MikeJTR Posted March 19, 2007 Share Posted March 19, 2007 There could be any number of reasons why the JTR radiator doesn't perform well in some of the above listed applications. The JTR radiator is nothing more than the 1984-1986 Camaro V8 base radiator (non-heavy-duty), with a thicker core. The actual core is used in 3/4 vans. The actual core has more surface area than the 1984-1988 Corvette radiator that is used on the RX7 LS1 V8 swap. In the RX7's with LS1, LS2, and a 500 rwhp LS7 engine, the Corvette radiator has performed well, even when road racing. According to MAS280, who had roadraced his LS7 RX7, his car with the Corvette radiator, was running cooler than the C6 Corvettes. I suspect Gretchen/Jason's problem has to do with high-rpm and coolant foaming. In previous posts, he stated the temperature went down when he changed to a pulley that slowed down the water pump. When he is running the radiator with more rows, the coolant may be less foamy as it goes through the radiator, and this would improve the cooling. It is also possible that his engine had debris in it that clogged the JTR radiator. This can be checked by running the engine fully warmed up, with electric fan running, and feeling the core with your hand, to see if some sections of the core are cool. There is a lot more to cooling than the radiator. Sometimes overheating problems are not diagnosed properly, and this can lead to all kinds of incorrect theories. One more point. When I investigate an overheating problem, I always use an infrared thermometer to measure temperatures going into the radiator, and out of the radiator. Most of the infrared thermometers will not read correctly on uncoated aluminum. With aluminum engine parts and hose fittings, I normally paint the parts with black paint, which allow the infrared thermometers to provide accurate information. Quote Link to comment Share on other sites More sharing options...
Bartman Posted March 19, 2007 Share Posted March 19, 2007 I'm running a 160 degree stat and have my fan's reprogrammed to turn on at lower temperatures. I can't say my problems have anything to do with the radiator at this point, but Jason's comments definitely caught my eye. Do you guys think that all else being equal that the JTR radiator would be comparable to the Summit aluminum unit? I have AC and live in a pretty hot area (well over 100 degree's in the Summer), so I want the most bang for the buck. I'm not in a hurry to buy another radiator, so unless there's a compelling reason I don't plan on doing this anytime soon. That being said, If the Summit can run really run 15 degree's cooler than I would consider that to be compelling. Quote Link to comment Share on other sites More sharing options...
m1noel Posted March 19, 2007 Share Posted March 19, 2007 Also, some fans/shrounds do not work well with some radiators. Some combinations will block air at speed and not allow good airflow. At least that is what I have been told. I am running the JTR radiator with a Ford van 2-speed fan and shroud. Although I haven't run it at anything over about 75 degrees yet it seems to be cooling fine. We will see this summer. MIke Quote Link to comment Share on other sites More sharing options...
Paz8 Posted March 20, 2007 Share Posted March 20, 2007 I installed the lower chin pan under the rad to the front X member, run an upper fan shroud only and chevy declutching blade on the water pump, junk yard $20 camaro rad. and the Zx overflow tank. With a 160 deg thermostat the temp gauge stays at about 170 deg, been street driving the car for about 8 months now with no problems. I know some people have opinions on engine driven fans stealing HP but here is the way I look at it. If the fan blade uses 5 horsepower and the electric cooling fans use 30 amps from the battery your charging system needs to put back 30 amps in the battery, this means more drag on the engine from the alternator, see, no free HP with electric fans. I like electric fans for the way they cool down the engine when the car in shut off and sitting. Don't forget coolant mixture should be 40/60 anti freeze/ water, no more than 50/50 mix. Quote Link to comment Share on other sites More sharing options...
deja Posted March 20, 2007 Share Posted March 20, 2007 I'm running a 160 degree stat and have my fan's reprogrammed to turn on at lower temperatures. I can't say my problems have anything to do with the radiator at this point, but Jason's comments definitely caught my eye. Do you guys think that all else being equal that the JTR radiator would be comparable to the Summit aluminum unit? I have AC and live in a pretty hot area (well over 100 degree's in the Summer), so I want the most bang for the buck. I'm not in a hurry to buy another radiator, so unless there's a compelling reason I don't plan on doing this anytime soon. That being said, If the Summit can run really run 15 degree's cooler than I would consider that to be compelling. Being in the computer industry and particularly the retail terminal field we do a lot of air flow studies with fans on some very hot processors. Granted this is not the auto industry but its amazing what a tiny modification will do to air flow. Your setup with the radiator tilted and the fans trying to basically suck air around a corner may not be the ideal situation. Air is approaching your rad through the grille and your trying to pull it down which could be causing a spoiler effect at the rad fins restricting air flow. We have has issues having the fan too close to a grille, too far away, having poor exit and entrance area for the air path. You name it we've experienced it. My guess is the problem is a combination of the components and how they are configured rather than just one component. Quote Link to comment Share on other sites More sharing options...
