I hate cars that over heat, hate them. When I put my Nova together the one thing that I wanted to make sure of is that it runs at a decent temp. It is a stock 1998 aluminum LS1 out of a Camaro SS with 40k on it. I bought the biggest aluminum radiator that would fit in the core support. I had an electric fan without a shroud, removed it, and replaced it with a shroud and another electric fan that seems powerful enough. I have a mechanical Stewart Warner gauge. It started out with the sensor in the rear of the driver’s side head but that scared the bejesus out of me! I had read that it is better to put the sensor in the boss on the water pump of an LS1 so I moved it. The readings aren’t as scary but it still seems to heat up. I have a 180 degree thermostat in it and the fan kicks on at about 195. If I am not moving it will get up to 225 in a hurry. I hate it!

I have wondered if the water pump might be weak since it will cool down if the engine is revved up. Now I am seeing 2 and 3 pass radiators and wonder if they work well. I just don't think it is the radiator but have to wonder about the pump since it does better just setting with some RPM. Do LS1s have issues with water pumps?

 

Your fan is probably the problem, followed by too small of a radiator. BTW, temp readings from the head is ok. That's where the PCM reads. Just remember there can be as much as a 10-15 degree difference between front/back or left/right. LS water pumps are great, so no worries there. What specific fan are you using?

 

What fan are you running. Factory ones pull over 30 amps and lots use 2 of them. Most generics are under 10 amps and wont pull enough air.
Also check your radiator seals, etc...make sure air flows through the radiator, not around it.

 

How is the fan controlled? Is it through the PCM? If so, the PCM can be calibrated to change when the fan(s) come on and go off. Factory for a 2002 Camaro is pretty high at 226 and if memory serves me properly, the 1998 PCM isn't far from that.

You don't NEED a dual pass radiator to run these engines or anything fancy in the cooling department. All that is necessary is a solid cooling system with good airflow. All that is needed is a quality radiator, no leaks or air pockets in the cooling system and a quality electric fan. Since you are talking temps at idle while sitting, the electric fan is all you get. As mentioned by Gary's 68, cheap fans are no good and good fans aren't cheap. I've seen people waste money too many times on parts store fans that hardly move enough air to disturb a dry leaf. I prefer OEM style fans because I know they pull enough air. Good fans cost more AND pull a lot of amps. If a fan doesn't need a 30 or 40 amp fuse (unless it's PWM) it's probably not going to cool your engine at idle in the summer no matter what radiator.

I'm also in KC if you want to talk in person.

 

In my Valiant, I run a factory 95 Ford Taurus radiator and single fan set up from the same car with a 30 amp relay. I have a 160 thermostat and an autozone replacement waterpump. It never never, ever overheats.......ever. I have cruised on the street in 95 degree outside temps, and when I kick the fan on it brings the temp right down to 160-180 where it should be. Just my setup and experience. Hope this helps, Eric L

 

I use a 16" spal sold by the fan man. It trips a 30amp fuse at startup.
Draws 25 amps at steady state.
Keeps engine just at thermostat opening point 185F with AC on. I've only tested at 88F ambient. Can't imagine seeing over 100F ever. Even if engine temp went up by 12 I'd be fine with that.

I'd try a better fan. Check how much yours draws.

Doug

 

Your fan is probably a cheap, ineffective piece of crap. But that's besides the point.

If you're going to have an aneurysm about overheating:
1: get rid of the 180 stat. That prevents nothing with regard to overheating. It sets minimum temp only. It does however, allow the engine to fluctuate temp more, get worse mileage, allow more carbon buildup, and shed heat that should be used for power. Further, a narrower range of temps gives the tune a narrower range to be right. Psychologically, a gauge that wavers is going to drive you nuts. A stable temp range is peaceful in comparison.
2: Get a mechanical fan. My DD is SBC (for now) and I have never wondered or worried whether it's working. Clutch going bad? I knew about it and it never let things overheat. A fan clutch that fails is noisy. An elec. fan that fails at the wrong time is expensive with collateral damage. Yes, I drive in 120deg temps. I switched from multiple v-belts to single serpentine and kept the mech. fan.

 

I prefer clutch fans myself, but its highly unlikely you will get one to fit an LS1 in a 62 Nova. But what im curious about is the OP says it will get to 225 in a hurry, but doesnt say if it gets hotter? 225 is normal for an LS1. Also I would hook a scanner up to it to see what the PCM says its at, could be a faulty gauge. If it isnt puking coolant, and is only getting to 225, its not overheating.

But my real question is, since im in the KC area,how have I never seen this car before???

