Radiator & front condenser clearance

A Fluidyne with shrouded sucker fans AND a front-mount A/C condenser CAN be installed with the rad in stock upright position but as you've found, its not easy. There are three minor mods most of us do to fit big radiators and/or front mount A/C condensers.
First, cut the few spot welds that hold the pusher fan mounts and remove the entire assembly. Shrouded sucker fans are far more efficient, will lower your running water temp and are simpler to install.
After that's done, add a pair of 3" long straps between the radiator top mounts and the radiator body mounts such that the rad tilts foward at a 20-40 degree angle (exact angle unimportant). The lower mount posts welded on the radiator will pivot in the stock rubber bushings and the welded frame brackets.
This is done strictly for convenience in servicing and installation; the lay-forward position will have no effect- positive or negative- on your engine water temp.
The last thing you need do is make a new upper sheet metal panel to fit the far smaller opening now between the front edge of the rad and the body, so all the air coming in the grille goes thru the rad, not up and around it. Not doing this will raise water temps by a significant amount. A simple flat sheet metal panel held with a few sheet metal screws will suffice.
NEVER use plastic tie-wraps to hold the shroud to the Fluidyne rad. The tie-wraps will eventually cause water leaks & ruin your radiator.

I just completed this task on one resto and am helping another owner right now with another.

Adding to Jack's remarks, we use the lower mounts and cut off the upper mounts. While fitting the new radiator/condensor & fan combo, we simply weld in new upper mounts in the ideal location.

Since we are in Texas, we are also using four fans. On the current resto, we fit even thicker, higher flow, SPAL fans up front.

After we finish the second conversion, I'll document the transformation and park it on the Space City site. We, Rob Pink and I, are doing a better job documenting it this time.

Eadiator suckers and shroud

Condensor/rad combo and pushers

Pushers

The fans are also serve as back-ups when Bill runs out of gas. They'll move the car forward as long as the battery holds out. :^)

John,
Do you have a part # for the condensor and the fans?

Thanks,
Ron

Ron

I can dig through my papers and find them. However, we used a different condenser on each application and were able to use thicker fans up front when we used a radiator without a rear shroud. The condensor pictured was acquired through Quella, the last at Vintage Air. We mounted both condensors to the Radiator differently because of design differences.

For that matter, how thick is your radiator?

This really does matter because the thicker 10" fans flow substantially more air. We bought the fans here http://www.the-fan-man.com/ I believe they are 13" suckers and 10" pushers. Best prices and inventory.

My radiator is from Quella also. Like the one pictured.

Ron

Thanks for the pics, I will have to check clearance on mine when I do the mock up this weekend.

Interesting with the 4 fan setup, have you tried with only the 2 fans and it ran hot? I question the surface area of the 4 motors which do not move air but act as a blockage, had that problem on a previous project. As long as I can get both coils to fit with the fans and shroud without any major mods, I will be happy.

Again thanks for the pics, they really help this old dog.

Angelo

Whether or not two fans would suffice is a good question and an issue we have debated ad nauseum locally. We did not try 2 fans with the rad/con combo. I type to slow to list the pros and cons we surfaced of both approaches.

This car has a dynod 600hp 427 Keith Craft motor that we figured it would generate a lot of heat energy. Suffice it to say, the cooling performance met our expectations, and we are mimicing the design on a second Pantera at this moment.

30 years of Pantera ownership experience has led me anecdotally down this path. In low speed summer traffic, one can't have too much air being pushed through the rad/com. Above 35mph when you have adequate flow, obstructions are less significant; above 50mph, obstructions are insignificant. I've played around a bit with the Pantera's cooling system. A few items we've learned are available in a cooling white paper at the Space City Pantera's website.

Angelo, I can't say definitely on the pusher shroud restriction, but I ran a dual 10" sucker fan shroud several years ago, and around town and at reasonable speeds they worked fine to keep the engine cool. On my favorite NV test road, ten minutes at a steady 140 mph saw the water temp gradually climb from 190F to 230F. Slowing down to 90 or so, the temp also slowly came back down.
A few years later with 12" sucker fans in a matching shroud, a repeat of the same road & speed showed no temp increase over a ten minute run. So I suggest that you run the largest possible fans in your sucker shroud. If that's not economically possible, cut the triangular areas between the smaller fans and cover the cut holes with flexible rubber flaps held only on on edge. The theory is, at very high speeds fwd air pressure thru the rad will push the flaps open, reducing any restriction due to the shroud or fan size. Then at low speeds, the suction of the fans will keep the flaps closed, improving shroud efficiency. Look at certain stock Honda and watercooled VW radiators from the '80s-up which use this flap principal to good effect.

Angelo, do consider the amp draw of the fan set up. I have the front mounted Meriah (sp) pusher fans, which I measured at 4 amps each, steady state. I also had a sucker fan behind the rad which had the thin "pancake" motor; that one took 11 amps. That's the trade off - the thin motors help with your mounting space, and are lighter, but take more electrical power. Rodney

Rodney is spot on about amp draw. I used relays for each fan as seen in the pic. We ran 4 guage wire from the ampmeter to the relay bridge. and as a doubler from the alternator to the amp gauge to handle the output of the 110 amp alternator. Again we are repeating this exercise on our current project; however, we are using a 175 amp alternator from DB as it will put out closer to 75 amps at idle. We calculate the system need about 81 amps with fans running and lights on. This ought to cover it

I have recently modified a Flex-a-lite fan shroud for a friends car with rubber flaps to aid cooling at high speed. The rubber flaps are an old idea that dates back to the 70's I think. I did the same to my own car with aluminium flaps a few years ago and cured my high speed over heating.

