Anyone out there mounted a Hughes F1 Air Gap intake onto a 318/360/5.2/5.9 V8 and willing to reporpt the results? Claims of better power and improved fuel mileage makes it very interesting.

The dyno results they have posted on their site are not correct. Both the Air Gap and the Mopar A1 will raise the power band from the kegger style intake.

I have run them and they are better except very low RPM, you pretty much need a manual trans and shifting around 2000 RPM to take advantage of the kegger TQ, it was a great idea but poorly executed. The long runners with no shar turns was a nice idea but then they cooked the air with a thin steel plate conducting heat from the hot oil right to the intake air an to really make sure it was hot they heated it up with a coolant passage right against the air going to the front runners and to top it all off the steel plate bends up between the bolts and lets pieces of the gasket fall out so it sucks oil into the cylinders.

The RPM air gap only gives up a tiny bit of TQ very low for a good chunk of power slightly higher in the RPM range. It is also a broader RPM range even though it is a tiny bit higher up.

Thanks HotRodDave, that's how I interpret the power gains of the Hughes over a modded Kegger. If I go with the kegger, I will modify it for better higher rpm flow (I have an extra kegger), and I already have the aftermarket plenum plate to seal the bottom of the kegger into the block valley. If there was a way to mod a kegger into an air-gap style I'd try that too. What I have read about the Hughes is the gains in mid-range and higher, and the fuel mileage gains.

One thought to consider. Before Air Gaps became a thing, we used to block off the exhaust crossover and use a lifter valley baffle plate to keep hot oil off the bottom of the intake. Milodon makes the baffle

Interesting. I've heard of windage trays for the oil pan but never knew about a valley pan to keep hot oil off the bottom of the intake. I'll consider that, especially if its adaptable to mounting the kegger onto a 5.2 Magnum. But if I use the kegger with the thick aluminum bottom plate I wonder if it still clears the valley baffle plate? This pic is the bottom of the kegger with the thick plate in place,

Never messed with a kegger intake, so I dunno if it will clear the baffle. I have always run the baffle myself, but on typical 4bbl intakes. Does it help? I dunno, but it beats cleaning out the cooked on oil inside the stock crossover heat shield setup, lol.

I do have an LA on the stand with one installed, but the intake is on. Maybe, if I get energetic, I'll pull the intake and measure.

I watched a video a few days back showing Powernation guys installing an intake on a Chrysler small block. Sure looked to be enough room between the mount surface for the intake and the bottom of the valley to allow a plate to keep hot oil off the intake bottom. One thing about intakes like Hughes Air Gap is the real air gap on top of the intake and below the mount surface for the throttle body. No matter the mods to the kegger, there is no real cool air flow gap between the bottom of the kegger and the top of the block valley. If the kegger bottom plate was angled up lengthwise it could create an air gap but then the block valley would have to be sealed off somehow. For that the Hughes Air Gap intake is a good setup to seal off the block valley and create a real air flow gap above the valley.

But even a Milodon valley baffle does not fully seal off the block valley. It just keeps hot engine oil from splashing directly onto to the bottom of the kegger plate. For that matter, could a block valley baffle be made to fully seal off that area? And can the crankcase breathe properly if the block valley was fully sealed off? Seems to me the block has to be able to "breathe" from both sides.

From 2006

All that shield is going to do is hold oil up net to the exhaust crossover baking it. I also see the crossover isn't blocked. As for the air gap design, I question how much "cool air" is getting in there. Maybe on a dyno there is a minor improvement, but under the hood, with an exhaust cross over? Relying on air that has passed thru the radiator? I guess cool is a relative term here.

I paint the bottom of my intakes and between it and the milodon baffle I have zero build up on it. How much is it helping? Who knows.

As for breathing, the entire valley is not sealed, there is room around the edges for air flow. Especially around the distributor drive location. Even one of those setups that seal to the china walls would still allow for breathing.

