Guest zbot43 Posted September 8, 2003 Share Posted September 8, 2003 This does seem to be an ongoing problem with people who have put chevy v8s in their Z's. Ok I 2 have a v8 powered 71' 240z. I have had this car most of my life, and up until I flipped it at what was Sears Point Speedway it looked like a normal 240z. After that I chopped the top off, and put fiberglass rear on the car. And in my infinite wisdom, I decided I wanted the front fenders to become part of the hood and lift up as one piece. It has only taken me 6 years to get that part working right. Now that I am actually ready to drive it, I have to deal with an overheating problem. It runs great, but the heat continues rise at an idle unless you crack the hood open I'd say one inch. I have no louvers in the hood, and honestly I really don't want to put any. I like the way it looks without any obstructions in the lines of the car. It also appears to be worst the longer the car is run. I can run all day on the freeway, but I don't dare get stuck in traffic. The temperature does rise on the freeway slowly, but stays under 230F. Now I have been searching through this website looking for my answer. I am looking for ideas to try. I have a 1970 Chevrolet nova radiator, a ford taurus fan and shroud, a hi-volume water pump with cavitation plate, I do have headers, and what else??? Now I just took out the 700r4, and put a t5 5speed in it's place, but haven't had a chance to drive it since. I feel that the air is getting stuck (heat) under the hood, but when I crack the hood open to let it out it goes up over the windscreen and in my face. So what else can I do???? Thanks, Marcello Quote Link to comment Share on other sites More sharing options...
Guest billy383Z Posted September 8, 2003 Share Posted September 8, 2003 Marcello, my suggestion is a better radiator. I use a Griffin 2 row aluminum racing radiator and a Flex-A-Lite 150 electric fan from Summit racing (or maybe it was Jeg's, I bought it like almost 7 years ago) in my car, and have no overheating problems in 95º to 100º summertime stop-and-go driving in South Louisiana. My 383 Chevy motor is running 9.6:1 compression ratio and iron heads...Also, if you haven't done it already, a complete flushing of your cooling system sure couldn't hurt. You may have some accumulated rust and scale blocking some of the smaller passages in your radiator or cylinder heads. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 8, 2003 Share Posted September 8, 2003 I think this issue has been thoroughly addressed on this site. The two most common problems are: *Chin scoop missing (allows air to come up under the car and pressurized the engine bay *Air flowing around the radiator instead of through due to not "poor" but not so great design in the area in front of the radiator. I plan to make a front funnel-like fiberglass inset to go in front of the radiator, as well as a fiberglass chin scoop to prevent this trouble in my Z. Plan to make and keep a mold if anyone else would like a set Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted September 8, 2003 Share Posted September 8, 2003 You could try this: http://www.georgiazclub.com/tips/ztech/v8cooling.htm Henry is the president of the Georgia Z Club and this is what he did to his V8 Z Quote Link to comment Share on other sites More sharing options...
Guest zbot43 Posted September 8, 2003 Share Posted September 8, 2003 I am very curious about the little fans in the fender wells. I had read that before but haven't seen anyone here saying they had done it. I had a griffin 27x19 two row radiator in this vehicle and it actually ran worse. I could not keep it cool. I moved this radiator to my landcruiser, and had problems again. I pulled it out of the cruiser, and put a radiator for 454 suburban in it (not aluminum) and it absolutely will not get hot anymore. My problem doesn't seem to be one while moving, which would make me think more about sealing everything up around the radiator and the chin piece. Those things are not going to make any difference when I am standing still. So has anyone here done either the heater cores in the lower front grille in front of the tires, or the little fans in the back of the fender wells? Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted September 8, 2003 Share Posted September 8, 2003 BAlford did the heater core thing: http://waskomtexas.com/zcar/re_car/engine_cooling.html Quote Link to comment Share on other sites More sharing options...
strotter Posted September 9, 2003 Share Posted September 9, 2003 I assume you've checked for things that might make the motor run warm - no vacuum leaks, timing not too advanced, cam not too radical, correct thermostat, idle not too high, no more than 45% anti-freeze, so on? My cooling system (in a '72) is right on the edge, but functional. My radiator is the one suggested by JTR, roughly the same size as yours, I have all the seals in the engine compartment, and I use the Taurus fan. That thing would cool off a volcano; I can't believe there isn't something else wrong somewhere. Quote Link to comment Share on other sites More sharing options...
Guest zbot43 Posted September 9, 2003 Share Posted September 9, 2003 Ok If I take the hood off, there is no problem. It works like a charm. But I can't drive down the road like that. And I am not short enough to not feel the heat coming over the windscreen. I think if I had a top on my car, I wouldn't be having this problem because I would just cut some more holes in my hood. I think I am going to try the fan idea. I just hate added more noises to my car. Quote Link to comment Share on other sites More sharing options...
