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- #2,341
Interesting idea.
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Interesting idea.
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I know that when I was tuning my GTI it was IMPERATIVE to know exactly what the fueling/air was doing when we were trying add boost/spark for the midrange. I figure you would at least know how close to stoich you were... then you could play with other things to achieve the best scenario. Right now you are kind of shooting in the dark.
Pure addiction Diesel in Hillsboro just got a dyno and do some tuning... I bet they could point you in the right direction. I had them do some work on my Ford and was happy with their service and knowledge.
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Mike, when was the last time you were in your aneroid? Maybe the fuel pin follower o-ring is leaking a tiny bit, causing glazing in the fuel pin bore, causing it to stick?
- Thread starter
- #2,344
I think it was the beginning of fall that I did find the fuel pin leaking, not much but starting to leak. I did pull that off and replaced that seal so that part was fixed.
On a side note I have figured out what the problem was, I'm just building up the story as I get there.
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On a side note I have figured out what the problem was, I'm just building up the story as a get there.
*shakes fist* Not fair!!
I think I'm ready for an intercooler and may upgrade to a hx30w. I want to keep it simple.
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*shakes fist* Not fair!!
I know something you dont know... I know something you dont know.
- Thread starter
- #2,348
- Thread starter
- #2,349
I think enough time has passed that I've been able to forget the fine details so I might as well continue with some posting.
In my hunt to find the culprit I started throwing more money at it. I had a theory that my camshaft lobes were worn out. I had another car in my past that exhibited some of the same symptoms of a funny/weaker midrange where the camshaft had seen excessive wear so it was a stretch. I really did want to grab a Colt or Hamilton but the funding just wasn't there so I focused on a stock replacement. I needed to get some parts out of the way to get access to the camshaft to swap it out.
I used this guy's thread as a guildline: Replace Your Camshaft, Lifters 'n Stuff . . . . - Dodge Diesel - Diesel Truck Resource Forums
I ordered a camshaft online and the wrong one came in so I returned that and went with a local supply house I've been getting a bunch of my parts from. They had one in stock so I grabbed it. Here's the stock part number for my engine 3929885.
When replacing the camshaft in a flat tappet system it's a good idea to also replace the tappets, some don't but I decided I would. I choose the 24V tappets (not common rail) that have a little wider surface area to better handle the load (CR 1.5" vs 24V 1.3" vs B series 1.1"). These are a drop in replacement. I suppose with a wider base it would actually open a tiny bit sooner and close a tiny bit later as it road the lobe to breath a tiny bit more. I made some wooden tappet tools to snug inside the tappet to hold them up when I was removing the cam and then hold up the new tappets when I was replacing the cam. They are 1/2" poplar dowels with a cross cut on the tip to fit inside the tappet. Easy to make and they worked great.
Once the dowels are inserted into the tappets they can be pulled up and out of the way to remove the cam. To keep them in place a rubber band can be used to pinch them together to keep the dowels from moving. Here's one of the manual images.
To get the tappets out a trough is used to catch the tappets or they'll fall into the oil pan from inside. I made my own trough from some air ducting. I then used some coat hanger to make long hooks as tools to persuade the tappets out. To fish the new tappets back in I made a little plug attached to a length of string that fit into the tappet from extra dowel pieces that would be snug but would let go once yanked. It actually all worked pretty good. I would use the coat hanger hooks for persuasion to tip them up as needed but it wasn't as tedious as I thought it would be.
For whatever reason I had bought a 6 pack of cam bearings back when I rebuilt my engine the first time. Since I had more and was installing a new cam I went ahead and replaced this bearing. I drove it out with a punch and tailored a driver from a flat piece and tube welded together to drive in the new bearing.
I used my press and popped the cam gear off the old cam and pressed it back on the new cam without issue. The new cam's lobes are a little wider than the original. I read some place where someone sprayed graphite (aerosol form) on the cam and then greased up the lobes. It was suppose to give the grease something to hold onto during the install so I gave it a shot. I did not see any abnormal wear on the old cam's lobes. I even measured it against my cummins manual spec and it was still just barely in spec. I figured this was not really the culprit but I was committed so I changed it out anyways. The new cam measured out better and some of the lobes on the old cam did appear to be starting the wear process so there's my justification.
