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With my last engine (383 with 6 lbs boost) I had a Becool radiator. At low speeds going uphill under load there was not enough airflow thru it even with dual spal 11 inch fans and a pusher fan and it would overheat and I couldn't run the AC in hot temps in city traffic. . I would have to pull over and stop let it cool, then I could continue. I pulled out the becool and put in a 3 core brass copper that was a lot thinner core and that solved the problem. I now have a 401 with 11 lbs boost. With temps in the 80s I cannot run the AC in city traffic-it just keeps creeping up. I am looking at the Ron Davis radiator but I'm unsure if it still allows enough airflow thru their 2 core. If there are any comparisons between Beccol and Ron Davis it would be nice.
I've been researching the heck out of this. No responses thus far so I'll reply on my own post.
It looks like an aluminum radiator will transfer more heat, but in slow speed situations fin count per inch is the critical difference. I've found that Ron Davis is up to 19 per inch=gonna overheat at slow speeds. I have not been able to find what fin count Be cool uses-anyone know? It looks like Dewitts uses 14 as middle of the road compromise.
Also I ripped out vertical rows of fins in the AC condensor (doesn't seem to effect AC cooling) to get more airflow to the radiator-and have an aftermarket trans cooler in front of the AC condensor that only covers an area on the passenger side in addition to trans fluid thru the radiator. Other info on my setup is a high flow water pump and a larger crank pulley, so the pump is overdriven, not underdriven. and a high flow 160 stat, fans on at 190. front fan on at 210.
Whatever the fin count on the Be Cool it was too much.
If Tom Dewitt reads this-can you help out on the fin count vs airflow question?
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I'll play....Have you thoroughly cleaned your condenser? Mine was doing this before the A/C system sprang a small leak and dumped the Freon. I agree that multi-row radiators tend to have worse flow at slower speeds/idle. As I've yet to repair/refill my A/C, I can't comment on THE RIGHT answer. Having said that, you MIGHT also verify you're idle timing isn't causing the hotter temps at lower rpms. There's a fine line between between too retarded and smoking your headers vs being too advanced. For me, advanced worked better than retarded. What we MIGHT have in common is the original, gross, dirty condensor. Sure I've sprayed mine a couple of times but never with a cleaning agent. Never tried a fin-straightening brush either AND, after 25 yrs, there's several bent fins.
FINALLY, there's the issue of how high it gets (temps) and how worried you are about that Also, what your mix is? There are a few additives that can help -- a little. OK...OK...tell us about your fans too. Original? Both working? Still using the dual 11s? Are both running ALL THE TIME?
timing is base 6 total 20 at idle, I program with ebl4 and stay conservative on timing.50/50 distilled water and coolant with water wetter added. fans programmed as above. I found out Be cool is 14 fpi and Dewitts is 15 to 16 fpi. Good point on the AC condensor condition-however as above I've stripped out vertical rows out of the fins in it for direct air to the radiator. Another thought is to remove the trans cooler from in front of the condensor-but I'm at a loss on where to move it to. On temps when it gets to 228 and still steadily climbing I shut off the AC, then it takes a while before it starts going back down and oil temps are hitting 255.
Grab your timing light and varify actual timing agrees with commanded timing in your tune throughout the rpm range. It might be happier with more advance at low rpm's. Mine likes to idle with 28 degrees at 750 rpm's and up to 36 degrees by 1200 rpm's at light throttle.
I'll play....Have you thoroughly cleaned your condenser? Mine was doing this before the A/C system sprang a small leak and dumped the Freon. I agree that multi-row radiators tend to have worse flow at slower speeds/idle. As I've yet to repair/refill my A/C, I can't comment on THE RIGHT answer. Having said that, you MIGHT also verify you're idle timing isn't causing the hotter temps at lower rpms. There's a fine line between between too retarded and smoking your headers vs being too advanced. For me, advanced worked better than retarded. What we MIGHT have in common is the original, gross, dirty condensor. Sure I've sprayed mine a couple of times but never with a cleaning agent. Never tried a fin-straightening brush either AND, after 25 yrs, there's several bent fins.
FINALLY, there's the issue of how high it gets (temps) and how worried you are about that Also, what your mix is? There are a few additives that can help -- a little. OK...OK...tell us about your fans too. Original? Both working? Still using the dual 11s? Are both running ALL THE TIME?
After getting a bright light behind and in front and trying to look further at/thru the condenser I'm thinking you have nailed it with that suggestion. I'm planning on buying a brand new condenser, then strip some vertical lines out of the fins just like I currently have. Second thing I'll do is space out the trans cooler a bit more from the condenser-I still have some room before it would hit the front pusher fan. Also I want to reprogram the front pusher fan to come on sooner.
The Becool radiator has 14 fpi so I'm considering throwing that in at the same time, just a lot of dollars! There wouldn't be much else I could do at that point except maybe try to custom fit a pair of 12 inch spal fans, but it doesn't look like you gain all that much from dual 11 inch spals.
