ISX

Seems to be some confusion around other parts of the interweb so I will go into full blown detail and end it all. Diesels technically need an air to fuel ratio (A/F) of only 14.5:1 to have enough to burn all the diesel, however, in practice this ratio needs to be around 18-24:1. Even higher ratios are sometimes needed to stomp the EGT back down where it belongs. But the misconception is that boost is everything and nothing else matters. Although I said 18-24:1, I will use 18 for this entire article to keep from writing the entire 18-24 bit. Just remember that this is only for an example as ratios over 18 are needed quite often. Using 18 parts air, we are left with 1 part fuel. Thing is, the air does not mean a volume of air or pressure of air per say, but is a matter of molecules. It means 18 molecules of air for every 1 molecule of fuel. With this ratio, our engines can only support 129HP if there was no turbo. That is at 80% Volumetric Efficiency (VE),80F, and 2600RPM. This is because at a given pressure and temperature, there is only so many molecules of air that can fit into a given space (or volume). It is the same as putting balls in a jar, only so many will go in before the jar is full. With the given amount in there, the 1 part fuel that is allowed for every 18 parts air is only enough fuel to create 129HP. But my engine is rated at 215HP so now what! 215HP requires almost twice the number of air molecules as it takes to support 129HP. The magic happens because air is compressible. In school you learned that solids are packed very tightly, liquids are loose, and air is very loose and just drifts around. By shoving the air together, you can pack more of them into the same area. With enough force, you pack them so tight that it is the tightness of a liquid and will phase change (if heat is also released) but that takes way more pressure than we can get with our trucks. Anyhow,this force is boost. With more boost, you pack the molecules in tighter so you can get more into the same area. To make 215HP, I need 9.8psi of boost to cram in the number of air molecules needed to support the 18:1 ratio. The number of molecules within a given volume is called the density, and that is the key to it all. However, boost is not the only factor. Temperature also has an effect. As I said before, you can compress the air so that the molecules are shoved closer together so you can make room for more molecules. Temperature changes change the size of molecules. Hotter air makes them bigger, colder air makes the smaller. That means if the air is cold, then you don't have to compress the molecules as much because they are already taking up less space because they are smaller, therefore, you need less boost to get the same number of air molecules in there. The 9.8psi figure earlier was at 80F, but at 0F I only need 6.2psi. So temperature has a big effect as well, but it is important to remember that this is intake temp (IAT). The intercooler does a very good job so varying the turbo intake temp with cold air intakes and such does not have as drastic an effect on IAT, though the turbo would be a little more efficient since the air it is pumping is denser, but that is debatable and not the topic of this article. We are then left with volumetric efficiency which is how well the air can actually get into the combustion chamber. Low temps and high boost equating to the support for high power does nothing if you can't get it where it needs to be. This is why 24V's have a higher volumetric efficiency. More valves allow for more area to let the air in, so a 12V might have a VE of 80% whereas a 24V might be 90% or something. Porting and polishing also helps as a rough surface hinders good flow. The intake manifold can also pose an issue during high load/power conditions because pistons 1 an 6 are way off to the side of it so the air has to slam into the bottom of the manifold then wander over to the far ends of the manifolds, therefore, 1 and 6 have a less VE than 3 and 4, which is also one reason 1 and 6 run hotter since the fueling is the same to all cylinders but with less VE on 1 and 6 they end up with a richer burn. Turbo drive pressure also has an effect which is directly linked to turbine efficiency. If the drive pressure is much higher than boost pressure, then scavenging during valve overlap is hindered. It is possible to get lower drive pressure than boost pressure with a turbo that is efficient. So there you have it, number of air molecules is key. Though comparing equal molecules of air with different IAT meaning less boost when colder, gives you much higher pressure and temperature at TDC for the hotter IAT/higher boost compared to the colder/less boost scenario. I am going to figure out the exact pros and cons of both. I did read an article this morning done at some testing center with everything the same except varying IAT and at low load colder air proved to have better efficiency. However, at part load higher IAT's had better efficiency. They didn't do a test for full load. But this is interesting and adds another layer of thought to this article which I will research some more and add to this article when I figure it out.

