A testimonial for aluminum radiators
07-13-2002, 06:46 PM
#1
Former Vendor
Thread Starter
A testimonial for aluminum radiators
HOT C4 by Tom Walilko
Does your C4 run warmer than it used to? Maybe you need a new, improved radiator.
Let me tell you the saga of my overheating C4. I bought a 1990 convertible in 1997, with 42K miles on it. For the next 3 years, it had no problems except for a failed water pump and alternator. On a 90 degree day, the car would idle along at 1 mph (in the Woodward Dream Cruise) with the A/C on full blast, and the temp gage never went above half scale.
But last year, at 85K miles, the car started running at 90 to 95% on the temp gage, if the outside temp was over 60 degrees. Why? Worried, I ran with the A/C off, which would lower the temp gage about 5%. I also tried to keep the speed over 70 mph, which would lower the temp gage about 5%. I tried turning the heater on full blast (not fun on 90 degree days), which would lower the temp gage about 10%. The car never boiled over or lost any coolant.
I replaced the 195 degree thermostat with a 160 degree – no difference. I ran for 2 weeks with no thermostat – no difference. I removed and disassembled the water pump – it was still like new. I replaced both radiator hoses – no difference. I put jumper switches on both electric fans – no difference. I inspected the radiator on the right side (the only place visible). Both the front & back of the radiator were clear of feathers, leaves, paper bags, etc. I back flushed the radiator 3 times and put in new coolant – no difference.
The old radiator hoses and overflow tank were clean. There was no evidence of oil in the coolant, or of water in the oil. Still worried about a blown head gasket, or cracked head or block, I considered getting an exhaust gas analyzer held above the radiator cap, or buying the dye you add to the coolant that glows under a black light when contaminated with combustion gasses. But first (since my Ford had 2 spark plug insulators stained green by antifreeze when the head gasket failed), I changed all the spark plugs – the old ones looked all white.
I changed the ACT, ECT, and temp gage sending unit – no difference. Since the car had never boiled over, or lost coolant, I decided the head/gasket/block failure was not likely. So the only thing left to do was a new radiator. The stock radiator is a marginal, minimal design, and the plastic end tanks with rubber gaskets made me worry about failure at old age & high mileage.
When I removed the radiator, I found the problem. I could see daylight through the top 3 inches, the left and right 3 inches of the radiator. The rest of the core (60%) was plugged with sand, so no air could get through. Could I flush it with an air or water hose? Maybe, but at 95K miles, I figured a new radiator was advisable. More cooling and better quality than the OEM unit was available from Griffin Radiator.
By the way, I did clean the old radiator. First I laid it face down on the driveway, picked it up 2 inches, and slammed it back down. After about 100 slams, I had removed 2 pounds of sand. Then I squirted the back of the radiator with a compressed air nozzle for almost 20 minutes, until no more sand came out. Then I could see daylight through the whole radiator. But there were still 1 or 2 grains of sand stuck between about every third fin in the core. The OEM radiator has fin spacing of 0.030" to 0.040", ideal for trapping sand! My new Griffin radiator has larger fin spacing of 0.050" to 0.080", meaning it's not a sand trap.
.
Griffin Radiator, in Piedmont, SC, (864) 845-5000, http://www.griffinrad.com, makes radiators for a C4, all 100% aluminum, and, I believe, all with an A/T cooler built in. The Pro Series (in stock) gives 38% more cooling than the OEM radiator. The HP Series (2-3 week delivery) gives 100% more cooling than OEM, for very high performance motors or race cars. The HP max Series (custom made to order) gives even more cooling. Each series come in 2 models, for 84-89 (with a radiator cap), and for 90-96 (without a radiator cap).
I bought a Pro Series for my 1990 C4. Conveniently for me, DeWitts Reproductions, in Brighton, MI, (810) 220-0181, who makes duplicate OEM radiators for early Vettes, is also a distributor of Griffin radiators, and is less than 50 miles from my house in Detroit. By the way, you can see color photos of all the radiators at http://www.dewitts.com. I compared my old and new radiators:
OEM Pro Series HP Series HP max Series
Weight 9 lbs 14 lbs
Tubes 1 row, 1-3/8”tubes 2 rows, 1”tubes 2 rows, 1-3/8”tubes 2 rows, 1-1/2”tubes
Core 1-3/8" thick 2-3/8" thick
Tanks 2-1/2" thick 3-1/8" thick
Installation of the Griffin radiator was not just a drop in, but not too hard, either. It was easier than you might think when looking at the car. The thicker tanks mean some trimming is necessary.
