FE Cooling issue

[951mat]

Haven't been around it a while but I'm getting frustrated with cooling issues and could use some help. I've read other posts on cooling and learned what to try, but I'm running out of ideas. After rebuilding my lonestar, I bought new radiator. A dual pass griffin (inlet and outlet on passengerside) with 1.25" tubes (400-600 hp model). Radiator is now at a slant vs vertical like my old set up. I'm playing with a shroud right now, but am afraid its not going to do the trick. Car just runs warm. Holds around 200 while driving on hwy, but any stop and go and warms up quickly 220+. T-stat is 180. Fan is from Vintage air like what Don Barns had on his lonestar (shrouded, 2700 cfm). Timing is 28 deg all in, about 14 at idle. Plugs looks good. They do look cleaner than they used to but I'm attributing that to the higher heat they've run at. My laser temp gun shows 168 in the upper radiator hose and 135 in the lower. I've heard of people having cool lower hoses, not me. Could the 1.25" tubes be too big, and water going thru radiator too fast?

Mat

[patrickt]

Originally Posted by 951mat

Timing is 28 deg all in, about 14 at idle.

Mat, are you sure about the 28 degrees total advance number? Most of us run more than that, say around 35, give or take, and depending on the type of heads. Before I did anything to address the heat, I'd first re-curve the distributor to add 20 degrees on top of the 14 you're running at idle and see if 34 degrees total takes the edge off that overheating.

[jwoodard]

A shroud will make a considerable difference, at least it did on my Lonestar, and I was running an FE as well.
Here's a picture of it.
[IMG][/IMG]
Also, check to be sure you have good grounds on your gauges. You might not be getting as hot as you think

[Dwight]

what is your anti-freeze water ratio?

We run about 25% anti-freeze and 75% distilled water. We have a lot of minerals in our tap water.
And one bottle of water wetter, your choice of brand.
Two much anti-freeze and she will run hotter.
Dwight

[Barnsnake]

With that much radiator you should be running at thermostat temperature at speed. Based on the data you supplied, either your thermostat is defective or your temperature gauge is wrong (my guess).
I assume you were idling and stationary when you took those infrared temperatures. In that circumstance a 33 degree drop across the radiator sounds pretty good.

[MaSnaka]

Make sure you got the right temp sender if it's an electric gauge. My car was doing the same as yours after changing the sender. I was using a universal model and now I have the specific sender and it runs cooler again according to the gauge. My suspicion is your infra red gun is trying to tell you 220 is really 168.

John

[RICK LAKE]

951Mat Here is some of the things to check. All these thing helped drop my coolant temps.
Start with the radiator, straight up and down help let the most air throught it without fan assistance. The more the angle the less the flow of air with out the fan running all the time. I have found that the splitter that ERA sell with the car work well. I like the look of the 2 small fans in the front but they don't do alot to move the air through the Radiator. They also block the air flow to the rad. Choice is yours on this.
Hoses, Are you running all rubber hose on the bottom line or steel with short turns. I have found that this hose will collapse when the motor is running if it doesn't have a wire support. Exhaust pipe works great for this run with just 2 short turns on the ends. Same applies for upper hose, more steel less rubber.
Pulleys, who's are you running??? If they are March, you will have a heating problem at Idle I went through the same problem of 215-225f at idle. March sells pulleys that slow down the speed of the water pump and Alt. This is the wrong way to go. You want to look at the custom Kirkham pulley set they sell. Water pump and crank shaft are the same size, look great and increase flow on the water pump. I would have to measure but 6" upper and lower are about the correct size.
Intake manifold gaskets and ports for coolant flow. Depending on who's manifold you are using, some need to have the grinder used to clean out the coolant passages. You can gasket match with the intake gasket and go in about 1" and clean out the scale. Becareful to not remove too much and cause a leak. Just good cleanup. Intake gaskets, if you are using the 1247 ones they slide down and partially block off the flow between heads and manifold. They should be RTV or High-Tac into the correct position on the intake manifold and allowed to dry before installing. This applies with the return on the oil from the heads too. Trim the gasket to make sure you get a clear return.
Thermo stats I use BB dodge RB motor ones and trim about 2mm off the outside edge. The hole is about a 1/2" larger than the FE one they sell. This means alot more flow through it. 2, 1/8" holes in the housing for air to get out on the motor. If you can find a garage with a vacuum coolant machine this works the best with removing the air and complete fill of coolant.
The last thing is getting a pressure gauge hooked to the coolant system, This is a long shot, a small leak of the headgasket. This would be the last thing to go through. This would be IF you have felpro 1020 gasket in the motor. Look for an funny looking crud on the inside of the valve covers, could be either side. AGAIN this would be last and sending out the heads for a pressure test.
The coolant mix has been talked about. I use 50/50% and 1 bottle of waterwetter.
Do you have the headers rapped or heat coatings on them? A big problem is getting the heat from under the hood area. I run to small fans that pull the heat from under the hood and go out the side vents in the fenders. Brings the temp down about 15-20 degrees.
Start with the thermostat going larger in flow and hoses and see what happens. I think with the thermostat, hoses and correct pulleys for speed of the water pump this should bring down your temps in the motor. Good luck Ps some of the guys park their cobra with the nose up on jack stand to help get all the air out of the coolant system and get a complete fill of coolant, it's a free trick. Rick l. Ps I have an Aluminum motor and went through all that is posted above to get my motor to idle in the 180's and race in the 205-210f range. I am also running a Griffen rad in my car after pulling the copper one from ERA. I was looking for lower readings too.

