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Old 07-25-2009, 01:30 AM
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Default Making the body vents usefull

Im in only the planning stages as you all know. Trust me Ill have a barbecue when my sterling finally arrives. your all invited!

OK back to subject.

Im an aircraft mechanic, so aerodynamics is part of my job, I have to perform repairs on aircraft that perform at 2.5 times the speed of sound, so many of the things I do daily require strict attention to details like we see everyday. Even in the aerodynamics of a sterling.

I made up some drawings of the sterling and made things to scale as much as possible.
I don't have these in digital format so Ill share intellectually. Please share your thoughts and practical experience in these ideas.

These are my ideas for using all vents in the bodywork so everythings functional, not just for looks.

Nose vents:
The under nose vents would be best served input to a cooling system and a radiator. The goal is not to disturb the beautiful nose of the sterling with gaudy holes and vents, but to make everything work for a purpose. One video on youtube I saw, actually had a small but wide radiator in the nose of a nova, and it fit perfectly with dual fans on it. So I now somethings out there, just gotta find it.

Nostril vents:
These supply fresh air into the cabin via a heater/ A/C unit.

Hip vents:
The current design of the hip vent apparently fits a Gatorade bottle perfectly, ok, they werent put there to be a cup holder. The will need to be moderately redesigned so they force air into them. The current stock design creates a buffeting zone where air tumbles over the open hole or pocket, not doing anything useful. Mearley opening the hole wont help, the bottoms, or leading lower edge will need to be dropped, and just a touch of clean up on the tops of them. the idea is that of a ice cream scoop peeling a piece of the airstream over the car for a purpose. This can then be ducted into the engine bay for whatever purpose you desire. For me, Ill feed my motors inter cooler fresh cool air with them.

Lower rear wheel vents:
These are tricky, as there is suspension to deal with etc. But if ducted correctly, and all obstacles maneuvered they can provide fresh air into the engine bay to keep from any hot air stagnancy that might occur. This will aid in keeping the engine bay cool, and component from premature failure due to excessive heat.

Now the problem with all this work is what happens when you come to a stop, or are stuck in stop and go traffic?

Well, I forget whom makes it, but there is a company that makes in line duct motors that can be connected to a temp switch and run off of 12volts. These can be used to force air through the systems while at slow speeds, while not obstructing airflow at higher speeds. So voila there you go, just a rough idea on what you can do, I'm sure there are many other ideas other than cup holders!

Lets hear them!
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Old 07-25-2009, 09:52 AM
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The 'hip' scoops were always a matter of debate. Until someone can secure their car in a wind tunnel, the actual functionality of any of the scoops is questionable. There are add-on scoops for all the vents available through SSC. We had this very discussion on the Nova forum as two of the members there are literally rocket scientists. The general consensus with them was that the upper vents actually suck air out of the engine compartment due to the design and the apparent low pressure zone. String tufting and a video camera in a follow car would confirm this in the event of a wind tunnel not being found (which, in fact, I have access to, but would cost somewhere around $8-$10K for a four hour session...not exactly wallet friendly!).
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Old 07-25-2009, 02:12 PM
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holy cow!!!

Wheres a swamp boat and some plywood when you need em?

I think the string tufting idea is a great one. perhaps someone could bribe a friend to operate the camera on this one.

With the leading edge of the vent nearly as high as the rear, the basic function could be the same as holding a bucket out of the car while driving. the air will enter the bucket until the pressure equalizes, then it simply buffets, or tumbles over the open hole.

Should the vent be reshaped even alittle bit to allow the air to be scooped or peeled off the air traveling over the body, and the ducting be large enough, it would provide a great ram air effect at speed to feed an airbox, or intercooler.

I know the local hardware store sells fiberglass tubing parts in various sizes, and shapes 6 to 8 inch should be good, then grafting it into the body and routing it into the engine bay.

The only thing is you'd need a screen and maybe some bladed louver to keep junk out, and the local punk kid from dropping a pen down your cars intake.
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Old 07-25-2009, 08:27 PM
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Yaughn, you started another excellent thread, and today I found/took a bunch of good pictures to help you (or anyone out there kicking around these ideas) to visualize some of the spatial relations that come into play.

(...which will help you pass the time until you sell some more stuff from the garage and get that Sterling so you can double check these things on your own.)

I agree totally that the nose vent area is the best location for the main engine radiator (and also the A/C condenser -- because once you find enough room for the main radiator, the A/C condenser usually just ads another 1/2 inch of thickness. It would be CRAZY to try to put it somewhere different than right there with the main radiator.) I say...do it.