KDP Repair/Timing Cover Leaks This will go over fixing the killer dowel pin and/or fixing the oil leaks that the timing cover is renowned for. I know I have things still on it in the video and did things backwards and stuff but do it the way I list and it will be a lot easier, I just took everything off that I needed to come off but doing it the way I list will save you from having to deal with a few things I ran into or it will keep you from getting close to messing something up Take the windshield washer fluid and overflow tank off of the radiator shroud and set them aside. They come off by pulling in the middle and pushing up. There are connections on the bottom of the washer fluid tank. Take the Fan and radiator shroud off. Fan nut is 1-7/16” and left hand thread (if you are standing in front of the truck, turn the fan clockwise to loosen). The shroud has four 10mm bolts on the sides. The bottom of the shroud has tabs that go into slots on the radiator, so it has to come straight up to pull it out of the slots. The fan and shroud come off together, it is hard to get the fan off by itself. Loosen the six 10mm fan pulley bolts, but do not remove, just loosen them. Take off the serpentine belt. Now you can take the fan pulley bolts all the way out and set the pulley aside. Take the fan pulley bracket off, four 10mm bolts. Take the RPM sensor off by taking the bolts out. There will be the sensor, a spacer, and a wire retainer thing. The sensor has a magnet in it so it will attract to the damper. Just set the sensor off to the side, no need to disconnect any wires. When reinstalling, get a feeler gauge and just let the RPM sensor lay on top of the thickest feeler. 0.030” is I what I used. Try to keep it level with the damper (yes, the damper goes on before you put the RPM sensor back on). Take the damper off, four 15mm bolts. If you have a manual you can put it in 5th and that will stop the engine. You will have to twist the damper and jiggle it around but try to pull it off as straight as you can. Look at the lines on damper, they should line up, if they are off, you know it is worn out. When reinstalling, use locktite and tighten to 92 ft.lbs. Take the bolt that holds the oil fill tube off, the one that goes into the intake manifold. You should be able to leave everything else on. Take all the timing cover bolts out, there are a million of them and some are long and some are short, all should be 10mm. When reinstalling, put all the long ones in first since there aren’t as many. The long ones also have a smooth hole since they have no threads for the first inch. Tighten the bolts to 18 ft. lbs. Make sure you put the cover back on going straight so you don’t mess up the crank seal. Fix KDP, tab it. Clean off the bolt and put locktite on it. Try to dry the hole that bolt goes in. Scrape off old gasket/silicone and put new one on. I used this international T442 that supposedly will keep it from ever leaking again, so far so good. If you use it you have to get it on quick (within 5 min) and put the cover back on the truck and tighten all the bolts finger tight (should ooze out a tiny bit, you can just use a deep well socket by itself to help get it finger tight). After another 5 min, torque to spec (18 ft. lbs.). Optional: I tapped all the bolt holes to try and dig the old lock tite out. If you want to do this it is an M8-1.25 tap. Make sure to use oil on the tap and blow the holes out and blow the chips off the tap after each hole. Optional: I also wire brushed every single bolt. That way I don’t have all this old lock tite that won’t do me any good and sure won’t help the new lock tite out.