[Dwight]

A few years ago I bought a March pulley set from Summit for my small block. The set came with under drive pulleys. I had a problem with the alternator at idle. I call March and they said they could not help me. I call Summit and they exchanged the pulley. I ask her why would March would not exchange the pulley? She told me that I was Summit customer, not March's. Makes sense.

I helped Lainhart with his FE overheating problem at idle, worked as it should at speed. We found several large pieces of powder coating blocking the lower hose. He has a pipe that passes thru the front part of the fame. It had been power coated and the coating on the inside had turned loose and was tangled in the wire of the hose. We replaced the water pump with Edelbrock's high volume pump. Added a adjustable fan control to turn on the fan at 195. 25/75 anti-freeze. Now it will sit and idle for 40 minutes with no over heating.
It does not get below freezing here in North Alabama very often. And our Cobras are safe inside the garage, so we do not need as much anti-freeze as our Northern friends. Anti-freeze transfers heat 20% less efficient than water.

Three Cobra ago, 8 or 9 years ago, Coach had a overheating problem. We chased the problem for a month or so. Changed t-stat several times, different fans, etc. I was doing some reading on the problem and came across something about anti-freeze and heat transfer. I asked Coach how much anti-freeze he had in the Cobra. We did the cal's and it was about 80%. We drained it out and added back 25/75 mix and all was well in Cobra land.

Most of the over heating problems are a easy fix. Just hard to find.
Dwight

[cobraman428]

You need to experiment. It is time consuming but you need to determine if it is a coolant restriction issue or not enough air across the radiator issue. Many thermostats I believe restrict the amount of coolant needed to properly cool these big FE's.. Temporarily take the thermostat out and drive it. If it stays cool, then your problem is water flow. You may need to knock out the center of the thermostat and enlarge the hole but you will want some restriction. Just create more of an opening than a normal thermostat or find a thermostat with a larger center opening but definetly use a 160 degree. In my experience, 2700 cfm is still not enough.

[lovehamr]

Matt, couple of things:
Timing is 28 deg all in, about 14 at idle.
I agree with others that's to little. I'm running 36 in my FE, all in by 2k.

My laser temp gun shows 168 in the upper radiator hose and 135 in the lower.
What does it say that your manifold temp is right at the sender? I just found out that I was using the wrong sender and that my gauge was wrong because of it. i.e. if your gauge says 220 and your temp gun says 180 at the sender then you have a gauge problem, not a heat problem.

I've heard of people having cool lower hoses, not me. Could the 1.25" tubes be too big, and water going thru radiator too fast?
But your temp gun does show a 30 degree drop from rad entry to rad exit and it doesn't sound like it's that hot anyway. If your water temp is 220, then the water exiting the the upper part of the engine will still be 220 not 168.