Yep, the nostril scoops on the hood could be used for ram air for climate control, but you have to route them through two tricky bulkheads to do so. Behind those silly little nostril vents is the most important transverse structural element to the front of the body. It is NOT a straight shot, but it is such an obvious solution that I think it's worth going the extra mile to make it work. Rick (and others) have done it. It's not a bad idea at all. But I'd also say that it isn't a necessary solution; if you have an actual blower box and climate control system, there are several adequate locations to pull in air. Overall, I say...do it.

Low hip vents: You have no idea how hard it is to duct a meaningful flow of air from them! Many of creative, clever builders have tried to "duct them correctly," but you just don't get much bang for your buck.

I'm going to let you in on a well-kept Sterling secret: Those lower hip scoops are almost useless. Not totally useless...but almost useless. They are mainly there because they look cool. I suppose they technically allow a little more air in towards the brakes and, arguably, bottom of the engine. But when you really look at where they are, with the car sitting there in front of you and various raw materials for ductwork around you, you see that it is VERY difficult to make them majorly functional.

The problem is that they end immediately in front of the rear suspension and rear tire (and there are no good alternatives routes to duct it meaningfully.) First, you run into the end of the rear torsion bars, and then, immediately, you hit the tire and wheel. You can't go upwards with a duct because it would get so long and twisty as to be almost totally useless and/or will hog space needed for air from the upper scoops, which I feel are more useful (more on that later, when talking about the upper scoops). Yet there was a time when I was obsessed with using those lower scoops for something big. So, then, I wondered if I could duct them so that they turn a quick corner and then run along the INBOARD side of the wheel and tire. Well, the entire rest of the suspension is there. And god-help-ya if you have a water-cooled engine with all of it's necessary ancillary accoutrements, because you'll need all the other little bits of room back there to route other things, like the plumbing for the cooling system, etc. You can try a quick turn through the body baffle that's there, but the gas tank is right on the other side. It seems like everything a person can try with those vents results in a restrictive, narrow, complicated duct with lots of bends. Darnit. They just can't be counted on for any MAJOR function (like a mid-mounted radiator) unless, maybe, you commit to an inline fan that runs almost constantly or you change the entire chassis and rear suspension to something different...which seems like a worthy project if trying to achieve other goals but isn't too practical just to make ducts work.


I think there is one very nice use for those lower scoops in a water-cooled application; they allow just enough space for a small (like 6x9 inch) oil cooler placed right at the scoop. With a small functional element placed right at the scoop, you might actually get a little useful air from the scoop. And because the wheel well is a little lower pressure, it helps to draw some air through and shed some heat from those coolers.

Here is a photo of that lower scoop area with the wheel off. I have a little oil cooler in there. IF a person totally relocated the gas tank and had an air-mix box for climate control in it's place, THEN maybe it would be worthwhile to turn the corner through the baffle and try to use that scoop. But that's a major undertaking. And where else can the gas tank go?

Making the body vents usefull-hip-scoop-area.jpg

Anyway, I think the coolest discussion is in regards to what to do with those UPPER side scoops.

Yaughn, I know you've asked for cut-outs/photos/measurements of a few things, recently, as you go about doing some mental mock-ups without a car present. The following photos are meant to hopefully help you see some areas of the Sterling from unusual angles to help you visualize what's there to work with in those rear scoop areas.

First of all, I agree that it would be very cool to modify the upper scoop so that it actually shaves off some major airflow. (I like the ice-cream scoop analogy, by the way.) I plan to open up those upper scoops on my blue car.

Okay, first...the stock scoop really does have a little inherent ram air potential. Yep, the stock scoop has that silly back wall and down turn to it, but it is NOT just flush with the body. I agree that the stock scoop seems to be inefficient, and I think maybe they made it that way just because it was easier to pull out or a mold. (If the scoop had an undercut, it would've made the mold crazy complicated in that region.)

Here is a series of photos starting from very low angles to see what the air flow sees.

Making the body vents usefull-top-scoop-tour-1.jpg Making the body vents usefull-top-scoop-tour-2.jpg Making the body vents usefull-top-scoop-tour-3.jpg

Making the body vents usefull-top-scoop-tour-4.jpg Making the body vents usefull-top-scoop-tour-5.jpg Making the body vents usefull-top-scoop-tour-6.jpg

In the last photo, I added an overlay to show plane that represents the lowest you can run any duct work from that scoop without interfering with the travel of a full size wheel and tire. (Note: I just have scrappy old Bug tires on the car right now, which are two inches smaller in diameter than tires that look good on a Sterling.)

