BAlford Posted June 5, 2002 Share Posted June 5, 2002 We have a 1982 280ZX with a Chev 350. The engine is basicly stock. It is running about 230 degrees on the hiway at 60 mph. We have two electric fans that come on at 200 degrees. One is mounted on the condenser blowing into the cond and raditor. The other is mounted on the back of the raditor. The front one blows back and the one behind the raditor sucks air. We have a 160 degree thermostate in the car. The raditor core is about 24 inches wide, it fills all of the area where the raditor sits. It is either a 3 or 4 core. We do not know what it came out of, we bought the car with the raditor installed, it's mot the original. You can see the car at: http://www.Waskomtexas.com/zcar Any Ideas? Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted June 5, 2002 Share Posted June 5, 2002 It looks from the photos that you are not running an AC compressor and the condenser is therefore not needed. That condenser is killing the air flow, especially at 60 mph. Remove it and keep the fans and see what happens. Quote Link to comment Share on other sites More sharing options...
Lewis Maudlin Posted June 5, 2002 Share Posted June 5, 2002 Your fan doesn't come on until 200? I have mine hotwired to be on when the car is running. That is important if you are running air. Quote Link to comment Share on other sites More sharing options...
BAlford Posted June 8, 2002 Author Share Posted June 8, 2002 We have removed the condenser and fromt fan. We added some liquid to the collant , no improvment.We are going to add a heater core under each front fender using water from the heater hoses. Quote Link to comment Share on other sites More sharing options...
Mike C Posted June 8, 2002 Share Posted June 8, 2002 I would switch to a 180 thermostat or maybe even a 190, the water spends more time in the radiator to shed heat. With 230 degrees and a 160 t-stat, it is open ALL the time and the water never gets to cool before being reintroduced to the hot engine. Also check to make sure you have coolant flow, that the t-stat isn't stuck shut. It couldn't hurt to invest in a new radiator cap as well. Another problem is that universal hoses don't always have the anti-collapse spring so check your lower hose to make sure it is not crushing shut and stopping water flow. Also double check the fans to make absolutely positive one isn't flowing the opposite you think and causing dead air right where you need flow the most. The core dimensions should be more than sufficient for a stock SBC. Add foam rubber seals to the sides and tops of the core to seal it to the core support so that air cannot run around the radiator but most go through it. Also pop your hood to the safety catch and see if allowing additional hot air to exit the engine compartment as you drive helps. It is possible that the impeller can come loose on the water pump shaft and basically freewheel in the coolant, so checking for sufficient flow is a neccessity. Crank it up cold and watch the coolant through the cap. If the t-stat is working, there should be virtually no movement in the radiator, but as soon as it opens should be a rush. It should then slow as the cool water is introduced to the engine. I'd buy a new Griffin aluminum radiator before I'd moneky around with adding the heater cores... Quote Link to comment Share on other sites More sharing options...
pparaska Posted June 8, 2002 Share Posted June 8, 2002 Great list of stuff to check, Mike C. I'd like to add two other possibilities: 1) the temp gage is reading wrong. Try a mechanical one. Electric ones can read incorrectly by 20 degrees - I've seen it happen on a few Autometer ones. 2) Maybe there's air in the system. Put the car up on ramps under the front wheels, start the engine with the cap off, and after it warms up, top off the radiator. I saw my temps drop 20 degrees on my Z after getting air out of the system. Quote Link to comment Share on other sites More sharing options...
Guest jwelch Posted June 8, 2002 Share Posted June 8, 2002 I think Mike is on the money with the thermostat. 160 is too low. I'm wondering if you would get better air flow with just the puller fan on the inside? I used to run an outside pusher and inside puller, after I went to the Dual Flex-Lite 2500cfm puller my problems went away. I also set my fan at about 180F. Good Luck Regards, Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted June 8, 2002 Share Posted June 8, 2002 Grumpy had posted some links awhile ago about this same subject. There are lots of threads in the archives for sure. I wanted to make a clairification about thermostats and dwell time in the radiator. A wide open thermostat does not reduce cooling capacity by speeding the flow through the radiator. Flow is what it is all about and a thermostat will present the same restriction whether it is a 160 or 195. Please look for the thread and read up. We need to put some of these urban legends to rest. The other advice on system integrity is right on the money. Quote Link to comment Share on other sites More sharing options...
Guest jwelch Posted June 8, 2002 Share Posted June 8, 2002 Greiman; Good advice, we should all do some reading so that "mythical" information isn't passed on. I just noted what worked for me but I did change 2 variables at once so did (X) or (Y) solve my problem? Regards, Quote Link to comment Share on other sites More sharing options...
Mike C Posted June 9, 2002 Share Posted June 9, 2002 The restriction in the t-stat is the same if it is the same size/design thermostat and they are both open. (ie both parts store types and not a Robertshaw high flow rim seal design) But there is no doubt that you have NO flow if the thermostat is closed (especially STUCK closed)and max flow for whatever speed the waterpump is turning when the t-stat is open, but reduced flow anytime it is partially open. What is different is the point at which the thermostat opens and close and there is lots of engineering in the selection of a thermostat beyond whatever temperature the gauge reads at including allowing the water sufficient time in the motor to extract heat from the block and sufficient time in the radiator to shed that heat. More important than water temp as previous discussions have included is oil temp. Has to be cool enough not to break down but hot enough to evaporate moisture. Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted June 9, 2002 Share Posted June 9, 2002 Good points!! Oil is a cooling fluid as well as a lubricator. If the coolant moves too fast through the engins it can't remove the heat from the block as it passes. You may have a restriction in the heater core as well. We had an infrared temp. guage at work and we found a lot of guages were out to lunch.Good luck!!! Quote Link to comment Share on other sites More sharing options...
BAlford Posted June 11, 2002 Author Share Posted June 11, 2002 We have proceded with the Heater cores, but have not installed them. Someone suggested that some of the air may be getting past the raditor. That may be corect. There is a space between the hood and the top of the raditor. I will check it out. Quote Link to comment Share on other sites More sharing options...
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