A while back there was some talk on getting some guides on doing the things we normally seem to take for granted, like the knowhow of changing your oil. Theres some things some people may not know so I figured I would go over them all. If anyone has anything else to add, by all means let us know. Alright here is the writeup on how to do this. The first thing is to try and get as much oil as possible into the oil pan. An engine that has been running recently (within maybe 3 hours) still has a lot of oil all over the engine interior and you need to let as much of this residual oil drain to the oil pan as possible before draining. You can change it right after it has been ran but the engine will be hot and so will the oil, making it a little hard on your hands when oil gets on them. It also leaves old oil in the engine which isn't necessarily bad but why change the oil if your just going to leave some of the old oil in the engine. If you want to do this, let the oil drain for an hour (or even overnight to get every drop). Sometimes it is better for wintertime when oil barely drains so draining a hot engine would be faster and allowing it to drain overnight ensures it all gets out. Keep in mind the new oil should be in a warm spot to easily flow into the engine. Next step is the oil filter. For some reason they always tend to tighten over time (or because you used a wrench to get it on last time) so you may need to use a wrench to get it off. It really doesn't matter if you damage it since you are going to throw it away anyways, but a strap wrench usually prevents any damage. If you do have to use something intense like channel locks, make sure to grab the bottom half of the filter because you might crush the filter and if it is on the top half, you may damage the filter head threads. Ideally, you should be able to get it off by hand (which is why you put it on by hand). I can always get mine off by hand but they are always tighter than when I put them on (or maybe I'm getting weaker). Depending on the year of truck, you should be able to wiggle it out without spilling a drop of the oil inside the filter, then you can dump the oil in the pan the engine oil is currently draining into. What you just unscrewed the filter from should be cleaned with a rag. Dirt gets up in there sometimes and it isn't the best idea to smash the new filter's gasket upon debris. I attached a pic of what I am talking about. Make sure the gasket from the old filter is not up there as well, if you forget to check and put a new filter on on top of another gasket, the 2 gaskets will not seal and the oil pressure will blow out between them. I have never had an oil filter leave that gasket behind but you never know, you will know when you forgot to check though.. Now get your new filter and write the current date and mileage on it with a sharpie BEFORE you do anything else with the filter (I did the next steps first and it made it a pain). Next step is to take the gasket off the new filter and get clean engine oil all over it until the whole thing is wet with oil, then push it back into the groove you took it out of. Now you can fill the filter to about an inch before it overflows, this will give you room to play before the oil spills out when putting it back in the truck. NOTE: If you spilled oil all over the place getting the filter out, you probably will spill a bunch of oil on the way back in, so you will have to judge how much oil to put in based on the degrees of tilt you had to attain to get the old one out. The previous tip about filling the oil filter is not recommended these days because debris can get into the filter/oil during the installation process and that oil is unfiltered and goes straight to the turbo bearings which is not good. However, I still believe it to be better than having the turbo starve for oil for the time it takes the filter to fill up. Just be aware of this and know that any oil that goes into the filter (the big hole in the center) is the same oil that goes out from the filter and into the turbo..the holes on the outer ring of the filter are the intake holes that send the oil through the filter media). Spin the oil filter on hand tight. I think the filters say go to where the gaskets gets tight as if you had the filter in a free spin and the gaskets resistance stopped it, then tighten 3/4 turn. I get it as tight as I can by hand and call it good. If you don't have good grip then you may need to resort to a filter wrench. This means dry hands dry filter, an oily filter tightened by hand is not exactly the tightest. Over time the filter tightens, I think because the gasket swells or something. Putting it on only hand tight ensures it can be taken off without channel locks or something drastic (hopefully). After the oil is drained, tighten the plug back up. My manual says 60 ft/lbs, and I wouldn't go a ft/lb more than that! You shouldn't have to take the plug out to drain the oil since it somehow drains out 4 little things on the sides so you should never have to start the plug into the threads, meaning you will never crossthread it. If you do take it all the way out, just make sure it threads in a couple full turns by hand so you know for sure it isn't crossthreaded. Fixing a screwed up oil plug can be expensive and laborous on these things. You can get lucky and thread it the next size up but it's still a lot of hassle for something so simple to not screw up. Now your filter should be in and tight, oil pan plug should be in and tight, so fill it up with oil. Every truck seems to be different these days so look up how much it takes. 94' 12V's take 10 quarts while 95'-98' 12V's take 11. Put the oil fill cap back on, start the truck, let it run a minute or 2, then turn it off. Check for leaks around the oil filter just in case you didn't get it tight enough by hand. If at all possible, leave it off for 3+ hours on level ground, then go back and check the oil level on the dipstick. Many people start it then instantly check the oil and wonder why it is not at the perfect mark. The perfectly full mark is an engine that has been sitting for a long time on a level ground. An engine that has been running has oil all over the engine and it takes a long time for it all to accumulate back into the oil pan, giving you a false reading until then. The dipstick has 2 marks; a full mark, and an add mark, with "SAFE" in between. The add mark denotes 2 quarts low. You have now changed your oil.

