ananimator Posted September 5, 2004 Share Posted September 5, 2004 Hello All, I'm hoping to receive my latest Z by this Friday. It is a 1974 with a V/8 conversion from Sacramento, CA. It has a slight overheating problem. I had a 3rd party drive it. He took it on a spirited 15 minute run including a period over 90 mph and when they returned he said it did start to get hot. He felt the radiator and there were no cold spots. There is a transmission cooler mounted right in front of the radiator. Could this be the problem? The electric fan was not running when the engine was turned off. Shouldn't it be on a thermostat and keep running until the engine cools? What do you think about about changing the oil to amsoil synthetic and adding water wetter to the cooling system? The previous owner's description of the engine follows: "The engine is has been rebuilt with about 3500 miles on it. The engine is a 1965 Chevy Corvette 327 small block. It has 10.5 to 1 compression pistons, 202 Camel hump heads, and a duntov 30-30 cam. Also, at the time that the motor was installed into the Z the following accessories were all installed new: Holley 650 Vacuum secondary double pumper carb, MSD Billet distributor, MSD blaster 2 coil, MSD 6AL box with rev limiter, Edelbrock Performer RPM intake manifold, Block hugger headers with header wrap, Milodon hi-flow water pump, Holley high performance mechanical fuel pump and adjustable fuel pressure regulator, Perma-cool 4 core alluminum radiator, custom alluminum shroud with electric fan, custom pulleys. The exhaust is dual 2 1/4" all the way back with a cross-over pipe into separate mufflers. The 700R4 transmission was rebuilt at the time of the motor install. It was professionally rebuilt and shifts hard. The only issue with the vehicle is it does run a little hot on hot days. It needs a larger more efficient fan. The current fan electric fan is from a late model GM car and doesn't cut it. On winter days it does fine but, she doesn't care for Hot August nights." I would appreciate any ideas on where to start. This is my first Z with a V/8. I'm excited! Thanks, Bill ZCSD # 337 IZCC # 3764 Quote Link to comment Share on other sites More sharing options...
Guest 77vegasz Posted September 5, 2004 Share Posted September 5, 2004 Try searching the archives on this subject as there is lots of information in there as this is a common issue with V8 Zcars. I live in Las Vegas which gts considerably hotter than your area. I was having some issues as well. I have a 18" Flex-o-Lite electric fan that is thermostatically controled. I run water wetter and 25% glycol and still had issues until I installed a shroud. I now cruise in 110 degree weather in the 190 to 200 degree range. Try a thermostat control and a shroud. I too have the trans coller infront of the radiator. Jon Quote Link to comment Share on other sites More sharing options...
ananimator Posted September 5, 2004 Author Share Posted September 5, 2004 Thanks Jon, I'll check the archives. Glad to hear you got your's under control. Bill Quote Link to comment Share on other sites More sharing options...
MikeJTR Posted September 5, 2004 Share Posted September 5, 2004 Read this chapter on V8 Z cooling: http://www.jagsthatrun.com/V8-chapters/V8-DatsunZ-Cooling-System.pdf Quote Link to comment Share on other sites More sharing options...
ananimator Posted September 5, 2004 Author Share Posted September 5, 2004 Thanks Mike, Excellent information! Bill Quote Link to comment Share on other sites More sharing options...
Pyro Posted September 8, 2004 Share Posted September 8, 2004 I have the black magic fan on a 350 chevy in a 240 and it works very well. Quote Link to comment Share on other sites More sharing options...
Greg SmileZ Posted September 9, 2004 Share Posted September 9, 2004 Pyro, What radiator are you using? Thanks, Greg Quote Link to comment Share on other sites More sharing options...
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