I'm reminded of my grandmother's many trips to various doctors, seeking the cause of her ailments and the magic potion that would cure her ills.

She never could accept the fact she was in her mid-'90s - and her problems were simply that she was getting older. She finally passed away a few months after turning 100.

Careful, the Dorman may look almost the same but its performance is far below the factory lincoln unit.
the blades are a different shape and there is one less blade.

i put a lincoln fan in another kellison with a 429 SCJ, which always ran hot previously, i used a flexolite programmable controller to set the on and off temps, and it worked flawlessly, had to make two clearance cuts in the shroud for hood hinge clearance and block off the opening between the rad and the inside of the body.

ok - I give
 

It's obvious the electric fan (Mark VIII) seems to be the best option...or one similar in CFM.

However, "The reason that I am running a mechanical fan is to move more air through the engine compartment to try to relieve the inherent heat of a Cobra"........ So many of the articles over the years talk about heat trapped in the engine compartment.....I'm not worry about HP...it'll be fine!

SO, I'll need some type of electrical fan (Mark VIII) to help out the Mechanical Fan...to keep it cool....
Maybe I'll get one shortly just to satisfy myself....before I mount the body..

(cycleguy55 - Sorry about Grandma!)

Thanks all, some very good info and thanks to ByronRACE and cycleguy55 for references for parts!
PJ

Maybe since the electric fan moves a ton more air thru the radiator, it will move air thru the engine compartment too, solving both problems.

Based upon what I see in your video ( https://www.youtube.com/watch?v=JTcaeBe7fAg ) it appears you have lots of room to install an electric puller. You could pull the shroud, install the fan, and re-install the shroud. You'd have the cooling you need for crawling in traffic and the mechanical fan to keep air moving through the engine compartment at all times.

Good luck.

Correct.

Cooling power vs vehicle speed.
 

I think you'll find that you need LESS fan when the vehicle is in motion; which is one major benefit of an electric fan. You're not burning power moving all that air needlessly. Better for gas mileage; which we all know if high on our priority list. :) My point is, a garage fan is nothing compared to the vehicle going down the road at 30+mph. In my case, the fan turns off and stays off at freeway speeds; even when climbing a grade. If you slow down below 30mph, it comes on. When you get off the freeway and pull up to the first stop sign, it turns on.

I just saw the video above. In my opinion, the engine fan is too far away from the radiator to make a shroud practical. As it sits now, it's doing nothing. Even if you did build a big elaborate shroud, you don't want all those shroud walls boxing off valuable space in the engine compartment making it hard to work on. I would put the big electric puller on it and enjoy the freedom of being able to service the front of the engine. There are no reliability problems with OEM electric fan designs these days. My daily driver has 230K miles on it, the climate control is always on auto, and the fan is always on. No issues.

Additionally, that garage fan is not a pressure blower. Most likely, very little air is actually going through the radiator; it's going around it or just swirling inside the fan housing.

Try the lincoln fan. If you're not amazed, return it. One advantage to amazon.

I agree with the above. The video shows the mechanical fan is way too far away. The garage pusher is likely not doing much either.

Oh, and by the way, it sounds FANTASTIC.

Thx for the input all. The video was prior to my fabricating a shroud. Yes it does take up a lot of space. It (mechanical fan only) holds pretty good (under 210F) for about 25 minutes...then I need that garage fan to keep it from getting too high. Underway it should be ok.
I don't think putting a puller fan (i.e. VIII) AND keeping the mechanical fan with shroud would work correctly...I would think the electric fan (while not running) would itself create a restriction, whereas the mechanical could not pull enough and result in kicking on the electric fan...
Again, thanks all for the input!

Restriction.
 

Even with the twin pushers on mine, turned off, moving down the road is enough airflow. That's with no shrouding in front of the radiator; just the body opening and air is free to bypass the radiator and flow all around it. It's still enough.

I can't imagine the single puller being more restrictive. If you like the shroud and mechanical puller, that should be plenty...especially if there's no fan clutch. It should be overkill if the shroud is designed right with no leak paths and the fan positioned at the right depth at the outlet so the fan is efficient. Even at idle when you're not moving, that should be plenty. If you have any leak paths where the fan is moving air that did not first flow through the radiator, the air will favor that path...especially at idle. Even a small 1/2" gap all the way around where the shroud meets the radiator will make a significant difference. The total area of a gap that large provides a less restrictive path than the radiator. If you look at OEM radiator and shroud designs, there's all sorts of seals and bits of plastic placed here and there to channel the air through the radiator instead of around it and to prevent hot-side air from recirculating around to the cold side and being sucked through the radiator again when the vehicle is stationary at idle.

My dad split the fan shroud on his E150 to make it easier to work on. The result of this created a 3/8" gap in the middle of the shroud on both sides, and about a 1/4" gap between the radiator and the shroud on the top half of the shroud. At idle, it would overheat. I duct taped up the fan shroud to experiment and it solved the problem. Ended up having to buy a new OEM shroud. The small stuff matters.

I have dual 12" fans on mine, thermostatically controlled (adjustable controller with prove in radiator fins) with an override switch on the dash. I have recently started turning the fans on about 1/4 to 1/2 mile before reaching my destination and, when I do, then fans rarely cut in after shutting off the engine. Before I started doing that I found the fans would run quite a long time after shutting the engine off. Obviously what I'm doing is cooling off the radiator enough to keep them from running, but I'm betting there's also a significant drop in under-hood temperatures as well.

Expansion/surge tank (and overflow tank);
I integrated a 2qt expansion/surge tank (and 1 qt overflow tank);
Initial timing @ 13 BTDC ; Total @ 33 BTDC (w/o vac)
80 F ; Ran Aux garage fan.
Much better; after 45 minutes of running (@idle) radiator pressure only went to 6psi and temp stayed under 210F.
So I'll plan an electrical Puller with high CFM...and the mechanical Fan
Time to move past this now.
Again, thanks all!
PJ

hold the phone........6 PSI?
what LB radiator cap do you have?

Radiator cap
 

I have a 21# right now because it was getting to 18psi (w/o expansion tank) and the 16# and 18# wouldn't hold. Now with the 2qt expansion tank there is more (air) volume so it's not nearly as high now.

Why don't you fill the whole system up full via the expansion tank?

Expansion tank is really the wrong word, it is a header tank, if you have an overflow bottle as well.

Gary

Perhaps I missed it, but I haven't seen any posts about the normal expansion / contraction of coolant in the system. Coolant expands at about 7% per 100°C / 212°F of temperature rise. That's why coolant recovery bottles have separate marks for Cold and Hot.

If your engine is 'cold' at 70°F, then going to 210°F, that's a rise of 140°F, and the coolant will expand about 4.6% (140 ÷ 212 x 7% = 4.6%). Assuming a total coolant volume of 15 quarts, the amount of expansion will be 0.69 quarts, or about 22 ounces or 1.38 pints (15 x 4.6% = 0.69).

It would appear the "pint + or so" amount of coolant being pushed out is quite typical - certainly well within the range of 'normal'.

BTW, running a 21# cap is okay if your system is designed and built for that level of pressure. Many cooling systems, OTOH, were designed for 15 PSI or lower and won't handle that pressure reliably. You have a new radiator, so may not have any issues running that kind of cap, but I would be cautious about using a higher pressure cap than the system is designed for.

thx for the info - cycleguy55
I was only using the 21# because it was getting to 18psi (w/o expansion tank) and the 16# and 18# wouldn't hold...it would push out coolant thus causing overheating. Now with the 2qt expansion tank there is more (air) volume so the pressure is not high now. I plan to go back the 16# and adjust coolant level.