I just pulled my stock radiator, shroud, and electric fan from my 79 Auto C3 last weekend. Now I'm looking for an appropriately priced, good performing aluminum alternative. There is NO budget for a "Direct Fit" Dewitts or BeCool, so please try to stay on subject and keep your individual opinions on my purchase decisions to yourself (I'm opening to considering other similarly-priced radiators to the Champion and I'm interested in a radiator that comes with a matched shroud and single or dual electric fans of appropriate capacity to cool 450 hp.)

I'm looking for tips when installing a Champion 3 Row radiator in a 79 C3.

• Detailed info on any modifications required or challenges with the bottom supports and stock bottom rubber pieces.
• Detailed info on any modifications required or challenges with the top supports and top rubber pieces.
• Reinstalling new foam seals- should you still do this after switching to a new radiator (I think so) and if so, do the stock pieces still work with non direct fit radiators, or am I going to have to make my own seals that fit the gaps after installing a non direct fit radiator?

I am specifically looking to give me the most possible radiator to hood clearance so that I can use an over-the-radiator cold air intake to feed my TPI-style front-facing throttle body and plenum intake. -- Are there after market radiators that are shorter? Are there things I can / should do to the bottom support bracket to lower the radiator to give me the best possible chance at fitting a CAI over the radiator?

-I'm also thinking that I'll switch to a radiator that does NOT include an integrated transmission cooler and I'll mount a dedicated, separate trans cooler ahead of the AC condensor... -I'd love any feedback or identified pitfalls there.



Adam

 

I have run Champion radiators in both my 80 Vette and my current 75 Vette. With the exception of cutting the corners square in the bottom rubber for the square tank, I didn't have to do any mods at all in the 80. The 75 was a different story. The drain is on the bottom back side of the right side tank. It interfered with the bottom of the right side frame horn. It is unbelievable how much difference there is from car to car with these old Vettes! Anyway, I used a cutoff wheel and trimmed about 1/4" off the front edge of the bottom of the horn and all was good.

I did not have the stock top mount for the 75, it had an aftermarket aluminum radiator of unknown brand in it when I got it with poorly made top brackets. I fashioned some new ones and painted them black. I lined them with some really stiff high density foam. It worked out really well.

The dual fans are Summit a piece that I mounted with 1/4" bolts with nyloc nuts through plastic tube so I could pull the fan up firm to the radiator without over tightening it.

I used a combination of a radiator support seal kit and some AC foam from the hardware store to seal it all up good. I had to do a little extra fabrication to seal to my L88 hood. I also put a seal at the back of the hood that almost everyone with an L88 hood neglects to do.

I've run down the highway at pretty good speeds in 90 degree heat as well as in town with stop and go traffic, and it stays cool, well except for when my so called high performance high flow thermostat stuck closed. I also have a PC spoiler which helps get more air to the radiator. Photos below.

Mike

 

 

I put the Champion 3 row in my 78 with no issues or mods at all. I have a dual fan set up from a C5 and had to notch the shroud in a few places where it hit the A-arms. Going over the top for cold air however, is another story. I have quite a pile of stuff on the shelf that I tried, I cut, I tried again and could never get it to work. The issue isn't so much the clearance at the top ( although it is an issue), but there is also clearance problems when you open the hood. Especially if you have a condensor up front. That was a must for me here in S.C.. I am not done with my project, but I spent a lot of time trying to get it to work and I finally gave up, bit the bullet and went for the Varam set up I mocked it up and it literally fell into place. It wasn't cheap by any means, but when I recalled all the other BRIGHT IDEAS I had, I figured in the long run this would be best. I even tried the 82 core support and it didn't help much unless you had the 82 TBI set up for the air to get in. It made no difference for the TPI. I'd be glad to send you pics if you would like.

 

Now we're talking!

-I do have the condenser up front.

You used a C5 Corvette-style Varam and that fit over the champion radiator with a stock 78 bottom support bracket?

-Can you explain the 82 core support thing? --Are you talking about teh bottom bracket that the radiator sits on? -an 82 sits lower than the 78-81s???

You made a Vararam work with a TPI intake, is that what I'm hearing?


Adam

 

Tell me more about the 82 core support thing.. is this the bottom bracket it sits in you're talking about or the top? How much clearance do you gain with an 82 core support?
Did you ever get your CAI working over the radiator? (I noticed that the 2 core and 4 core Champion radiators are 1/4" shorter than the 3 core models.)


