as title says, 70 chevelle with a 350 mild cam, performer intake, 4 core rad, fan shroud from a 76ish monte, flex fan with spacer mounted on my water pump, and 160 thermostat. While cruising i run approx 190 and today sitting in traffic at 30 degrees Celsius (86 Fahrenheit) i hit 230 as soon as i started to cruise again it went back down to 190. what could be the problem and where do i start?

thanks

If you're running one of those 'decorative' flex fans with blades hardly wider than 2 inches, that could be the issue. Also make sure your fan is at least 1 inch into the shroud, but not all the way into the shroud either. Go to store.summitracing.com and punch in part# FLX-1380 That fan will cool about anything.

Flex fans don't move much air. They are also dangerous. I had one dent my hood and had another just miss my head when it flew apart while I was tuning a car.

Since you experienced this problem while sitting still, it means your basic set up is not up to the task.

1. I would make sure your radiator is clean. Use water with Wetter water or Royal Purple's additive. (Make sure to drain some out and add anti-freeze in September!) Plain water is more efficient at cooling than anti-freeze.

If you still experience the same temps:

2. Replace that cheap flex fan with a factory style clutch set up.

Or he could go with a FLX-418. That fan is plastic, rated to 8000RPM, and moves TONS of air, although it is a bit noisy. The best part is the price: 20 bucks.

I have heard of factory fans flying apart too. And they aren't rated to 8000RPM either.

as title says, 70 chevelle with a 350 mild cam, performer intake, 4 core rad, fan shroud from a 76ish monte, flex fan with spacer mounted on my water pump, and 160 thermostat. While cruising i run approx 190 and today sitting in traffic at 30 degrees Celsius (86 Fahrenheit) i hit 230 as soon as i started to cruise again it went back down to 190. what could be the problem and where do i start?

thanks
here is my answer .. you would never worry again even in 14 miles of parade traffic
see link
http://www.chevellecooling.com/m3_view_item.html?m3:item=SPAL%20TWIN%2011%20INCH% 20FAN%20KIT
Don

yea im using one of those decorative fans, the fan is about 1/2 in the shroud and 1/2 out, how can i tell if the rad is clean and what will the wetter water do? absorb more heat? the rad was pressure tested, there are no visible damaged fins, and the coolant is 50/50 mix and is about 4 months old.

Change the fan and your issue will be resolved. I wouldn't bother with the water wetter for now. The water wetter works, but it won't drop your temps from 230 down to 180 degrees. A good fan will.

I was told, because I've been having some cooling issues, to change my thermostat, I too run a 160 and run at about 190. they told me to put a 180 in there because when I run at 190 and go down the thermostat will close and stay in the radiator and cool

I hope this makes sense

Make sure your timing isn't retarded also, that would contribute.

A good flex fan (Derale) will move tons of air and hold up, but they are noisy.

If above two items don't do it, then I'd say your radiator is suspect. Just because it's "4-row" doesn't mean it's capable. A good aluminum (Alumitech) would be a worthwhile replacement if that's a problem area.

Given the problem, it does seem to be airflow related only, which points primarily to the fan. Swap it out and see what happens.

What Mark suggested is right on the money.

Since it cools down to 190 shortly after leaving traffic its likely a poor airflow issue so try the better fan like Mark stated.

After you get a better fan if this is a manual trans you can idle it up a little more then normal like 950-1k rpm to pull more air thru the rad when in stop/go traffiic & even if your running auto trans try to bump up the idle speed a tad if possible to help move more air.

And if running a perf cam you need at least 16-18 deg base timing,anything less is retarded which can also increase temps esp when in traffic at idle.

Scott

Guys, I've had my malbu 400 , (all original) get up to 220 or 230 fo maybe a minute while stuck in traffic, creeps up to 210 - 220 rarely 230 ,but as soon as you start moving it drops right back to 190, and 185 when cruising.I just assumed this was normal, never any overheating etc,car runs great , great pressure , no issues....but what is the highest temp a guy should let it idle at ? Should I be concerned ? thx

DeadDog,todays motors are designed to be ok at 220 deg f but our 30-40 yr old motors dont like 220 deg f and as for 230 deg f that pushing it,it's too high IMHO.

