Cooling issue

[PNJSNAK]

Now that the temp in NE Ohio is below freezing????
I thought I would put it out there about an overheating issue I have had since I built the car in 2001 (finally)!
No matter what time of the year, spring, summer or fall.
After driving for 15 to 20 minutes the water temp goes over 210degrees F.
I have a 180 degree thermo in a 351 Winsor approx 350 HP, cast iron heads.
I have run the engine until the thermo opens to get what air I think is in the engine out. I run 50/50 water and antifreeze. I run the overflow to a catch can and the overflow of tha catch can runs to the ground area.
If I open the heater valve then close tithe temp goes down to 200 but soon goes back up. I get concerned that the temp can go up to 220 in the summer.

I am tired of being concerned and am looking for some help solving this issue when the weather warms up in the spring.

Any suggestions would be appreciated.

Is there a cooling specialist in NE Ohio?

Jim

[Dirty Harry]

Is there any chance that you have the head gaskets backwards, blocking a coolant passage? Is one of the radiator hoses (typically the lower one) collapsing? Did you try drilling a small hole in the flange of the thermostat and orienting that hole to the top? Did you try having the front of the car elevated when you filled the radiator? Has the distributor gotten loose and rotated, causing the ignition timing to be 'way off? If you changed the engine from v-belts to serpentine belts, did you make sure the water pump isn't turning the opposite direction? Has a baffle gotten loose inside a muffler, resulting in excessive back pressure? When the car is up to temp, use an infrared thermometer to compare the temps of both radiator hoses. These are just a few "outside the box" ideas to possibly help solve a 13 year problem.

[cycleguy55]

A 50/50 mix of ethylene glycol and water with a 15 lb. radiator cap boils at 265 deg. F. - I see no problem with 210 or 220 deg. F. I have a 180 deg. thermostat in my BBF and it runs around 190-200 on the highway, but will regularly creep up above 210 when in traffic - and I've never had any problems.

[Ron61]

All of my performance cars ran best at around 215/220 and I have ran them for years on the track and street with no problem. I used to have to block off the air flow on the Cobra when it was cool to get the temperature up to that as it was sluggish when it was down below 200. And look at NASCAR. Theirs run at 220/230 all day long.

Ron

[joyridin']

Does it do it when you are parked as well as driving down the road? I'll assume you checked the temp with another gauge and replaced the thermostat. Have you checked for a leaking head gasket?

[Large Arbor]

If its not the above, I would drain the fluid and change it for starters. I would then look to make sure the fan is operating properly and start with the movement of the air. I run a aluminum FE and on the hottest days it will get to 200, but with the fan on, it never goes above.

Phil

[DanEC]

I would agree that even 220 is not a big worry on a summer day, although most would like to see it a bit lower just for piece of mind.

Picking up on Joyrider's comment - have you actually checked the temperature with an infrared temp gun on the thermostat housing or upper radiator hose? I would not automatically assume the gage is completely accurate.

[jhv48]

With a 180 degree thermostat and an appropriately sized radiator with appropriately sized fully shrouded puller fans, your engine temps should never get above the point where the fans come on. Generally that point is around 195 degrees.

If the temp still climbs after the fans are on, then your cooling system is suspect. A good sized radiator with a shrouded puller fan is capable of cooling an engine much bigger than the one you're running. I suspect either your fan isn't pulling enough air, you have no shroud around it or your radiator is too small.

All this assumes that you've checked your thermostat to make sure it's opening at the prescribed temp.

[cycleguy55]

Originally Posted by Large Arbor

If its not the above, I would drain the fluid and change it for starters. I would then look to make sure the fan is operating properly and start with the movement of the air. I run a aluminum FE and on the hottest days it will get to 200, but with the fan on, it never goes above.

Phil

Phil: Are you running a thermostat? 180 degree? 160 degree?

[Karl Bebout]

I spent 'way too much money and time with my overheating problem on my BBC. Even went to the point of taking the water pump apart to ensure the impeller blades weren't spinning on the shaft. Never found the culprit. The very same block had run fine for many years at .060 over and the heat started when I cleaned it up with another .010 over bore. Still can't imagine that taking a measley .050 of material off the cylinder walls made the difference but...I finally bit the bullet and ran Evans waterless coolant. Still ran hot, but didn't worry about it since there was never any pressure created ( ran a 7# cap just to keep the bugs out) and the good full synthetic oil I ran was good for the 250* I'd hit on the strip. Costly stuff, but worth it for my peace of mind.

[cycleguy55]

Perhaps everyone already knows this, but at the risk of offending those that do I'm going to write it for those that may not. The temperature rating of the thermostat is the temperature at which it starts to open, and it is most likely not fully open until the temperature rises another 15 or 20 degrees - so 195 or 200 degrees F.

