Thran69

Before anyone in this thread jumps to any crazy, nonsense conclusion, that this has been fixed in other threads or that I have no idea what I'm doing. Well, it probably has, and I don't know what I'm doing. What I have done is days of research on this topic. I have talked with top Car restorers, I also talked with the best air conditioning technicians in the business. (i figured air conditioning split is just like a car, taking heat from where you don't want it to where you do.) Everyone has their opinion on what is wrong.

So some background. I have 1968 big Block 454, .030 Over, internally its stock, for the most part, Forged crank, and a mild cam. I have an S475 single turbo strapped to my motor. It has an 180 Degree thermostat. it has a V8 RADIATOR ALL ALUMINUM 4 ROW from radiator express. It has a summit high flow water pump. The only thing that isn't new, is the fan. Which is a mark 8 fan from a Ford Taurus. It has a two stage relay for the two stages low and high. The fan on high has supposed output of 4,500 cfm.

I cannot get my car to cruise and maintain temperature. I can do burnouts all day long, and temperatures never climb. I take a 5-minute trip and I'm pegged.

I do not have my hood on, it needs about a month of repair and I've been impatient. Most people say this is my problem

I'd love to hear everyone's input, because frankly at this point ill try anything. Some guys even said putting restrictors in the radiator like the old Ironheads. I have seriously heard of everything under the sun.

The car isn't "overheating" with the Evans Waterless Coolant, but it's still getting too hot (240degF) to run. Something is not right.

You guys can laugh at me, it's okay.
I tried making a video fixing it, and all I did was waste money.

The13Bats

Here is my food for thought,
And no, i wont laugh, its not funny to me,

Evans as you see isnt a fix for a car running too hot, its just another coolant with its own pros and cons,

The mark fan blades are larger than a taurus blades, different housings,
No mark fan motor was true 2 speed,
Mark fans had computer controllers,
some tbird, cougar fans look just like the mark fan, but are 2 speed and do move the same mark big cfm of air on high,
The smaller 2 speed taurus moves a lot of air but less than the mark, tbird and cougar fans, i would personally want more fan with that engine, are you sure air flow direction is correct?

I have ran countless cars including corvettes with no hood and never a cooling problem,

Restricting coolant flow to cool better is a myth many still cling to.

If the coolant is flowing normal and not blocked up and i will only guess it is,
then you dont have either enough radiator, fan, or both, i dont know how much hp its making but i would have thought that radiator to be enough...hum.

jim2527

Without a hood all the air is going over the top of the radiator not through it. Air takes the path of least resistance.

Antz81

Had a look through some of your videos, It looks like you have removed the front air dam. Maybe it just wasn't there in the one I looked at. If you do have it removed then you need to install it. This helps to direct airflow into the radiator when cruising.

The13Bats

I ran both my 66 327 and 81 radical 350 with no hoods for a spell in florida weather no cooling problems,

In his case as the coolant starts to get hot the electric fan with its shroud will/should kick on so hood on or off doesnt matter the fan will now pull air through the radiator, not around it so while no hood might cause fans to run more it still shouldnt overheat, because we do have a fan behind that radiator pulling,


Question to op,
If you leave the fans running does it still overheat driving over 35?

blue by you

i would put on the bottom air dam to push the air up to the radiator, it is needed

jim2527

I'm in no way disagreeing...

Sounds like the OP has a lot of basic issues that may be contributing.

Something I stumbled across in regards to electric fans....

1. Do old fans from 90's still maintan their cfm as the motors age?
2. Replacements for the typical Ford fans may not have name brand motors. Do 'Asian made' motors in new replacement fans have the CFM as original FoMoCo fans?

The13Bats

I hear you,

I did a lot of research on that mark fan subject,
You bring up good questions, i cant imagine an electric fan pulled from a junk yard car 20 plus years ago would have 100% of its orginal vigor,

I plan to buy a new aftermarket 94 tbird fan, it will as far as i know be imported, however, being that the better replacement parts companies guarantee to match oem specs i will "hope" cfm is the same, but what is the same in this case?

That is another mystery, in my research cfm guesses for that mark fan ranges from 2k to 5k plus, ford is pretty hushed about its cfm rating,

one test i feel is flawed and or biased placed the mark fan around 3k so that doesnt float with the countless feedback i have read where the mark fan out cooled this or that aftermarket fan that we know the cfm rating of,

Then hit ebay, some really crappy low dollar electric fans boast of super high cfm, this is simply bs.

My guess and take that for what it is would be the mark,tbird,cougar fans on high have to be 3500 cfm or better to cool some of the things they cool,

Thran69

From my understanding its the right fan, but I can double check it. I remember when installing it that some people were claiming it to having 8,000 cfm. It has a proper relay, that kicks on the high while disabling the low. My father scavenged it from a junker, this is the only thing that isn't new. The relay is from http://www.thehollisterroadcompany.com/. The fan is powerful enough on high to suck my hand with considerable force to the radiator.