Now, the take-home realization in all of these (and the following) photos is that you have to keep the duct work pretty high up in the body if you want to deliver air to the front of the engine compartment.

I originally thought that I would duct air slightly down and into the side of the engine compartment, without having to puncture the top part of the engine area (like, behind the rear window, above the original engine cover.) But the problem is, the wheel is in the way. You simply don't have room to go down and directly into the engine compartment if the air is already that far back over the wheel. Said another way, if you're going to change the scoop so that it captures lots of ram air (by cutting out the back wall of the scoop), then you either have to wrap duct work way back a little aft (not inboard) to the tire OR just stay up high and cut through the UPPER baffles of the rear of the body. (See following photos.) With the original upper scoop, you can kind of route some duct work into the front of the engine compartment. That's the way it was intended by the designers. But if you open up the rear of that scoop, then the air is delivered further back than the designers intended -- now over the top-dead-center of the wheel -- and therefore you'd have to turn it 180 degrees just to get it forward far enough to duct it in front of the wheel, which kind of defeats the purpose of opening up that duct more.

Here are some more photos showing that necessarily "high" routing of the the high ducts if the back of the scoop is seriously opened up (which is what I plan to do with my blue car.)

Making the body vents usefull-top-scoop-tour-7.jpg Making the body vents usefull-top-scoop-tour-8b.jpg

Making the body vents usefull-top-scoop-tour-8.jpg Making the body vents usefull-top-scoop-tour-9b.jpg

And here is the area in which you'd THINK it would be easy to route a duct to, but is actually darn near impossible because the wheel is in the way.

Making the body vents usefull-top-scoop-tour-9.jpg

And just to reinforce these recommendations/space constraints, here are three more photos from unusual angles under the rear fender, looking up from different angles. It might take a second to get your orientation, but together, they give a good feel for the usable space that exists behind the upper scoops.

Note: The metal you see is NOT stock Bug (obviously). Those rails with all the holes in them represent the top of an inner fender insert that I'm fabricating and the bottom (in my opinion) of the usable air space behind the upper scoops/above the rear wheels. On the driver's side I'm going to route air to the engine compartment as shown above. On the passenger side I have my K&N air filter (show in the forth photo).

Making the body vents usefull-top-scoop-tour-underfender-1.jpg Making the body vents usefull-top-scoop-tour-underfender-2.jpg Making the body vents usefull-top-scoop-tour-underfender-3.jpg

Making the body vents usefull-engine-support.jpg

Lastly, I know there has been talk of using the space behind the rear cockpit wall (ie, over the transaxle) for things OTHER than the gas tank. I've included some photos of this area (although it is not easy to capture with photos) just to give a feel for its basic dimensions.

Its dimensions are favorable for a gas tank.

You could also use it for nice storage...but you'd have to relocate the gas tank.

It's also a nice amount of space for an air mix box for a heater and A/C. Problem is, you'd have to relocate the gas tank, and there are precious few places for the gas tank to go.

But as far as putting the main radiator there, I am still an ardent believer that this space is NOT a good one for a main radiator in a Sterling. It's not the right shape. The space is only 11 inches high and is no wider than a "normal" radiator, which makes for a very small radiator overall. And there is NO good way to get air to it. You might as well put it in a sealed trunk. Anyone looking at all of the above photos has to start to get an appreciation for the fact that neither of those sides scoops could competently put air in front of a radiator mounted here. You'd have to scoop the air in and channel it backwards and around corners to make it work. You would never get any good passive cooling or air flow.

Making the body vents usefull-space-over-trans-1.jpg Making the body vents usefull-space-over-trans-2.jpg Making the body vents usefull-space-over-trans-3.jpg

Standard disclaimer: Nothing is impossible. Obviously anyone can try whatever they want with any scoop. I've seen guys simply mount lights in the nostril scoops, and you know what? It actually looked pretty cool!

But whenever I write a longer tutorial like this it's because I feel a responsibility as one of the "senior" Sterling owners (in terms of length of time with the car) to give people a heads-up on things that I and other builders have tried that worked versus things that we've tried that didn't work. There are very few things that haven't been tried before, and I love it when we can learn from other's (including MY) past mistakes and misadventures.

At any rate, I hope this helps to visualize some of the spacing constraints in the rear of the Sterling.

(My fingers are really tired! )
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Old 07-25-2009, 09:22 PM
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what do you think of putting a radiator in front of the front wheels?
i moving the as tank upfront and putting a frig in its place
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Old 07-25-2009, 09:34 PM
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You have an ass tank?! I just put my ass in the seat!