 

Where there's a will, there's a way. With the cooling issues in C3 corvettes, I went with a big aluminum radiator, full shroud, mechanical and electric fans. The mechanical is the thermo controlled and moves A LOT of air but can be noisy. Electric comes on with thermostat and/or AC trinary switch.
If you need the LS1 intake for hood clearance, you can use a snake head intake elbow to clear the fan. I ended up making one out of fiberglass.

 

This is almost the same setup I have in my Cutlass except I'm using a stock copper g-body radiator. Works perfectly. Runs between 160 and 180 max and stays very stable.

The guy saying to run a mechanical fan...no. Don't do that. Run an OEM electric fan. Or pay the big bucks for an aftermarket fan that actually works. The cheap fans are simply rubbish.

 

Makes two of us... unless I missed it somehow which does happen from time to time.


Novas Forever, you really need to scan the car and see what the PCM thinks is happening and why. If you don't have access to the tools, I do. A 160 or 180 stat in these engines is completely worthless without the tune to compensate for it.

 

I've replaced at least 5 of these LS series engines water pumps. All vehicles had over 150K on them before the pumps went out, GREAT PUMPS

 

I have a 5.3 in a 1992 pickup using the 1992 radiator with this fan http://www.ebay.com/itm/16-INCH-FFD-CYCLONE-ULTRA-ELECTRIC-COOLING-FAN-3600-CFM-LOW-AMP-DRAW-SUPER-DUTY/160746572676?_trksid=p2050601.c100271.m3466&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D29558%26meid%3Df68eddae49824f478989c8923158ebf3%26pid%3D100271%26rk%3D1%26rkt%3D4%26mehot%3Dpp%26sd%3D160746572676%26clkid%3D5141142240625871894&_qi=RTM2067267 and an aluminum shroud For 2 years now and my temp never goes higher than 185 degrees(I have a 160 stat) plus I have a/c on the truck. I have my fan come on around 182 degrees.

Do you have your fan setup as a pusher(bumper side of rad) or a puller(engine side of radiator)?

 

I am back. I am thinking it is the fan too now. It does not draw 20 amps but does move some air. I wanted to use a 2 speed Taurus fan but Chevy IIs have small engine compartments and it would not fit. Now that a Volvo fan is an option that is what I am shooting for. It looks like it will work with the current shroud I have without hitting the water pump.

I would love to have a mechanical fan but F-body water pumps are not set up for them and there is no way there is enough room anyway. I have actually seen it get up to 250 in traffic but go down to 185 in the open. I understand that an all aluminum engine is different than a cast iron one and will adjust my thinking for it.

You KC folks have not seen my car because I usually stay around Lee's Summit. I go to Johnny Ray's quite a bit. You can look up on older video of it on YouTube. search for 1962 Chevy II Nova. I have been to Heartland over by Joe's Crab Shack but it is like my car is invisible. It is unassuming but is much more than just an old black Nova. It is not a painted up POS. I will get over there more often this summer so maybe you will see it there. Look for a black Nova that looks like the paint is 12 inches deep with red interior and an automatic that looks like a stock shifter in an SS.

When I put the LS1 in my car 10 years ago it was unusual and quite a unusual. I could not have done it without the help of people on here and at Steves Nova Site. Be glad that there is help for you guys now.

I will come back and let everyone know how the bigger fan works out.

 

I bought my rad and duel fan set up from rock auto for $238 it's from a n 02 camaro ls1 works perfect , is not loud and car never goes over 210. Fits right in my 83 cutlass . This is with only 1 fan set up the other is for when Ac kicks on and I haven't hooked it up yet. Rad is only 11/4 wide aluminum I fig good enough for gm good enough for me

 

I'm using the stock 3 core copper rad from my 71 cutlass with dual fans from a ford windstar activated by the ECU. The low fan comes on at 170 and the car hasn't gotten over 190 yet. It will idle all day at 180. I haven't had the second fan kick on for any reason yet, but these fans draw a ton of amperage. I had them running off 30 amp auto-reset breakers and they would flip the breaker after 10 seconds. Right now i've bypassed the breakers, but am looking at getting 50 amp ones for some protection. I'm running a very short power directly from battery through breakers to relays to fans using 10ga which they need. I'm with everyone else thinking your issue is with your fan.

 

If it only gets that hot idling in traffic, then goes down on the road, it's most likely an air flow problem, and a better fan should help. I assume its a puller fan and not a pusher? Fans mounted on the back side of the radiator are way better than ones mounted in front, and also remember that the air you pull in also needs to be able to get out of the engine bay, but if it's fine on the highway it sounds like that isn't a problem. I've had a single fan and shroud off of an old Celebrity for years and it works great. Did you have some kind of cheap aftermarket fan on it?

also. I've been to Johnny Ray's and Jackson drive quite a bit, but just don't recall seeing this car. Or maybe I have seen it, and the hood wasn't open???