No oil is trapped between the shield and it mounting point, as there is a standoff between the two.
The SS has as an attribute reflective radiant heat quality,
SS also is relatively a poor heat conductor.
The exhaust crossover on the head is blocked and has no ability to bake anything.
The opened manifold crossover allows ambient air movement that is cooler relatively than cam valley air.
This car also has the Mildon lifter valley shield.

if one studies a properly installed pvc system, where the pvc valve is installed on one valve cover, and a breather installed on the opposite one, you can see "air" is introduced by the breather, sucked through the crank case by the pvc valve, then exited into the intake manifold.
this also provides the benefit of not allowing the crank case to build up pressure, thus blowing out seals and gaskets, causing oil leaks.
this is why a pvc system is a must on almost every engine built and installed, from street to race applications.
just my personal life experience and opinion of almost 60 years playing with these toys.
your results will vary.

so the consensus is that a valley baffle is a worthwhile addition to the small block Mopar engines, and it does not have to fully seal around the valley to be effective right?

Interesting that a stock 5.2 Magnum has no valley baffle other than the intake manifold bottom plate. Yet stock V8 engines from GM have a pretty complete valley baffle that nearly seals off the block valley from ambient air:

You guys are talking about two different motors. The original post was referring to the " Hughes F1 Air Gap". This is for the magnum motor NOT the LA. Magnums don't have the exhaust cross over like the LA's did. If you are building a drag car then i might worry about hot oil hitting the bottom of the intake. I really don't think it's an issue with EFI magnum. And if it is how much? You may get minuscule amount of power with a cooler intake. That's up to you to decide if you want to "insulate" it or not. The LA's i would agree to block off the cross over. But they are for carburated engines that's why they are there. Emissions also when they had the EGR ports in them.

Good points. Whether I go with the modded Kegger and throttle body, or spend the bucks for the Hughes Air Gap, I'll still install a valley panel. Why not? When I am in the 5.2 Magnum to do other updates I might as well do it all in one shot.

Andy, with my 49, I gained a another mpg by simply pulling air from outside of the engine compartment. That big domed hood holds a lot of heat around the top of the motor through the summer, but I also remover the outside air from the filter housing through the winter. The cold in the winter was causing a stumble on a cold motor, and your in a colder environment then I am.

just my opinion, take it for what its worth, but I don't think that hot oil splashing on the bottom of the intake is going to be a huge problem for the kegger, and may actually be an improvement during the colder months you also intend to drive the truck.
I also don't believe I would want to give up any low rpm torque, a expensive new intake would cost. You keep working on dropping the cruising rpm to gain the mpg you are seeking. That "little torque drop" the aftermarket intake will cost you at low rpm, just to gain more at slightly higher rpm, might be way more harmful then you think. If you have to step into the throttle more to keep the truck moving over slight hills, it may kill any advantage you may gain. The low rpm torque is exactly what the 4.7 lacked, but you are considering taking the 5.2 in that direction.

As usual Gene, after some more research and thought, and your input, I have found more than enough evidence that my overall goals to start with are probably best done (cost wise too) to stay with the kegger. I don't plan to do any bracket racing, and my driving habits with my old Dakota rarely had me going over 5,000 rpm, all well matched to the power curve I'll use daily with a kegger intake. I'll mod the extra kegger I have for the flows gains available with my own time and work, same for the throttle body. Some winter nights in the shop with a grinder and bits can net some gains for both. And like you said, some thoughtful intake air management for those gains as well. The Hughes Air Gap intake is nice, but over $500 nice? More I think about it, the harder it is to justify.

Just an FYI if anyone is interested, MT ran one of the Engine Masters shows on the magnum engine yesterday(S6 EP23). The name of the company that made the intake i spoke about is Utawesome. The dyno results over the stock kegger was a "ladder" Paralleled the stock one over the rpm band. They swapped over to carb intakes after this. They started to build power after the 4K mark.

As expected, "They start building power after the 4K mark." is not an rpm range one would expect to see too often in a vehicle one is chasing fuel mileage with. 4 K + rpm and gas mileage don't generally go together.

