[Nascarmark]

Hi Tim. Received your message. Anytime an injector bubbles, it's because the sealing washer isn't sealing correctly to the cyl head & cyl pressure & fuel is getting past the copper sealing washer.
In most cases it's due to the cyl sealing area is no longer a nice smooth surface. Whether rust, dirt or soot has contaminated the surface. Usually rust has eroded the sealing surface some. Some get lucky by just torquing the inj down an additional 5ftlbs or so. So instead of 42ftlbs, go to say 50ftlbs. If that doesn't seal it, you will have to pull inj & clean cyl bore bottom with a bore brush or in worse case a flat head screw driver.

 

[T_Swindler]

I saw this online: Injector hold down nut torque? | Dodge Cummins Diesel Forum (cumminsforum.com) I am not sure this is the way to go as I believe in torques that the manufacturer recommends.

 

[T_Swindler]

Thanks Mark,

I was reading some information online and some have gone up to 70ft-lbs. Not sure I would go there. I will add a few ft-lbs to see if it seals. The head is new. The seals, injectors are new. I used the proper torque on each bolt and nut. In short, it should have worked.

 

[GLTHFJ60]

edit: nevermind

 

[T_Swindler]

GLTHF J60: You are always welcome to post here. I read some of your past posts on other threads. Your input is valuable.

I torqued to 55ft-lbs. that should do it. If not, I will pull the injector and clean the bore.

I am adding a temporary radiator mount. I want to run the engine until Hot to see if that tiny bubble on the head gasket will go away. Heat may be the answer.

 

[char1355]

If you were running without coolant then the head gasket leak must be oil. Not very common to see oil leaks there. The pressure for oil is nothing compared to cylinder pressure.

 

[Nascarmark]

New cyl head doesn't mean perfect surface in inj bore but yes, 55ftlbs won't hurt anything & most likely will do the trick.

 

[T_Swindler]

Charles: Maybe oil or maybe not. Could have been a cleaning solution, condensation and it was the size of a pinhead. Saying that, it probably was residual oil when I removed the valve cover to fill the engine. A few drops may have spilled over to the head. I do not suspect an oil leak though. I will run on Sunday after I connect the radiator and recirculate the power steering pump to allow the engine to heat up and see it seals. Some 409 can be used to see if the small bubbling remains. I will post a short video as well.

UPDATE: Sunday came and the weather did not cooperate. I lost my help to push the engine out of the garage as well. I will repost when I get this last run in.

 

[T_Swindler]

I was finally able to get a good weekend day and start the 4BT. Started right up. No leaks of any kind. The engine started at 50psi at idle. After warming to about 170 degrees it went down to 38psi at idle and 58 psi when revved a bit. Now that the engine is complete, I have started disconnecting the wiring harness from the 6.2 and will pull the engine next weekend (weather permitting).

 

[T_Swindler]

I am thinking back to the engine test run yesterday. I noticed that the transmission adapter plate was too hot to hang onto after the engine was warmed up then shut down. I couldn't hold onto it with my bare hands and had to use a few rags to hang onto it. Also, while the engine was warming up, I opened the radiator cap and added distilled water to top it off. The system was full at that point. I then noticed water spitting from the vent below the cap every few seconds. Probably nothing on both accounts. The hot adapter plate was noticed when I tried to pull the engine back inside the garage. The adapter plate seemed to act like a big heat sink for the engine. The water spitting from the radiator fill neck vent is probably due to a faulty radiator cap—just observations post-run.

 

[Russ McLean]

.... The water spitting from the radiator fill neck vent is probably due to a faulty radiator cap—just observations post-run.

1. The coolant expands as it heats up, and the over pressure pushes liquid out of the fill neck vent. If you have a catch can (a.k.a overflow bottle), the engine will siphon the coolant back as the engine cools off.

2. On the radiator cap, check the brass disk on in the center of the round rubber seal. The brass disk should be spring loaded against the rubber seal. If it is dangling, replace the radiator cap.

