Overheating Issues, Perplexed

[jwd]

Originally Posted by ERA Chas

And what do you do when your idle vacuum is 7" with a 250+ cam?

Well, if you have a MSD dizzy, you can use a GM vacuum advance unit (that's all MSD uses) part.# vc 1807, 1808, 1809 or 1812 depending on how you want to fine tune your timing curve. All of them start at 5" of vacuum and are all in by 7".
Vacuum advance is one of the most mis-understood parts of an engine and my guess is that 99% of those out there have no idea how to properly tune an engine for the best performance.

Jim

[Jerry Clayton]

If you have the idle eze---do you???
The throttle blades should be set so as to only have a small portion of the transfer slot showing, sort of like a square hole showing vs a slot. and then set idle speed with the idle eze valve

[elmariachi]

Originally Posted by Jerry Clayton

If you have the idle eze---do you???
The throttle blades should be set so as to only have a small portion of the transfer slot showing, sort of like a square hole showing vs a slot. and then set idle speed with the idle eze valve

I have experimented quite a bit with the Idle Eze. With both transfer slots at .020 like a square, the car would not idle at 16, 18 or 20* initial no matter how far out I went with the Idle Eze. So I set the Idle Eze at the default setting of 1.5 turns out and went in on the primary idle screw about 1/2 turn. It now idles fairly smooth at 1000 rpm.

I also tried running it with the Idle Eze closed (Don Gould and a couple others offline said that I didn't have enough cam to benefit from it and to close it) but the problem then was an unstable idle.

[Jerry Clayton]

I think the idle eze is a very good thing altho of course they aren't on some carbs and none of the holleys---for years I have been putting a 1/4 npt plug in the center hole of the base plate and drilling a small hole in it for idle air that I get to the center with a small cross milled groove on the top side of the base plate--it usually takes from an .085 up to .125 depending on engine and cam size--i have been able to get a steady idle at around 850rpm on most engines and that is low enough that the mech advance hasn't kicked in and the engine will shut off without dieseling---most times also the idle mixture screws will be at 1 1/4 turns to as little as 7/8--never had to go past 1 1/2

We also take the feed wire for the fan directly to the alternator like you except we do use a relay to turn the fan on and off---

I noticed going back and reading all this thread that initially with the pic of your radiator that you said it was a 3 core(post 12) and later a 2 core (post 68). Is it a 1 inch tube or a 1 1/4 tube and how many fins per inch???

Glad to hear your making progress

[elmariachi]

Originally Posted by Jerry Clayton

--i have been able to get a steady idle at around 850rpm on most engines and that is low enough that the mech advance hasn't kicked in and the engine will shut off without dieseling---most times also the idle mixture screws will be at 1 1/4 turns to as little as 7/8--never had to go past 1 1/2

Jerry, would the fact that I am at sea level in Houston have any effect on mixture? I can run it at 1 to 1 and 1/4 turns out on the primaries, but it likes 1.5-2 a lot better and the plugs look better as well.

Originally Posted by Jerry Clayton

We also take the feed wire for the fan directly to the alternator like you except we do use a relay to turn the fan on and off-

I noticed going back and reading all this thread that initially with the pic of your radiator that you said it was a 3 core(post 12) and later a 2 core (post 68). Is it a 1 inch tube or a 1 1/4 tube and how many fins per inch???

Yes, I am using a relay as well, tied to a 180* thermo electric switch.

I just corrected that post #12, that should have been 2-row, thanks for catching that. The PRC I have is a 2-row radiator with 1" rows. As for fins-per-inch, there are 16 individual fins, or 8 "V"s in one inch. How does that compare?

Thanks for the help and advice.

[xlr8or]

Question for elmariachi... Are you doing this testing with the hood on the car and closed? Is there a rubber seal around the hood opening? If yes on the hood installed it's an easy test to try it out without the hood. Underhood temps could be contributing to your problem.

[elmariachi]

Originally Posted by xlr8or

Question for elmariachi... Are you doing this testing with the hood on the car and closed? Is there a rubber seal around the hood opening? If yes on the hood installed it's an easy test to try it out without the hood. Underhood temps could be contributing to your problem.

All testing is being done with the hood up in the driveway. I have a rubber seal between the hood and body. For what its worth, once I managed to get the car to idle at 195F using the second pusher fan in the nose, I observed the following IR temp readings with my new gun:

- Intake manifold surface by the temp bung 180-185F
- Valve covers on header side 165F
- Carb body 135F
- Expansion tank surface 200F

This is in the hot sun with oil temp level at 215-220F.

[elmariachi]

My guess would be 20-30 amps at idle, which will not be enough.