I did have concerns with a pushrod or two so I ordered some new and improved ones from Smith Bros. for a much better pushrod than stock at a pretty decent price. In the foreground is the old pushrod where you can see some metal deformation. This may just be the manufacturing process. I did roll them on a flat surface and I couldn't see any big wobbles but having higher boost and running stronger valve springs it seems wise to strengthen these up.
With everything back together I poured a bottle of zinc additive in the oil to aid in the cam break-in. I did the 20-30 mins at 2000+rpm break-in and then changed the oil. I poured in another bottle of zinc additive to drive around with. As suspected this did not fix the midrange issue but these were the last parts I had not touched in the engine.
After all of this I decided to play with timing. Sure enough it appears I was running more timing than expected and after dropping down to the 15 degree range that solved my problem. I must have been in the 18+ range and with the timing advance on the VE pump it was definitely higher than that when pushing more rpm. Pretty silly but found the too high setting for my system/set up. With timing back in the 15 degree range my idle smoke is almost gone (once warmed up), boost pressure along with some power screw adjustments down is back to 50-55psi, egts came up just a little, and it quieted down a little. Overall driving rpm range feels stronger. It still puffs a little more black smoke on take off than I'd like but that may just be my compromise with a mechanical pump, bigger injectors, and fueling the compounds.
I drove it for a couple months and played with more fueling and turbo adjustments. I even started building a rear drawer/fridge set up and getting components to set up a rear power distribution set up. I even compounded the paint to clean it up a little. Then one day after I was under hard acceleration (a Toyota pick-up was being stubborn about me passing him), I got to a parking lot and noticed a couple drips coming from under the engine area. After I got home I tracked it down to a coolant leak... from the rear freeze plug... again.
In my hunt to find the culprit I started throwing more money at it. I had a theory that my camshaft lobes were worn out. I had another car in my past that exhibited some of the same symptoms of a funny/weaker midrange where the camshaft had seen excessive wear so it was a stretch. I really did want to grab a Colt or Hamilton but the funding just wasn't there so I focused on a stock replacement. I needed to get some parts out of the way to get access to the camshaft to swap it out.
I used this guy's thread as a guildline: Replace Your Camshaft, Lifters 'n Stuff . . . . - Dodge Diesel - Diesel Truck Resource Forums
I ordered a camshaft online and the wrong one came in so I returned that and went with a local supply house I've been getting a bunch of my parts from. They had one in stock so I grabbed it. Here's the stock part number for my engine 3929885.
When replacing the camshaft in a flat tappet system it's a good idea to also replace the tappets, some don't but I decided I would. I choose the 24V tappets (not common rail) that have a little wider surface area to better handle the load (CR 1.5" vs 24V 1.3" vs B series 1.1"). These are a drop in replacement. I suppose with a wider base it would actually open a tiny bit sooner and close a tiny bit later as it road the lobe to breath a tiny bit more. I made some wooden tappet tools to snug inside the tappet to hold them up when I was removing the cam and then hold up the new tappets when I was replacing the cam. They are 1/2" poplar dowels with a cross cut on the tip to fit inside the tappet. Easy to make and they worked great.
Once the dowels are inserted into the tappets they can be pulled up and out of the way to remove the cam. To keep them in place a rubber band can be used to pinch them together to keep the dowels from moving. Here's one of the manual images.
To get the tappets out a trough is used to catch the tappets or they'll fall into the oil pan from inside. I made my own trough from some air ducting. I then used some coat hanger to make long hooks as tools to persuade the tappets out. To fish the new tappets back in I made a little plug attached to a length of string that fit into the tappet from extra dowel pieces that would be snug but would let go once yanked. It actually all worked pretty good. I would use the coat hanger hooks for persuasion to tip them up as needed but it wasn't as tedious as I thought it would be.