I completely understood that when going in, I just felt that my car was operating on the brink of being normal. I thought this new fluid would help the heat exchange, but in reality, the best heat exchange is pure water.

Not sure which dam you're talking about, maybe the ginormous shroud that usually goes over the fan? We are now drawing air through the radiator, and have it more than 85% covered. Please look at the pictures and get back to me.

http://imgur.com/a/2VrPM <-----------PICTURESSS

The reason I'm bringing this up, my father says it has to be the hood. I feel just like The13bats said, regardless if you have a hood or not. Your cars cooling system should be capable of dispersing the heat generated by the motor.
I can do 4 burnouts and not go above 185. I drive for 5 minutes at 40mph and it's at 220. After another 15 minutes of driving it will climb it 240. When I stop, it slowly, Goes back down. Then I get into a debate with my father on what actually OVERHEATING is for a motor. Which is another question of mine, What is normal operating temp (200-210?) and what is overheating temperature.

While flushing the motor, we watched the fluid flow through the radiator. It appears to be flowing well even at idle.

Sounds like the verdict is possibly a fan? This was in 93 degree heat.

Big2Bird

If the timing is too retarded, or the engine is running lean, it will run hot.

cooper9811

The air dam in question would look like a spoiler under the nose of the car - here is a pic of a stock '68 front spoiler:



This also functions as a "scoop" to force air up towards the radiator at speed.

The fans could also be an issue, have heard different things about that fan you are using. It might be inadequate for the cubic inches you are running, but I cant say for certain.

If the radiator itself is adequate (sounds like it should be, as an aluminum 4-row) - my opinion is that the combination of no air dam and no hood are the bigger issues. Air is not being directed to the radiator.

Thran69

Check the video, last 1 minute. The spoiler/Scoop is on there.

The13Bats

Dont get me wrong, if we jumped in your car cold on a circle track got it to 45 it should warm up to operating temp but not overheat from forward movement, however, with no fan at all and the hood off i could see the air taking that path of least resistance like jim said and spilling over , around the radiator,

But we have a fan in the scenario and if everything is working and temps creep up from no hood the fan should come on to cool it back down, hood or no hood, the fan is pulling that air through the radiator,
hence why i asked does the fan run at speed, if the fan runs at speed but the car still runs hot besides a zillion little things your radiator might simply be too small,

However, if the fans do not come on at speeds then they are hurting not helping with the hood off, making the path through the radiator even more restricted and the path over it more attractive to tge air flow,

Also keep in mind forward movement alone should cool a car if the cooling system is correct, my asking about fans running at speeds and will it cool then is part of my troubleshooting,

Your picture showed things blocking airflow,
I dont know what the lower stuff was but the letters across the top are not needed, do you have other stuff blocking flow like perhaps an intercooler

Thran69

We have Fast Sportsman XFI controlling the timing vs boost. I checked the timing at the time and did not find it to be a problem. Locked it out, checked. Etc.

cooper9811

Yes, I see that now - it was hard to see against the background. Still suspect the hood - the radiator seals should prevent air from rushing up and over the rad into the engine bay (or in your case, up and out with no hood) - I would think this will be part of the problem.

I ran my car with bad seals against the hood and around the radiator for some time, and suffered from rising temps on the road (I have a 427 SBC, so good cooling is important). After I did the following:

- replaced the seals on top of the rad support
- resealed around the perimeter of the radiator to the rad support
- ensured I had a good fan

Then the cooling issues stopped. I would focus on air flow and the path it is taking first.

Thran69

Yes, the fans are running at speed. When traveling at 35mph and the car is above 200, The ECU is Calling for 2 fans which in my case is High level on my single fan. The ECU is set to 190 first fan 200 second fan. Still, overshoots every time and stays there if I'm driving. I hope this answers your question if not, I'm not understanding it.

The13Bats

Yeah, ive been up about 20 hours so i might word things weird to say the least,
Yes, you answered my question, with fans on at speed it should cool regardless of hood on or off, it doesnt,

So could anything be plugging the coolant flow, perhaps bad thermostat, or lower hose collapsing, have you tested it with no stat just to see what it does,

Thran69

Negative, That was an option we were going to try. Off to sleep. I'll reply in a bit.

cv67

make sure you rlower hose isnt collapsing on you
Hold your revs in N to 3k for about 30 sec see what happens

Does your shroud have any flaps in it?

Had both issues same syptoms.

1Hotrodz

Bingo we have a winner!
timing too advanced will run hotter