JB_BA Posted September 9, 2003 Share Posted September 9, 2003 SO THAT'S why the previous owner of my car had that fan down there...I thought it was some funky heater setup he'd rigged...as it blows into the car. I'm about to go make sure, but it's got to be to pull the air from the engine bay...and I blew the toggle switch it was hooked to the second day I had it when I hooked an electric fan up to it also. Hehe, looks like with a bigger toggle switch I'll have a pretty good cooling setup. Thanks for that info! JB Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 9, 2003 Share Posted September 9, 2003 Curious, I wonder if we change the mounts on our radiators to make the radiator at an angle just slightly not perpendicular to the ground (top tilted away from the front of the car) if this could help in blowing the hot air out of the engine bay. (Of course, this would only be done with an electric fan). Perhaps the geometry of the car is such that the radiator is not even perpendicular to the ground and is actually at an angle slightly forward relative to the ground and thus actually forcing the air upwards. Has anyone ever checked the surface of their radiator with a level? :| Hmmm... Quote Link to comment Share on other sites More sharing options...
Phantom Posted September 9, 2003 Share Posted September 9, 2003 My LS1 has NO, I repeat NO overheating problems despite being run in Texas in the summer with the AC on. It has the Z radiator recored to 4 rows and the twin, three-speed fans & shroud from a '98 Camaro Z-28. I do have the stock hood with the two vents originally provided on the 77-78 280Z. Quote Link to comment Share on other sites More sharing options...
Guest zbot43 Posted September 9, 2003 Share Posted September 9, 2003 Now, I am really interested to hear about the fans on JB's Z. I also think my Z has a little more containment of the air on the hood. The fenders are welded to the hood, so there is no air getting through there, and so are the little inspection covers at the back corners of the hood. I think I did to good of a job sealing the top surface. At one time I did try and tilt the radiator back so the pulled air would go down and out, but at the time I don't think I was using good enough fans. I wasn't using the taurus fan at that time. I only had a 16" Spal fan on it. Man, I am wondering if I should try that again now? Quote Link to comment Share on other sites More sharing options...
flibuoy Posted September 10, 2003 Share Posted September 10, 2003 I agree the subject has been pretty well covered. In fact I posted a fairly long one myself last year. I stand by my opinion that IF the radiator is in good shape, IF the pump is working right, IF the fan is well shrouded (as the Ford 2 speed is) then the car should cool pretty well. I suspect some problems may be result of weak pump or engine tune basics. I do not believe airflow through the bay is a problem. Look at a late Camaro bay for example: if you drop a wrench it will never get to the ground but they cool just fine. The panel under engine is probably a good thing at highway speeds to keep pressure from building inside bay and thereby slowing flow through radiator. At speeds above 35 or so cooling should never be an issue(eliminates the fan and shrouding as culprit) without an underlying problem with flow of water or tuning of mixture, timing. My old one had 4 core copper radiator, cutdown (way down) fan blades, A/C, and lots of HP, and cooling was never an issue in Houston traffic. This one will be aluminum Camaro/Taurus 2 speed and expect even better performance from the LT1. Interestingly when I put a good shroud on the old one I could then remove trans cooler/oil cooler/extra heater core that were all fixes by previous owner. john Quote Link to comment Share on other sites More sharing options...
JustAFantaZ Posted September 10, 2003 Share Posted September 10, 2003 I had cooling problems until mas28O finally helped me drop a big old 5-row radiator in(Mike, what car was that from? A Nova?). We had to cut the front frame rails to fit it in, but it worked. I had two electric fans from AutoZone hooked up two manual switches inside, and when one went out, the car still kept cool in the infamous Texas heat. Before that big radiator, I tried my stock Z radiator with a milder 350 motor. Then when I beefed up the motor, I added an extra row to it. All I remember is that I couldn't let myself get stuck in rush-hour stop n go traffic and my car would cool fine. But every now and then I got stuck. Two electric fans blowing full blast, one pull, one push, was the only thing that kept it from boiling over. Eventually, I got two hood louvers from a '77 or '78 Z from the junk yard and had a body shop cut holes in my '76 hood. I think that might have helped a little bit, but I don't know because that was after the big radiator swap, iirc. Quote Link to comment Share on other sites More sharing options...
Guest zbot43 Posted September 19, 2003 Share Posted September 19, 2003 Ok after reading everyone's posts again I decided to go back and give it one more try. I decide to go with the idea that there was nothing else wrong except getting the air through the radiator. I went back and noticed to my surprise I had pulled out the Ford Taurus fan, and shroud. I didn't remember doing it, but I did. I had a 16" Spal fan with it's shroud. Nothing like the shroud on the Taurus fan. It was doing the job, until you closed the hood. Well, I put the Taurus fan back in, and all my problems are gone. Thank you all. I found the Taurus fan in another car I was working on. I swear I don't remember pulling it out. So now I am wondering if I had stuck with the Griffin fan, and used the Taurus radiator would I have been happy? Quote Link to comment Share on other sites More sharing options...
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