Project Cool Fuel Take: 1

[CherBear]

How to keep the fuel in the injector rail cooler and lower the air temp. inside the intake manifold?

Place an insulating barrier on the underside of the intake manifold to shield it from heat radiating from the exhaust manifold:

http://www.angelfire.com/my/fan/manifold.html

It's a simple, cheap solution and trust me, it works.

I have wrapped my actual rail with the stuff. It works, but not as well as I had hoped.

Instead of my XJ having heat induced stumble at around 85*, it just does the same thing at at 95*.

Maybe I need more insulation.

 

[Dr. Dyno]

You still need to insulate the intake manifold to see any real benefit, otherwise the injector rail is just conducting heat from the manifold and getting hot.

 

[Milford Cubicle II]

The PO of my jeep had a nice reflective wafer type material that was shaped to fit directly between the intake ports. I through it away for whatever reason :doh:

Before I tossed that, I never had any hard start/stumbling/heat soak issues but after that I did. I wrapped the fuel rail and the injectors with reflective tape and A: it didn't solve the problem completely and B: the adhesive didn't stand up to the heat either.

I dunno if that wafer insulation was factory or not but it certainly did a good job. I've not been able to find another one since then.

But my theory is that since air moves through the manifold MUCH faster than fuel moves through the fuel rail (and also because the manifold is aluminum), it would be more effective to insulate the intake and try to reflect as much heat from the exhaust away from it than to try to insulate the exhaust to prevent the heat from escaping until it's out of the engine bay. The is because cool(er) air is constantly flowing through it the intake, which will keep it cool. The key is to prevent it (the intake) from absorbing other heat, hence, insulate it.

However, this helps but doesn't solve the hot fuel thing since it's its own system. Unfortunately the fuel inside the rail moves sloooow, giving it plenty of time to absorb heat. Especially after the engine is off and the fuel isn't moving at all. Wrapping the fuel rail and injectors would be a good idea IF the fuel moved through them much faster, but it doesn't. So by wrapping them in insulation, even though it keeps radiant heat from being absorbed, it also holds in the heat that is absorbed. Thus, it seems to me that the best solution is the one that I described early that I threw away, lol and Dyno's solution. Both of which block a lot of convective and radiant heat from the exhaust manifolds while still allowing free air flow around the rail and injectors, which seems to work better than anything else thus far.

 

[Fryphax]

If I saw this set up on a vehicle I was looking to purchase I would laugh, quite hard, and walk away.

 

[bjoehandley]

Now to throw a blowtorch into the matter here..........
http://www.hotrod.com/techarticles/...ppened_to_smokeys_hot_vapor_engine/index.html

 

[Milford Cubicle II]

If I saw this set up on a vehicle I was looking to purchase I would laugh, quite hard, and walk away.

That's good to know. Nice contribution to the thread, douchebag.

Now to throw a blowtorch into the matter here..........
http://www.hotrod.com/techarticles/...ppened_to_smokeys_hot_vapor_engine/index.html

That's a very interesting read. I dunno though, almost everything about it seems to fly in the face of modern engine theory. Such as how on earth to keep an engine from detonating like crazy while forcing in HOT air. Basically, the complete opposite purpose of an intercooler :dunno:

I'll admit though, I haven't read the entire article thoroughly yet. I'm probably missing something.

 

[Keithmania]

I find this thread and interesting read if for nothing more than the exercise of it and I just shake my head at the posts that want to piss on the idea. Why post if you don't like it? Or is there some compulsion to be an ass? Anyways, kudos Milford, I'd like to see your results.

 

[tbburg]

Coming to this thread late, but:

Milford Cubicle II: You've been running this setup for almost 2 years now, How's it working? been worth enough to upgrade/simplify the system? Have you done any testing; OBD readout recording, dyno, anything?

My hunch is from a power perspective, it's not making much difference, and here's why: The engine management is adaptive. In a carbureted engine, the fuel mixture is adjusted and fixed by volume. As the fuel changes temp, it gets more or less fuel by weight for a given volume, so the fuel mixture changes with temp. With the feedback loop(O2 sensor) the computer sees the leaning effect as the under-hood temps rise, and adjusts for it.

