The Stovebolt Site Forums The Shop Area The HiPo Shop Replacement radiator does not fit. Looking for suggestions

I have a 54‘ Chevy 3100 that I’m restoring. Also switching to a SBC. I needed a new radiator so I purchased a Champion 3 row as a direct replacement. Everything I saw online looked like this was a direct replacement to the original radiator. My issue is that that cross bracing on the core support is not allowing the radiator flanges to sit flat as they should. The top set of holes is fine. Middle I’m about 3/16“ out and then the bottom is almost 3/8“ out. Has anyone else run across this and if so what did you do to correct? I bought the radiator a couple of years ago so there’s no returning it. The new radiator is about 1/2“ thicker than the original. But it seems like Champion would’ve accounted for that and welded the flanges on correctly to compensate. I’m not an aluminum welder so anything like that I’d have to find someone to do.

My thoughts are either remove the cross bracing on the core and weld them possibly on the back of where they are now. Or I could just shim out at each location. I thought about a 3/8“ piece of bar stock between the radiator flange and core but that would push the top a ways out and not look as clean. I’m open to thoughts and suggestions.

Also I’m planning on running an electric fan and shroud. Right now the shroud I have measures 1 1/4“ from where I mount the electric fan to the fins on the radiator. Anyone have any thoughts on a minimum distance a fan shroud should be compared to the radiator? I know I could mount the fan directly to the radiator but I like the idea of the shroud. Just want to make sure it’s actually helping me and I’m not doing something to decrease the effectiveness of it. Thanks for any thoughts or comments.

Adam

SOME radiator supports had no cross bracing from the factory. I think you'd be fine to remove the bracing and reweld the braces farther forward. I'm assuming your new radiator has a thicker core than the stock one, which is causing the issue.

Need to see actual pics of the interference. Kevin is correct, many aftermarket support frames do not have any "crossmember." But I would like to see what crossmember you are talking about. If it is what I think it is, remove it. If it what I think it is, it is not necessary for structural strength, so leave it removed. I would refer to it as a gusset or a bracket for something.

Fan:
1. I assume no original mechanical fan, just electric?
2. A SBC should cool just fine, no need to go overboard.
3. Electric fan should be mounted per mfg instructions.
4. Normal installation of a stock mechanical fan and shroud is fan blade about 1" from RAD and blade half in shroud and half out.
5. Fans are only for low idle RPM's..........under 30MPH. Ram air cools otherwise. A shroud and electrical fan could possibly block/decrease ram air flow in some DIY efforts.
6. The only reason I see for electric fans is lack of space or as a band aid for overheating. A mechanical fan works otherwise and is fail proof.

I would agree with most of the above, but not all.

At the power levels you are probably targeting and a radiator that size, ram airflow is most likely sufficient at speed. With trucks pushing more power, thinner radiators, or smaller frontal areas the fan becomes significant at higher speeds. That said, your radiator appears to have the ports for an automatic transmission. If you are running an auto, you will be dumping more heat into it, especially carrying heavier loads, and that will have an impact.

I have had better success with electric fans that mechanical ones. The clutches on mechanical fans fail in non-obvious ways and it can be a real pain to track down what the problem is. An electric fan has more obvious failure modes and (in my experience) is less prone to failure.

The electric fan also has the advantages that it can ramp up to full speed while you are stopped, giving you full cooling for yoir engine and/or AC. Additionally it consumes no powerand makes no noise when it is turned off.

An electric fan does require more wiring and a sufficiently large alternator to support it, but if you are going to an SBC anyway it is unlikely that you would find an alternator small enough to be a problem.

You haven't disagreed with anything I have said but you have made up scenarios to disagree with. I was speaking of a 1954 mechanical fan, no clutch on those. Don't know if the SBC year he has, has a clutch. You can mount a non clutch on it.
No use in discussing scenarios of what a "motor pushing more power" needs. That is off topic and encourages off topic discussion.
A clutch is much less likely to fail than an electrical fan's thermostat, motor, wiring, fuse, connectors and plastics.

The in-radiator transmission cooler feature does not affect the temperature of the coolant in the radiator. Adds no impact.

Thanks for the comments guys. Surprised that some didn’t have the braces. And yes the new one is wider but I guess it makes sense they can’t move the radiator accordingly for clearance on the cross bars as it would put the radiator to close to the stock mechanical setup. The braces I’m calling the „X“ and the lower cross piece. Basically a rod welded in. I decided to try and massage the rods to see if I could get that to work. I grabbed the torch and heated by where they attached to the core. Then took a larger hammer and a steel dowel and was able to put an „offset“ on the rod. Then ground a flat on the rod. Between a couple rounds of that I was able to get enough clearance.

I was going back and forth on the mechanical or electrical fan but decided on an electrical. With the modification I made to get the radiator to fit the shroud I have and fan fits nicely luckily. Thanks again guys for the thoughts.

Adam

Good work.
When you said crossmember I thought you meant the one in pic. Not rods. Some do have a gusset/crossmember but they are GMC not Chevy. The rods don't do much either. You can remove them if you need to. Good luck with the build, let us know if you need other help. But looks like you know what you are doing just fine.

The rods help with keeping everything square up front. If it were mine, I would make 3/8" spacer bars for either side of the radiator. And if the gap at the outer top bothered me, I would find a way to nicely install a rubber flap. Most everyone's eyes don't fall to that area, but more to the sheet metal cover that holds the latch. I had left ovr interior paint in my gun, so I painted that panel. Now, whoever looks at it says "Cool!"

Did you notice the 1/2" gap I have between the radiator and the core?

Nice work Adam. I just cut my X brace and horizontal brace off to make '49 Desert Cooler Harrison radiator fit my '50 radiator bracket.
I recommend using a Flex fan on the water pump. The blades are cupped at idle to provide maximum air flow, but flatten out at higher RPM, reducing drag on the engine. The one I use is quiet.
I have a serpentine belt setup with the right spacer to put the fan 3/4" from the radiator.
My engine temperature stays at 180 most of the time. On a hot day with the A/C on, it climbs up to 190.

1. Did he tell you how much power he is making? If not, you have no more idea than the rest of us and helping make an informed decision is helpful. The greatest majority of SBCs also have clutch driven fans, so the failure rate of those clutches is relevant to the discussion.

2. Say what you will, I have had more mechanical clutches fail than electric fans. To each their own on what they trust.

3. Basic thermodynamics: trans fluid is run through the radiator to cool it. More heated liquid == more thermal load in the radiator. More thermal load requires more airflow to keep it cool.

As the OP has solved his problem, locking this down.