New to the FEBO Family + Overheating Big Block

[Eric Johnson]

Hi everybody. My name is Eric. I have a 1973 Cuda I found in a field when I was in high school and I've been building and rebuilding it ever since. The car was raced before I found it and the original motor was gone so I've never been concerned with keeping it original. It has gone through many changes and currently has a new stroked and supercharged 440 in it. It started off as a mild stroker build but of course it spiraled out of control into what it is now. It has a forged crankshaft with H-Beam roads, forged 8.5:1 pistons, Edelbrock Rpm Heads with enlarged valves, Lunati solid roller cam with Lunati 1.5 roller rockers, 2" Headers, Edelbrock RPM intake with a Dan Davinci custom 950 Blow Thru carb, Vortech centrifugal supercharger running around 5 psi at 3000 rpm, MSD ignition boxes and electric fuel pump. That engine wasn't supposed to get that crazy but it somehow did anyways.
So one of the big problems I'm having with it is overheating. The engine can go from cold to 180 in about 3 minutes idling from a cold start. It runs fine until I get into traffic and the temp rises pretty damn fast. I'm kind of convinced the radiator is too small but several people have told me they don't think so. The radiator is a Wizard Cooling radiator that was custom built for the car. It has the same height and width as the stock radiator but it has 2 cores which is their thickest radiator. It has a built in shroud with 2 Spaul paddle pans. I have also moved the oil filters to the side of the engine compartment where they run through an oil cooler before going back to the engine. With all this being done, it still gets hot fast. I know the thermostat is in correctly and is a 180 degree thermostat. I'm pretty certain I have no air pockets in the system but I may retry to bleed it just incase.
So this was by far the biggest most powerful engine I've ever built so there is a lot I am still learning. Just wondering if you guys have any helpful tips you've ran into with big hp street engines in "small" cars. Thanks very much!

 

[340challconvert]

Eric
to FEBO from New Jersey
Nice work bring that Cuda back to life; looking good.
Just curious what type of water pump you are running?
Some high volume pumps may actually run the coolant through the system too quickly to cool effectively, especially at idle, in traffic. I have seen this issue before w BB Mopars?

 

[DetMatt1]

Welcome to the site from the Motor City!
Is this a new engine and this has always been the case or did this overheating problem come out of the blue?

 

[Fishgutz]

Hi Eric, Beautiful Cuda, looks like a lot of work paid off. Redline makes a product called Water Wetter, it helps the coolant transfer heat more efficiently. It maybe a quick, easy fix to your problem. I have used in the past and it really works.
Happy Hot Rodding
Fishgutz

 

[Eric Johnson]

Eric
to FEBO from New Jersey
Nice work bring that Cuda back to life; looking good.
Just curious what type of water pump you are running?
Some high volume pumps may actually run the coolant through the system too quickly to cool effectively, especially at idle, in traffic. I have seen this issue before w BB Mopars?

That's a good point. Im running a high volume water pump. I tried researching before I went with it and I guess theres a lot of debate as to which is better, high or low. I was thinking switch to a low volume pump to give the coolant more time in the radiator.

 

[Eric Johnson]

Welcome to the site from the Motor City!
Is this a new engine and this has always been the case or did this overheating problem come out of the blue?

I had a 440 in it for years. I replaced it with this engine. Its not like a brand new crate engine. Its a late 60's hp block that was built. The machining work was done at a good shop around here and they went through everything so I dont think theres an obstruction in the block. The problem has started ever since this new engine but this engine has always been supercharged with all these performance parts on it so I cant say if theres an issue with the block but I suppose there could be.

 

[Eric Johnson]

Hi Eric, Beautiful Cuda, looks like a lot of work paid off. Redline makes a product called Water Wetter, it helps the coolant transfer heat more efficiently. It maybe a quick, easy fix to your problem. I have used in the past and it really works.
Happy Hot Rodding
Fishgutz

I tried that. I have read about non glycol based coolant which I guess has a slightly higher boiling point? I think the higher boiling point allows the coolant to get hotter without building as much pressure. I was thinking trying a new lower volume water pump and changing the coolant to non glycol based this spring.

 

[moparlee]

Welcome to the site Eric from Michigan. Are you getting any flow at all thru the thermostat? I check mine in a pan of water on the stove, heat it up and see what temp it opens up at.

 

[Eric Johnson]

Welcome to the site Eric from Michigan. Are you getting any flow at all thru the thermostat? I check mine in a pan of water on the stove, heat it up and see what temp it opens up at.