Under the black fiberglass top cover over the radiator are 3 items: the A/C condenser in the front, the radiator in the middle, and the electric fans at the rear. When I removed the top cover, I was relieved to find the radiator can be lifted right out, without moving the condenser or fans. Also easy – all work is done from above, with one exception: you have to lay under or beside the car to drain the radiator and to remove the bottom radiator hose and A/T cooling line. But that can be done without even jacking the car up.
Start by removing the radiator hoses and A/T cooler lines, if you have an automatic. Then remove the air cleaner & air cleaner housing. Next, on a 1990-96, remove the round rubber plug above the top right corner of the radiator, so you can access the vent tube clamp. Disconnect the vent tube.
Now you can remove the top cover. Remove the 5 bolts across the top rear edge of the cover. On the left side, remove the 2 bolts holding the fan relays, then the nut & 3 bolts holding the cover to the left frame rail. On the right side there are 4 fasteners. Remove the front nut, the 3rd fastener (nut), and the 4th fastener (bolt). (The 2nd bolt holds the A/C lines.)
On the left & right sides, towards the front of the cover, there are 3 screws. To reach them, unbolt the car's horns from both frame rails. Then use a 9/32 nut driver or socket to remove the lower 2 screws on each side, just below the frame rails. The upper screw on each side must be removed with an open end wrench or pliers.
Now pry & wiggle the left side of the cover up off the frame rail. Lift the left side up until it is above the right frame rail. Now wiggle & cuss until the radiator cover comes free from the A/C lines on the right side. Now lift out the old radiator.
There are 4 rubber pads that hold the top and bottom of each radiator tank in place. They have recesses the radiator fits into. The recesses are too small for the new radiator, since it has 5/8 inch thicker tanks. So all 4 pads must be removed and trimmed. The pads are about 6 inches long, and hold both the A/C condenser (front) and the radiator (rear). Lift out the bottom pads. Pull the top pads from under the top cover.
There are 4 fiberglass ridges on the radiator bottom cover that surround and hold the bottom rubber pads. The ridges must be ground or cut away where the new radiator will sit, or it will sit too high to get the top cover on. I did this with a ¾ inch grinding wheel in my Dremel motor tool. You might want to play it safe, and protect the A/C condenser with a piece of plywood or sheet metal, so it can't be nicked by the grinding wheel. The ridges are 1 inch high, and need to be less than ¼ inch high.
Next, trim the 4 rubber pads. First, take the top pads and cut off the front part 2 to 2-1/2 inches long, using a hacksaw or serrated steak knife. Reinstall the front parts in the top cover. Push them in, then grab the rubber nibs with pliers, and pull them through. Next, cut the rear of the top pads to 3 inches long, and trim them to ¼ inch thick with a saw, or knife, or a bench grinder. Reinstall the trimmed pads. Or, replace the rear of the top pads with new rubber 1-1/2 by 3 by ¼ inch, and glue them in place in the top cover. Now do the bottom pads. Cut off the front 2-1/2 inches and reinstall, then cut or grind the rear parts to ¼ inch thick, or replace with new rubber 1-1/2 by 3 by ¼ inch.
On a 1990-96, the new vent tube fitting (top right rear) is farther back than the original. Therefore, you must trim the top cover a little. With about 7 inches of hacksaw blade, with a handle or tape or vise grips on one end, cut as follows: at the vent tube hole, cut horizontally from the 9 o'clock position of the hole, back to the rear of the cover. Then cut from the 6 o'clock position, horizontally left to the rear of the cover.
3 inches below the vent tube hole, the upper A/T cooling tube hole was about ¼ inch too high on my car for the new radiator. With the top cover off, you can lower that hole ¼ inch with a file, or use a Dremel grinding wheel with the cover on or off.
Now you can reassemble the car. Note: the radiator hose fittings on the new radiator are 3/16 inch smaller than the OEM. Old, stiff hoses may not crush down too well, so new hoses are advisable, and double hose clamps, side by side, may be needed.
So how did it cool? Great. With a 160 degree thermostat, cooling the A/T and A/C and engine, my scan tool says the results were as follows.