echocluster@hotmail.com Posted May 31, 2009 Share Posted May 31, 2009 do you know what the part # for that summit rad? Quote Link to comment Share on other sites More sharing options...
Venture Posted June 10, 2009 Share Posted June 10, 2009 When you guys talk about the JTR radiator. Are you talking about the one JTR sells with the thicker core, or the 85-92 4.3L Chevy van radiator that they recommend in the manual? Has anyone running the Griffin had any problems with cracking after long term use? Quote Link to comment Share on other sites More sharing options...
HICKL Posted June 10, 2009 Share Posted June 10, 2009 I live in the brisk cold of Houston and have been running the stock radiator with my 383 for years and have never had a problem. Sit in stop and go traffic in 95 degrees and she holds stable. I would try it, worst case, you swap it later. Jeff Quote Link to comment Share on other sites More sharing options...
jt1 Posted June 10, 2009 Share Posted June 10, 2009 If the stock radiator is in good condition, and you put a good fan & shroud on it, and work on the airflow, it may well do the job in street driving. It would be worth a try. I have been using a 24x19 Griffin for about 5 years with no issues. jt Quote Link to comment Share on other sites More sharing options...
jnjdragracing Posted June 12, 2009 Share Posted June 12, 2009 We use a Griffin radiator with no issues. But yet we are mainly a drag car not street. John Quote Link to comment Share on other sites More sharing options...
pparaska Posted June 15, 2009 Share Posted June 15, 2009 I've used the Camaro Radiator that JTR recommended many versions ago in their manual. It worked fine most of the time with a 375hp 327, standard pulley sizes, even with A/C. The problems I had with it were due to air in the system and the airflow at speed going AROUND the radiator, not through it. When I went to the 500hp 406, I bought a dual pass C&R Racing radiator. I started having problems with the 406 and 2 things helped greatly: 1) I sealed all the holes in the radiator support, a buddy (Glenn) made a pan that seals the lower opening in the Xenon airdam to the radiator support bottom edge, and I made sure that the radiator seals to the radiator support on the back side, all the way around - this helped GREATLY at speed. Just the other day I realized I had not completed the seal between the bottom of the radiator support and the bottom of the core. I had sealed all the way around using closed cell foam (pipe insulation black foam rubber split "tubes), but forgot to seal the bottom edge of the radiator support to the radiator seal. I fixed that and now it runs 30 degrees cooler on a 90 degree day. 2) I installed a water filler neck on the intake manifold above the thermostat, along with a radiator cap at that location. I did this to help the system automatically bleed air out. The cap on the filler neck is now the highest point, so the air gets pushed out through the overflow tube below the cap, and the recirculating bottle replenishes the coolant. These two things have really helped keep the engine cool! Quote Link to comment Share on other sites More sharing options...
jhm Posted July 30, 2009 Share Posted July 30, 2009 I took Pete Paraska's words to heart, and came up with this setup. Bottom and side pieces fabbed from aluminum sheeting and top piece from thin-gauge galvanized steel sheet. Theoretically, it should be directing nearly all airflow through the radiator, and blocking all other air passage into the engine compartment. May even give a tiny "pressurization" effect to the cold air intake, if it results in a higher static pressure in the vicinity of the filter. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted July 31, 2009 Share Posted July 31, 2009 I run this GM 4 core radiator, I think its too a van, but it will keep temps at 220 while sitting in traffic, no fan with ambient air temps around 110-118. Quote Link to comment Share on other sites More sharing options...
Miles Posted August 5, 2009 Share Posted August 5, 2009 I am using teh JTR radiator with a Flex-A-Lite 180 electric fan and a high flow water pump. The radiator and fan fit together tight with no air gaps. Looks stock. Average engine temp is 185 to 210 in traffic. On days over 100 the temp has gotten up to 220. Miles Quote Link to comment Share on other sites More sharing options...
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