WARNING! This procedure must be done with a cold engine. Engine coolant should be below 140°F. I set my valves today, figured I would show everyone how I do it. As long as you know the firing order and valve lash (which are both on the cummins id tag) you can set the valves. This is called the valve overlap method. Basically the pistons have running mates. Running mates are pistons that go up and down together in exactly the same positions, as in they both hit TDC at the same time. The difference is that one of them is on the compression or power stroke, and the other is on the intake or exhaust stroke. To find the running mate, you simply take the firing order and split it in half. Our cummins' firing order is 153624. So splitting it in half would mean 153-624. If you put the second number under the first, you would have 1/6 5/2 3/4 So 1 is 6's running mate and 5 is 2's, 3 is 4's. Since the running mates are 360 degrees out of phase, when one of the hits TDC compression/power stroke, the other is hitting TDC exhaust/intake stroke. This is perfect for setting valves because you can simply watch the running mate of one piston and it will be on the exhaust stroke with the exhaust valve open, when it hits TDC and transitions to the intake stroke, the intake valve will open. Once you see that intake valve move, stop. This is TDC, or as close to TDC as we need to be. The running mate will be on the very end of the compression stroke and the start of the power stroke and the valves will be on the opposite side of the cam lobe since they must be shut during the compression and power strokes. You can now adjust the running mates valves, intake and exhaust. For example. To do the valves on #1, you would watch #6. The #6 will open and close the exhaust valve and once the exhaust valve closes and the intake starts to open, you stop and now you know it is at TDC. Since 1 is it's running mate, you know 1 is on TDC compression/power so you can do both valves on #1. Now look down the line and you will see that the exhaust valve on #2 will be open. Since 5 is after 1 in the firing order, 5 will be the next valves you adjust, and since you watch 2 because it is 5's running mate, you will watch #2's exhaust valve close and start to open the intake, you stop and do the valve on number 5. Basically you will be turning the engine 120* to do each valve. You will do them in the same order as the firing order. Here is the reference order. Do 1 by watching the valves on 6. Then 5 by watching 2. Then 3 by watching 4. Then 6 by watching 1. Then 2 by watching 5. Then 4 by watching 3. The next one you watch will have the exhaust valve open so that will be a clue that you are doing it in the right order. It is a very fast and bulletproof way of doing it. It works on any engine also. Just split the firing order and stack them and you have your running mates like I showed earlier, it always works.

Switched Grid Heaters For those wanting a switched grid heater, here is how to do it on a 12V from 1989 on up to 1997. The 1998+ trucks throw a code (P0380 and P0382) so for those with that system, you will have to just disconnect the leads that go to the grid heater itself. When winter comes, just reconnect them. The reason for doing something like this is because the truck will run the grid cycle if you run into the store or something and this is not necessary and is a load on the batteries and alternator, so why have it when it’s not needed during these scenarios. The controversy begins when you use it as a selector switch as to if you want to use the grids at all at a said temperature. The truck will start fine down to 32F and below that it will still start fine but is much happier with the grids. The problem is, this is very hard on the engine when it has to start with nothing but the heat of combustion. The temperature at which this degradation occurs is unknown but it’s a safe bet to say that 50F and below should be using the grid heater. The grids will still cycle up to 60F, but I think that last 10F is a buffer zone that is up to you. Why use the grid heaters at all? If you choose to remove the grid heaters or disable them, there are a few consequences of that action. All I will tell you is that starting it cold with no grid heater will make it hate the cold. My truck started up with no smoke, on the first crank, with no grid heater at 0F when I first bought it, this was even at 250k miles. The next year, it was starting the same, but I HAD to use the grid heaters. Don’t push your luck with them, use them every chance you get. What about my batteries? Driving short distances in the winter is the worst thing ever. Your grid heaters are going full blast on the morning start and your battery is getting killed. It will last a little while, maybe a week doing these cold short driving stunts. After a week, you really need to drive it for a long distance or charge the batteries using a battery charger or even exchange them with