Agreed. Most of my driving in my old Dakota (4.7V8 5-spd manual 3:55 rear) had me in the 2500 t0 4000 range as I rarely needed to exceed that range for my driving style. Now, the 2001 4.7V8 was not a strong engine torque wise until it spun up to about 3300 rpm. I'm replacing the 4.7/manual with a built 5.2 Magnum and the 8-spd auto trans, so it should be a lot more torquey and responsive, and the power range from 2500 up to 5000 is more in my range of driving and needs. Especially since the first two gears in the 8-spd are lower ratio than the manual trans. In fact its not till 3rd gear that the 8spd matches the current 5spd in my Dakota. That should make my 56 pickup much more fun and responsive even with the kegger setup. A modded kegger will help the 5.2 perform to my needs for the few times I get to or exceed 5000 rpm. My goal for highway driving should have the 5.2 humming along at about 1700 rpm at 70mph, which I know is good for at least 20mpg.

Ive done a few things to minimize heat transfer to the air in there.

The easiest thing to do is to take 4 extra valve cover bolts with the studs sticking out the top and use them for the corner of the steel plate and use a couple nuts on the stud to hold a second plenum plate suspended below the actual plate.

You can also ceramic coat the plate to help keep heat out.

Last thing I have thought about doing would be to grind away the entire thermostat and coolant passage at the front leaving only basically a flange against the head, use a big drill bit to drill the coolant passages to a round shape, tap them, thread in two pipe nipples and plum in a remote mounted thermostat housing to keep the 200 degree coolant out of the intake.

I think the runner design in the keg is superior for low end TQ production but the immense heating of the air from both the giant coolant passage and oil from the crank case and cam negates all the gain from those long runners. If you watch the AIT on a scanner while driving around it is crazy how hot it gets even in zero degree weather 100 degree IAT is very common.

hot Rod Dave, is there a chance you might have pictures of that keg intake with the separated coolant passages? Some of us don't mess with this stuff on a daily basis and can't visualize in our heads what you are doing here. The few times I've had a keg intake off a motor, I was just looking at the bottom of it, and then torquing the intake bolts back in place as a stock intake.

HRD there is a middle ground to be had temp wise by running a 160 or 180 thermostat and running a bigger radiator and electric fan set up. Magnums were designed to run hotter due to emissions and to squeeze every last bit of fuel mileage out.

Doing this on my 5.9 in my van made a huge difference in under hood and coolant temps. Temp gauge doesn't get over 185 now even towing another vehicle. Used to run at about 210 no matter what.

With a cruise rpm of 1700 I would definitely keep the kegger. The torque curves don't change in favor to the air gap v/s the kegger until about 3500 rpm.

Please understand me, I am trying my best to have a clear understanding of what is going on here. This old mechanic and racer didn't used to care much about fuel mileage, but back then fuel wasn't $3.75 a gallon either. Now that I no longer race, the shoe is on the other foot, fuel mileage has a slightly higher priority.

So, is what you are saying as far as the current wisdom that a motor operates at its highest efficiency at 200 to 210 degrees, is incorrect? Isn't the highest efficiency point also the closest balance between power and fuel mileage?

I understand that the goal to achieve the highest fuel mileage and the most power at the same time, are probably a contradiction of terms, but at some point those two things have to reach a crossroads (or at least come closest to each other) on their different paths.

What is going on here is a few guys trying to determine where that closest point is between fuel mileage, and power out put, may lay, and what is needed to get there.

Under the hood temps is an interesting thing. On my 49 Dodge truck, the high hood combined with the channeled body puts that 5.2 Magnum keg intake in some pretty warm air during the hot summers. I have discovered that ducting the fresh air for the intake from below the engine compartment has improved the summer performance, drivability, and fuel mileage. But in the winter months (the truck is driver year around in the north west corner of IL), I have to disconnect the fresh air tube and pull the warmer air from under the hood, or it stumbles and runs poorly. That 195 thermostat sure helps during the winter. I'm not so sure I'd be willing to give up the current winter driving performance for a slight gain through the summer. It is often the only transportation we use during the winter (because of the 4x4 option).