With weather in the 60s, above 30 mph the engine stays at 160 degrees, or 170 degrees at speeds of zero to 25 mph.
With weather in the 70s, above 30 mph the engine stays in the 170s, or 180s at 0-25 mph.
With weather in the mid 90s, above 30 mph the engine stays in the 180s, or 190s at 0-25 .
The highest engine temperature I have seen, idling/stopped on a 96 degree day, was 199 degrees.
By the way, turning off the A/C cools the engine 10 degrees cooler than listed above.
By the way, you should check both DeWitts and Griffins websites. Griffins covers more models for all kinds of cars, but has few photos, and no prices. DeWitts has photos of all Corvette radiators, and prices.
Also, Griffin recently expanded from 25 employees to 100, to meet the demand for their excellent products. They also raised their retail prices significantly, because they wish to become a wholesaler, and to discourage retail sales.
To keep his sales volume up, DeWitts started offering a large discount on Griffin radiators.
I don’t know how many distributors Griffin has, or in how many states, or how many of them offer discounts like DeWitts. You can call Griffin and ask.
If you phone a credit card order to DeWitts for an in stock radiator, he can ship by UPS the same day. That’s great service. ‘Nuff said? (No, I don’t know anybody at DeWitts, and I never dealt with them before. I’m just a very satisfied customer. And my favorite hobby is helping people (like Corvette owners) whenever I can.
Tom Walilko
Does your C4 run warmer than it used to? Maybe you need a new, improved radiator.
Let me tell you the saga of my overheating C4. I bought a 1990 convertible in 1997, with 42K miles on it. For the next 3 years, it had no problems except for a failed water pump and alternator. On a 90 degree day, the car would idle along at 1 mph (in the Woodward Dream Cruise) with the A/C on full blast, and the temp gage never went above half scale.
But last year, at 85K miles, the car started running at 90 to 95% on the temp gage, if the outside temp was over 60 degrees. Why? Worried, I ran with the A/C off, which would lower the temp gage about 5%. I also tried to keep the speed over 70 mph, which would lower the temp gage about 5%. I tried turning the heater on full blast (not fun on 90 degree days), which would lower the temp gage about 10%. The car never boiled over or lost any coolant.
I replaced the 195 degree thermostat with a 160 degree – no difference. I ran for 2 weeks with no thermostat – no difference. I removed and disassembled the water pump – it was still like new. I replaced both radiator hoses – no difference. I put jumper switches on both electric fans – no difference. I inspected the radiator on the right side (the only place visible). Both the front & back of the radiator were clear of feathers, leaves, paper bags, etc. I back flushed the radiator 3 times and put in new coolant – no difference.
The old radiator hoses and overflow tank were clean. There was no evidence of oil in the coolant, or of water in the oil. Still worried about a blown head gasket, or cracked head or block, I considered getting an exhaust gas analyzer held above the radiator cap, or buying the dye you add to the coolant that glows under a black light when contaminated with combustion gasses. But first (since my Ford had 2 spark plug insulators stained green by antifreeze when the head gasket failed), I changed all the spark plugs – the old ones looked all white.
I changed the ACT, ECT, and temp gage sending unit – no difference. Since the car had never boiled over, or lost coolant, I decided the head/gasket/block failure was not likely. So the only thing left to do was a new radiator. The stock radiator is a marginal, minimal design, and the plastic end tanks with rubber gaskets made me worry about failure at old age & high mileage.
When I removed the radiator, I found the problem. I could see daylight through the top 3 inches, the left and right 3 inches of the radiator. The rest of the core (60%) was plugged with sand, so no air could get through. Could I flush it with an air or water hose? Maybe, but at 95K miles, I figured a new radiator was advisable. More cooling and better quality than the OEM unit was available from Griffin Radiator.
By the way, I did clean the old radiator. First I laid it face down on the driveway, picked it up 2 inches, and slammed it back down. After about 100 slams, I had removed 2 pounds of sand. Then I squirted the back of the radiator with a compressed air nozzle for almost 20 minutes, until no more sand came out. Then I could see daylight through the whole radiator. But there were still 1 or 2 grains of sand stuck between about every third fin in the core. The OEM radiator has fin spacing of 0.030" to 0.040", ideal for trapping sand! My new Griffin radiator has larger fin spacing of 0.050" to 0.080", meaning it's not a sand trap.