[Garage10]

Hey guy's
Just google taurus fan and all kinds of 4x4 forums come up with lotsa guy's showing how to wire these up or go to delta current controls web or dccontrols.com as they have a neat variable speed controller for the fan or a complete package. But, he's real slow and kindof a p!@#k to deal with. Still waiting for mine. When/if I get it in I will post results.
Brent

[undy]

Originally Posted by Garage10

Hey guy's
Just google taurus fan and all kinds of 4x4 forums come up with lotsa guy's showing how to wire these up or go to delta current controls web or dccontrols.com as they have a neat variable speed controller for the fan or a complete package. But, he's real slow and kindof a p!@#k to deal with. Still waiting for mine. When/if I get it in I will post results.
Brent

"dccontrols.com" doesn't work. Can you provide a link to your suppliers site?

Keep us posted..

Dave

[vettestr]

El or Undy,
I am now confused (spend a lot of time there) about the actual fan assembly you bought. Is it a SVO, Sable or Mercury etc.. can you define a model and year as a target for me. I realize many models might interchange but a specific would help me. THANKS

[elmariachi]

Originally Posted by vettestr

El or Undy,
I am now confused (spend a lot of time there) about the actual fan assembly you bought. Is it a SVO, Sable or Mercury etc.. can you define a model and year as a target for me. I realize many models might interchange but a specific would help me. THANKS

My fan has not arrived yet but the Seller reaffirmed that its the Lincoln Mark VIII that was also used in the Taurus from approximately '92-'98. My advice is to go to eBay and search for "Lincoln Continental Fan" and "Ford Taurus Fan" and read through the auctions and you'll start seeing a pattern of fan types/blade styles. Some guys selling these to the 4 wheel drive and hot rod crowds state in their auctions that you should stay away from the aftermarket new Taurus replacement fans because they don't have as much cfm. I don't know if this is true or not, but I figured I would start out with a used $50 fan and if its works decide from there whether to buy a new one or not.

I hate linking to eBay because once eBay drops the listing, the links are dead in this thread, but here is the fan type I bought:

and here is the monster fan.

Read the Seller's feedback on each and you'll what people say about these fans.

[vettestr]

THANKS,

With that I found ..... Part # on my fan is: F2DE 80607-AB

"A Mark 7 or 8 is going to be a lot harder to find than a Taurus. Tauruses are everywhere..." from google then a chat board

[undy]

Originally Posted by vettestr

El or Undy,
I am now confused (spend a lot of time there) about the actual fan assembly you bought. Is it a SVO, Sable or Mercury etc.. can you define a model and year as a target for me. I realize many models might interchange but a specific would help me. THANKS

The Lincoln Mk 8 uses an 18" fan with a much larger shroud, 26" x 19" I believe. The 90-95 3.8L Taurus uses the same fan motor as the lincoln but has a 17" fan and a much smaller shroud, 21" x 16". The Lincoln will move a bit more air but at the price on an unacceptably large fan and shroud for 90% of Cobra applications. The 90-95 3.8L Taurus fan seems to be the most popular "transplant" fan by far. Stay away from the "SHO" fans as they're smaller and weaker that the 3.8 Taurus and Lincoln.

Dave

[elmariachi]

Dave is right, since my original post on this fan subject I have since learned that the SHO fans are smaller and some of the early ones were single speed only I think.

Its hotter'n hell here in Houston this week (100*+ and 50%+ humidity) and I can't wait to try this out. While waiting on the fan I got impatient, so I dropped my TKO to fix a small bearing retainer leak and I dropped my oil pan to fix a leak there. Now if I can fix this cooling problem, I might actually see how my new Cobra looks with the hood closed.

[Thoroco]

My name is Dave Chapman from The Hollister Road Co the maker of the relay kit for the 2 speed Mark VIII fan mentioned above. I read through the posts on the overheating issues and can offer some basic suggestions.

First is that it doesn't matter if you have a 5000 CFM fan and a 10 row radiator if you can only get 3000 CFM out of the engine compartment. So air in has to be less than or equal to air out.

Next is the primary purpose of engine oil is to cool the engine by removing the heat created from the friction of moving parts. One of the best ways to reduce engine heat is by using an oil cooler either passive or fan cooled.

Third is the water must be able to be transfer the cylinder heat into the water and back out to the radiator and into the air in a reasonable manner. Straight water is not very good at heat transfer. Use a 50/50 mix of anti-freeze or use aftermarket products like Water Wetter Additive. They break the surface tension on the internal block areas so the heat will transfer to the water and again to the radiator. Anti-freeze will absorb more heat per pound than straight water before it gasses off or boils. You can also use a radiator mister that helps transfer the heat out of the radiator but that can get messy.

I haven't had my head under the hood of a Cobra since 67 but as I remember it was tightly packed with a 427 so it may well be the air can't get out of the compartment fast enough to let air past the radiator. You could also have air flowing around the fan assembly bypassing and not drawing through the fan shroud.
Tight motors make more heat so the oil cooler would be a good start in cooling down you motor.

