Chevy Nova Forum banner

1 - 20 of 44 Posts

·
Registered
Joined
·
1,124 Posts
Discussion Starter #1
Has anyone had any success keeping a 500 hp 383 stroker with a 3000 stall cool with a Champion Radiator in a first gen Chevy II? I have about to come to the conclusion that my 3 core Champion radiator is very restrictive and is difficult to get enough air flow through it with an electric fan at idle. I have experimented with several different fans, including a 1990 Taurus from (from a 3.8L V-6). Even with the Taurus fan, it is creeping up to 230+ degrees when it is over 90 degrees outside at an idle. Naturally, when I get over 45 mph, it starts cooling back down.
 

·
Supporting Vendor
Joined
·
23 Posts
Your conclusion is probably accurate. Any 3 core in aluminum is susceptible to this. The most efficient core in aluminum is 2 rows with at least 1" tubes. That's why you don't see many 3 row aluminums on the market. I'll send you a PM with some options if interested in upgrading.
 

·
Registered
Joined
·
9,963 Posts
Has anyone had any success keeping a 500 hp 383 stroker with a 3000 stall cool with a Champion Radiator in a first gen Chevy II? I have about to come to the conclusion that my 3 core Champion radiator is very restrictive and is difficult to get enough air flow through it with an electric fan at idle. I have experimented with several different fans, including a 1990 Taurus from (from a 3.8L V-6). Even with the Taurus fan, it is creeping up to 230+ degrees when it is over 90 degrees outside at an idle. Naturally, when I get over 45 mph, it starts cooling back down.
I would think that it's not an air flow problem A Taurus fan on high speed will definitely move enough air through your radiator to cool it at idle if running at 45 mph will cool it. The Champion radiator has a core only 2" thick with three rows of .63" tubes, so it will be thinner than any 2-row radiator with 1+ inch tubes. We used a 380325 2-row Summit radiator and had troubles keeping the engine over 170° when the weather was cool.
Let's clarify the 500 hp issue. 500 hp occurs at one spot in the rpm range, and when you are cruising at 45 you are making a small fraction of that, and at idle even less. I would suspect you have a coolant flow issue and need to move more coolant in the low rpm ranges.
 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #4
I would think that it's not an air flow problem A Taurus fan on high speed will definitely move enough air through your radiator to cool it at idle if running at 45 mph will cool it. The Champion radiator has a core only 2" thick with three rows of .63" tubes, so it will be thinner than any 2-row radiator with 1+ inch tubes. We used a 380325 2-row Summit radiator and had troubles keeping the engine over 170° when the weather was cool.
Let's clarify the 500 hp issue. 500 hp occurs at one spot in the rpm range, and when you are cruising at 45 you are making a small fraction of that, and at idle even less. I would suspect you have a coolant flow issue and need to move more coolant in the low rpm ranges.
Mine must be a 4 core radiator then because it is 3" thick. I had not considered a water flow issue. I am going to double check my lower radiator hose to make sure it isn't collapsing. I have used both a 1994 GM pick up water pump and a 1990 Corvette water pump (both are reverse rotation with my serpentine belt set up) and had the same issues.
 

·
Registered
Joined
·
9,963 Posts
Mine must be a 4 core radiator then because it is 3" thick. I had not considered a water flow issue. I am going to double check my lower radiator hose to make sure it isn't collapsing. I have used both a 1994 GM pick up water pump and a 1990 Corvette water pump (both are reverse rotation with my serpentine belt set up) and had the same issues.
Must be an old radiator. Champion doesn't list a radiator with a core thicker than 2". They have tanks that are 3.25" thick, but the cores are listed as 2".

 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #6
I bought it 7 years ago.
 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #7
I am going to pull the cap off of it and look inside to count the cores when I go over to the shop later this afternoon.
 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #8
I would think that it's not an air flow problem A Taurus fan on high speed will definitely move enough air through your radiator to cool it at idle if running at 45 mph will cool it. The Champion radiator has a core only 2" thick with three rows of .63" tubes, so it will be thinner than any 2-row radiator with 1+ inch tubes. We used a 380325 2-row Summit radiator and had troubles keeping the engine over 170° when the weather was cool.
Let's clarify the 500 hp issue. 500 hp occurs at one spot in the rpm range, and when you are cruising at 45 you are making a small fraction of that, and at idle even less. I would suspect you have a coolant flow issue and need to move more coolant in the low rpm ranges.
Are you using this radiator in a 1st Gen Chevy II? If so, how did you mount it in the car?
 

·
Registered
Mike - 74 Nova Baltimore, MD
Joined
·
1,484 Posts
If the radiator is able to cool the engine while driving 45 mph, I would think that the radiator is able to meet the cooling needs of the engine. Poor coolant flow... or air flow from the fans at idle are definitely prime candidates.
I am not familiar with the air flow characteristics of the Taurus electric fan, so I will defer to Mike G's opinion on that item.

Another thing to consider is your ignition timing at idle. If it's too low (retarded), that will make your engine run hotter at idle. As your rpm's increase, so would your timing (unless yo have the advance locked out).
  • Do you know what your initial timing at idle is?
  • What type of distributor are you using?
  • Is your distributor vacuum advance connected?... and if so, is the VA connected to a Full Time vacuum source?... or a ported/part time vacuum source?
You may also want to check that your carb's idle mixture is not too lean. Lean air/fuel ratio will also make an engine run hotter.