The fans in these pictures pull 3000CFM (1500 each) so they are not the most powerful fans available but should keep the car cool.

I am about to install a single 16" sucker fan on an MG V8 and cant make sense of the Summit racing website. Some of the fans claim to full 3600CFM and only draw 10 amps whereas other fans, also 16" claim to pull 2500CFM and 20 amps. Twice the current draw and a lot less air? Can someone explain this to me..

It's interesting what Rodney says about thinner fans drawing more amps, maybe that's the reason?

Johnny

I used a power file and reciprocating saw to remove the plastic.

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quote:

Originally posted by Johnny Woods: I am about to install a single 16" sucker fan on an MG V8 and cant make sense of the Summit racing website. Some of the fans claim to full 3600CFM and only draw 10 amps whereas other fans, also 16" claim to pull 2500CFM and 20 amps. Twice the current draw and a lot less air? Can someone explain this to me.

Could be misleading advertising, not comparing at like test conditions, or different efficiency of fan and motor designs. I wouldn't rely on the Summit advertising. They often provide incomplete or inaccurate information; whatever they think sells. The best way to decide is go directly to the manufacturer's website and see if they have a flow curve that maps current draw to flow for a given static pressure (positive pressure for pushers, negative for suckers). This is usually a few inches of water column pressure. Then compare fan flow/current draw performance at like pressures. This at least will tell the story on the air moving side of the equation.

There are differences in optimal fan/impeller design for positive versus negative pressure use. However, in this pressure range, for axial flow flans, this is usually minimal to negligible and you will usually find the biggest issue for a given impeller design is the fan's proximity to the radiator. As the fan gets closer it can concentrate instead of distribute flow across the heat exchanger (not utilizing all of its cooling area) and also disturbs the efficiency of the fan by artificially imposing higher static pressure drop. Many years ago I designed a lot of air-air systems (ambient air removing heat of compression from compressed air) and the best results were always achieved with sucker fans, a well design plenum/shroud, and fans that were mounted at least the diameter of the impeller away from the heat exchanger. Packaging constraints always required compromise on the latter. The more pressure drop in cooling air flow across the radiator, the less critical the amount of fan space.

So all of this is kind of a windy explanation (sorry) for what common sense and experimentation has taught us; choose the best performing suckers, make a good shroud that is sealed to exposes the entire radiator surface arae and is sealed to the fan inlet, space as far from the radiator as space permits but also in such a way that it does not unduly obstruct and compromise the discharge side of your fans.

On a side note, all of my comments above were in systems that never had any forward velocity. The practical way to address this is the flappers that maximize flow area which you have already addressed (and quite nicely executed I might add). You'll never move more air with your fans than you do at speed as long as you maximize the area for flow across the cooling surface.

quote:

It's interesting what Rodney says about thinner fans drawing more amps, maybe that's the reason? Johnny

The motor design is another design trade. Fan manufactures know for the reasons mentioned above packaging constraints are always an issue. So pancake fans are popular. In the speed and torque range of these fans it can be more difficult to achieve good motor efficiencies with pancake motors, so it may actually be the case that one motor requires more current than another to achieve the same torque, thus air flow. This is why I suggested going to the manufactures website for actual test/performance data.

-Hope that helps.

Best,
Kelly

Kelly,

Thank you for sharing your in-depth knowledge of fans. We now know who to ask in future!
I have a better understanding now. I will talk to the manufactures before I make my choice.

Johnny

I'll eventually need to move my condensor to the front to accomodate 180s. For those that have rolled their own, could you offer some sources and possibly part numbers for front mounted A/C condensor?

Best,
Kelly

One option is to measure the frontal surface area of your radiator. Then go to VintageAir.com and select the largest condensor that you can fit in front. It is pretty straight forward. Another option is to call the vendors. At least Quella and Hall offer them.

FWIW for my future reference I have Vintage Air 14 x 22 Super Flow Condenser, Part # 03262-VUC written in my files.

On a related note are you guys installing a high pressure switch into your A/C system when you upgrade?

Julian

I am located in central florida and it is brutal in jul/aug/sep around here. I leaned my rad slightly back and completely covered the front w/a condensor from the guys at Nostalgic Air Parts. The guys over there were great! I have a single 16 spal and although the car does see temps of 200 or even 205 for a short time while stopped on the hottest of days in 30 minute bumper to bumper traffic. I must say, the a/c blows ice cold... I have not even turned my cooling fan on since Nov... I am very happy w/the level of service and the system works as advertised. I was a bit nervouse about blocking off the front of my car w/a condensor. But, no problem, works good... Nostalgic Air Parts 813-413-8421 sales@nostalgicairparts.com

Don't flame me for the debris... I drve my car every day and treat it like an old truck... I love this car!!... This system combo has worked out very well, I'm very happy w/it...

Hey young man,
How is the coil mounted? I don't see anything mounted to the top rail holes, what am I missing? Does the foam strip help or hurt? I think it might help the a/c but hurt the radiator cooling efficiency a bit, might want to run a test with and without to compare?

I think I have my mock up about figured out on mine, gonna take it apart when I go for the painting tho. Am getting prices this week for a pro to paint it, if it is afordable I will go that way, if not.....will practice with a paint gun first, on the wifes car, snicker.

Here's a pic showing the side mount. These condensers have mounting flanges on all four sides.

John

The guys at Nostalgic wanted me to keep that foam in there, they felt it was important to route the airflow... It's mounted at the sides as shown by JB.... Boy, that core looks bad I guess I should have cleaned it before I took the shot... The grind mark for my welder ground doesn't look too good either...