Cooling the fuel going to the rail may prevent heat-soak by cooling the fuel rail after the engine is shut off.


As for the "hot vapor" system, it makes plenty of sense. The efficiency gains mentioned are not un-realistic. It sounds like a way to get diesel like efficiency out of a gas engine. Honda developed a high efficiency ceramic motor a few years ago that operated in the 2500 deg. range. Efficient as hell, just didn't last very long.

We only use inter-coolers/heat exchangers/etc. to dump waste heat that we can't use. Mainly it's to deal with conventional metallurgy and avoid detonation with conventional gasoline delivery systems. The hotter a cylinder operates, the more efficient it operates. The limit is where parts start melting. Think the hot vapor engines are confusing? Check out this: ever heard of a six-stroke?

 

[bldeagle10]

this really is a good idea, HP wise i dont feel like there would be much gain, but i feel like the motor has the opportunity to run much more efficiently and from what im hearing you may even see slight MPG gains. i would be interested to figure out a way to use, like you said, a refrigerant system off a little fridge like the ARB's. wouldnt have to be motor driven since its electric and those things have a very low electric draw so you wouldnt lose much power there and if you had a dual battery or higher output alternator you really wouldnt see loss at all... you are just giving me ideas of my own.

 

[coldoath]

Interesting project man. Would like to see some pics.

Btw this thread brought out a lot of douche bags. Idk why they feel like they need to be dicks. XXXX them.

 

[Milford Cubicle II]

Coming to this thread late, but:

Milford Cubicle II: You've been running this setup for almost 2 years now, How's it working? been worth enough to upgrade/simplify the system? Have you done any testing; OBD readout recording, dyno, anything?

My hunch is from a power perspective, it's not making much difference, and here's why: The engine management is adaptive. In a carbureted engine, the fuel mixture is adjusted and fixed by volume. As the fuel changes temp, it gets more or less fuel by weight for a given volume, so the fuel mixture changes with temp. With the feedback loop(O2 sensor) the computer sees the leaning effect as the under-hood temps rise, and adjusts for it.

Cooling the fuel going to the rail may prevent heat-soak by cooling the fuel rail after the engine is shut off.


As for the "hot vapor" system, it makes plenty of sense. The efficiency gains mentioned are not un-realistic. It sounds like a way to get diesel like efficiency out of a gas engine. Honda developed a high efficiency ceramic motor a few years ago that operated in the 2500 deg. range. Efficient as hell, just didn't last very long.

We only use inter-coolers/heat exchangers/etc. to dump waste heat that we can't use. Mainly it's to deal with conventional metallurgy and avoid detonation with conventional gasoline delivery systems. The hotter a cylinder operates, the more efficient it operates. The limit is where parts start melting. Think the hot vapor engines are confusing? Check out this: ever heard of a six-stroke?

It's funny that you should mention the crower engines, they're at least partial inspiration for this idea. If cool(er) water changing phases into steam can extract energy (heat) from the combustion chamber, then why couldn't gasoline? Obviously, I don't mean for it to add another power stroke, but it seems reasonable to me that it could be used to lower combustion chamber temps and fuel atomization thus creating more power/efficiency and smoother operation.

Interesting project man. Would like to see some pics.

Btw this thread brought out a lot of douche bags. Idk why they feel like they need to be dicks. XXXX them.

Thanks man, and I have a few pics on the first page.

this really is a good idea, HP wise i dont feel like there would be much gain, but i feel like the motor has the opportunity to run much more efficiently and from what im hearing you may even see slight MPG gains. i would be interested to figure out a way to use, like you said, a refrigerant system off a little fridge like the ARB's. wouldnt have to be motor driven since its electric and those things have a very low electric draw so you wouldnt lose much power there and if you had a dual battery or higher output alternator you really wouldnt see loss at all... you are just giving me ideas of my own.

