Guest tom sixbey Posted April 5, 2002 Share Posted April 5, 2002 i put in a Ford style griffin 24X19 in front of my L24, and there is hardly any difference in temperature over my original unpressurized(due to holes) 3 core copper/brass... The car runs a little over 1/2way on the gauge at idle, and climbs to about 3/4ths on the gauge when moving! - my ENTIRE cooling system has been replaced. - any suggestions? Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted April 5, 2002 Share Posted April 5, 2002 To lean?? To much advance? stuck thermostat? Dave Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted April 5, 2002 Share Posted April 5, 2002 " my ENTIRE cooling system has been replaced. - any suggestions?" Tom, what water pump, Tstat are you running? Any reason to think you may have any blocked passages in your block at all? I assume you don't have any custom front end treatment severely limiting air incoming? And Dave's suggestions are common faults you can easily have; have you checked your plugs IMMEDIATELY after the condition that's making it run hot? Shut down while cruising if possible and pull over and see if they're running lean. Your overall timing curve all nailed down? Quote Link to comment Share on other sites More sharing options...
blueovalz Posted April 5, 2002 Share Posted April 5, 2002 My similar problem was self-induced. Too small an underdrive pulley on the crank. finally had to go back to the OEM size pulley. Quote Link to comment Share on other sites More sharing options...
Guest tom sixbey Posted April 5, 2002 Share Posted April 5, 2002 well, the water pump and thermostat are new (stock/180Degree), so i'm assuming that's ok, because they made an improvement when i first put them on with the old radiator. My pulleys are stock. My front end is completely stock, my mixture is a hair rich, and my timing is at factory spec. I believe that since my radiator is set back about a 1/4" from the factory radiator support that incoming air is finding it easier to go around the radiator than through it - especially with the inline 6 being 1/4" behind the electric fan - this would possibly explain why it runs hotter while moving... I'm gonna try to solve this problem by building a ram air box that seals the grille opening to the radiator cores - funneling ALL of the oncoming air through the radiator.... I am also going to buy some VERY large NACA ducts and place them backwards on my hood for air extraction purposes... - i'm gonna need some advice on that one though. Quote Link to comment Share on other sites More sharing options...
74_5.0L_Z Posted April 5, 2002 Share Posted April 5, 2002 Tom, Pardon my silly question, but have you measured the temperature with a calibrated gage. Before I switched from the stock Z gages to the autometer mechanical gages, my temperature looked high and my oil pressure low. After going to the mechanical gages, I can now put actual values to pressure and temperature. The car run between 180 and 190 all the time (185 degree thermostat), has 70 psi of oil pressure (warm on the highway). Before my stock water temp gage indicated about 3/4 scale. Good Luck, Dan Quote Link to comment Share on other sites More sharing options...
Guest tom sixbey Posted April 5, 2002 Share Posted April 5, 2002 i havent done that yet - and i've been meaning to because my inlet hose is just too cool for the gauge to seem accurate. you're not the first person whos told me to do that... i might be running cool and not even know it... are the mechanical gauges a lot more accurate than electrical? Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 5, 2002 Share Posted April 5, 2002 Search the site. I have a few posts on how inaccurate the Autometer electric temp gages can be (20 degrees off). I'd just go mechanical on oil pressure and oil/water temp. Quote Link to comment Share on other sites More sharing options...
Mike C Posted April 7, 2002 Share Posted April 7, 2002 Running fine at idle but hot at speed is also characteristic of a car with a collapsed lower hose. Make sure your rubber is in good shape and that the expansion spring is still in the lower hose and not broken or missing. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 8, 2002 Share Posted April 8, 2002 If you are running the Datsun centrifigal fan/water pump combination and due to age or wear the fan may not be turning fast enough to draw enough air thru the radiator to cool.I have experieced this problem in 620 Datsun Pick-ups and my stock 280Z and fixed the problem by binding the fan directly to the pump with a few screws and weldinfg wire and eliminating the centrifigal action. Sounds like a screaming turbo charger coming full bore at you, but runs cool!. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted April 9, 2002 Share Posted April 9, 2002 Tom, I feel your pain. I run the same damn radiator and have been battling cooling problems as well. I have a greater disadvantage in that I have a 5.5" thick intercooler sitting in front of my radiator blocking all the air to it. You will be hard pressed to outflow the stock mechanical fan and most electric fans are not up to task. You will need 2200cfm+ to cool you system. I would put the stock mechanical fan back on and run the electrical jobber as a pusher fan. I am not sure if I am too enthused with the performance of the chevy 24"x19" griffin radiator. Some run it with no problem, but I have battled with it from day 1. TimZ is sending me his old single core Ron Davis unit to try out as it should have better efficiency, but lower capacity. Anyway, I now run the mechanical fan with the permacool as a pusher and it runs rock solid at 180deg. I also cut a large slot in my hood above my intercooler to route cold air to the radiator. The things you will do for power! Quote Link to comment Share on other sites More sharing options...
