Jeep Hood Vent Install

[SavageSun4x4]

Chrysler LeBaron Hood Vent Install
Found a set of these on one of the Jeep boards, sent the guy some ducats and they were mine. They needed a good cleaning when I got them so I just put them in the dishwasher with the supper dishes and ran it on the pots, pans, and hood vents cycle. They came out clean to say the least.

Stopped off at Home Depot and picked up some Krylon Fusion Gloss Black plastic rattle can and gave them 2 good coats. Then shot them with Krylon Clear and I was now ready to install.

Gather up tools and proceed to do the install.

Install:

Tools required.
• Painters tape
• Cut-off wheel or
• Metal cutting blade jig saw
• Dremel tool for touch ups
• Flat and half round hand held files to clean up edges
• Tape measure
• Straight edge at least 24” long
• 3 Pencils
• Drill with bits
• Big Friggin Hammer, BFH
• Tube of adhesive outdoor caulk
• Krylon paint

1. Decide where you want them, up front, middle or towards the rear. From a ‘works best here’ viewpoint, the best I can ascertain is that as far forward as you can put them. Which is just right at the leading edge of the raised section in your hood. I base this upon the AEV hood and other posts where folks have done tests to see where they worked the best.
2. Using your pencil and straight edge mark a centerline down your hood using the footman loop as the center locater.
3. Place your vents where you like and measure off the centerline to insure proper placement.
4. If your vents have mounting openings, use them to drill pilot holes.
5. Cover holes using blue Painters tape.
6. Using a pointed object, like the pencil I told you to get find your pilot holes.
7. Using a piece of heavy weight paper flip your vents over and create a template.
8. Taking the template, with the pilot holes identified, place it over the tape and puncture the template using the pencils I told you to get. One pencil in 2 opposite corners.
9. Using the third pencil draw your outline
10. Repeat the above on the other side.
11. Using a tool of your choice, cut-off wheel or jig saw but not your swinging Richard cut out the hole you just outlined.
12. If you did it correctly, it will drop in, if not get the BFH and beat the vent into submission if it is close. If not get the Dremel and open it up some until the BFH will force the vent into compliance.
13. Insure a good fit and get some good quality outdoor adhesive caulk and put a few dabs around the inner edge.

Time required:
About 4 hours including painting the vents.

Cost:
From junkyard, about $5 each more or less, off e bay or some Jeep BB about $15-$35 more or less.

Pics:

http://homepage.mac.com/donpryor/PhotoAlbum36.html

Results:
To be posted at a later date

[ChrisK]

Great Writeup! I moved it to the DIY section since it is a writeup. Now, it won't get buried in all the other general topics.

[SavageSun4x4]

Sounds good to me...

[DsrtJeeper]

Don;
I have to ask........why all the measures to decrease underhood temps? My '03 TJ crawls all day long on the hottest of days with the AC on and never goes over 210*. These engines are built to run that hot for clean emissions. Is the supercharger raising your temps? Nice write up!

[SavageSun4x4]

Don;
I have to ask........why all the measures to decrease underhood temps? My '03 TJ crawls all day long on the hottest of days with the AC on and never goes over 210*. These engines are built to run that hot for clean emissions. Is the supercharger raising your temps? Nice write up!
The answer is both simple and complex. The issue is that the SC uses engine oil to lube it and it brings this oil off the oil sending unit on the side of the engine, up thru the SC and down into the pan. Heat rises and what I have is it engine oil heat now on top of the engine and running thru the SC.

That in itself is not too bad as I can crawl and even run the AC, but my temp needle will move to the outer edge of the 0 in 210. No its never overheated, BUT the problem is pre-detnoation. I can overcome that by running 91-93 octane. However if I can keep the engine temp at a steady 210 I can run 89 and if I don't drive hard I can run 87.

My thoughts were, its not a problem witht the engine or radaitor that makes it run hot, but rather a two fold issue. VERY hot engine bay which results in feeding the VERY hot air into the combustion chamber. So, I reasoned if I can reduce the engine bay temps, the engine will run cooler AND will intake cooler air, thur requiring lower octane.