I'm posting 2 pictures. Pic 1 is the side view of the truck. Its important to notice how far above the top of the fender line the top of the hood is. The truck's radiator cap is only about 3/4" above the top of the fenders. Pic 2 is a view with the camera sitting on top of the fender surface just in front of the hood, while the truck was still in red oxide primer. Everything above the top of the radiator cap is housed inside of the raised part of the hood from pic 1. That raised hood is about 8" above the top of the fender, and the top of the factory Dakota air cleaner housing is only 3" under the center of the hood. Everything you see in pic 2 is above the fender line on the truck, hanging around in hot (and probably not moving hot) air through the summer.

My 49 sheet metal is channeled over an unmodified 93 Dakota 4x4 chassis. It has a 96 5.2 Magnum (mounted on replacement original Dakota motor mounts), coupled to an RE46 od auto trans, the Dakota 4x4 transfer case, front axle and rear 8 1/4 rear, both housing 3:55 gears. (Yes, the 4x4 functions and has been used.) The truck currently rides on 235 75 15 Goodyear Trailblazer tires (I have no clue the tire diameter). The truck has passed 25,000 miles of use since June of 22. On the highway @ 65 mph (in the summer), the truck pulls a very consistent 18-19 mpg, around town in the warmer months it averages 13 mpg, but that drops to 10 during the winter months (winter highway also drops about 3 mpg). At roughly 8,000 - 10,000 mile a year, fuel mileage matters. The truck weighs in around 4850 lbs, I'm not driving a light weight race truck here. This old man is pretty content with the performance of the truck, but the facts are, a steep incline @ 65, on cruise control, will drop the trans out of OD and unlock the converter to maintain the speed on the hill climb. Often it will shift back into OD and lock up the converter before it reaches the top of the hill. Squeezing a few more Ft lbs of torque at 2500 rpm wouldn't hurt, if it didn't cost a lot of money.

My old low compression (10.3 to 1 actual) NHRA stocker would pick up .05 to .10 seconds with a 180 degree thermostat over 140 degrees without a thermostat. It had a radiator that would allow it to idle for an hour without overheating if necessary.

I like those ideas. I have an extra kegger so I can study mods to limit heating the kegger. For cooler air under the hood I've thought about getting the center section of the hood louvered, maybe with the louvers facing forward.

I have thought about adding louvers to the center of the hood, but my concern is about adding water under the hood in a rain storm, and given the cold air drivaibility with a simple fresh cold air duct to the air filter housing in the winter on my 49, removing all the under hood heat that the louvered hood would do in the winter could cause a big issue. Another concern is that these hood centers are a bit on the weak side to begin with, when it comes to supporting the two outer pieces. Every one of these trucks I've had, I had to weld up cracks and reinforce the hood centers. They all have cracks starting at the front edges where the side panels attach. i believe louvers would make that weak area even worse.

These hood center pieces are not just laying around where you can just pick one up.

If you really plan on driving it year around up there in Green Bay, you need to consider what effect a summer only modification may have on the winter function. Cold air for the motor may be good in the summer, but may not be so good in the winter. Most of these guys are not driving their stuff in cold weather.

Exactly. That's why I thought the louvers would actually face rear opened rather than front, kind of like the cowl induction idea of the 60s era Chevelle. Then plan for an insulator panel to slide in place on the underside of the hood center for winter driving to block off the underhood opening. Since you have far more experience with these old Dodges you input is invaluable. I suppose when I get to that phase of the project I can perhaps design in some more structure to the center section of the hood that Dodge never planned to provide.