 

[T_Swindler]

YUP, thought of that too. Since I filled the system to the max capacity, the expansion left the coolant nowhere to go until enough pressure built to overcome the spring force in the radiator cap. Thus the spitting of fluid. The cap in actuality probably works just fine.

 

[char1355]

Glad to hear things are coming together. On the hot adapter plate, you must remember if the engine temp is at 170 deg, that area is probably 20-30 deg hotter. The back cylinder of a 4bt gets hotter due to the way the coolant circulates. So that piece of aluminum could be up in the 190-200 deg range. A bit toasty for the bare hands.

 

[T_Swindler]

On to the next issues. I was looking at Johnpp77 build (85 Chevy 4x4 4bt 4l80E). He talks about his adapter plate and how it was .037 out of tolerance. 4 torque converters and another transmission later worked it out. I purchased an adapter plate and reported that the starter's bolt holes needed to be drilled out a bit for it to work. I decided last night to pull the trigger on a Destroked adapter. I never heard of a problem with those.

I mounted the AC compressor today as well. Needless to say, my belt is too short, and the belt tensioner for the main belt is in the way. The pulleys do not align true as well. What do you all think of the idea of moving the tensioner over 1-1/2 inches?

 

[T_Swindler]

Charles, funny thing - the water temp probe was at the back of the engine. I thought the adapter plate wouldn't be that hot, but it was toasty.

 

[T_Swindler]

Pulled the old drive train today. I will start prepping the frame and getting ready to drop the 4BT in.

 

[char1355]

On your tensioner issue, there are at least 4or 5 different designs. The one you have is Cummins EH97116 shown in the first photo below and that one was used the the accessory pulley setup. Alternate mounts were EH97034 shown in the second photo and EH9705 in the third photo. Not sure if either of those move the tensioner any significant amount. Your issue is that extra tensioner for the V belt which pulls the belt into a higher position causing the interference. 4bts with accessory ac or vacuum pump didn't normally have that. Their tension was adjusted in the bracket itself. Below is a photo of a CPL767 with the vacuum pump and it has the same tensioner setup you have. Not exactly sure how to cure this. One option could be a fairly uncommon accessory pulley that mounted on the crank instead of the fan. Don't know the part # for that one and it is rarely seen. There is one twin groove crank pulley which is a marine item and it's as expensive as hell. Like $800. You mentioned the belt not lining up correctly. Is your ac bracket a Cummins item or an aftermarket? Could be you just need a different drive pulley or maybe a spacer. If I were going to guess, I'd think the EH9705 would have possibilities. The tensioner on that one mounts to the left side of the holes that attach it to the head where the one you have places the tensioner to the right side of the holes. That would probably give you the 1.5". Here is a list of the parts for that one. Bracket 3919736, tensioner 3922900, tensioner bolt 3904446, and bracket bolts 3925186 (2 req). Like I said this is just a guess.

 

[T_Swindler]

This is a dilemma. The A/C compressor bracket is aftermarket. Looking at it, I considered welding another plate to the bottom of the compressor bracket and redrilling holes to move the compressor out an inch, but that would not solve the pulley issue which drives the compressor. Another thought was to move the tensioner over about 1.5 inches. I guess more thought is required.

 

[Russ McLean]

Three dimensional Tetras....

 

[char1355]

On the belt issue, is the compressor groove closer to the cab or farther forward. If it's forward you can possibly space the Cummins pulley out or possibly even flip it depending on how much misalignment you have. Wonder how the company who made the bracket intended to drive it? Like I said, that EH9705 might accomplish getting the tensioner out of the way. I'll try and look tomorrow and see if I have one of those. I have one of that style but it may be the EH97034 which won't help any. Those darn brackets are kind of expensive considering they are nothing more than some steel plate with a few holes in it. I looked back at some old photos and I believe this is the EH9705 setup. If you look the center of the tensioner mounting point matches the center of the water pump so you could get an idea of how far over it is compared to what you have now.