So Far:
Removed headlight trim rings.
Raised front of hood 1/2" for better air flow
Installed 4" alum flexy tube from Home Depot from under radiator up to air filter.
Installed hood vents.

BINGO, it-they works.

I could have used the Kenne-Bell lube system of just filling the SC with oil and not passing oil thru. But I am not in favor of that.

I could have used a lower temp thermostat, but that will affect the computer and lower temps in the winter. Didn't want that.

[DsrtJeeper]

I've read alot about the supercharger on various boards and I'm not sure it's for me. I think I'd build a stroker first or maybe run the 505 Performance turbo kit for the 4.0. Are you still happy with the supercharger; Don?

[danno]

The supercharger is the simplest install... much simpler than the 505 Performance Turbo Kit...

Also the supercharger is intercooled...

[SavageSun4x4]

I've read alot about the supercharger on various boards and I'm not sure it's for me. I think I'd build a stroker first or maybe run the 505 Performance turbo kit for the 4.0. Are you still happy with the supercharger; Don?
I've had the SC on for over 2 years and about 30k miles. If I had it to do over again and spend the money, I WOULD. Its simple, bolt on, doesn't alter anything and works.

If you go the Turbo route, suggest you keep my posts on reducing engine bay temps, because you are going to need them...

[DsrtJeeper]

The supercharger is the simplest install... much simpler than the 505 Performance Turbo Kit...

Also the supercharger is intercooled...

So even with intercooling; there's a high temp problem? It sounds to me that the 92 octane might actually be needed in this application. The MPFI on my '89 YJ calls for 92 octane and runs much better with it.

Stroker long block delivered to my door $3450.00. That includes Rousch Racing pistons, Eagle Rods, reworked stock cam, double roller style timing chain and gears, brass bearings and freeze plugs, Hesco head,etc.......

Too many choices! :D

[SavageSun4x4]

So even with intercooling; there's a high temp problem? It sounds to me that the 92 octane might actually be needed in this application. The MPFI on my '89 YJ calls for 92 octane and runs much better with it.

Stroker long block delivered to my door $3450.00. That includes Rousch Racing pistons, Eagle Rods, reworked stock cam, double roller style timing chain and gears, brass bearings and freeze plugs, Hesco head,etc.......

Too many choices! :D

All the intercooler does is cool the incoming fuel air mixture.

I considered a new engine and a possible stroker kit. I went with the SC for several reasons.

Simliar cost and ease of install. Able to pass emissions testing on a single pass. Does not effect the computer or driveability, only works for you when you want it too [boost].

Just wait until you try to dial in that stroker with a HESCO head (ache). And when its all said and done the result is only a few HP/torque gains over the SC. Which if you drive a Jeep you have to ask yourself, is it a Jeep or a Corvette?

[DsrtJeeper]

All the intercooler does is cool the incoming fuel air mixture.

I considered a new engine and a possible stroker kit. I went with the SC for several reasons.

Simliar cost and ease of install. Able to pass emissions testing on a single pass. Does not effect the computer or driveability, only works for you when you want it too [boost].

Just wait until you try to dial in that stroker with a HESCO head (ache). And when its all said and done the result is only a few HP/torque gains over the SC. Which if you drive a Jeep you have to ask yourself, is it a Jeep or a Corvette?

The Hesco head is amazing when installed and used correctly unlike some of the yahoos whining on the web. The stroker I speak of will work with my stock computer and the driveability is much like a V-8 powered Jeep. The power is useable and does not come on like a light switch. The stroker is also guaranteed for 1 year, no questions asked.

I agree that the SC is much easier to bolt on. I was just curious about it mainly.

[joedokes28]

I Still don't understand why you don't / won't run 91octane gas with the S/C.

So you save $3 at the pump. You can't use the extra power the S/C provides because you're using $hitty gas, so what's the point of the S/C to begin with?

All of this just doesn't make sense.

[SavageSun4x4]

I Still don't understand why you don't / won't run 91octane gas with the S/C.