.
Griffin Radiator, in Piedmont, SC, (864) 845-5000, http://www.griffinrad.com, makes radiators for a C4, all 100% aluminum, and, I believe, all with an A/T cooler built in. The Pro Series (in stock) gives 38% more cooling than the OEM radiator. The HP Series (2-3 week delivery) gives 100% more cooling than OEM, for very high performance motors or race cars. The HP max Series (custom made to order) gives even more cooling. Each series come in 2 models, for 84-89 (with a radiator cap), and for 90-96 (without a radiator cap).
I bought a Pro Series for my 1990 C4. Conveniently for me, DeWitts Reproductions, in Brighton, MI, (810) 220-0181, who makes duplicate OEM radiators for early Vettes, is also a distributor of Griffin radiators, and is less than 50 miles from my house in Detroit. By the way, you can see color photos of all the radiators at http://www.dewitts.com. I compared my old and new radiators:
OEM Pro Series HP Series HP max Series
Weight 9 lbs 14 lbs
Tubes 1 row, 1-3/8”tubes 2 rows, 1”tubes 2 rows, 1-3/8”tubes 2 rows, 1-1/2”tubes
Core 1-3/8" thick 2-3/8" thick
Tanks 2-1/2" thick 3-1/8" thick
Installation of the Griffin radiator was not just a drop in, but not too hard, either. It was easier than you might think when looking at the car. The thicker tanks mean some trimming is necessary.
Under the black fiberglass top cover over the radiator are 3 items: the A/C condenser in the front, the radiator in the middle, and the electric fans at the rear. When I removed the top cover, I was relieved to find the radiator can be lifted right out, without moving the condenser or fans. Also easy – all work is done from above, with one exception: you have to lay under or beside the car to drain the radiator and to remove the bottom radiator hose and A/T cooling line. But that can be done without even jacking the car up.
Start by removing the radiator hoses and A/T cooler lines, if you have an automatic. Then remove the air cleaner & air cleaner housing. Next, on a 1990-96, remove the round rubber plug above the top right corner of the radiator, so you can access the vent tube clamp. Disconnect the vent tube.
Now you can remove the top cover. Remove the 5 bolts across the top rear edge of the cover. On the left side, remove the 2 bolts holding the fan relays, then the nut & 3 bolts holding the cover to the left frame rail. On the right side there are 4 fasteners. Remove the front nut, the 3rd fastener (nut), and the 4th fastener (bolt). (The 2nd bolt holds the A/C lines.)
On the left & right sides, towards the front of the cover, there are 3 screws. To reach them, unbolt the car's horns from both frame rails. Then use a 9/32 nut driver or socket to remove the lower 2 screws on each side, just below the frame rails. The upper screw on each side must be removed with an open end wrench or pliers.
Now pry & wiggle the left side of the cover up off the frame rail. Lift the left side up until it is above the right frame rail. Now wiggle & cuss until the radiator cover comes free from the A/C lines on the right side. Now lift out the old radiator.
There are 4 rubber pads that hold the top and bottom of each radiator tank in place. They have recesses the radiator fits into. The recesses are too small for the new radiator, since it has 5/8 inch thicker tanks. So all 4 pads must be removed and trimmed. The pads are about 6 inches long, and hold both the A/C condenser (front) and the radiator (rear). Lift out the bottom pads. Pull the top pads from under the top cover.
There are 4 fiberglass ridges on the radiator bottom cover that surround and hold the bottom rubber pads. The ridges must be ground or cut away where the new radiator will sit, or it will sit too high to get the top cover on. I did this with a ¾ inch grinding wheel in my Dremel motor tool. You might want to play it safe, and protect the A/C condenser with a piece of plywood or sheet metal, so it can't be nicked by the grinding wheel. The ridges are 1 inch high, and need to be less than ¼ inch high.
Next, trim the 4 rubber pads. First, take the top pads and cut off the front part 2 to 2-1/2 inches long, using a hacksaw or serrated steak knife. Reinstall the front parts in the top cover. Push them in, then grab the rubber nibs with pliers, and pull them through. Next, cut the rear of the top pads to 3 inches long, and trim them to ¼ inch thick with a saw, or knife, or a bench grinder. Reinstall the trimmed pads. Or, replace the rear of the top pads with new rubber 1-1/2 by 3 by ¼ inch, and glue them in place in the top cover. Now do the bottom pads. Cut off the front 2-1/2 inches and reinstall, then cut or grind the rear parts to ¼ inch thick, or replace with new rubber 1-1/2 by 3 by ¼ inch.