As I wrote before, my engine runs around 190-200 on the highway, consistent with the proper 'fully open' temperature of my 180 degree thermostat, but will creep up above 210 when in traffic on a hot day. As soon as get rolling or even if I bring the revs up a bit (e.g. 2,000 RPM) the temperature will immediately start dropping. Clearly there is lower coolant flow at idle and the temperature climbs a bit, but 210 or 220 degrees is well within the boiling point of my system (60-70% ethylene glycol, 13 lb. radiator cap).

That lower coolant flow at idle and/or power consumption of the water pump at higher RPM is why many people switch from belt-driven water pumps to electric water pumps. Perhaps it also has something to do with the consequences of losing a belt 100 miles from home. I don't know, I certainly haven't seen the need - at least so far.

The temperature gauge gets its reading at or near the coolant neck outlet, so it's the temperature leaving the engine - likely as hot a spot as any, other than a spot reading right at the closest point to a cylinder.

On my engine the sensor to turn on the cooling fan is at the radiator inlet, as recommended by Flex-A-Lite, so it's probably reading pretty much the same temperature as the gauge. It's adjustable and turns the fan on when my gauge indicates about 205-210 degrees. Once the fan is on, the temperature climbs very slowly, and only reaches 220 if it's a very warm day (e.g. 90+ deg. F). As soon as get rolling or even if I bring the revs up a bit (e.g. 2,000 RPM) the temperature will immediately start dropping.

Maybe it's just me, but I'm curious about what a second temperature gauge sensor at the radiator outlet or water pump inlet would read. Is the temperature differential 10 degrees, 30 degrees or 50 degrees? Anybody know?

[Large Arbor]

I run a 180 degree thermostat. I think the aluminum just cools a little faster than non-aluminum motors. It will get to 200 on a 90 degree day sitting in traffic with the fan on, but as soon as I start moving it drops back to the 180 number.

Phil

[RICK LAKE]

PNJSNAK J im have a couple of things for you to check,
#1 what is the ratio of the pulleys on the front of the motor? Are you running a March setup? If so the water pumpcould be turning too slow and causing your hot problem. Ratio for crank to water should be a min of 1-1. Measure the diameter of both pulleys and get back to us.
#1A thermostats, They are not all the same. I have been through the overheating problem with my car. Everything helped a little but still got running in the 205-210F on the track and the motor was slow to cool off. When got back to the pits, put a box fan in front of the opening and ran it for 10-15 minutes with the motor off to cool the car down. I even tryed an $800.00 Griffin radiator. Agained helped a little but not the cure. The list I have givin you. Is all the things I tryed. IMO here's the winner that did the most,
Thermo stat housing is too small on the small flow side. This is for an FE motor but sure that same problem happens on all motors. I did the same repair for a Pont 400 motor and got great change in temp. High flow thermostats are just a sales pitch. Maybe they do and maybe they don't. I tryed them all. from Summit and jegs. I went back to the beginning. I got the correct diameter thermostat for the motor and started to look at all the other thermostats with 53-55MM size. I then looked at each one for the opening. I found that they are not all the same size. The FE thermostat is about 7/8". I then started measuring everything else on the rack and found that Dodge 383-440 motor have a thermostat that is 2MM larger and the opening is 1 1/4" That's alot of added flow. I got the thermo stat and trimmed 2MM to get it to fit in the manifold opening and cleared the housing. My motor at this time was a 452 FE with 9.2-1 compression small hydro flat tappet motor. All Torque. This motor is up to operating temps in about 2-3 minutes at idle depending on outside temps. The hotter the faster up the guage climbs. Here's the thing, once it hits about 190F on the gauge it drops back in to the 150's and goes back and forth until is levels out in the 180's which is what I am running. After 20 minutes on the track, I see about 205-208 temps. I do run an oil cooler which also helps control the temp of the motor. I have gone to a 484 motor and still running the same numbers with about 150 more HP. I have finally solved my problems with the car.
Side note ERA has an air deflector for their cars, it works. You have to remove the dual small fans to get better air flow and this helps bend the air to the bottom of the radiator for more cooling. ERA has their radiators layed back at a 20+ degree angle and air doesn't like to bend. Another reason for a fan shroud and sealing around the opening inside the car with high temp foam strips or some kind of high temp tape.
#2 Some one all ready said up side down head gasket on the one side. They will go on either way but the steam holes are blocked . It's an easy mistake.
#3 Do you have the AUX dual cooling fans in the opening of the raditor. They look cool but block alot of air. Try removing them and retest the car.
#4 radiator shroud for the fan to pull 100% of the air through the fan.
#5 Fan CFMs, some of the guys Have gone to Tauras fans on there car These fans pull alot of air through the radiator. Not sure on hook up or how many amps this pulls. Need a good relay and recommend 10 gaue wire for hooking this and running it.
#6 if these ideas are not working from above and you pull the intake manifold to get to the head gaskets, check both the coolant passages on the head and intake manifold to match the gaskets in size. May need to get a dremmel tool and clean out the casting from when it was made.
I am going with the fact that you have gotten all the air out of the motor and this problem is still happening. YOu may want to goto a garage and have the coolant system vacuumed down to start and see if all the air is gone.
Good luck jim with the problem. I am going with my first couple of ideas here and you will be fixed. I hope it's not the head gasketed up side down. Think it's the arrow must be pointed to the front of the motor. Doesn't matter if you see it or not. Check with Fel-Pro site for side bars on installation. Rick L Ps I left off radiator caps, I like running a low pressure ones with 13 psi or 15psi. Anything more and I want to find a way to drop the pressures. This is not to say there is anything wrong with running a high pressure cap of 17 or higher. A couple of the guys run pressure gauges for the cooling system. this gives you an early warning sign about overheating a motor of head gasket is starting to blow.

