2eighTZ4me Posted June 22, 2009 Share Posted June 22, 2009 Bone stock 280Z. - Radiator in good shape, never rusted, clear/green distilled h20/antifrieeze - Brand new (2000mi) FACTORY Nissan 180 degree thermostat - Fan clutch in good shape. Spins maybe 3-4 blades when spun by hand then stops - Radiator shroud in place - Timing set to 33 degrees total advance - Radiator full of water, no leaks or water loss whatsoever - Brand new water pump - Stock 81ZX motor w/115K mi. just installed When I drive extended periods ( 15+ miles) with the A/C on, the temp gauge in the car creeps up between the M and the P on teMP. I got a Mr. Gasket 15psi radiator cap with the temp gauge on it. With the gauge in the car reading b/t the M and the P, Mr. Gasket says 210 degrees. Ambient air temp approx. 97 here in ATL yesterday. I cut off the A/C and it drops, but not a whole lot (200ish). I had this problem with the old motor (but not as bad), and have searched ad nauseum on this site - picking up tidbits here and there. I read somewhere that ignition timing can be a cause of overheating, hence, I listed my setting above. I did not check initial timing, only timing at 3K rpm's. I've replaced / checked everything having to do with the cooling system, and am completely stumped as to why it does this. It is far more prevalent on my ride home from work (95+ degrees) than it is in the morning (~75 degrees). (That's a given) - but far worse with the A/C on. This problem has slowly been manifesting itself over the past 2 years, to the point where I need to address it before it kills my mule motor. The internal gauge never got as hot as it did yesterday on a 100 mile trip. The radiator has always been flushed and filled and has never had any rust in it. It is, however, about 12 years old. I'm down to 2 options. Replace the radiator, or muck with ignition timing. I can't think of any other factors that I haven't addressed. What do you guys think? Also - (stupid question) do you check ignition timing with the vaccum source connected or disconnected? Quote Link to comment Share on other sites More sharing options...
woldson Posted June 23, 2009 Share Posted June 23, 2009 Cleaning out the rad fins and condensor can help alot. Over time they aquire alot of bugs, road tar etc. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted June 23, 2009 Author Share Posted June 23, 2009 I forgot to mention that I did that when I had it out of the car last month for the motor swap... hit it good with the air compressor. Hmm - maybe it's the AC condenser sitting in front of the rad causing this. I did NOT clean that out at the time of the swap...... Seems to be doing "better" now - although I haven't had to use the AC for the past couple days. I double checked my timing last night and I have 14 degrees initial timing and 34 degrees total timing at 3K RPM's. That's well within acceptable range..?? Another one of life's little mysteries...... Quote Link to comment Share on other sites More sharing options...
woldson Posted June 24, 2009 Share Posted June 24, 2009 Can't really say that my 82 na did very well with the stock fan. I did see on some later models zx that they put in a fart fan for the condensor. The mod I've done in misc I'am thinking may not even be enough in stop and go on a hot day. Need more drive time to figure it out. Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted June 24, 2009 Author Share Posted June 24, 2009 Hmmm - well - everywhere I've read, the stock fan/shroud FAR outperforms any electric fan you could possibly put on. This was also reaffirmed when I spoke with Bill Williamson at Ron Davis Radiators. I can also attest to that fact, as I had a stock fan on my racecar and it cooled great. I put on the biggest SPAL electric fan they sell, and it does ok - but not like the stock unit. Also - doing some digging on Blue's tech site yesterday, I found out that advanced timing (not retarded) promotes better cooling. I am going to fart around with that tonight and see if I can get it a little cooler. Quote Link to comment Share on other sites More sharing options...
woldson Posted June 24, 2009 Share Posted June 24, 2009 Naw I was referring to a stocker with a fart fan on later model 83 turbos. This fan was on the condenser. This is why I mentioned my 82 with stock fan did not perform that well in hot, stop and go traffic. Sooooo, maybe a condenser fan? Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted June 24, 2009 Author Share Posted June 24, 2009 Hmmm - well - gotta get the condenser blown out and cleaned up first off - and then that all goes out the window when I put in the turbo setup with that fat daddy AZC intercooler in front of the whole shootin' match. Tempted to just bucker up and install the AZC radiator this weekend and horse with moving the AFM and see how that works for a week or so. It's just so dang hot down here, working on cars is not in the Top 10 list! Quote Link to comment Share on other sites More sharing options...
woldson Posted June 25, 2009 Share Posted June 25, 2009 This is why my car may go to my better half. That damn condeser will have to stay......However cam, higher compression will make her eyes go wide!! Already have the cam and n47 head and headers, just need meth injec, and mega,,,,,oh, and money...... Quote Link to comment Share on other sites More sharing options...
rossman Posted June 25, 2009 Share Posted June 25, 2009 Does the temperature go up while sitting/idling then drop while driving? If so, you might want to try an electric pusher fan on top of your stock fan. Have you read the head cooling thread? There are lots of good tips in there including using Water Wetter and lowering the % of EG. Blocking off the FI recirculation might help although you'll have to be careful not to rev the engine cold and it will screw up your cold idle valve. I blocked off my FI recirculation line and never noticed any problems but I live in a temprate area and there are rarely any truely "cold" cold starts. Running as much static advance as possible will help. I advanced my timing as much as possible (on a stock N/A setup only) until I could hear knock then backed off a few degrees. Have you checked if your damper has slipped? Maybe you aren't running as much advance as you think you are. Quote Link to comment Share on other sites More sharing options...
jasper Posted June 25, 2009 Share Posted June 25, 2009 Does the car run hot at highway speeds? That is when the engine makes the most heat, and the radiator has to get rid of the most heat, and air flow is at it greatest. if this is not a problem..... At low speeds, radiator air flow is most likely the issue. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted June 25, 2009 Share Posted June 25, 2009 timing at 30 to 36 total on the highway should work.fan clutch would only be an issue in city driving.anything past 35 mph would be related to the radiator-or it could be just bugs in the ac condenser.i have a 77z with intercooler,ac,radiator but i havent ran it enough (its being worked on ) to tell if the ic will make it over heat.it got stays high 90s to low 100s here but its dry. Quote Link to comment Share on other sites More sharing options...
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