On a 1990-96, the new vent tube fitting (top right rear) is farther back than the original. Therefore, you must trim the top cover a little. With about 7 inches of hacksaw blade, with a handle or tape or vise grips on one end, cut as follows: at the vent tube hole, cut horizontally from the 9 o'clock position of the hole, back to the rear of the cover. Then cut from the 6 o'clock position, horizontally left to the rear of the cover.
3 inches below the vent tube hole, the upper A/T cooling tube hole was about ¼ inch too high on my car for the new radiator. With the top cover off, you can lower that hole ¼ inch with a file, or use a Dremel grinding wheel with the cover on or off.
Now you can reassemble the car. Note: the radiator hose fittings on the new radiator are 3/16 inch smaller than the OEM. Old, stiff hoses may not crush down too well, so new hoses are advisable, and double hose clamps, side by side, may be needed.
So how did it cool? Great. With a 160 degree thermostat, cooling the A/T and A/C and engine, my scan tool says the results were as follows.
With weather in the 60s, above 30 mph the engine stays at 160 degrees, or 170 degrees at speeds of zero to 25 mph.
With weather in the 70s, above 30 mph the engine stays in the 170s, or 180s at 0-25 mph.
With weather in the mid 90s, above 30 mph the engine stays in the 180s, or 190s at 0-25 .
The highest engine temperature I have seen, idling/stopped on a 96 degree day, was 199 degrees.
By the way, turning off the A/C cools the engine 10 degrees cooler than listed above.
By the way, you should check both DeWitts and Griffins websites. Griffins covers more models for all kinds of cars, but has few photos, and no prices. DeWitts has photos of all Corvette radiators, and prices.
Also, Griffin recently expanded from 25 employees to 100, to meet the demand for their excellent products. They also raised their retail prices significantly, because they wish to become a wholesaler, and to discourage retail sales.
To keep his sales volume up, DeWitts started offering a large discount on Griffin radiators.
I don’t know how many distributors Griffin has, or in how many states, or how many of them offer discounts like DeWitts. You can call Griffin and ask.
If you phone a credit card order to DeWitts for an in stock radiator, he can ship by UPS the same day. That’s great service. ‘Nuff said? (No, I don’t know anybody at DeWitts, and I never dealt with them before. I’m just a very satisfied customer. And my favorite hobby is helping people (like Corvette owners) whenever I can.
Tom Walilko
07-13-2002, 09:46 PM
#3
Melting Slicks
Re: A testimonial for aluminum radiators (Tom DeWitt)
Nice post, I just had to replace my Vette's radiator, stock one cost me ~$200 from Dal. What's this unit cost?
Eric
Eric
07-14-2002, 12:55 AM
#4
Melting Slicks
Member Since: Jul 1999
Location: Olive Branch (Memphis suburb) MS
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Cruise-In II Veteran
Re: A testimonial for aluminum radiators (silver & red CE)
$495 :cheers: http://www.dewitts.com./pages/produc...asp?ProdID=250
07-14-2002, 01:49 AM
#5
Team Owner
Member Since: Mar 2001
Location: Cincinnati, Oh USA
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Re: A testimonial for aluminum radiators (Tom DeWitt)
You might have been able to use your garden hose and blast water backwards through your original radiator and removed the sand and then put it back in the car. I hope you cleaned any sand out of the a/c condenser too. My 87 vette has 177k on it and the original radiator which I keep clean. I get 200 F at stoplights in mid 90's weather too, but I get mine with the installation of a Stewart water pump and a manual fan switch. The Stewart pump cost me $104 and the switch I had in my surplus parts box.
07-14-2002, 11:31 AM
#6
Burning Brakes
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Re: A testimonial for aluminum radiators (jfb)
One thing I've often wondered is if you they are making a radiator for use in a C4, why don't they make it a drop in replacement without having to make all the little changes? Just always curious about that. Doesn't sound like too tough an install though and your post is great. It should be helpful to a lot of people who are considering swapping over to the alum radiator.
