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Tom, I have an odd question or two bouncing around in my head, and you're the only guy I "know" that might be able to offer up some thoughts or numbers. The story:
I have more radiator capacity than I need, and possibly this would be an area that could be included in my weight reduction efforts.Thanks,Mike.
Mike, The 69 BB is the largest (27.5") core ever installed in a Corvette and it doesn't surprise me you have more than you need. You could down size to a single row 1.5" (38mm) tube core as long as the face area (18.5 x 27.5) was similar in size to what you have now. You also would want to have narrow end tanks , this would cut about one gallon of system capacity or 8 lbs. DeWitts could custom make one like this but you might be able to find a random oem model with plastic end tanks that you could adapt into the car for really cheap.. As far as all the flow and pressure drop stuff goes, don't lose any sleep over that. Yes, the Dp will be higher with a single row but who cares. You want good cooling with the lightest possible weigh, this is the way.
Mike, The 69 BB is the largest (27.5") core ever installed in a Corvette and it doesn't surprise me you have more than you need. You could down size to a single row 1.5" (38mm) tube core as long as the face area (18.5 x 27.5) was similar in size to what you have now. You also would want to have narrow end tanks , this would cut about one gallon of system capacity or 8 lbs. DeWitts could custom make one like this but you might be able to find a random oem model with plastic end tanks that you could adapt into the car for really cheap.. As far as all the flow and pressure drop stuff goes, don't lose any sleep over that. Yes, the Dp will be higher with a single row but who cares. You want good cooling with the lightest possible weigh, this is the way.
Tom, I appreciate the reply (and I certainly appreciate your not telling me I'm crazy ). I found an OEM radiator that will meet most of my sizing and packaging requirements for this "experiment", and I'm finishing up the fabrication to install it. I obviously don't have any hard data yet to show if this expenditure of time will be productive, but I do know that if I don't try this, that if in the course of a future track day I find myself in a cornering situation where another car has just a smidgen/miniscule better cornering speed than me, I know I will regret not taking the effort to try to further reduce the front end weight of my car.
I recall in a book by Carroll Smith several years ago that a well known acquaintance of his (a race car designer IIRC) made the comment that he estimated about 90% of his bright ideas didn't pan out. I figure if even the big boys have ideas that don't always work, it shouldn't be too big of a risk of embarrassment for a small time guy like me to try some odd stuff.
I installed the test/track radiator I obtained. It has about the same frontal area as the stock radiator, smaller end tanks, a single row of tubes, no pressure cap feature, and thankfully, the same type of air vent line on the top. Got the various hose shapes worked out to hook it up, and filled. Took it for a test drive the other day (mid 90s temperature), and things went well. I have a 195* thermostat in the engine, and the engine temps ran their usual 200*. Damn happy and relieved. This wasn't a proper/fair A-B comparison to the DeWitt radiator I had in the car, as I have run the DeWitt radiator for years with the front three grills about 90% blocked off (to minimize the airflow that ends up under the car), and in this test I left out the center grill block/sheet to allow more air to the radiator for this test. Once I get some actual track time with this radiator I can then see how much of the front grill I can start blocking again.
This modification should be about ten pounds lighter in radiator material and water/coolant weight. Pretty much all of it ahead of the front axle.
I installed the test/track radiator I obtained. It has about the same frontal area as the stock radiator, smaller end tanks, a single row of tubes, no pressure cap feature, and thankfully, the same type of air vent line on the top. Got the various hose shapes worked out to hook it up, and filled. Took it for a test drive the other day (mid 90s temperature), and things went well. I have a 195* thermostat in the engine, and the engine temps ran their usual 200*. Damn happy and relieved. This wasn't a proper/fair A-B comparison to the DeWitt radiator I had in the car, as I have run the DeWitt radiator for years with the front three grills about 90% blocked off (to minimize the airflow that ends up under the car), and in this test I left out the center grill block/sheet to allow more air to the radiator for this test. Once I get some actual track time with this radiator I can then see how much of the front grill I can start blocking again.