Bottom line, with the temps that you've written I question whether you have a heat problem or not. Use your temp gun some more and see where you are.

[Jerry Clayton]

go verify the temp gun on a pot of boiling water and then check your rad water temp with a real thermonmetr

[lovehamr]

Good call from Jerry as well.

[patrickt]

FWIW, I took her out today, ran her, then put the infra-red heat gun on her while she was idling in the garage with all fans on (pushers and puller). She was holding steady on the Smiths gauge at 90 Centigrade, which is 194 Fahrenheit. The gun measured the coolant areas on the aluminum intake manifold right at 192 to 193 degrees. The upper radiator hose was at 201 degrees, the lower radiator hose was at 172 degrees. These were pretty consistent numbers, measured a couple of times. I still think 28 degrees timing on an FE could easily make it overheat when you're running it. That's absolutely the first thing I'd change, and I wouldn't touch anything else until she started overheating with a good 34 to 35 degrees of total timing in her.

[gsharapa]

I agree with most of the posts already submitted and would start with the timing first. 28 degrees total is way to far retarded. I'm running 38 total advance at 3,000 RPM and many run 36. Keith Craft told me these FEs like a lot of timing and actually dyno mine at 40 total advance althought with the crap fuel available today I backed it down to 38. Good shroud is important and then I'd be checking air/fuel mixture. If it's leaning out that could be causing it to heat up also. These FE run warm anyway as mine is usually at 200 running around in the low to mid 90s in Texas...

[Bill Bess]

Patrick is correct, timing first, check operations with infered gun, themostat with small by- pass hole. Buy a ford Taurus fan & shrold (2=speed factory fan) this fan has fixed numerous cobra heating problems.


Check out some of the entries regarding heating problems, good luck
Bill

[undy]

Another thing...

A lot of aftermarket and custom wiring harnesses as well as undersized alternators aren't up to the task of handling the high amp fan(s) needed to cool a hot FE. I'm running the Taurus 2 speed fan/shroud on mine and it needs 40 amps to keep it running. I've run #8 wire for the fan circuit, fused at 50 amps. I was getting 10.5 volts to the running fan with 12.5 volts from the alternator using the "fan circuit" in my Painless Wiring harness.

BTW... I went with Griffin's "800 hp" radiator, twin 1 1/2" tubes. It made a big difference over my old Griffin with the twin 1 1/4" tubes.

[Barnsnake]

Mat,
You've been given a number of great tips on improving the cooling efficiency of an FE in a Cobra.
I would still strongly recommend that you verify the accuracy of the temperature gauge before implementing any of them. It is extremely difficult to cure a problem that doesn't actually exist.

[elmariachi]

Originally Posted by Bill Bess

Patrick is correct, timing first, check operations with infered gun, themostat with small by- pass hole. Buy a ford Taurus fan & shrold (2=speed factory fan) this fan has fixed numerous cobra heating problems.

x2 on the timing suggestion. You give that 427 36* total timing at 2500 rpms and you'll feel like you just got another 100 horsepower in your seat.

[951mat]

Thanks for all the replys. I did find my dyno sheets and that showed 32 degrees timing for max power, not 28 like I thought. I advanced to 32 with little to no change. I never have believed my laser temp gun, but threw that out there anyway. I did put my temp sender in a coffee cup of hot water with a thermometer and it seems to be fairly accurate. I did boil the thermostat and it opened as advertised at ~180. I pulled 2 plugs that look good (not lean) but will look at others. Will keep you posted.

[951mat]

I'd like to think this is a simple fix as it usually is, but here's another observation. After starting my car in the garage, the temp start to build very quickly. I bet within 5 minutes, my gauge is reading 180. 10 minutes pushing 200 and increasing. At highway cruising speeds, it stays right around 200, but if I give it a burst up to 90+ mph, I can see an almost immediate 10-15 degree increase on the temp gauge. It then cools to 200ish again after a couple of minutes. I'm not loosing any coolant. Could that be a sign of a slight exhaust leak finding its way to a water passage. Maybe I should retorque heads?


Mat