On the subject of cooling the kegger, looking at a visual comparison of a Kegger and an aftermarket air gap intake, its pretty clear there is an area on an aftermarket intake that mostly separates the coolant from the intake manifold. However, the air gap manifold also still maintains closing off the block valley. If a kegger were cut like the red lines indcate it would separate the coolant section of the intake from the air chamber, but it would also open up a gap into the block valley. Even if a piece were TIG welded in, it would also have to close off the gap eposing the block valley. The red lines indicate areas that really only close off the valley. The heavier red line indicates where perhaps the front of the kegger body could be cut from the area behind the thermostat and water passaages, and then TIG weld in bar stock to again seal off the intake side of the kegger body. But something would have to be welded back in, or bolted on from underneath, to close off the opening to the block valley. Would there be any real gain then in trying to separate the coolant portion of the kegger from the air intake portion?

Do you intend to make the cowl vent functional? If so, allowing warm air from under the hood out directly in front of the cowl vent may not be the best idea. If you don't intend to make the cowl vent functional, the rear facing louvers with a slide in panel to close it up during colder months (or hard rain) may work out OK.

I have considered adding a pair of smaller louvered panels at the back sides of both hood sides, but we also drive most of the summer with the door windows open. My cowl vent functions, so when its open, most of the time, the door windows are where the air inside the cab exits the cab. If the cowl vent is closed, there is a lot more wind noise inside the cab and you can feel the air coming in the open door windows.

Functioning AC would probably solve the under hood air venting issue, but the radiator on my 49 is almost against the grille, putting an AC condenser up there is going to be a challenge.

Looking at the bottom of a modded kegger, seems the only other option could be an "air gap" bottom plate, kind of like mentioned earlier. If the bottom plate were a two level plate with the max gap between the two, it would at least keep the hot engine oil from contacting the bottom of the kegger plate. But without an actual inlet air gap at the front and outlet air gap at the rear of the kegger plate there would only be a gap to limit direct heating, but no actual air flow gap under the intale runners.

Again, I'm hoping using most of the cab functions from my Dakota helps out here. I even plan to use the Dakota cab back wall vents (the ones between the cab back wall and box front wall) to help expell hot/higher pressure air from the cab. Since I also plan to use the entire Dakota windshield wiper system (hopefully with both sweeping the same direction) I do plan to not have a cowl vent at all. Without a cowl vent I can use that area under the cowl/dash for other systems.

Without the cowl it may allow me to plan for a louvered center section on the hood. SO much planning and designing. At some point I do have to start cutting/fabbing/welding/etc.

Does the area behind the grill bars and ahead of the radiator allow space for the AC condensor? Here again I hope to use all those components from my Dakota. AND, I have a tranmission cooler to plan for (the 8HP-70 trans has a cooler). But that may also mount at the back/underside of the cab if there is sufficient airflow underneath the cab. I will be changing the engine fan to electric, mounted to the backside of the radiator. That may allow for some extra room between the back of the radiator and the front of the engine, maybe.

Things are pretty tight in front of the radiator on my 49.
The most forward point on my original Dakota frame is the round holes that the radiator support used on the Dakota 4x4 frame. A 4x4 frame is different then a rwd Dakota frame, that may make a huge difference. I used the bottom 1/2 of the Dakota radiator support bolted into the original mounting holes on the frame because I started with the original Dakota radiator (that lasted about 4,000 miles and was replaced with a Champion aluminum radiator that better fit in my truck, after modifications to the mounting brackets.
Pic 1 shows under the hood, looking straight down on the top surface of the original Dakota radiator. The factory clutch fan is still present in this picture, it had to be removed to make clearance for the electric fan attached to the new radiator, and make room for the rerouted upper hose. As you can see the red primed nose piece is very close to the radiator at the front. The only clearance between it and the radiator is the thickness of the nose piece itself, less the factory bent nose piece reinforced grille openings. If there is anything more then 2" of actual clearance, I would be surprised. Your 56 grille opening is completely open where the 49 grille openings are pretty much just slots cut into the sheet metal, so that too will help.

