mcguirjf

Getting the 1989 ready for racing this year and cooling is on top of the list. Ran a Track Night event at Thompson, CT and was constantly at 235F.

I know this is normal and they are designed to run hot, but if I'm gonna do any form of endurance racing I need to get those temps down.

I'm about to pull the plug on buying a Dewitt's 2 core radiator, and was curious if I can run the 1990-1996 Radiator with remote pressurized expansion tank?

Is there an advantage to going with the 1990-1996 style coolant system versus the 1989? Easier bleeding?

I notice the 1990-1996 radiator does not have a provision for the coolant level warning sensor. I see a sensor on the underside of the expansion tank in pictures. I guess this is the same sensor.

One last observation is that 1990 used this remote pressurized tank which was a L98.

I also noticed the 1990-1996 coolant systems still uses the overflow tank.

Let me know if I can go with the 1990-1996 style radiator in a 1989.

0Tom@Dewitt

Nope, won't fit in the plastic box that holds the radiator.

mcguirjf

If I source a 1990-1996 shroud (I guess upper only) I should be able to update the radiator?

Thanks again!

Is there any benefit to having the remote surge tank?

WVZR-1

The upper and lower supports are different, they're technically not 'shrouds' but most frequently mentioned using that terminology. There's very much different!!

ctmccloskey

There are plenty of tricks for keeping your temperature in check. I have a 1968 C3 Convertible with a 427 running 12.25-1 compression ratio.

To make it street-able I have done the following:

Reduce the amount of anti-freeze in your coolant. I have found way too many people use too much a/f in their coolant mixture and this makes the car run hotter than normal. If this car is driven in the northern parts of our country you will need some A/F but most shops and mechanics use to much A/F. You want a good pressure cap also. I replace my thermostats every three or four years to be sure I have a good one.

Snow Performance Methanol Injection system
This systems squirts 150 psi water into my manifold under the carburetor and cools the combustion as well as boosting the octane to 115. This alone makes a big difference and is fairly easy to install.

Edelbrock 8861 Victor aluminum water pump
A good solid performer that moves the coolant at a higher volume at low speeds.

Evans NPG Coolant
This stuff raises the boiling point and transfers the heat OUT of the engine into the coolant more efficiently than anti-freeze. The engine runs very happily and is able to handle the extra heat.

BE-COOL Radiator
A good solid aluminum radiator is better at getting rid of the heat. You have lots of choices here but be sure to get the shroud and fans for the radiator. I have 2 Spal fans behind the radiator which have independent controls that use PWM for speed control. I also clean the radiator with "Coil Cleaner" made for A/C compressors to keep the aluminum from corroding and inhibiting the transfer of the engines heat.

Last but not least is open up the airflow to the radiator, in my case I removed my front license plate to allow more air to get in.

On the 1968 C3 if the headlights are in the "up" position then more air goes straight to the radiator and does what it is supposed to do. I also remove any blockages on the air getting out of my engine bay. On my 1968 the gills are wide open so I route the air that way.

Be sure to check your power steering fluid temperature when you are running hot. Most P/S failures have ties to running too hot and the seals fail first. I would install an external cooler on the P/S system and maybe even an external cooler for the engine oil. For track use I would have a good set of coolers and especially if you are using an automatic transmission. Coolers, coolers and another cooler.....

I hope that these tips might be of use to those out there with hot running cars.

mcguirjf

More info I found regarding the use of a surge or expansion tank versus a recovery tank.

All C4's 1984-1996 have a recovery tank located under passenger front headlight. In 1990 they added an expansion tank above the HVAC blower motor.

The primary reason for the remote expansion tank in 1990-1996 is to aid in filling of coolant and bleeding of air in the coolant system. This "should" have been done since 1984 as the radiator has always been below the engine.

Having the additional expansion tank in the 1990-1996 provides "no" improvement in the dissipation of heat from the coolant system.

So now I have to decide if I want the convenience of having a remote expansion tank. Current state I just jack up the front and use a Lisle funnel to bleed the air out. Usually requires two three heat cycles to get all the air out.

With tracking of the car I will be required to run straight water during the event so coolant changes will be more frequent. I will see if I can source used 1990-1996 parts for cheap and see what modifications are necessary to make it fit in a 1989. If the modifications are minor then I will go with the 1990-1996 radiator design. I will update everyone on the results.

http://blog.cantonracingproducts.com...on_vs_recovery

WVZR-1

OP - do you still have the AC in the car? Does it work? Does it need to be there? What do you do for fresh air to the throttle body?

mcguirjf

Yes factory R12 AC is still there and works. Would not use it during events, but would like to keep it there.

I do clean the condenser and radiator every year and remove any debris.

Intake air is from the stock air box. I will definitely have to make one as I have seen the ribbed tube between the MAS and TB collapse.

WVZR-1

AC complicates it maybe considerably. You need the upper and lower supports, the '90+ radiator, '90+ shroud and appropriate fans for whatever. A '90 or '91 L98 would be maybe the best buy if you could find someone parting a car locally. Using the '90/'91 condenser you only need adapt the lines to the newer.

Maybe you have a conversation with T DeWitt regarding radiator and cooling options using his fans, shroud and insulators. The rest pretty straight forward. Heater isn't an issue when doing this using the '90+ cowl tank.

This is the '90 package which could be considered same for '91 I believe. Brackets for the center (painted) deflector are different. I could supply you with a part# list if it would help.

0Tom@Dewitt

FYI, the Evans waterless coolant will actually run hotter than a standard 50/50 coolant because of the absence of water. A higher boiling point can also be accomplished with a high pressure rated cap however, higher boiling doesn't mean running cooler. All that means is if you run into trouble (like traffic jam on 90 degree day) it would be ok if the coolant temps went up to 240-250 for a while. A 50/50 mix with a 15# cap is good to about 275.

mcguirjf

mcguirjf

mcguirjf