You could try this simple test to determine if your radiator is at fault. When your engine temps start to creep up while at idle, put your car in neutral and rev your engine to the RPM that you normal see when cruising at 45 mph and hold the rpm for about 30 seconds to a minute (also confirm that your electic fan(s) are running).
- If the coolant temps begin to drop, the issue is probably not in the radiator. I would be looking at low coolant flow at idle (as Mike G suggested) or a timing and/or carb adjustment.
 

·
Registered
Joined
·
9,963 Posts
Are you using this radiator in a 1st Gen Chevy II? If so, how did you mount it in the car?
I put the 380325 radiator in a 64 that we raced in Mexico. I made some mounting brackets from strap steel and mounted it like the later radiators that use the rubber cradles at the bottom and the mounting straps at the top. The straps were bolted to the radiator support. You can see the top straps in this pic.

 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #11
I double checked and I do have a 3 core Champion radiator.
 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #13
I am guessing the cores were about 3/4" so with 3 of them it was about 2.25" thick.
 

·
Premium Member
1968 Chevy II Nova, Central Arkansas
Joined
·
1,991 Posts
I agree with Mike I don't think airflow is the issue. I have a 500hp 383 in my 3rd gen with a Champion radiator and I am cooling it with a mechanical fan and a fan shroud. I usually run around 190 degrees. It may creep up to 200-205 if I have to sit long enough at a stop light with the a/c running. What kind of water pump are you running?
 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #16
I experimented today. Several people have mentioned that stall converters can create a lot of heat and I had spare transmission cooler and a small fan so I installed them in line to my radiator to see if precooling my transmission fluid would help. It doesn't seem to have made any difference. I may head to the junk yard and buy a mechanical fan with a clutch just to see if that will cool it.

I have tried 2 different water pumps. My serpentine brackets came off of a 1994 Chevy Pick up. Until recently, I had the OEM water pump for a 1994 Chevy Pick up on the car and have since switched to a 1990 Corvette water pump (both pumps are reverse rotation because of the serpentine drive) because it allowed me to gain 1.25" of clearance between my water pump and the radiator. I have had cooling issues at idle with both water pumps.

Also, when the motor started heating up at idle, I put it in neutral and held the rpms up to about 1100 or 1200 for a minute or two. It didn't seem to be cooling off at all by doing this. What did help was turning the A/C off. That alone cooled the motor down about 10 degrees.

I ordered a new lower radiator hose from Napa this evening with a spring in it. It didn't appear that the lower hose was collapsing but at this point, it is inexpensive to try.

Here is a link to the fan/shroud that I am using. CCI-1790 | Cooling Components

404103
 

·
Registered
Joined
·
21 Posts
First, get the real fan and A/C fan clutch back on, with the full shroud. The picture above says volumes on how to do it right.

Then, fix the timing issues, and set the carb up right.
 

·
Registered
Joined
·
166 Posts
I experimented today. Several people have mentioned that stall converters can create a lot of heat and I had spare transmission cooler and a small fan so I installed them in line to my radiator to see if precooling my transmission fluid would help. It doesn't seem to have made any difference. I may head to the junk yard and buy a mechanical fan with a clutch just to see if that will cool it.

I have tried 2 different water pumps. My serpentine brackets came off of a 1994 Chevy Pick up. Until recently, I had the OEM water pump for a 1994 Chevy Pick up on the car and have since switched to a 1990 Corvette water pump (both pumps are reverse rotation because of the serpentine drive) because it allowed me to gain 1.25" of clearance between my water pump and the radiator. I have had cooling issues at idle with both water pumps.

Also, when the motor started heating up at idle, I put it in neutral and held the rpms up to about 1100 or 1200 for a minute or two. It didn't seem to be cooling off at all by doing this. What did help was turning the A/C off. That alone cooled the motor down about 10 degrees.

I ordered a new lower radiator hose from Napa this evening with a spring in it. It didn't appear that the lower hose was collapsing but at this point, it is inexpensive to try.

Here is a link to the fan/shroud that I am using. CCI-1790 | Cooling Components

View attachment 404103
Just remember, when the AC is running the air going thru the AC condenser is going to be higher than normal. So the air going thru the radiator is going to be higher which makes the engine temp run higher. If in traffic, turn off AC, put in Neutral or run the heater some. Or all three.
Dave
 

·
Registered
Joined
·
18 Posts
Has anyone had any success keeping a 500 hp 383 stroker with a 3000 stall cool with a Champion Radiator in a first gen Chevy II? I have about to come to the conclusion that my 3 core Champion radiator is very restrictive and is difficult to get enough air flow through it with an electric fan at idle. I have experimented with several different fans, including a 1990 Taurus from (from a 3.8L V-6). Even with the Taurus fan, it is creeping up to 230+ degrees when it is over 90 degrees outside at an idle. Naturally, when I get over 45 mph, it starts cooling back down.
I don’t know if this helps, lol. I had same radiator on a 550hp 383 and it would run real hot. Switched to a 2 core griffin with 1.25 tubes and it ran super cool. Idk if it’s the tube size or what but I had no luck with champion
 

·
Registered
Joined
·
1,124 Posts
Discussion Starter #20 (Edited)
I don’t know if this helps, lol. I had same radiator on a 550hp 383 and it would run real hot. Switched to a 2 core griffin with 1.25 tubes and it ran super cool. Idk if it’s the tube size or what but I had no luck with champion
This is the EXACT info I was looking for. Was yours overheating at idle, driving down the road, or both? Also, what kind of fan and shroud are you running?
 
1 - 20 of 44 Posts
Top