I haven't really seen timing as an issue with overheating but I have seen very lean motors run hot. You may want to look at your jetting to see where you are. If you’re down in the low 60's high 50's then you might want to jet up a bit.

As for the Alernator being large enough to operate the Mark VIII or Taurus fans, 100 amps will do it if you don't have A/C or a big Audio system. The fans don't run off the alternator they run off the battery as do all the electrical components. The alernator is for charging the battery not running components. The test for that is disconnect the battery and everything will work for about 2 hours maybe longer, disconnect the battery and your alternator will burn up within 2 hours of use.

The big amp draw on the Mark VIII is miliseconds and its from dead stop to high speed. Starting on low doesn't have that issue and if you are using a 180 to start on low then you step through to a higher temp sensor like a 195 then your not starting from dead stop and the amp draw is reduced greatly. I have a 180 and a 195 on my truck and it cycles low speed on 180 to high speed 195 in traffic back to 180 and then off while on the Hiway. I'm using 60 amp relays that can take a 150 amp spike and 50 amp fuse that is a Slow Blow and takes the 100 amp millisceond spikes.

If I can answer any questions for you on cooling let me know. info@thoroco.com

[undy]

Originally Posted by Thoroco

My name is Dave Chapman from The Hollister Road Co the maker of the relay kit for the 2 speed Mark VIII fan mentioned above. I read through the posts on the overheating issues and can offer some basic suggestions.

First is that it doesn't matter if you have a 5000 CFM fan and a 10 row radiator if you can only get 3000 CFM out of the engine compartment. So air in has to be less than or equal to air out.

Next is the primary purpose of engine oil is to cool the engine by removing the heat created from the friction of moving parts. One of the best ways to reduce engine heat is by using an oil cooler either passive or fan cooled.

Third is the water must be able to be transfer the cylinder heat into the water and back out to the radiator and into the air in a reasonable manner. Straight water is not very good at heat transfer. Use a 50/50 mix of anti-freeze or use aftermarket products like Water Wetter Additive. They break the surface tension on the internal block areas so the heat will transfer to the water and again to the radiator. Anti-freeze will absorb more heat per pound than straight water before it gasses off or boils. You can also use a radiator mister that helps transfer the heat out of the radiator but that can get messy.

I haven't had my head under the hood of a Cobra since 67 but as I remember it was tightly packed with a 427 so it may well be the air can't get out of the compartment fast enough to let air past the radiator. You could also have air flowing around the fan assembly bypassing and not drawing through the fan shroud.
Tight motors make more heat so the oil cooler would be a good start in cooling down you motor.

I haven't really seen timing as an issue with overheating but I have seen very lean motors run hot. You may want to look at your jetting to see where you are. If you’re down in the low 60's high 50's then you might want to jet up a bit.

As for the Alernator being large enough to operate the Mark VIII or Taurus fans, 100 amps will do it oif yu don't have A/C or a big Audio system. The fans don't run off the alternator they run off the battery as do all the electrical components. The alernator is for charging the battery not running components. The test for that is disconnect the battery and everything will work for about 2 hours maybe longer, disconnect the battery and your alternator will burn up within 2 hours of use.

The big amp draw on the Mark VIII is miliseconds and its from dead stop to high speed. Starting on low doesn't have that issue and if you are using a 180 to start on low then you step through to a higher temp sensor like a 195 then your not starting from dead stop and the amp draw is reduced greatly. I have a 180 and a 195 on my truck and it cycles low speed on 180 to high speed 195 in traffic back to 180 and then off while on the Hiway. I'm using 60 amp relays that can take a 150 amp spike and 50 amp fuse that is a Slow Blow and takes the 100 amp millisceond spikes.

If I can answer any questions for you on cooling let me know. info@thoroco.com

Dave, Your 180 and 190 sensors, are they electric, exterior cap tube or designed to go into the coolant?

Dave

[Thoroco]

They are single terminal 3/8 pipe thread. they screw into the head or manifold

[undy]

Originally Posted by Thoroco

They are single terminal 3/8 pipe thread. they screw into the head or manifold

... thanks.

[elmariachi]

Hi Dave,

In my case, an oil cooler will not apply in this situation because my oil is not overheating and I need to keep the temp up to where its presently running at 210-220*F for performance and wear reasons common to these engines. I agree about the limited room in the engine compartment. Fortunately with many of these cars, the radiator is slanted back at the top, so the fan actually discharges down around the oil pan and on the ground beneath the car. But coupled with headers and a cast iron block and heads, its hotter'n hell in there. My new fan JUST arrived this evening and it fits my radiator perfectly. I am confident this Taurus fan will do the trick, based on the fact that my existing 3600 cfm puller, along with the old 2100 cfm pusher laid in front, kept it idling at 197*F. That's without a shroud.