This modification should be about ten pounds lighter in radiator material and water/coolant weight. Pretty much all of it ahead of the front axle.
Nice Mod, I hope it all works out.
I take it you don't street the car to often.
I can only imagine what blocking off the front grilles would do in 90 temps, sitting in traffic.
Nice Mod, I hope it all works out.
I take it you don't street the car to often.
I can only imagine what blocking off the front grilles would do in 90 temps, sitting in traffic.
A few things. I've got a decent spark curve/advance at idle, so this engine doesn't overheat easily (the stock timing curve was a disaster). And, there's two chin openings under the two outer grills that feed air to the radiator. The pace car spoiler helps too.
I just skimmed through this sticky, but I only saw mentions of Champion and Dewitt. I have no experience with either of those. When i was shopping for a replacement radiator I was turned off by the "pieced together" look of the Champion and the $$$ of the Dewitt.
I wanted something that looked like it could be OEM. I found Cold Case. https://www.coldcaseradiators.com/pr...mance-radiator
The end tanks are formed and the welds looked good. Installation was pretty straightforward, but I ended up slightly relocating the lower supports to get a perfect fit. The lower tube/hose clears the sway bar with no problem. Performance has been good and my temps are now between 180 and 190. I've been happy with the product!
ps. It comes natural but i painted the fins black and left the sides natural.
Brand New member. Been a lurker and have solved many problems with my 1981 C3 by reading the posts.
The wealth of info is just amazing. I used a three row Champion as a cousin bought a Griffin. We compared
the two and other than the cheap cap on the champion there isn't much diff. I use two electric fans with a staggered
on setting and even at 100* with the ac on no issues. Last I will say Thank you again for all the questions answered
as a lurker. There is some very smart guys here and just the way the problems get sorted is great.
hi, replacing a leaking 79 L82 manual with AC 4 core factory electric fan running 100%.. debating recore or new aluminum.. found this at Zip.. anyone install one? will it be as good as 4 core?
mine runs a slow ramp to 160 f and now that it is cooler 140f to 160f.. will have to check what's in thermostat or not.. hot weather ac on driven hard 220 f.. but got slow leaks in radiator and looking inside some build up of minerals in and around tube openings so I know not performing ideally.
Price point is about the same as recore on that new one which is why I am struggling and both choice made in USA. thanks!!
My 4-row oem rad I had recored 24 years ago has sprung a leak a few weeks ago. I took delivery of a Cold Case, 2-row, 1-1/4" tubes, a few days ago from Summit. I didn't even consider getting another recore as aluminium is the way to go for a replacement. It appears some of the newer rads like Cold Case and Dewitts are using 2-row vice 4-row as it cools better, so they claim. Core thickness is about the same for both at ~2-1/2". The 4-row rads, like my oem, use tubes that are less than 1/2". So be aware that a 2-row rad has the same or better cooling than a 4-row rad. But do compare prices between the two aforementioned makers et al and tube size. Some models are 1" and some 1-1/4" which have more cooling capacity.
I will not be going with electric fans. My oem 7-blade clutch fan blows more air than I'll ever need.
My 4-row oem rad I had recored 24 years ago has sprung a leak a few weeks ago. I took delivery of a Cold Case, 2-row, 1-1/4" tubes, a few days ago from Summit. I didn't even consider getting another recore as aluminium is the way to go for a replacement. It appears some of the newer rads like Cold Case and Dewitts are using 2-row vice 4-row as it cools better, so they claim. Core thickness is about the same for both at ~2-1/2". The 4-row rads, like my oem, use tubes that are less than 1/2". So be aware that a 2-row rad has the same or better cooling than a 4-row rad. But do compare prices between the two aforementioned makers et al and tube size. Some models are 1" and some 1-1/4" which have more cooling capacity.
I will not be going with electric fans. My oem 7-blade clutch fan blows more air than I'll ever need.
