of coolant.

• Using a funnel to avoid spills, fill the radiator with a 50/50 mixture of

the specified type of coolant and distilled water.

• Note: If the top radiator hose sits higher (at any point) than the radiator

cap, then locate a vent that is usually at the highest point in the system.

Open this vent before filling and close the vent once the radiator is full

and prior to starting the vehicle.

• After all excess coolant is wiped or rinsed away the system should be

visually checked for leaks.

• Turn on engine and wait untill the thermostat opens; then check the

system and add more coolant as needed.

• Check for leaks under the vehicle and around all the hose connections.

• Test drive the vehicle, check the engine temperature and re-check all

connections to ensure the cooling system is functioning properly.

• Congratulations - the installation of the new radiator is now complete!

Information Supplied by Silla Cooling Systems.  To purchase products manufactured by Silla- Call 866 723 3977 and speak to a Radiator Expert Today !