So you save $3 at the pump. You can't use the extra power the S/C provides because you're using $hitty gas, so what's the point of the S/C to begin with?

All of this just doesn't make sense.
Well it really doesn't work that way. Running more octane than required doesn't give you any more hp/torque. If your engine is not pinging or your experencing pre-detonation issues then pumping 91 instead of 87 will make little or no difference. On the highway on trips I will kick it up to 89 just to tackle the hills that will sometimes cause a bit of pinging.

I wish better/more octane gas ='d better hp/torque, but it doesn't.

[mingoglia]

Don is right, higher octane doesn't give you more power. Octane is basically how hard the fuel is to burn, it's useful in high compression high heat situations where the fuel/air mixture is likely to detonate before the spark plug fires (detonation).

If you want to get completely technical, the amout of BTU of high octane fuel (91+) is actually slightly less than 87 so theoretically the fuel has less ability to "get work done" and therefore has less power (althouth the difference is so slight you don't actually notice).

Some folks may see an increase in mileage or power with the higher octane. This is because of two reasons. The first reason is that some engines have a knock sensor that when triggered retards the engine. When the engine is retarded, it wastes a tone of fuel. I proved this myself with my Navigator. When we ran out of fuel here the trucks just transported low octane to the pumps and the 91 octane pumps ran out. I have to run 91 in the Navigator, and as a result of my knock sensor my economy went down dramatically. I normally get about 13mpg on the highway, that went down to 6mpg instantly. I actually bought some octane booster half way to Payson from a service station to get this mileage up.

The second reason fuel economy may go up could be similiar to this engine heat problem. If there's some outside reason why your engine/compartment is extremely hot, or your engine isn't tuned right, your economy may go up because the fuel is compensating for these outside conditions.

Mike

Well it really doesn't work that way. Running more octane than required doesn't give you any more hp/torque. If your engine is not pinging or your experencing pre-detonation issues then pumping 91 instead of 87 will make little or no difference. On the highway on trips I will kick it up to 89 just to tackle the hills that will sometimes cause a bit of pinging.

I wish better/more octane gas ='d better hp/torque, but it doesn't.

[joedokes28]

That in itself is not too bad as I can crawl and even run the AC, but my temp needle will move to the outer edge of the 0 in 210. No its never overheated, BUT the problem is pre-detnoation. I can overcome that by running 91-93 octane. However if I can keep the engine temp at a steady 210 I can run 89 and if I don't drive hard I can run 87

You said it yourself. Why sacrifice and run 87? It's as though you're goal here is to run cheaper (by .20 cents!?!?!?) gas

[mingoglia]

One quick follow-up and to bring this slightly off course... diesel. One of the reasons diesel can run such high compression is because there isn't a fuel/air mixture. Air is not metered in these engines, only fuel is. The air is let into the cylinder and fuel is only introduced at the very end of the cycle once the air is compressed and nice and hot. Because of this, "detonation" can't happen. I have detonation in quotes because technically detonation pretty much describes how a diesel engine works.... it's a controlled detonation after the fuel is introduced to the compressed air in the cylinder.

Mike

[joedokes28]

Don is right, higher octane doesn't give you more power. Octane is basically how hard the fuel is to burn, it's useful in high compression high heat situations where the fuel/air mixture is likely to detonate before the spark plug fires (detonation)

I understand octane. Doesn't create more power unless the engine needs it, such as in a turbo or s/c'd application.

Wouldn't you say that a supercharged engine is higher in compression )due to boost) and higher in heat?

There is not an s/c'd car on the market that doen't call for premium gas so why would you put the cheaper fuel in your jeep when it clearly needs the higher octane?

[joedokes28]

One quick follow-up and to bring this slightly off course... diesel. One of the reasons diesel can run such high compression is because there isn't a fuel/air mixture. Air is not metered in these engines, only fuel is. The air is let into the cylinder and fuel is only introduced at the very end of the cycle once the air is compressed and nice and hot. Because of this, "detonation" can't happen. I have detonation in quotes because technically detonation pretty much describes how a diesel engine works.... it's a controlled detonation after the fuel is introduced to the compressed air in the cylinder.