For whatever reason I had bought a 6 pack of cam bearings back when I rebuilt my engine the first time. Since I had more and was installing a new cam I went ahead and replaced this bearing. I drove it out with a punch and tailored a driver from a flat piece and tube welded together to drive in the new bearing.
I used my press and popped the cam gear off the old cam and pressed it back on the new cam without issue. The new cam's lobes are a little wider than the original. I read some place where someone sprayed graphite (aerosol form) on the cam and then greased up the lobes. It was suppose to give the grease something to hold onto during the install so I gave it a shot. I did not see any abnormal wear on the old cam's lobes. I even measured it against my cummins manual spec and it was still just barely in spec. I figured this was not really the culprit but I was committed so I changed it out anyways. The new cam measured out better and some of the lobes on the old cam did appear to be starting the wear process so there's my justification.
I did have concerns with a pushrod or two so I ordered some new and improved ones from Smith Bros. for a much better pushrod than stock at a pretty decent price. In the foreground is the old pushrod where you can see some metal deformation. This may just be the manufacturing process. I did roll them on a flat surface and I couldn't see any big wobbles but having higher boost and running stronger valve springs it seems wise to strengthen these up.
With everything back together I poured a bottle of zinc additive in the oil to aid in the cam break-in. I did the 20-30 mins at 2000+rpm break-in and then changed the oil. I poured in another bottle of zinc additive to drive around with. As suspected this did not fix the midrange issue but these were the last parts I had not touched in the engine.
After all of this I decided to play with timing. Sure enough it appears I was running more timing than expected and after dropping down to the 15 degree range that solved my problem. I must have been in the 18+ range and with the timing advance on the VE pump it was definitely higher than that when pushing more rpm. Pretty silly but found the too high setting for my system/set up. With timing back in the 15 degree range my idle smoke is almost gone (once warmed up), boost pressure along with some power screw adjustments down is back to 50-55psi, egts came up just a little, and it quieted down a little. Overall driving rpm range feels stronger. It still puffs a little more black smoke on take off than I'd like but that may just be my compromise with a mechanical pump, bigger injectors, and fueling the compounds.
I drove it for a couple months and played with more fueling and turbo adjustments. I even started building a rear drawer/fridge set up and getting components to set up a rear power distribution set up. I even compounded the paint to clean it up a little. Then one day after I was under hard acceleration (a Toyota pick-up was being stubborn about me passing him), I got to a parking lot and noticed a couple drips coming from under the engine area. After I got home I tracked it down to a coolant leak... from the rear freeze plug... again.
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kcustom73
Stretched it...
I feel the pain. Finally get the 40 dialed in to see coolant dripping from below the fan shroud. Time to pull the rad again. Glad to hear you got it figured out.
Timing!!! Have you been measuring with the dial indicator adapter that screws into the bosch pump? I need to time my IP.
- Thread starter
- #2,352
No dial indicator. I had done the math on how much of a turn affects timing but I also jumped a tooth on the gear so that tooth jump must have been larger than research and I predicted. I'm sure others can run more timing but my setup seems to like the 15 degree range better.
- Thread starter
- #2,353
Well, here we go again. The only way to get to the rear freeze plug is to pull the engine. So I enlisted the help of my sweet wife when I needed another set of arms and yanked it out. From above it's hard to tell the freeze plug had moved but once I got the tranny adapter plate off it was obvious. JB Weld did not stop the plug from pushing out.
I was a little worried my JB welding experiment might make it hard to get the freeze plug out but it wasn't a problem. The plug came out easily by tapping in the top and pulling with pliers from the bottom and I was able to clean up the surface with a razor and sand paper.
Moving forward I needed a better solution than trying to fix a freeze plug in this hole. The higher power 6bt guys have already dealt with this by using a coolant bypass system. The reason I didn't go with something like this the first time is that my tranny adapter plate covers up the bolt holes used to secure a better block off plate. After reviewing more online images I saw that the that the 6bt guys have a factory tranny adapter plate (dodge) that doesn't use the top two holes on the back of the block. I figured that if these bigger, heavier, more powerful 6bt guys pushing crazy torque weren't having adapter plate failures that I could cut mine down with my lighter, smaller, less powerful 4bt and not run into any trouble. So that's what I did, I put together a coolant bypass system and cut off the top two bolt holes from my Cummins to GM adapter plate.