Thank you Lee. The thermostat appears to be working correctly based on the temp gauge. It’s a 180 degree tstat and usually opens around 185-190 then the temp drops to around 175ish. It’ll stay there until I get into traffic or stop signs, etc. so it seems like once there’s not as much air flow like while moving that’s where the problem begins. So that’s why I keep thinking it’s the radiators too small.

 

[moparlee]

Thank you Lee. The thermostat appears to be working correctly based on the temp gauge. It’s a 180 degree tstat and usually opens around 185-190 then the temp drops to around 175ish. It’ll stay there until I get into traffic or stop signs, etc. so it seems like once there’s not as much air flow like while moving that’s where the problem begins. So that’s why I keep thinking it’s the radiators too small.

I forgot to mention the radiator size when I replied. You probably need at least a 3 core and maybe even a 4 core.

 

[tonysrt]

You don't mention were you're located, but if in a hot zone may just be the nature of the beast. In the summer my Gen 2 hemi doesn't like to stop for red lights very long. In cooler weather runs at 180 all day long. I have a 26" be cool Radiator and a shroud in a 71 Cuda.

 

[AUSTA]

When you say 2 cores are they 1 1/4 size also the model of the Spal fans they are the a good fan you should be able to check by current draw the blasters are around 25 to 30 amps great for slow traffic also what do have in front of the radiator oil coolers etc ?

 

[Eric Johnson]

When you say 2 cores are they 1 1/4 size also the model of the Spal fans they are the a good fan you should be able to check by current draw the blasters are around 25 to 30 amps great for slow traffic also what do have in front of the radiator oil coolers etc ?

Yes they are 1-1/4” cores. I could check the current at the fans. They definitely pull some air when they’re on I can feel it through the radiator. The only thing infront of the radiator is the oil cooler which is maybe 6”x4” approximately. It doesn’t block a whole lot of the fins.

 

[AUSTA]

So once you pick up speed the engine cools down you would think there is not enough airflow over the radiator what size fans are they also how much advance at idle.
There is a lot in that engine bay we know the air in going in but can it get out does it cool down if you open the hood at idle.

 

[Eric Johnson]

So once you pick up speed the engine cools down you would think there is not enough airflow over the radiator what size fans are they also how much advance at idle.
There is a lot in that engine bay we know the air in going in but can it get out does it cool down if you open the hood at idle.

The engine gets so hot so fast once it reaches past 190 it doesn’t matter if the hoods open or not. The only way it stays cool is running it 30 mph or faster.
I was brainstorming with a buddy of mine today about it and here’s the strange thing, it goes from cold start to 180 in like 3 minutes. He thinks the timing may be too retarded? I remember setting the timing based off a carbureted 440 which I believe was 5 degrees before tdc, I think. My boost timing controller has a boost reference that reads intake air pressure and adjusts the timing off that reading. So when I set the timing I’m wondering if that boost controller is messing up the timing at lower rpms causing it to run hot at slower speeds. It could still be a radiator issue or a whole bunch of little things. It’s hard to know where to start. But I’m guessing start with the timing.

 

[fasjac]

Hi Eric, fasjac here and welcome! I’m new as well. I’ve had this issue before as well with a 500 stroker 6pack. Nothing close to what you have but, I was using a high flow water pump (circular fins) with a 180 tstat. I changed the pump to mopar performance and 160 tstat. So far so good. Runs between 180-190 degrees now. Very nice car!!

 

[WDO72]

Welcome from California! Nice work on the car! Very cool!

 

[fasjac]

Hey Eric, I may have missed this in the earlier post but, is the water pump housing factory or aluminum aftermarket? The reason I ask is because I ran into an aftermarket several years ago that had a casting issue. When you looked at the openings off the motor, they look perfect and matched gaskets etc. The problem was, when you checked the openings all the way through a borescope, those passages (on one side) narrowed way too tight causing a similar problem. Got hot too fast and would only cool down somewhat at cruising speeds. Just thinking out loud.
Way cool set up man!

 

[MOPARMITCH]

Welcome to the Madness !!!!

 

[Chryco Psycho]

I agree with advancing the timing , the factory spec is not for performnce builds , initial timing should be around 14-16* but with a limited curve so it will not go past 34* total . this should mae a huge difference in cooling . The factthat it will stay cool when moving 30 mph + indicates not enough air flow withthe electric fans , but try the timing first