[Mdman352]

#5 from Rick Lake.
Use a (shrouded from the factory) fan from a Lincoln Mark VIII. Use only the high speed, as it is a 2 speed fan. Use a heavy duty relay and appropriate wire size as it draws 45 amps (?). Cured my FE issues. Also, you will definitely need to upsize your alternator.

[Dwight]

Lots of good responses

I'll add mine

try using 40% antifreeze and 60% distilled water. To much antifreeze will make the motor run hotter. Been there done that.

My friend installed a rebuild water pump on his 351W. He set the motor up on my test stand to break it in and check for leaks.
It would run for 15 minutes and then the temp would go to 250 plus.
After months of trying different things he pulled the pump and found they (the company that rebuilds the pump) had installed the wrong impeller.
New pump and all was well.

Check your radiator size

Had one FE with trash in the return hose. It would overheat at idle but not on the hiway.
Cured a few with new high volume pumps.
Over drive pulleys are not for street cars!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

If your going to own a Cobra you should buy a good (not Sears $80 POS) infrared thermometer.
Check the temp on the base of the sending unit in the intake and compare it to the gauge reading. Most gauges are off 5 to 8 degrees. Some as much at 15 degrees.

Best of luck

My buddies and I have chased a lot of overheating problems thru the years.

Dwight

My motor makes about 480-500 hp. Which is heat! Lots of heat.
Last June on I-65 north of Nashville Tn. it took me 77 minutes to go 4 or 5 miles.
My car idled the whole time and never got above 220 degree. Most of the time it was 200. I have a 195 T-stat. When it got to 220 I just rev'ed the motor for a few minute and it dropped.
I wanted to do the Happy Dance in the middle of the interstate. No over heating problems.

[Bobcat]

What cycleguy said about thermostat "ratings" .... X2 ! So many people think that a 180 degree thermostat will hold the temps at 180 degrees . There is also a tolerance of =/- a few degrees on the settings . Test your thermostat by putting a piece of string in the seat , drop it in water and bring it up to boiling while monitoring the temp . When the unit drops off the string is when it is stating to open , note the temperature .
FWIW , I run a consistant 190 degrees except in traffic when it will get to 195 to 200 degrees .... drops when I get up some speed . Track is about 195 to 200 degrees .
You might want to verify that your gauge is reading correctly before spending a lot of time and money on other things .
Check your timing ... it can have a big effect on engine temps .

[Mastiff107]

Evans. Never have to worry and never have to change it. If it's good enough for all of Jay Leno's cars it's good enough for mine.

[Dave Van]

Be sure that the fan is running in the right direction. If the wires are reversed it will blow the wrong way. no cooling.

[Xack]

Originally Posted by Dwight

Lots of good responses
Over drive pulleys are not for street cars!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Dwight,
Is this comment for centrifugal pump impellers vs. scroll impellers, like Edelbrock?

Can you elaborate on this for us please. I have an Edelbrock pump (scroll impeller). I changed it on advice which stated improved temperature control. I installed a small pulley (~3:1 ratio to crank pulley) in order to get the idle RPM up to get the pump to work better at idle state. I am concerned that what I've done is up the RPM's on the pump at highway speeds to cause too much pressure on the block to possibly blow the freeze plugs!, especially if there is any restriction at the thermostat. I have placed a gutted thermostat so I do not have temperature control at all. Am I doing things here to cause more problems for myself or improving things? It sounds like to me, possibly making things worse by changing pumps, pulleys and removing thermostats.

Should I just go back to the stock, centrifugal impeller, my mildly overdriven water pump pulley and a 180 degree thermostat?

Thanks, in advance,
Xack

[Dwight]

Ok, Xack,

I need to correct my statement to say underdrive pulleys.

First; I'm not an expert in anything!

I think if you have changed the pulley to overdrive at idle, that would be the correct thing to do.

I don't think you can blow your freeze plugs at hiway speed.

I like a t-stat because I have a heater. Some guys don't use t-stats in their Cobras. And it's not a problem for them.

Just my humble opinion

maybe someone with more experience can chime in.

Dwight