There is actually a lot of good vertical space in front of the front wheels, and it's certainly easy to get air there. The problem is that the space there isn't very wide, and if you cut through the internal sides of the "tub" of the trunk, you lose a lot of the strength of the nose.

Then you'd have a saggy nose in addition to having your ass in a tank.
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Old 07-25-2009, 10:14 PM
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Great write up warren,

It seems Ill be having to wait on many things, including a sterling. LOL

Alot of people are broke nowadays so even the mighty craigslist isnt proving its metal.
Im not giving up either, just getting a little frusrated, as of course Id like a sterling in my garage today if it were possible.

I wanna sit in it and vroom vroom sounds. without any windows, hydraulics nothing but a pan wheels body and roof.

Still looking forward to it though, Im sure my wife isnt. LOL

I think my first adventure will be of course rust removal, and getting everything cleaned up, and fit for a restoration project.

Somethings like the interior work, dash, and exterior work can be played with, but Ill have to buy supplies as well, fiberglass, resin, wiring. lotsa work!
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Old 07-26-2009, 10:14 AM
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Oh! While looking for a photo of something else, I found this older photo of the area above the transaxle. I apparently had the wheels off that day, so it shows the area even better. You can also see my hydraulic clutch slave cylinder. Other brackets you see are for things like engine compartment fans, cruise control, etc.

Making the body vents usefull-space-over-trans-4.jpg

The "cradle" making up the bottom of this area is to hold my custom gas tank. I wanted to use the stock Nissan fuel pump, so I cut the mounting flange for it off the Nissan tank and welded up a whole new tank. It ended up being about 19 gallons.
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Old 07-26-2009, 11:07 AM
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Ive been looking at the same idea, of a custom fuel cell.
Your gonna need that huge tank to feed that beast of a motor. I think our plans for bigger 20+ MPG car engines will negate installing a larger gas tank to feed em! going 200 miles on a tank just aint my idea of fun.

In that one photo, I couldnt believe it. That thing is huge! I know you said it was a V6, but is that an in line 6? it looks it. LOL
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Old 08-02-2009, 12:01 PM
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Yeah, the V6 definitely fills the engine bay a bit. But I think the proportions of a V6 are actually quite good for our cars. A V6 is not much longer than the bug engine because it's cylinders are more closely spaced because doesn't need lots of cooling fins. And, ironically, it's actually not any wider at all. What a V6 is is a TALLER engine than the Bug engine, which accounts for a lot of the cut-outs I had to do. (But, I also did so simply to improve access).

Of the four engine types I've had personal experience with -- 1600cc Bug, Nissan V6, Mazda Rotary, and Dodge 2.2 inline four cylinder -- by far the clumsiest-fitting one was the 2.2 inline 4. It was too tall and too long. It looked like crap. The V6 actually fit BETTER than the inline 4.

Here's an overhead photo of the general fitment of a V6 engine in our cars. Notice that it stays inside of the "magic box of non-interference" quite nicely from front-to-back and side-to-side.

Making the body vents usefull-engine-overhead.jpg

That's the good news. But like I said, the bad news was the HEIGHT of the engine. Here are some more photos showing how much taller the engine is in relation to the stock deck height/height of the original engine cover. Notice that it pokes up high enough to actually interfere with visibility out of the rear window a little.

Making the body vents usefull-engine-height-1.jpg Making the body vents usefull-engine-height-2.jpg

And here are two more showing height and general fitment of the V6 again. In the second photo, I had a sheet of metal laid out to reflect the minimum height that the new engine cover must be to provide clearance. There isn't must wiggle room in that dimension. I'm worried about rear visibility. (Please disregard all of the other strange things you might see in these pictures. Apparently I was experimenting with a rear bumper, a new spoiler, fender flares, various louvers, fans for the engine compartment, AND bigger high side scoops that weekend. Geez. I must have had too much sugar that morning!)

Making the body vents usefull-engine-height-3.jpg Making the body vents usefull-engine-height-4.jpg

Perhaps other V6 engines would be shorter height-wise. It seems like, in all pictures I've seen of V6 Sebrings, the engine never stuck up quite this far, so maybe the Nissan is just a little taller than other options.

Off topic a little, I do wonder was my MPG will be with this car (as it relates to the question of how big a gas tank should be). My thoughts were that the 300ZX donor car got in the high teens, and thus a Sterling at half the weight should possibly get in the 20s when it isn't being driven hard. But these are just total guesses. I wouldn't say that my rotary Sterling is particularly good on gas. I did, however, drive the whole 3 hour round trip to Carlisle and back on one tank with a pretty good reserve left. That's not a bad range.
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