Adam

 

The 82 core support is identical except in the center of the top where the 82 has a slight V indentation. Like maybe 2"across and maybe 2" down. That is to handle the TBI intake that actually comes through the hood. But It goes through the hood too far back to use with the TPI so the hood is not helpful. It would have been too easy for the core support and the hood to just swap out for a TPI. I know the support is the same because...I got my hands on a good one for a good price and tried to go over the top and it didn't work. I actually ended up cutting the top support because a few members had cut the support and welded a piece of 4" pipe in the center. Again, that worked but what no one mentioned was it ended up being too low for a condensor to work . The top pic is the stock core support. The 82 has that V about where those 2 large holes are. The rest is the Varam ( it was not for a C5 but a GTO). Again, it's getting mocked up right now but the plastic base sits flush with the top of the core support. The sides of the base might need to go down a bit but the ABS plastic will bend easily with a little heat. And the top of the filter looks a tad too high, but nothing is bolted down yet. And ther is a good amount of adjustment availble. The only thing I need to do is route the top radiator hose. Or maybe notch out the plastic base so the hose pops up into it then seal .the opening with foam. This seems way more promising than all the other ideas I have seen. The other thing is I am using a MAF sensor, which takes up some real estate. If you have a speed density system, that won't be there. Search the forum, I got the idea on line, so it must be right!! Jim

 

I think I like the Vararam solution... I have a speed density system so sounds like an even better option...


Adam

 

Guys: Can you use the stock-style radiator hoses with the Champion radiators or do you need some ugly, flexy-type stainless hose kit or is there some other option?


Adam

 

What will work? Some SS exhaust pipe-for $10 I used a 45 º mandrel bent piece.\

You can cut the hose- put the pipe on the bend

It also keeps the hose from collapsing.

 

 

I think Champion may have a couple of radiators that could fit in a C3 so can't give a comprehensive answer - but in my case, with a Champion 3 row rad, I was able to use stock-style hoses (before I switched to a serpentine and had to change the upper due to routing).

 

The serpentine set up from the C4 makes it impossible to use the stock hoses. Thermo housing comes out in a different place at a different angle.
That is what I am figuring out now, but Richard's idea of the stainless exhaust tubing sounds like the way to go. All the other "KITS" that I found didn't have the angles/lengths that I needed. Get done with one thing and there are always 2 or 3 more waiting in line. I keep reminding myself that this is how I have chosen to have fun!!

 

Thanks everyone for the great feedback.

Now I have questions on CFM capacity required to cool my engine at idle....

I'm looking at the 3 Row Champion radiator (up to 750 hp rated), the aluminum fan shroud that I believe goes across pretty much the entire surface of the radiator, and a single 16" fan (because they only make a single fan shroud for this radiator). -I'd definitely upgrade to the Spal "2049" 16" high performance curved fan, which is rated @ 2024 CFM (0 static pressure). This fan is recommended for use with 3 core radiators and AC condensers.

I've also bought a high flow aluminum water pump and a high flow thermostat (185F) and I have aluminum heads.


My concern is that many sources recommend between 2,500 and 3,000 CFM worth of airflow for a V8 or for a V8 making 450 hp. -My thought is that driving around town at low speeds my engine's output will be WAY less and assuming I've got pretty good ignition timing, I'd like to think that rest of the cooling system being pretty good and having a nice big fan shroud means I can get away with the SPAL fan and 2024 CFM. (I also have the PC spoiler helping to stuff air through the radiator.) ---I DO have a 2,400 stall TC, though and using the integrated trans cooler is pretty tempting...

-If I start finding the engine running hot in the summer months (I live in Seattle so it doesn't get that hot here, but if I go on the otherside of the Cascades you can get 100 and even 110F summer temps.) my plan would be to offload the trans cooler duties to a dedicated trans cooler.



Anyone think what I have with a good 16" SPAL just won't be enough airflow?


Adam

 

Now I need to look into how to wire the stupid thing to have it controlled by my Holley EFI...

I think the stock holley harness only has a single integrated relay and I'm going to be using that for my fuel pump, so I think I just need a control signal / IO signal going to the fan relay's control side and then I don't need a thermostat going to the relay at all. (Just my digital thermometer going to the ECU and then the ECU will trigger the FAN relay.)


Adam

 

Those pictures really ARE worth thousands of words.

I think I'll setup some craigslist notification rules and try to find a used Vararam and build a solution off of that. Really looks almost perfect. I'd LIKE to come up with a solution that lets me use a bell mouth / velocity stack entry right upstream of the air filter to smooth the inlet flow; I came across a back to back CFM test of an air filter of this type and I was surprised to see the improvement that a bell mouth after a filter could make in inlet flow.

--Here's the video I was thinking of; it's showing an air filter with an integrated bell mouth: Having said that, I saw a quote by Prof Blair who indicated that the theoretical advantage of an ideally shaped bell mouth entry to be 1.5%; on a 440 HP engine that's 6.6 "free" HP.

I've been thinking this whole time that the C5-style Vararam might work and it's only $99, but I really like the GTO vararam that you went with (I don't like the price as much, though).


Adam

 

Thanks again everyone for your help!

I finally bit the bullet and ordered the 3 Row Champion Radiator (CC718), Shroud made for a single 16" fan (718FS16), upgraded to the SPAL-2049 High Performance 16" fan, bought the shiny polished billet cap $20), and a relay and wiring kit minus the thermostat (EFI will control it).

$446 for everything before shipping. $554.91 to my door.
Pretty happy with the price for what I got on paper; will see what it's like when it gets here...


Adam

 

IIRC those C5 style ducts are kinda tall/thick. Not sure one would fit even with the '82 style surround.

 

OR- kill two birds with one stone-

get a radiator like this-