Read an article in StreetRodder about two types of heat problems 1st is fine at idle hot when running down the road and my type fine running down the road and hot when sitting at lights or getting into a show. They mention two fixes for my malady: more water flow sooner by swapping out a 180* thermostat for a 160*, or move more air over the radiator. I can do either or both or I also wondered about moving the hot air away from the motor. The thermostat change is easy - and I really do not remember but I think I have a 180 in there.... I have an electric fan that can push and/or pull and room in front of the radiator but I am concerned that it will block the nice air flow I have going down the road now??? Finally I am trying the move hot air out - I set up two computer case fans on my hood with louvers. This seems to help, but I am still undecided about it & think I am probably not moving enough air out Oh yeah it is a 48 Stude M-5 truck with a 350 with a mild cam ram horn exhaust manifold, and 3x2 intake What would you do?
Id doubt the computer fans would be worth the effort. I'd personally go with a good electric fan on the radiator. It pulling in air, and blowing back air will cool it down a good measure
This won't help if it is running way hot at any time. 350 with those pieces should not run hot at all if it has enough radiator, or if the airflow is good. if you don't want to use your electric fan, get a factory OEM used deluxe clutch fan setup. The one you want has a curly spring showing at the front center. That is a bi-metallic spring that re-engages the clutch lock-up if it senses very high air temps from the radiator. You can hear them kick in, with a roaring sound. They move a lot of air.
Im running into similar issues and I'm suspecting that my specific problem is timing. A new water pump, new aluminum radiator, less than 10k on the engine rebuild & the car runs hot when the car sits still. I believe I need a bit of of advance at low RPM, going to play with that tonight. I've been told to make sure that I'm pulling manifold vacuum for the distributor advance & that if the vac isn't enough at low RPM that it will cause the engine to run lean and create more heat. Good luck fighting the heat battle, because its free I would experiment with timing first before spending any money or spending time fabricating fan mounts.
I'm no expert by any means. But on my current car I went with an electric water pump and I've been amazed at how cool the car runs at low speeds and idle. Full water flow all the time seems to make a huge difference.
It has a shell not a full shroud. I am very happy with the way it is running, but I will check the timing I believe it is a 3 or 4 row radiator built by a local guy here in the bay area - and about 2 years old Temps Im talking about are 195 while running down the road and as high as 210 and an over heat higher than 210 last summer pulling into a show.... Thanks for the responses!
Running hot at idle or low speeds (but ok at normal road speed) is usually caused by lack of air flow through the radiator core, or waterpump flow at low engine speeds. The latter, not very common, would be from faulty impeller on the waterpump, or low speed caused by too low idle speed or underdrive pulleys. Lack of air flow is usually caused by no fan, or a fan too far away from the radiator to pull a good amount of air through the radiator. A couple examples here would be:no fan, a fan cut down too small, or commonly a fan 2 inches away from the radiator with no shroud or a poor shroud. This can be remedied by putting a decent fan (stock solid 4 blade fans work just fine) within an inch or less of the radiator. This pulls air through the radiator, not just from the radiator. A borderline radiator could cause an overheat at idle but usually also at highway/high engine load speeds. Timing and carb idle tuning are almost a given here. If either is out you can not properly correct the situation, at best you will bandaid it. So first, check the timing, check for vacuum leaks (causing a lean condition at idle) then Idle adjustments on the carb. Not just idle speed, but also-more importantly idle air/fuel mixture. Then make sure your fan is doing its job. it should at the minimum **** a piece of cardboard to the front of the radiator at idle. If it wont even do this, start with the fan. A fan spacer and or shroud is minimal cost compared to a cooked engine, or even an oil change and coolant flush due to extreme overheating.
FWIW, 210 isn't overheating. The '90s and up Corvette fans don't even come on until 220. If you've got everything else right, you don't have a problem. If it isn't puking all the coolant on the pavement, just drive on. Having said that, check your temp with a good thermometer in the radiator inlet. Verify the gauge reading is what it is. jack vines
Again it's air flow that is diminished at idle. Cures: fan as big as possible ie mechanical or electric. Shroud that is covering half the fan blades of an mechanical bladed one.
210 is warm/ borderline hot, but not 'overheating' 230+ is bad. However, I dont like temps that high either. 210 doesnt give much cushion. if you are running 195ish on the road, try a 160 thermostat. You might also want a higher flowing thermostat. Stewart used to list them, now many places do. They look like a deep dish version of a common t-stat. They work well letting more coolant flow especially at lower speeds when needed. If youcan keep the temp down a few degrees before getting to a show by running a lower temp t-stat, you have more time before it builds temp in traffic. I run a 160 t-stat in the 54 chevy, stock radiator, 4 blade fan, 327 with about 36*timing (total) , 650 holley vac secondaries, moderate cam, no accessories other than alt, auto trans, 336 gears. This weekend I drove to CT 160miles each way at about 95* and 70%humiditiy. Three hours at 3k rpm and the car never got over 180*. In traffic it rarely sees 190* even in the summer or chugging lead east in 90* weather in early Sept. my point is that cars shouldnt run that hot if they have correct components. I am sure it is something simple. Just need to find and fix it.