I ordered a block-off plate with a pre-tapped hole for 1/2 npt (ebay). I then read tons of threads about coolant bypass systems and decided I wanted to run with a safety valve rated to open at 35psi rather than 50psi others were running. There is no hard evidence but some suggested that regular rear freeze plugs on the cummins start popping out around 80-90psi. One might ask how a cooling system with a 15psi radiator cap can get up to 90+psi and the answer has to do with a couple of factors (simplified version): If the thermostat isn't open the radiator isn't able to actively bleed off pressure, pushing more boost/power creates more opportunity for the coolant around the cylinders to bubble/vaporize and that adds coolant pressure, the cummins water pumps flow a lot and add some rpms and it produces more pressure, and the way the cummins block coolant flows allow more pressure to build up at the back of the block. The real problem is pressure so relieving the pressure via a coolant bypass system at the end of the block is a better solution than just trying to get a tighter fitting freeze plug. Some clip the vanes on the water pump but I don't want to loose low engine speed coolant flow due to stop and go traffic and slow rock crawling.
While I believe I got a good safety valve, I didn't get the right kind. This one had a pull ring to manually actuate it. The problem is that the shaft is not sealed on the back side of the valve (coolant goes in the male threaded side, once 35psi is reached the valve opens and the coolant and pressure go out the female side, this side is then connected to the upper radiator side to keep the coolant in the system). Luckily I thought about this as I studied it in my hands before I installed it and modified it by cutting down the shaft, threading the hole and inserting a short screw. I then coated it all with JB Weld to seal it up. I was committed to use this valve instead of send it back so the lesson is don't start with this version with the pull ring in the first place.
I did run into a couple while-I-was-there projects with all sides of the engine easily accessible. One was the rear main seal. It did look like it was starting to leak.
Better to do it now. So I pulled it and replace it with a new one.
I spent some time cleaning up the adapter plate and the sides of the engine. Here's the new oil seal, adapter plate, block-off plate, and safety valve installed. Instead of nine bolts holding on the adapter plate I now have 7, probably still overkill. All bolts got red locktight.
Clearance for the block-off plate. I ground the top of the adapter plate down/out far enough to be able to remove the block-off plate in the future if needed without having to pull the engine. The block-off plate has an o-ring to seal but I also used some sealer to ensure no coolant leakage.
Number 2 while-I'm-there, Flexplate inspection. It's not flat anymore, and this one is suppose to be flat. You can see the space between the level and the center of the plate.
Also noticed some cracks in the flexplate. Not good.
My only option (thank goodness it is still available) was from Cummins. It was not cheap but I wasn't about to install a cracked flexplate so I ponied up and bought a replacement. I inspected the wave ring that bolts to the flexplate and saw no evidence of fatigue so it was reused. All bolts torqued to spec.
I routed the coolant bypass return, 5/8" hose, to an existing port going to the upper radiator. I added a Tee and a barb so I could use that one port for the return and my fan controller temp sensor. I might move the temp sensor over to the other side of the thermostat where my dash gauge sensor is located but for now this will work and it doesn't stick up far enough to contact the underside of the hood.
This is the small turbo's exhaust side gasket (outlet) that wasn't sealing very well anymore. I bought two of this same gasket and stacked them and install them both.
Another while-I'm-there were the oil drains on my turbos. I wasn't happy with the hose I used the first time and they were making a bit of a mess.
So I picked up some silicone 7/8" from source automotive that is local to me and re-did the lines. These were my bigger leak offenders and why I ended up cleaning the side of the block.