another vehicle that drives long distances. Hooking up the switch On the driver’s side fender well, there are the 2 grid heater relays. They control the 2 grid heaters individually. The positive wires (orange and yellow) are controlled by the ECM and are what turns the grid heaters on and off. There are 2 other wires that are green (one on each relay). Those are the wires you want to tie together and put a switch in between the ground source and the relays, thereby making the relays have no ground when the switch is off and having ground when it is on. This way, the grids will work exactly the same as stock when the switch is on. It is also easier as you only need to run one wire from the 2 relay grounds, to the switch in the cab, and then any good ground inside the cab. In this video, you can see the grid heaters being switched on and off, the ECM continues to cycle, it doesn’t know that they really aren’t cycling. This allows you to turn the switch off and if you turn it back on and the ECM is still signaling the relays, they will work when you turn the switch back on without anything knowing the difference. The clicking is the switch being turned on and off, you can see the voltage drop when the grid is on. embed video plugin powered by Union Development

Operation At the time you turn the ignition key to the ON position the PCM/ECM looks at the IAT (Intake Air Temperature) temperature and determines if the manifold is cold enough to need pre-heating. Typically this occurs when temperatures are below 55-65*F. You'll notice that the battery voltage will fall slightly more than normal during this time that the WAIT TO START light is lit. Once started the grid heater will continue to cycle on and off to maintain proper manifold temperature. There are 2 grid heater elements. The PCM/ECM will determine if one or both elements will be used. Here are the times and temperatures you should see. Intake Manifold Temperature Key ON position Pre-Heat Cycle Time Ignition ON, Engine NOT Running Post-Heat Cycle Ignition ON Engine Running Above 59F (15C) 0 Seconds No 15F to 59F (-10C to 15C) 10 Seconds Yes 0F to 15F (-18C to -10C) 15 Seconds Yes Below 0F (-18C) 30 Seconds Yes When temperatures are below 0*F it’s suggested to cycle the grid heater twice to help aid in starting. Block Heater use can offset intake temperatures, since the block will warm incoming air. Grid Heater(s) - Power Requirement 1 Element 2 Elements 95 Amps 190 Amps 1140 Watts 2280 Watts Starter – Power Requirement 350-700 Amps (Depends on temperature and oil viscosity) Alternator Output 120 Amps As in anytime you start the vehicle and grid heaters are active it will take longer to recharge the batteries. So be sure to run the engine longer to ensure the batteries are charged back up. Typically about 10-15 miles is a enough distance to re-charge the batteries in arctic cold temperatures. Both grids on will provide a heating temperature of 500F as proved in the video. When the grids heater(s) are running, you can tell when both or just one grid is running. You hook a voltmeter up to any point on the truck and measure exact voltage. In the video, you can see voltage drops to 11.75V, indicating that both grid heaters are running. When the voltage slightly releases to 12.20V, one of the grid heaters has stepped out. That grid heater then also steps out and regular charging voltage of over 13V is seen. Only one grid heater is needed after the initial dual grip operation to keep intake temperature up, so then you can see only one grid turning on and off with every time it drops to 12.4V. Driving at low speeds can make the grid heater stay on seemingly endlessly as the cold air is driven into the engine at a high rate with the grids failing to heat it up to the temperature that the grid heater(s) turn back off. You have to get the RPM and engine load just right, it also has to be during the state that you haven’t turned the grid heater cycling phase off (going over 20mph). Basically, you might be going 15mph up a hill and the grid heater will cycle on and instead of turning off the next second like normal, the threshold temp is never met and the grid will stay on for a seemingly endless time. Like I said, the conditions have to be perfect in order for it to do it. Just an interesting tidbit.. It is surely hard on the alternator and batteries. The grid heaters will then shut down when you go over about 20mph, retain sufficient intake temperatures, or shut the engine back off. The grids typically run about 3 minutes while idling, cycling on and off to maintain temperature, and finally canceling the cycles. Grid Heater Relays There are 2 grid heater relays, one for each grid heater. Each are ran by the ECM individually. The green wire on each of them is ground. The yellow and red wires are for each unique relay and serve as the positive lead that goes to the ECM. Upon being sent positive voltage, the relay energizes and the grid heater turns on.