You will know if its too hot under the hood. The carb floats will start to sink as the fuel boils in the carb. I have that problem if I sit in a lineup too long.A carb spacer plate or insulator might cure it.
What are you running in the radiator? Straight water? 50/50? Stock radiator? Is it clean? Posted using the Full Custom H.A.M.B. App!
some guys run those after market flex fans .... and they are junk the blades are thin aluminum, and tend to lose there curve and flatten when this happens no air is moving look cool but real pos
You say your running a 3 or 4 core, so it's copper/br***. Swap out to aluminum and it will make a huge difference.
best bet is a multi blade fan (18"?) with thermal switch fan clutch with shroud. but, if must use electric fan look at Cooling Components fans with shroud, excellent product. can use an automatic open/close or an adjustable switch. thermostat temp will not really do much, if anything. but, a "big mouth" high flow one should help. there are high flow water pumps from places like Flow Kooler. But, sometimes these will push too fast and radiator does not have enough time to cool water down. Enos Components, likely others, sell a simple plate that you rivet to blades on existing water pump impellers which keeps water pockets from forming. also, do you use a heater? if not do you have a byp*** hose running from intake manifold and water pump-considered ugly but, again will help prevent water bubble build up. running about a 15LB radiator cap? using over flow tank? Evans Non Glycol Based Coolant helps also.
A friend of mine had a '49 Merc chopped sled. He ran a sbc with A/C. Using an aluminum radiator with mounted shrouded fans, it still ran hot. He finally louvered the hood and temps dropped. He could actually use the A/C sitting in traffic on a hot day. In my '52 Chevy running a sbc with A/C, I use a dessert cooler radiator. It's a 4 row triple p*** br***/copper. The hottest it get sitting in traffic is 180 with the A/C on. I use a mechanical fan and shroud. The main thing that caused my engine to at 210 was the vacuum advance was frozen.
Airflow and proper components are the basics , So is the timing ,see how it acts by changing from ported to manifold vacuum, as ported kills the advance at idle (smog deal) . Make one change at a time so you don't end up chasing your tail.
Bottom line, not enough cooling. My bet , from many [too many?] years experience is the rad is plugged or too small. Just because it was built by a local guy doesn't mean it is large enough. Ben
Yes it will make a huge difference - but the opposite of what you want. It is a well do***ented fact from scientific experiments that copper and br*** conduct heat far better than aluminum. In other words, heat dissipates faster from copper and br*** than it does from aluminum. Aluminum radiators were used for weight savings on race cars and are a technology that has been jumped on by certain manufacturers to promote as a 'desirable' technology for the street. It is not. Add to this that many aluminum radiators are cheaply made by having the tubes epoxied to the tanks and you have a recipe for failure - don't you Griffin? Once the epoxy dries and cracks, as it surely will over time, your radiator is non repairable history. I have had three aluminum radiator failures and every time I have had to throw them away and replace with copper and br***. Stick with your copper and br*** radiator which not only conducts heat better, but is also repairable. The problem is that many people are all too ready to jump on the latest bandwagon or buzzword product without researching the product properly. As others have said, a Cooling Components Inc. shrouded electric fan is about as good as it gets. And one more word of caution: check electric fan ratings as there is a lot of BS about com ratings. The simple rule of thumb is that if the fan motor is not powerful enough to draw the amps then it cannot pull or push the com. The CCI fans I have use 70 amp relays and pull some serious amps. If a fan pulls amps in the mid teens it just does not have the power to even pull the skin off a rice pudding! Getting the hot air out of the engine compartment is just as important - some louvers or holes in your engine compartment will not only help the hot air exit but will also mean less heat build up in the cab....
Well major hot weather here in Northern California. I changed to a 160 high flow thermostat and think this may have helped. I took a ride around town then out on the highway and then let the truck sit and idle for 15 min and my temps were just below 210 and it did not overheat. Next test is a show on Saturday......
Here's a trick my buddy did on his g***er to overcome the same problem. Every time we got stuck in line, or a traffic jam, his car began to get hot. He purchased two big heater cores off an Ebay auction for about $10 ea., and then two Spal fans in 8" diameter. Mounted one core up under the front fender on each side, and attached the fan to them. Then he routed a hose from the normal heater outlets on the engine to each core in series, and hooked up a fan switch on the dash. Now when he gets stuck in traffic he flips the switch on, and the extra cooling is enough to keep the temps down.
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