With all that done I put the engine back in and adjusted a few wires that I've wanted to clean up. Did a tire rotation and checked my rear spacers. It started right up and I took it for a spin. I have been experimenting with my big turbo's exhaust housing side though the vgt adjustment I have. I ran it up to an 18mm size and tightened it back down to 14 cm to see what that difference would do. After driving it for a week I gained 5 psi in boost pressure but basically shifted more of the work to the big turbo. I didn't notice much difference with the egts and I'm not sure it was any more peppy than before. Overall all it was feeling pretty good. After this week of commuting in it however, I noticed some loud engine noise at the end of the week when getting on the freeway upon acceleration. Then close to home it just got a lot louder in engine noise so I have since parked it.
I haven't found a smoking gun yet. I've inspected all the valve train with nothing out of place. I pulled the oil pan and inspected the oil with no abnormal metal shavings on my magnet. The trust bearing #4 is intact, no scoring on what I could see on the underside of the cylinder walls, camshaft looked fine. It started like normal and had normal power so the fuel system seems fine. I pulled my torque converter cover I made and watched it while it ran and it seems fine but maybe there's more there that I can't see. I'll keep looking but am afraid I'll have to pull the engine again to find it. For now it's holding down the concrete in the carport.
I was a little worried my JB welding experiment might make it hard to get the freeze plug out but it wasn't a problem. The plug came out easily by tapping in the top and pulling with pliers from the bottom and I was able to clean up the surface with a razor and sand paper.
Moving forward I needed a better solution than trying to fix a freeze plug in this hole. The higher power 6bt guys have already dealt with this by using a coolant bypass system. The reason I didn't go with something like this the first time is that my tranny adapter plate covers up the bolt holes used to secure a better block off plate. After reviewing more online images I saw that the that the 6bt guys have a factory tranny adapter plate (dodge) that doesn't use the top two holes on the back of the block. I figured that if these bigger, heavier, more powerful 6bt guys pushing crazy torque weren't having adapter plate failures that I could cut mine down with my lighter, smaller, less powerful 4bt and not run into any trouble. So that's what I did, I put together a coolant bypass system and cut off the top two bolt holes from my Cummins to GM adapter plate.
I ordered a block-off plate with a pre-tapped hole for 1/2 npt (ebay). I then read tons of threads about coolant bypass systems and decided I wanted to run with a safety valve rated to open at 35psi rather than 50psi others were running. There is no hard evidence but some suggested that regular rear freeze plugs on the cummins start popping out around 80-90psi. One might ask how a cooling system with a 15psi radiator cap can get up to 90+psi and the answer has to do with a couple of factors (simplified version): If the thermostat isn't open the radiator isn't able to actively bleed off pressure, pushing more boost/power creates more opportunity for the coolant around the cylinders to bubble/vaporize and that adds coolant pressure, the cummins water pumps flow a lot and add some rpms and it produces more pressure, and the way the cummins block coolant flows allow more pressure to build up at the back of the block. The real problem is pressure so relieving the pressure via a coolant bypass system at the end of the block is a better solution than just trying to get a tighter fitting freeze plug. Some clip the vanes on the water pump but I don't want to loose low engine speed coolant flow due to stop and go traffic and slow rock crawling.
While I believe I got a good safety valve, I didn't get the right kind. This one had a pull ring to manually actuate it. The problem is that the shaft is not sealed on the back side of the valve (coolant goes in the male threaded side, once 35psi is reached the valve opens and the coolant and pressure go out the female side, this side is then connected to the upper radiator side to keep the coolant in the system). Luckily I thought about this as I studied it in my hands before I installed it and modified it by cutting down the shaft, threading the hole and inserting a short screw. I then coated it all with JB Weld to seal it up. I was committed to use this valve instead of send it back so the lesson is don't start with this version with the pull ring in the first place.
I did run into a couple while-I-was-there projects with all sides of the engine easily accessible. One was the rear main seal. It did look like it was starting to leak.
Better to do it now. So I pulled it and replace it with a new one.
I spent some time cleaning up the adapter plate and the sides of the engine. Here's the new oil seal, adapter plate, block-off plate, and safety valve installed. Instead of nine bolts holding on the adapter plate I now have 7, probably still overkill. All bolts got red locktight.