Mike

So there's basically never an occurance of a diesel running lean?

[SavageSun4x4]

I understand octane. Doesn't create more power unless the engine needs it, such as in a turbo or s/c'd application.

* Kinda sorta, but the engine has to have more factors in play than just a turbo/sc and high octane, got to have a compression ratio to take advantage of it.

Wouldn't you say that a supercharged engine is higher in compression )due to boost) and higher in heat?

* Yes..

There is not an s/c'd car on the market that doen't call for premium gas so why would you put the cheaper fuel in your jeep when it clearly needs the higher octane?

* True, however they are engines that were designed for a SC. The Jeep I-6 is not. In this case it is only an add on. The compression ratio is fairly low @ 9.1. I doubt that the SC gives it much more than a point or less and that would be at full boost. Since I don't drive the Jeep like I stole it from the Soprano's, I don't often hit full boost, I have been able to reduce the under hood temps and get colder/denser air to the intake/combustion chamber, which allows me 'beat' the system. The key here is colder/denser air to the intake. This also cools the intake/combustion and gives a richer air/fuel mixture allowing the Jeep to run a lower octane than one would typicaly use with a SC.


Read between the lines above.

[mingoglia]

So there's basically never an occurance of a diesel running lean?

Nope, it won't run lean. On a gas engine your fuel is metered to be roughtly 14:1 ratio (give or take a few). This fuel ratio doesn't change (or shouldn't change very much) A diesel engine can run as lean as 100-150:1 when it's ideling, but may run 6:1 when laying on the coals. This is one of the reasons a big rig will idle while they're sleeping as they may only burn a few cups of fuel an hour while ideling because they're running 100:1 at that low of RPM. Yeah, they have to keep warm in the winter, but if they were using a ton of fuel while sleeping you'd bet more of them would just get a better sleeping bag. :rolleyes: A gas engine typically burns slightly more fuel when ideling (as opposed to a slight load of course, not a full load).

With regards to saving $.20. Well, you only *need* to run the minimum octane level in order to avoid detonation. If he's not detonating on 87 octane, then 87 it is. I also believe he should probably be running 91 all the time due to the super charger. The supercharger is introducing compressed air into the engine at a much higher temperature. After all, not only is it pulling in air for the engine compartment, but it's compressing it which generates a lot of heat (back to the diesel engine again as a diesel engine wouldn't even fire if it didn't have hot enough air in it as a result of the air compression process).

Most engines that come with a super charger or turbocharger are a lower compression ratio of their normally aspirated counterparts for the very reason of detonation. Although not a high compression engine to begin with, the 4.0L with a Supercharger in my opinon surely requires high octane...

A way to find the proper octane if you can't use a calibrated ear would be to try the different octanes and use the one that yields the best fuel economy. Or more specifically, the lowest octane possible while not giving up fuel economy.

Mike

[SavageSun4x4]

you only *need* to run the minimum octane level in order to avoid detonation. If he's not detonating on 87 octane, then 87 it is. I also believe he should probably be running 91 all the time due to the super charger. The supercharger is introducing compressed air into the engine at a much higher temperature. After all, not only is it pulling in air for the engine compartment, but it's compressing it which generates a lot of heat...

Although not a high compression engine to begin with, the 4.0L with a Supercharger in my opinon surely requires high octane...

A way to find the proper octane if you can't use a calibrated ear would be to try the different octanes and use the one that yields the best fuel economy. Or more specifically, the lowest octane possible while not giving up fuel economy.

Mike

True. That said: I approached this in a very methodical process. Goal 1 stop pre-det even when using 91+ octane. That accomplished I continued with the effort of lowering under hood temps. In fact this was the first thing completed. But I still had high engine operating temps. What put the pre-det to bed was running the 4” alum duct from under the radiator up to the air filter and the removal of headlight trim rings.

