FAN SHROUD PROJECT

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bertvorgon
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FAN SHROUD PROJECT

Postby bertvorgon » 12 Apr 2008 19:57

One of the reasons of the long term success of my motor, and any performance motor for that fact, is of keeping things cool. Keeping the thermal load under control cannot be understated, and as the compression and power goes up, that becomes even more of a task. While getting a good sized radiator in there is paramount, getting the air to flow through the rad, as efficiently as possible, is a big bonus too.

The air can and will stall to a certain extent, and take the path of least resistance sometimes, going through every other opening it can find. With that in mind, a common practice is to seal, and/or build walls and dams, to make the air go just through the rad. This is a very simple project I have wanted to do for some time. So, with a sheet of construction paper in hand, I made the templates, four pieces in all. Then, with everything laid out, and looking ok, I transfered the paper paterns to 3/32" aluminum sheet. I rough cut those on a shear, then, bent them as needed. I then laid out the holes on the aluminum, then transfered that to the rad support, and drilled that. Bolting everything together loosely, let me check that all dimensions stayed true to the originals. I put a small bend in the bottom piece, as a bit of an "aero dynamic lip", and, I though it just looked a bit better than a straight piece.

I used stainless screws and Nylocs for the hardware. I even siliconed the openings right beside the rad tanks and the start of the fins, so no wasted air escapes going through the cooling fins and cores.

Total cost of project was about 25.00, which was the paint, the stainless, and a small piece of aluminum from the salvage guys.
Attachments
inside view showing rad support cutout.jpg
This shows the botton piece cut out for the rad support brace, and a slot for the fan wires
bottom view of lip.jpg
This shows the slight bend I put in the bottom piece.
finished.jpg
this is the finished shroud, ready for installation.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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bertvorgon
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Re: FAN SHROUD PROJECT

Postby bertvorgon » 12 Apr 2008 20:00

A few more pictures. Using construction paper, or any stiff paper, is the way to go. As it may seen to take a bit more time, it is very easy to bend and shape the paper with sizzors and some tape, to get the patterns to fit perfectly. I used a tad of "Kentucky Windage" when I bent the aluminum, but was amazed how close it was compared to the paper patterns. The paper was almost as thick as the aluminum, so the radius of the bends was virtually the same between the two.

Food for thought at any rate, and as I have watched Andy at Specialty Engineering, do this to almost every customer car, be it street and for sure race cars, it can't be a bad thing to do, and it's not like it costs a ton to do.

I think anything that you can do, to get proper air flow though your radiator, your oil cooler, and of course for us turbo guys, your intercooler, only helps in the longevity of things, and lets you maximize your ability to really lean on the motor hard, for a long time if required.
Attachments
fan mounting cutouts.jpg
The right side has the cutouts for the tabs on the electric fan.
installed with stainless hardware.jpg
Final installation with stainless screws and Nyloc nuts.
roughed in pieces.jpg
Showing the initial mock up for fit.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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bertvorgon
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Re: FAN SHROUD PROJECT

Postby bertvorgon » 12 Apr 2008 20:29

proper ducting makes the air go through the cooler, at whatever air speed the ducting can allow.

This shows the shrouding for my oil cooler on the right, fed by a duct where the turn signal used to be, and the intercoller on the left, fed through where the high bean light used to be. These shrouds are totally sealed to the sides of the appropriate cooler, and are very tight to the respective frontal body work. Pretty much all of the vailable air has to go through the coolers core.
Attachments
oil cooler on the right, intercooler on the left.JPG
Oil cooler on passenger right, intercooler on driver left.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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510-Trevor
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Re: FAN SHROUD PROJECT

Postby 510-Trevor » 12 Apr 2008 21:05

I see you also have a tight fitting undertray.
One thing that I'm curious about, with all the attention to ensure the air travels into the engine compartment through the proper openings, is the air flow in limited by how much air can get get out. In other words, could cooling be improved by raising the back of the hood, or by adding a vent near the back of the hood? Or is more than enough air able to spill out from under the car?
1972 Yellow 4dr - 1972 Red 2dr

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bertvorgon
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Re: FAN SHROUD PROJECT

Postby bertvorgon » 12 Apr 2008 21:33

It is our opinion that the airflow is more than adequate out and under the car. I'm not sure what you meant by tight fitting under tray. If you mean that aluminum plate just under the front by the pulley, that is only a deflection plate for airflow wash coming down the backside of the rad. The rest of my engine bay is totally open under the engine and tranny. My air filter is underneath that, and, I was picking up heated air, due to the very high negative pressure behind my big airdam, which was pulling the air really down behind the rad.. The down force on the front of my car is considerable, and at 130+ MPH, my car is incredibly stable.

We also know, from years at Westwood, and a couple of the other Specialty 510's, that cooling was never a problem.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

Danthewire
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Re: FAN SHROUD PROJECT

Postby Danthewire » 12 Apr 2008 21:57

Treveor,we found on our many race cars that the base of the windshield and cowl area was a high pressure area,this is an ideal place to get the engine air from.We opened the cowl area up and made an air box to go over the top of the motor and under the carb,and used the hood to seal the top. Worked like a hot damn.We always found the car to work better with the hood sealed down onto the fenders.We also found that if you layed the top of the rad back slightly in most cases the car ran slightly cooler.We guess that more area of the cooling fins on the rad were getting the air on them As Keith says that front air dam creates a big low pressure which should do the trick.Watch those screws Keith I screwed one together once,screw came loose,drove over it ,ruined a tire.PS nice looking car.DAN

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510-Trevor
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Re: FAN SHROUD PROJECT

Postby 510-Trevor » 12 Apr 2008 22:06

Thanks guys, thats all good info to know.
1972 Yellow 4dr - 1972 Red 2dr

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bertvorgon
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Re: FAN SHROUD PROJECT

Postby bertvorgon » 13 Apr 2008 10:22

I used stainless BOLTS, with Nyloc Nuts, for that express purpose of having nothing fall off, PERIOD. With the vibration from these cars and motors, a constant nut and bolt check is required. Any other small screws, I usually use some teflon tape, or Locktite the buggers.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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defdes
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Re: FAN SHROUD PROJECT

Postby defdes » 13 Apr 2008 10:45

Danthewire wrote:Treveor,we found on our many race cars that the base of the windshield and cowl area was a high pressure area,this is an ideal place to get the engine air from.We opened the cowl area up and made an air box to go over the top of the motor and under the carb,and used the hood to seal the top.

Do you have any pics of this????

Danthewire
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Re: FAN SHROUD PROJECT

Postby Danthewire » 13 Apr 2008 11:51

Yes Keith, I agree about the nuts and bolt maintenance issues,we were just slow learners.Defdes I don't have any pictures of the ducting,sorry but that was back 25 years ago.We had 4 or 5 diffrent cars,that we experimented on.Sorry I can't be more helpful.DAN

djlotus
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Re: FAN SHROUD PROJECT

Postby djlotus » 13 Apr 2008 13:57

It's funny, I was wondering if there was a radiator dam for these cars. Now I know. Might have to try this if I can scrounge up some sheetmetal.


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