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Originally Posted by drive it
After getting a bright light behind and in front and trying to look further at/thru the condenser I'm thinking you have nailed it with that suggestion. I'm planning on buying a brand new condenser, then strip some vertical lines out of the fins just like I currently have. Second thing I'll do is space out the trans cooler a bit more from the condenser-I still have some room before it would hit the front pusher fan. Also I want to reprogram the front pusher fan to come on sooner.
The Becool radiator has 14 fpi so I'm considering throwing that in at the same time, just a lot of dollars! There wouldn't be much else I could do at that point except maybe try to custom fit a pair of 12 inch spal fans, but it doesn't look like you gain all that much from dual 11 inch spals.
If you already haven't done so, I'd try cleaning the old condenser first. If nothing else, it might lower it's temps by removing dirt (that could act like insulation). Straight fins too. Also, check between radiator and condensor -- if you haven't already. You'd be surprised at the junk that gets around the condenser and into that space.
There are lots of youtube videos to guide you on cleaning condensers.
Finally, you might be able to make/install baffles that will direct SOME air around the condenser. Seems like I've seen one/two try this over the years.
Oh yeah...Big Mouth air diverters MIGHT help a smidge too. THough I'd bet on it helping more "at speed".
1) Ditch the pusher fan
2) Change the condenser and don't worry about trimming the fins
3) Move the trans cooler. Get a kit with a dedicated fan. I would suggest laying it down in the front of the nose. Cut a hole through the front inner fender and allow the fan to draw air up. You can be cheap here https://www.summitracing.com/parts/s...BQPS8C1yvmG3QU or spend more money
Thought would post a couple pics on where I moved the trans cooler. Doesn't block the radiator now and will still get lots of air to it. If anyone else is working on moving things around I hope this helps. Also the new AC condensor I got is the updated flat plate instead of the tube and fin. I will still pull the fins out of 5 rows spread across it. The flat plate is supposed to need 30% less size than tube and fin and the area I'm clearing of fins is only 20% of the size so I think it will still work fine for the AC and allow a lot more air thru it to the radiator at slow/no speed. And the fans are sealed against the radiator. I'm going to leave the pusher fan and rewire it to come on the same time as both Spal fans. If this does the trick I will be very happy!
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Even though I've had my radiator out a couple of times AND swapped to a non-OEM style (that required modest mounting modifications), I don't know what I'm looking at in the prior images. Maybe I'm not the only one?
Behind where the booster fan sits (in my 89), is the condenser that precedes the radiator. I your 1st pic (above), I feel like I'm looking at a small trans cooler followed by what? It looks like a "back-stop of plastic" vs fins of the condenser or radiator? The other pic of a tunnel/shoot is also bewildering.
For me, more explanation or images are necessary before I can understand what you did. I've also never heard of a "flat-plate" condenser. Link please?
Even though I've had my radiator out a couple of times AND swapped to a non-OEM style (that required modest mounting modifications), I don't know what I'm looking at in the prior images. Maybe I'm not the only one?
Behind where the booster fan sits (in my 89), is the condenser that precedes the radiator. I your 1st pic (above), I feel like I'm looking at a small trans cooler followed by what? It looks like a "back-stop of plastic" vs fins of the condenser or radiator? The other pic of a tunnel/shoot is also bewildering.
For me, more explanation or images are necessary before I can understand what you did. I've also never heard of a "flat-plate" condenser. Link please?
I believe the first picture is "looking" towards the front of the car, that "backstop" is the front side of the housing, the air cleaner would be right on the other side of the "backstop"...in this picture, the condenser and radiator haven't been installed yet...so tranny cooler, pusher fan, condenser, radiator (topish to bottomish in the photo- slight angle).
The second picture, I can only guess is a close-up of what seems to be possibly an aftermarket front bumper cover, where maybe the fog light/turn signal openings or center of bumper cover have/has been converted to cold air ducts!?👍
I believe the first picture is "looking" towards the front of the car, that "backstop" is the front side of the housing, the air cleaner would be right on the other side of the "backstop"...in this picture, the condenser and radiator haven't been installed yet...so tranny cooler, pusher fan, condenser, radiator (topish to bottomish in the photo- slight angle).
The second picture, I can only guess is a close-up of what seems to be possibly an aftermarket front bumper cover, where maybe the fog light/turn signal openings or center of bumper cover have/has been converted to cold air ducts!?👍
Sorry for a lack of clarity-yes first pic is looking forward at where I moved the trans cooler to, which has air from a front license plate opening directly to it. Also here is the difference between tube and fin and flat plate condensors.
Also the intercooler is thru the front hood so it does not block air to the radiator either. Once it's together I'm going to measure out if an oil cooler will fit behind the radiator-near where the factory put a power steering cooler.I just wish our vettes had a decent size grill opening for air-would be so much easier!
Another radiator upgrade thread question