Pic 2 this pic was taken during the inner fender portion of the build. We are looking at the front radiator mount bushing from inside the passenger side wheel well. The piece on the left top corner of the pic is the Dakota inner fender at the front end where it was cut off. The shiny black area below the inner fender is the Dakota frame, just to the right of the inner fender, and above the frame, you can see the rubber bushing that is the actual radiator supporting bushing. it is important to know that the outside diameter of the lower rubber bushing is 2" in diameter, that should give you a size reference of the things in the picture. The shiny new metal is the support piece that holds the front nose piece onto the radiator support. it is bolted to the nose piece (the large rusty looking piece at the bottom right side of the pic) with 3 1/4" bolts you can sort of see and is also bolted to the radiator support. That piece is in the form of a "Z" The small flange with the bolt holes is flat against the nose piece, with a 90 degree bend pointing straight back. the next bend is also a 90 degree bend that is welded to the front of the radiator support. The large piece that covers the right top corner is the sheet metal piece that the headlight is mounted to.

Pic 3 kind of clears up pic 2. The 3 bolts to the left of the grill opening are the 3 bolts that hold the shiny metal to the nose piece, and you can see where it is welded to the radiator support. You can also se the back cover for the headlight holder. that has not yet been cut for the headlight mounting. The headlight holder is actually screwed to this sheet metal. You can also imagine the challenge of routing AC hoses or trans cooler lines into that area. Again, you have a rwd frame, not a 4x4, and the opening on the 56 Grille is wide open at the center. You may not have the problems I had.

one thing i enjoy about this thread, the explanation of Andy's problems, and Gene's expertise and [possible] solutions, get my foggy brain working to see things i might miss in solving some of the problems i encounter in my own, unrelated, projects.
kudos to both of you !

I am by trade a mechanical engineer and 30+ year trainer for both motorcycle rider classes and for hydraulic hose. So over the decades I've learned to be very specific and clear as possible when typing messages. But I am no where near the mechanic and fabricator the likes of Gene and others on this forum (Russ/Dabee). I have been my own motorcycle mechanic over 45 years and some of my bikes have miles getting close to 200,000. On a chassis swap I have a lot to learn. Gene has been priceless for practical solutions and realistic choices to avoid making mistakes once I really dig into this project. Gene's experience of multiple chassis swaps will hopefully make my 1st chassis swap/vintage build a well planned out success.

I previously worked 17 years as a chassis design engineer for Pierce Mfg on Class 8 fire trucks. I primarily did axles/brakes/air brake/ABS systems, but I learned a lot from my other coworkers about drivelines, cooling systems, engine/trans, and from a lot of test driving and training. Actually got to work directly with Bosch ABS engineers here in northern Minnesota and northern Sweden. That included developing test driving skills, surprisingly easy to spin a 40,000 lb fire truck, even on dry pavement. Just after I got a job in the hydraulic hose market I got an offer from Bosch to be their heavy truck ABS application engineer. But no way was I interested in relocating to Chicago, I'm a Wisconsin boy through and through, so I passed on that offer. Good thing too, because six years later Bosch ABS sold out to WABCO.

This idea is intriguing. I have an extra kegger I bought cheap, so I could do much of what you detail. Machine out the entire current thermostat mount and coolant runs from the kegger. But I was thinking of having a friend TIG weld thick wall tube stubs onto the remaining ports for the coolant. Then use a remote thromostat mount with stubs plumbed into it for short hose runs to the stubs on the kegger. May also make for a cleaner/easier to access setup for the thermostat which right now on the 5.2 is kinda buried behind everything, and would make for cleaner hose routing from the radiator to the thermostat housing. This would nearly separate the hot coolant flow from the kegger entirely.

However, my 5.2 Magnum has the air conditioning compressor mounted right over where any possible tube or hose routing would have to route for a remote thermostat application. So that idea is out as I want AC in my 56 pickup. So I'll do what I can to isolate hot engine oil from the bottom of the kegger and leave it at that.