I agree about an electric compressor being the way to go, they only draw a couple of amps max, which is a negligible difference in mechanical draw on the alternator. And I'm not even exactly sure what to expect from it. To be honest, I just hope that it would help either: power, efficiency, smoother engine operation (longevity), or maybe just help my FM reception, hell, I'll take any of it And if any of those effects are great enough that it makes the whole cost worth it, then I'll be ecstatic. I just want to get the project done, test it, then share some numbers. It's unfortunate though that it'll be difficult to get definitive results with all the intervening variables, but I'll try.

 

[bldeagle10]

after reading this thread, it gave me a lot of ideas, everything from cooling the fuel at the fuel tank, insulating the fuel line, running a copper line next to the fuel line and having the two lines put inside of a single hose (copper line would obviously have refrigerant in it cooling the fuel line, if that makes sense). ive just thought about it alot and if you could get a little fridge compressor on there and have it be reasonable, or even if i can look at it and get ideas from it, i would seriously contemplate doing this. here in az with 115+ degree summers, driving the jeep kinda sucks. everything is just way to hot for comfort and i think this with some other modifications could really improve the way my motor runs.

 

[Milford Cubicle II]

I need either:

A very small electric fuel pump

or for my ideal (for now) set up:

A very small 12 volt refrigerant compressor

On the fuel pump, I've found universal electric fuel pumps but they're always a little pricey and way too big. As far as the 12 volt refrig compressor, I haven't been able to find jack squat. I suspect I'll have to call up Engel or ARB and just straight up ask them who makes the crap for their junk :dunno:

 

[bldeagle10]

i wouldnt be surprised if they manufacture their own stuff. at least i know ARB fabricated almost everything in house for their suspension and exterior parts... i will do a little research as well.

 

[Finaltheorem47]

Edit: You can build a meth injection system for less than $80 btw.

I'd like to learn more, could you discuss this in more depth Bryson? Thanks

-Final

 

[bldeagle10]

The ARB 37-Quart Fridge Freezer represents the latest in portable freezer-fridge technology and features, including a Danfoss compressor with smart electronic control to enable rapid cool-down to the target temperature, cooling setting based on the exact target temperature (in Celsius or Fahrenheit) rather than 1, 2, 3, etc. dial settings, integral thermometer that displays in either Celsius or Fahrenheit, an integral battery monitor with three different settings that will shut down the Fridge Freezer if the vehicle's battery depletes to a predetermined voltage level and turn on the Fridge Freezer if the voltage rises to a certain level, the ability to run on 12/24v DC or 100-240v AC power and the power cords to run on both power sources, a 12/24v DC plug with detachable fitting that can be fitted to Merit/Hella sockets as well as standard 12v sockets, a removable heavy-duty lid that swivels on stainless steel hinges and does not detach inadvertently, a cam-lock latch for the lid, a recessed digital control panel, recessed steel handles that double as tie-down points, rubber feet to secure the Fridge Freezer in place, steel cabinet sides to withstand heavy use, rear clips to prevent inadvertent disconnection of the power cables, reversible basket to segregate the contents of the unit or to create one large area for storage of longer items, a detachable partition for the basket, an integrated evaporator to simplify cleaning, an integrated drain plug to facilitate draining, a dairy/fruit compartment that is designed to hold its contents at slightly higher temperatures than inside the basket, a 50-can total interior capacity, an internal LED light that turns off when the lid is closed, and a three-year warranty. External dimensions are H17" x W15" x D28".

so out of all that the only important part was. Danfoss compressor.

 

[Milford Cubicle II]

Thanks for the info man, that sent me on a very productive googling escapade!

Leading to this thread:

http://naxja.org/forum/showthread.php?t=1064657

 

[bldeagle10]

np. took me about 30 seconds to find ^.^ im a google magician

 

[usaf_mike]

cant wait to see this finished with results

 

[zachandandy]

Not exactly the same thing, but a very similar fuel rail mod on a wj resulted in 16hp and 29lb/ft at the wheels. Heat soak is more of an issue due to the u shaped fuel rail, and it's a v8, but that is huge.