Are you running a stock w/pump and stat or a hi flow pump with hi flow stat?

Are you running a std/stock gm 4 blade fan or 7 blade clutch fan with std or hd/ac type clutch?

Whats the base & total timing and are you running a vac adv?

Where is the temp sender,in the intake or in the head where it will typically read at least 8-10 dewg hotter then the rest of the motor is actually seeing at the time? If thats the case then your 220-230 deg temps are suddenly /realistically 210-220 deg max,still not great but better then 230 deg.

Since your motor cools back down after getting back p to speed after sitting in traffic it shows your rad is likely ok. It's more likely an airflow issue when at idle that's casuing the increased temps or at least one of the issues that could cause the motor to run hotter at idle. If your running a clutch fan i bet the fan clutch is either going bad or its the std duty unit that's marginal with some appalications.

Try Napa's 271303 - H/D clutch or Hayden's 2747 H/D clutch if your running a stock type gm 7 blade 772 fan,you should use a stock shroud too.

Idle the motor a little higher too so it can pul in more thru rad too when at idle.

Also make sure your runing enough base timing (16-18 deg)if you motor has a perf cam because less timing then that can cause increased temps at ilde & lower engine speeds before full total timing comes in due to retarded base timing . You should also have approx 18 deg mech in dist in by 2800 rpm,then 16-18 base + 18 deg mech in dist =34-36 total which isnt a bad place to start for dialing in a street perf ign curve.

You should also be running 93 fuel when trying this ign curve to avoid detonation and then try lower grade fuel later to see what your setup can tollerate ,you should also be running a vac adv for street use too.

Scott

I got one of these and it is loud as a jet, but my car can idle at a red light in the 105F Sacramento heat all day and never break 190F.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=DER%2D16928&N=700+115&autoview=sku

I also have a cheap flex fan, stock radiator and stock water pump and I can idle in 100 degree weather all day and my car will never see temps above 190.

I was told, because I've been having some cooling issues, to change my thermostat, I too run a 160 and run at about 190. they told me to put a 180 in there because when I run at 190 and go down the thermostat will close and stay in the radiator and cool

I hope this makes sense

It really doesn't make sense. Closing the thermostat will also keep water in the block longer and raise the apparent temperature of the motor. The key to cooling is flow, both water and air.

thanks guys ill start trouble shooting it

as title says, 70 chevelle with a 350 mild cam, performer intake, 4 core rad, fan shroud from a 76ish monte, flex fan with spacer mounted on my water pump, and 160 thermostat. While cruising i run approx 190 and today sitting in traffic at 30 degrees Celsius (86 Fahrenheit) i hit 230 as soon as i started to cruise again it went back down to 190. what could be the problem and where do i start?

thanks

I have almost the same set up as you do except that I have a 3 core, a factory clutch fan, and a 180 t-stat. Mine runs at 180° and 190° in the hottest desert temps (and my God it has been hot here) even idling for 20 minutes. Check the timing, I run 10° BTDC minimum and lose the flex fan, put a real factory clutch fan with a good thermostaticly controlled clutch. Your using a shroud from a later a-body like myself you need a larger diameter fan to fill the shroud, I used one from a 78 - 87 El Camino with a clutch fan for a 78 350 El Camino. If you can keep the temps under 220° then all is good, it doesn't need to run at 180° or below, mine is a bit on the cool side but I figure with time the temp will come up due to use.

here is my answer .. you would never worry again even in 14 miles of parade traffic
see link
http://www.chevellecooling.com/m3_view_item.html?m3:item=SPAL%20TWIN%2011%20INCH% 20FAN%20KIT
Don

I don't know about he rest of you guys, but I find these "sponser" post tacky.

The whole appeal of TC has been the reliable info you could get here, but now you have filter all the marketing crap!

Larry It is a fact Don will refer you to a site that promotes his own product. Openly he follows the guidelines set out by the leaders of this site. But one thing will remain constant. Nobody, but Nobody, offers more help on a particular area than Don. Yeah he toots his own horn but if I had the biggest and the best I would too.

Guys like him make this the most credible site around. He really does not ask a lot in return. Please refer me to posts where Ground Up has responded and they get a lot of business from here.