Clearance for the block-off plate. I ground the top of the adapter plate down/out far enough to be able to remove the block-off plate in the future if needed without having to pull the engine. The block-off plate has an o-ring to seal but I also used some sealer to ensure no coolant leakage.
Number 2 while-I'm-there, Flexplate inspection. It's not flat anymore, and this one is suppose to be flat. You can see the space between the level and the center of the plate.
Also noticed some cracks in the flexplate. Not good.
My only option (thank goodness it is still available) was from Cummins. It was not cheap but I wasn't about to install a cracked flexplate so I ponied up and bought a replacement. I inspected the wave ring that bolts to the flexplate and saw no evidence of fatigue so it was reused. All bolts torqued to spec.
I routed the coolant bypass return, 5/8" hose, to an existing port going to the upper radiator. I added a Tee and a barb so I could use that one port for the return and my fan controller temp sensor. I might move the temp sensor over to the other side of the thermostat where my dash gauge sensor is located but for now this will work and it doesn't stick up far enough to contact the underside of the hood.
This is the small turbo's exhaust side gasket (outlet) that wasn't sealing very well anymore. I bought two of this same gasket and stacked them and install them both.
Another while-I'm-there were the oil drains on my turbos. I wasn't happy with the hose I used the first time and they were making a bit of a mess.
So I picked up some silicone 7/8" from source automotive that is local to me and re-did the lines. These were my bigger leak offenders and why I ended up cleaning the side of the block.
With all that done I put the engine back in and adjusted a few wires that I've wanted to clean up. Did a tire rotation and checked my rear spacers. It started right up and I took it for a spin. I have been experimenting with my big turbo's exhaust housing side though the vgt adjustment I have. I ran it up to an 18mm size and tightened it back down to 14 cm to see what that difference would do. After driving it for a week I gained 5 psi in boost pressure but basically shifted more of the work to the big turbo. I didn't notice much difference with the egts and I'm not sure it was any more peppy than before. Overall all it was feeling pretty good. After this week of commuting in it however, I noticed some loud engine noise at the end of the week when getting on the freeway upon acceleration. Then close to home it just got a lot louder in engine noise so I have since parked it.
I haven't found a smoking gun yet. I've inspected all the valve train with nothing out of place. I pulled the oil pan and inspected the oil with no abnormal metal shavings on my magnet. The trust bearing #4 is intact, no scoring on what I could see on the underside of the cylinder walls, camshaft looked fine. It started like normal and had normal power so the fuel system seems fine. I pulled my torque converter cover I made and watched it while it ran and it seems fine but maybe there's more there that I can't see. I'll keep looking but am afraid I'll have to pull the engine again to find it. For now it's holding down the concrete in the carport.
I love how easily you can pull out the engine when you want to. I can change oil with the same ease 
.
.
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Holy crap man. How many times have you pulled the motor now?
On an unrelated note I wanted to let you know I'm in the process of shamelessly copying your triple sticks.
On an unrelated note I wanted to let you know I'm in the process of shamelessly copying your triple sticks.
I feel your pain, if you end up needing hard parts for the engine get a hold of me before you buy anything, I had new or like new most of the parts you just bought I could send you.
kcustom73
Stretched it...
boots, sorry to hear about your luck. Having similar issues with my 40. Looks like I'm also replacing the flexplate. Good luck finding the problem.
Oh man Mike, this is not good.
- Thread starter
- #2,359
Thanks all for the support and offers. I've certainly pulled the engine more than I want in a year but sometimes that's the only way. I'm considering dropping the tranny next time if it ends up being something with the flexplate. The worst part for me is dealing with the fluids. Usually if there is a problem after I've worked on it it's been something that I've touched last so internal engine drama this round doesn't seem likely nor have I found any evidence to support internal damage. I don't know... I think I'll take a few more days off from it.
- Thread starter
- #2,360
It looks like your lever mount base is nice and strong, my first version was too wimpy. One thing I can think of is if you can get away with straight links it might be better (put the bend in the lever and not the link) or at least use a little thicker links than I did. I'm excited to see your improved version.