Having had the SC on for a couple of years, I have learned that the ambient temp dictates the octane level I need to run in the Jeep. As fall comes on I have been able to drop down to 89 and later 87 as it got cooler. Moreover, as spring set in, back to 89 and then 91 in the heat of the summer. Knowing this and having solved my pre det on 91 I decided to try a tank of 89. Well it worked, but figuring I still had some 91 in there when I filled up I continued with the 89. It worked great. Then I started playing with the 87 octane as I got the temp stable at 210. This also worked. Now at highway speeds, if I need to pass and have to go full boost I will pick up pre-det as I get past the peak torque curve in 3 and 4th gears. Solution, don’t try to pass at 70 mph. I mentioned earlier that on trips I usually run 89 and that is the key reason for it.

In the dead heat of August when the ambient temp is 118 and street temps are the high 120’s, I suspect that I might need to go to 91 octane again if I needed to battle rush hour traffic. Not having to do that and being able to pick and chose my driving times I have been able to successfully run 89 on the highways and 87 in town. It is my thinking that winter will allow full-time 87 on both streets and highways.

[mingoglia]

Sounds like you got everything under control. On stock supercharged vehicles, the manufacturer has to assume a bone head is going to get in and jump on the gas no matter what the conditions are. Because of this, it's safe to require 91 all the time. Sounds like you're adjusting your octane based on the conditions you're going to drive. In addition, you're adjusting your driving based on the temperature and speed.... looks like you're good to go (as you already know)....

Mike

[SavageSun4x4]

Sounds like you got everything under control. On stock supercharged vehicles, the manufacturer has to assume a bone head is going to get in and jump on the gas no matter what the conditions are. Because of this, it's safe to require 91 all the time. Sounds like you're adjusting your octane based on the conditions you're going to drive. In addition, you're adjusting your driving based on the temperature and speed.... looks like you're good to go (as you already know)....

Mike
That and I know what pre-det sounds like and can do. Sammy Studhorse who is just showing out for his girfriend and also has the CD at 2 decibels above nose bleed, will at best will only wonder what the rattling is under the hood is and his girfriend will think its cute.

[joedokes28]

That and I know what pre-det sounds like and can do. Sammy Studhorse who is just showing out for his girfriend and also has the CD at 2 decibels above nose bleed, will at best will only wonder what the rattling is under the hood is and his girfriend will think its cute.

Savage, I've read every write up on your site and you're a sharp guy with a TON of $$ invested in your jeep.

You've said it a billion time on many forums, "there's no free lunch". It's even in your sig.

I have one question for you? Why run 87 in your rig knowing that if you have to stab the gas, it may ping? "Why" is my only question.

[cactuscatcher]

Don;
I have to ask........why all the measures to decrease underhood temps? My '03 TJ crawls all day long on the hottest of days with the AC on and never goes over 210*. These engines are built to run that hot for clean emissions. Is the supercharger raising your temps? Nice write up!

The reason is pretty easy, the SC Don is using is a friction induction device, it will regardless of intercooling, hood vents, hood removal, operation in Antartica always increase both the tempature of incoming and exhausting air through the engine. He is attempting to reduce the increased tempatures within the motor during operation to a level that is only sligtly higher than a stock 4.0 in a state during which the vehicles fuel/air/exhaust parameters will retard timing only to the base level at which point his increased density (but much hotter than yours) fuel/air mixture will burn properly.


So even with intercooling; there's a high temp problem? It sounds to me that the 92 octane might actually be needed in this application. The MPFI on my '89 YJ calls for 92 octane and runs much better with it.

Stroker long block delivered to my door $3450.00. That includes Rousch Racing pistons, Eagle Rods, reworked stock cam, double roller style timing chain and gears, brass bearings and freeze plugs, Hesco head,etc.......

Too many choices! :D

The intercooler in that system is a low efficency unit and it is not designed to lower engine operating tempatures, it is designed to lower the tempature of the incoming air charge into the motor.

The stroker kit will if properly installed generate more power at cooler tempatures but it will require more fuel at all times to do so, even with the parasitic lose from the SC compressor the SC will achieve small power increases at approx less fuel consumption than the larger volume motor.