Guest jwelch Posted April 12, 2002 Share Posted April 12, 2002 Hi Tom, I had a similar problem with my 260Z. Turned out to be the fan clutch. Not sure if yours has a fan clutch or not. Mine was so bad that you could stop the fan with your hand while it was running. "I DON'T RECOMMEND STICKING YOUR HAND IN THE FAN TO DO THIS LIKE MY BUDDY DID." He was so confident that it was the fan so he tried it, he is so lucky to have fingers. Regards, Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 12, 2002 Share Posted April 12, 2002 i wouldnt recommend taking out the clutch on the fan and basically bolting it to the waterpump. The fan has a clutch for a reason, it isn't meant to be spun at those kind of rpms when cruising. Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted April 12, 2002 Share Posted April 12, 2002 Ditto with the whole gauge thing. I replaced stock water temp gauge with a VDO 250 degree and chevy sending unit, well it ran 205/225 but with a lazer temp reader we could not find temp anywhere near that. Called VDO and they said to use there sending unit which was never recommended to me! All is well now. So you never now. Stock Datsun gauge was 25+ degrees off when I had it. Thats why I replaced it in the first place. Mike Quote Link to comment Share on other sites More sharing options...
Guest Thurem Posted April 18, 2002 Share Posted April 18, 2002 Get a 5$ cooking thermometer and fit it in your cooling system. Be creative... Thure Quote Link to comment Share on other sites More sharing options...
blueovalz Posted April 18, 2002 Share Posted April 18, 2002 I didn't catch this if it was mentioned before, but have you made sure all the air is out of the circuit. I had a real hard time getting the filler (with my Griffin radiator) above the highest water level in the motor. In fact I had to add a filler inline on one of the hoses, closer to the block so that it was the highest part of the fluid system. Those steam pockets can cause a lot of problems. Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 18, 2002 Share Posted April 18, 2002 Good one Terry. On my Z, the top of the thermostat housing outlet is about at the same leve as the fill for the radiator. I had a silly idea - how about if I jack the front of the car up a bit and then let it run with the cap off, get warm, top the radiator, shut it down, put the cap on, let it draw out of the recirculating overflow bottle? Maybe do that a few times. I just don't want to have to put another filler on the car - but one that fills at the thermostat housing like dedenbear (sp) etc. sells might be a good idea (but not cheap). Quote Link to comment Share on other sites More sharing options...
blueovalz Posted April 19, 2002 Share Posted April 19, 2002 Great minds think alike. I couldn't see myself an old man and still jacking up the front of the car to check the fluid level. That's when I decided to add a second filler. You can see the second filler at the bottom, left of center in the photo. Quote Link to comment Share on other sites More sharing options...
pparaska Posted April 19, 2002 Share Posted April 19, 2002 Thanks for the pic Terry. I'm just thrashing like mad to just get my car together and the thought of ONE MORE MOD is painful at this point. I'll probably be looking for one of those thermostat housing based coolant fill thingies to handle this problem. Quote Link to comment Share on other sites More sharing options...
Guest tom sixbey Posted April 19, 2002 Share Posted April 19, 2002 about fans, i went through two defective fan clutches from auto zone before i decided on the electric fan. I installed the 16" flex-a-lite trimline (i knew it was a weak fan) but it definately improved the cooling. I am planning a ford swap, so i went ahead and mounted a ford style 24X19 griffin - so basicly on the stock motor, the hoses have to be criss-crossed to connect to the appropriate inlets - i probably have 5 feet of hose in my system, but it is done very neatly, and all of the hose is good. the steam pocket issue is one i'm contemplating. I'll probably put a filler in my upper hose like you did, Terry. Quote Link to comment Share on other sites More sharing options...
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