Thanks 2 row here with one inch, says should work l82 and ac..i also am keeping belt fan, and it also has electric fan from factory. 2 one inch do the job compared to four core copper brass? Yours were 11/4
im ordering the dewitt from zip..will report...whats consensus on temp for thermostat?and or brand, tips advice? 160f 180f 195f i think original? Failsafe aftermarket or vendor oem style
update, zip says superior to my radiator. It is a @Tom DeWitt ..ordered original bottom hose too...will probably start with 180f fail stant thermostat, i bet mine has a 160f in it as gauge and ir gun confirms about there, don’t want to add heat but heard throughout forums 180 better than 195 original and 160 may not allow egr or carb heater to release? Also with heater on it drops to 140f this morning..
Different temperature ratings of thermostats all have their pro's and con's. Imo, the 180* is the proper thermostat for street cars because oil lubes best at or near that temperature.
I"m working to get my '76 stingray running again. It's been in storage for 9 years. When I was last driving it the temp would climb on a hot day as I recall to 200-210 degrees. It has a 427 sbc with Hooker headersidepipes and a griffin 31" x 19" two core aluminum radiator (the big tubes, cant remember the size) and a dual Spal electric fan/shroud setup controlled by the FAST xfi controller. Shroud is very well sealed to the radiator. Water pump might also be the issue. It was an aftermarket for circle track use I think. As I recall, the heat would build up at idle and then cool down on the road, but its been a long time since I have driven it. Can't drive it now because I have to rewire it due to a mouse...
Any recommendations for a top end radiator? I would like the specific part number and cost if anyone has it. Would a 2-core Dewitt or a 4 core Champion radiator be better? What about the water pump?
David
Last edited by Corvettedave02; 09-07-2019 at 12:05 PM.
Any recommendations for a top end radiator? I would like the specific part number and cost if anyone has it. Would a 2-core Dewitt or a 4 core Champion radiator be better? What about the water pump? David
1976 is a split year, in other words they used 77 radiators in the 2nd half of production. The easiest way to tell which one you have is to look at the upper hose connection. The 76 was curved and the 77 was straight.
So, 1139073A for 76 and 1139077A for 77.
Thanks TOm. It’s modified with electric spal fans without the original shroud so I doubt it matters. I already customized the mounting system for the griffin radiator. I’ll check your link.
Last edited by Corvettedave02; 09-07-2019 at 04:37 PM.
I took delivery of a Cold Case, 2-row, 1-1/4" tubes, a few days ago from Summit
How was it packaged? The Cold Case I ordered from Summit had crushed inlet and outlets. Fin damaged as well. Sent it back and like a fool had one dropped shipped. A lot of fin damage out of the box. I was so frustrated and wanted to get back on the road so I installed it. Long story short I went to drain it this morning. Nope. Petcock wouldn't turn as it hit the lower mount bracket. Sent it back this afternoon. What hassle.
Haven't installed yet. Mine had a dented outlet pipe in shipping. It looked like the rad was repackaged and then sent to me. Also, the repack may have been missing some styrofoam. Anyway, filed a claim with Summit. They discounted the rad another $75 and I got the outlet round again. The price is now very attractive. I'm happy up to this point. Install in a few weeks and see how it goes.
Haven't installed yet. Mine had a dented outlet pipe in shipping. It looked like the rad was repackaged and then sent to me. Also, the repack may have been missing some styrofoam. Anyway, filed a claim with Summit. They discounted the rad another $75 and I got the outlet round again. The price is now very attractive. I'm happy up to this point. Install in a few weeks and see how it goes.
06-30-2019, 12:08 AM
). I found an OEM radiator that will meet most of my sizing and packaging requirements for this "experiment", and I'm finishing up the fabrication to install it. I obviously don't have any hard data yet to show if this expenditure of time will be productive, but I do know that if I don't try this, that if in the course of a future track day I find myself in a cornering situation where another car has just a smidgen/miniscule better cornering speed than me, I know I will regret not taking the effort to try to further reduce the front end weight of my car.