I Still don't understand why you don't / won't run 91octane gas with the S/C.
So you save $3 at the pump. You can't use the extra power the S/C provides because you're using $hitty gas, so what's the point of the S/C to begin with?
All of this just doesn't make sense.

Very little, the learning/logic porition of the fuel metering program will retard the timing of the 4.0 to match exhaust temps and oxygen levels automatically unless those sensors are changed or the CPU is reprogrammed the actual net horsepower gain will be very slight as the CPU will force engine exhaust temps to remain within the same parameters regardless of what counter measures are attempted to lower them.

[cactuscatcher]

One quick follow-up and to bring this slightly off course... diesel. One of the reasons diesel can run such high compression is because there isn't a fuel/air mixture. Air is not metered in these engines, only fuel is. The air is let into the cylinder and fuel is only introduced at the very end of the cycle once the air is compressed and nice and hot. Because of this, "detonation" can't happen. I have detonation in quotes because technically detonation pretty much describes how a diesel engine works.... it's a controlled detonation after the fuel is introduced to the compressed air in the cylinder.

Mike
A diesel engine does not use octane which is a measure of combustion temperature limits, diesel fuel is measured in cetane which define combustion pressure limitations of the fuel.
Gasoline is far too low in actual combustion pressure limits to function properly in the diesel. The greater combustion pressure is the result of the higher compression ratio used by diesel engines. In a gasoline engine the compression ratio (which controls the compression temperature) is limited by the air-fuel mixture entering the cylinders. The lower ignition temperature of gasoline will cause it to ignite (burn) at a compression ratio of less than 10:1. The average car has a 7:1 compression ratio. In a diesel engine, compression ratios ranging from 14:1 to as high as 24:1 are commonly used. The higher compression ratios are possible because only air is compressed, and then the fuel is injected. This is one of the factors that allow the diesel engine to be more efficient.
A primary difference between a gasoline engine and a diesel engine is the manner in which engine speed is controlled. In any engine, speed (or power) is a direct function of the amount of fuel burned in the cylinders. Gasoline engines are self-speed-limiting, due to the method the engine uses to control the amount of air entering the engine. Engine speed is indirectly controlled by the fuel injection/air flow monitoring system. The predefined limits control the amount of air entering the engine. In such a system, the rate of air flow dictates the amount of gasoline that will be mixed with the air. Limiting the amount of air entering the engine limits the amount of fuel entering the engine, and, therefore, limits the speed of the engine. By limiting the amount of air entering the engine, adding more fuel does not increase engine speed beyond the point where the fuel burns 100% of the available air (oxygen).
Diesel engines are not self-speed-limiting because the air (oxygen) entering the engine is always the maximum amount. The diesel engine speed is limited solely by the amount of fuel injected into the engine cylinders. The engine always has sufficient oxygen to burn and the engine will attempt to accelerate to meet the new fuel injection rate. The diesel engine can accelerate at a rate of more than 2000 revolutions per second which is the primary reason why a slow response variable speed spool induction device like a turbocharger works so well when properly setup with the diesel engines air control systems. In the diesel engine there is not a fuel/air ignition system as the diesel does not require an ignition system because the fuel is injected into the cylinder as the piston comes to the top of its compression stroke. When fuel is injected, it vaporizes and ignites due to the heat created by the compression of the air in the cylinder.

[cactuscatcher]

So there's basically never an occurance of a diesel running lean?

Yes, it absolutely can run "lean", and running lean causes injector failure, piston scoring, and although this almost always occurs from mismatched injector delivery rates it can be a very serious problem within the diesel engine and diesel fuel does require cetane increases or it will pre-detonate prior to achieving the designated or desired combustion pressures.

[joedokes28]

Lot's of good info above cactuscatcher

[SavageSun4x4]

Don, I understand your experience here, I use run a modefied turbocharged car and detonation was always a concern.

I think you may have overlooked one thing that might make a HUGE difference here...simply:

OIL COOLER.