Larry,
I have to second the fact that Don is one of the most helpful folks I know. He is an asset to this site. Don will go far out of his way to make sure you are satisfied.

I don't believe there is any pressure to do business with him and he will still help you.

Just a comment.


Larry It is a fact Don will refer you to a site that promotes his own product. Openly he follows the guidelines set out by the leaders of this site. But one thing will remain constant. Nobody, but Nobody, offers more help on a particular area than Don. Yeah he toots his own horn but if I had the biggest and the best I would too.

Guys like him make this the most credible site around. He really does not ask a lot in return. Please refer me to posts where Ground Up has responded and they get a lot of business from here.

thanks again

John,Great point,Don from Alumitech along with Mike Lewis/Carl-CNC/BillK/Gary-Go Fast/ to name a few are guys that spend countless hrs helping all of us out here in t/chevelle which i knowi appreaciate a lot. Yes sometimes they get buisness from us but many times they dont either because of long distances etc. But either way they are always willing to help us by giving thier experienced advice to keep us on track or get us out of trouble when we are buidling our motors, are having motor problems, or just plain need good advice for a good solid performing combo.

Scott

John,Great point,Don from Alumitech along with Mike Lewis/Carl-CNC/BillK/Gary-Go Fast/ to name a few are guys that spend countless hrs helping all of us out here in t/chevelle which i knowi appreaciate a lot. Yes sometimes they get buisness from us but many times they dont either because of long distances etc. But either way they are always willing to help us by giving thier experienced advice to keep us on track or get us out of trouble when we are buidling our motors, are having motor problems, or just plain need good advice for a good solid performing combo.

Scott

For some member's that feel im here strictly promoting product , sorry you feel that way .. I think there missing the point ...what I am here doing is pointing out what they may be able to do to solve there cooling issues .. im sure everybody has a Summit or Jegs catalog lying around ... but if you don’t know about the other choices out there ,you could buy something that doesn't do the job . Ground up .. another sponcer here ,as one member pointed out dosent pop in to answer questions .. and im sure there plenty busy also .
Do I need the business ...trust me im doing fine... plenty busy trying to keep up with demand .. cant build fast enough to keep product on the shelf ..Cranking out over 1000 units a year my self ... but I do take the time to pop in and offer help here to those less informed , along with countless customers calling at aprox 30 a phone call my day gets pretty full ..Scott also needs to be commended as he points out many ways to correct issues in depth.

once again guys thanks for your support .
Don

I think the only people that feel "some" people (basically those mentioned by Scott above plus a couple others) are promoting their own products are correct to a point. They are really promoting their knowledge, which of course leads to their products.

When you are top-notch AND willing to help others regardless of what product you have or buy, that's not a fair statement to make about them. It offends me, quite frankly, to hear someone belittle the expertise so freely shared by a few people just because they are in that business. Where else are we to receive that expertise? To say that's why Don or the others are doing this is a statement made out of ignorance.

I don't mean that in a derisive way, just that there's a lack of knowledge on the part of someone that would say it.

how do you get a fan shroud from a mid 70's Monte Carlo in there? that thing would be wedged between the block and radiator, with no room for anything at all.
as already stated, either get a good oem style clutch fan with the proper shroud, or get an electric fan from the junkyard. a fan from an 85 Celebrity with a 4 cylinder kept my Monte right at it's cut in temp of 200 degrees all day long, and if i bypassed the temp switch and grounded the relay it would stay at the 190 thermostat temp.
if you do go this route, grab the fan harness out of the car when you get the fan- it has it's own little harness that includes a relay, fusible link, and temp switch all in one easy to remove sub-harness that doesn't tie into anything else on the car. the temp switch in those cars is designed to kick the fan on at about 135 degrees, but NAPA can hook you up with a switch to come on at a lower temp- pick one about 10 degrees higher than your thermostat so it isn't running all the time when you are going down the road.

the shroud was a 2 piece so i simply took the off the piece i didnt need, but as said above my fan sits 1/2 in and 1/2 out the shroud, this weekend i plan to figure it out, first need to find a old GM fan front the junk yard.

Sponsers help support this site also. If They post Their website's to help with product's We could use to fix a problem, Ain't that what We need? Beside's, We're lucky to have the Pro's around to help Us out.