DO you know what your oil temps look like?

You would be surprised, but OEM oil coolers are quite common, easily being found on late model twin turbo 300Z's. Not only would they reduce heat, running cross the top of your engine, but they would reduce internal heat as well and prolong the life of your SC/Engine.
Your dead on with that and the oil cooler had crossed my mind several times. There is really a method to the madness here. This was more or less an experiment in various ways I could solve the problem. Going from the simplest to more complex. As someone said, why didn't you just install another radiator and thermostat? I wanted to take various approaches that might have small or incremental gains. Other folks can use these ‘tricks’.

Yes, a oil cooler is on the horizon. So I will let you in on some thinking… I have been exploring the possibility of using a radiator for auto trans and running the engine oil thru there. Increase in engine oil amount and keeps it cooler to boot. You have any thoughts on this???

[SavageSun4x4]

Lot's of good info above cactuscatcher
Thanks to Catcuscatcher for getting to all these questions. First, he is right on, second, I am running late to leave for Pomona, Ca for the Offroad Expo.

Just glad that Catus has got my back on this...:D

Talk to you guys Sun nite if I am back...

[joedokes28]

Your hood vents did come out nice.

[LKD TJ]

This has got to be one of the more interesting threads I have read. Thank you all for putting in your years of knowledge to help us understand.

[Quasimotor]

I looked at the Kenny Belle SC option and kind of dimsissed it. Mama says detonation is the devil, and well heat and a blower just seemed like a dumb idea to me. I also looked into the 5.7 hemi and found it was a bit more work than I wanted, and no cruise control.:(

So I wonder now, after seeing this thread, if using the Hesco/Patriot head, in conjunction with a S/C might not be a bad option? Aluminum head usually allow .5 compression ratio increase on same octane due to heat loss compared to a stock cast head. So maybe just use the aluminum head with a stock size or slightly larger combustion chamber volume (lower the compression slightly), and the SC and it might just be less prone to pre-ignition and make the SC work that much better? (better flowing head works well with a S/C)

I still think 110 degree days and an air compressor (Super charger) on top of the engine is a funky idea, but with the advantage of the aluminum head and lower compression this might not be a terrible setup.

Does anyone know if they make a lockwire head gasket for the 4.0?

[cactuscatcher]

Quasi you may be able to get a custom gasket made by Gasketworks or Hussy Copper but it may be overkill as well. The Mopar performance gasket is rated to 12:1 and should hold quite well in a low C SC engine.

[SavageSun4x4]

"I would be mindful of flow characteristics. Although our I6's are generally low RPM engines, I know this is a concern for high RPM engines. You don't want oil starvation to the SC/Engine."
Yes that can be a concern if one is not careful. I met with the folks from a radiator company the other day to discuss the issue of running engine oil thru a built in cooler in the radiator for auto trans. What they suggested was running the exit flow from the supercharger to the intake on the radiator and back to the oil pan. This will prevent the engine and the SC from starving for oil because the oil cooler is on the return side. Not sure when I will do this, perhaps next summer, but its on the list of todo's.

"So I wonder..., if using the Hesco/Patriot head, in conjunction with a S/C might not be a bad option?"
Your correct on the alum head allowing you to raise the the compression due to the heat transfer of alum vs iron. I considered this and then found out the HESCO head is about $1500 bucks and I couldn't jusitfy the cost when I wasn't sure of the results. Seemingly I have solved the issue of pre-det and the cooler intake and engine bay temps have results in better performance and mpg.

In summary:
I thank all for the suggestions and I do appreciate them. That said: What I am doing is trying different options to see if there are positive results. Yes, it would be easy to just have shoved in a bigger rad or cooler thermo, but that is not the purpose of this. Plus, I wouldn't have anything to write about other than my Jeeps was hot so I stuffed in a bigger radiator. And, like it says on my website "built to get you there, engineered to get you back". Its not just for me, but all Jeepers out there that read the boards. Like you I am always looking for a cheap, driveway fix that works and its to that end that I do the things I do. Enjoy...