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Discussion Starter #262
Thank you char1355. I am a jack of trades and master of none. I did pull the trigger on a new exhaust manifold. I found an aftermarket on Amazon for $129.99. After considering your previous post about my particular exhaust manifold; I thought about how a turbo at an angle could prematurely wear out. After consideration I thought that the weight of the shaft and impellers could put some pressure on one side of the bearing which wouldn't be a problem while running but could wear the bearing after the oil drained from the bearing at shut down. Starting the engine and the turbo beginning to rotate might cause some premature wear on the side of the bearing with pressure. This is just speculation on my part. I finished timing the injection pump tonight after work.
 

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That manifold is basically the one that replaced yours. Swings the turbo out from the block but doesn't have the downward tilt. It can be interesting because that one in reversed position can work in a twin turbo setup. Puts the small turbo up front, leaving room down below for the 2nd one. The regular down manifold won't work that way because the top turbo will hit the #1 injector. I have one of the ones like you have. If you want to try something for adding just a small bit of performance, do a little porting work. Lay an exhaust gasket on the manifold and mark the port area. You could also bolt on a gasket and spray paint over it to get a reference. Then just smooth out the area removing the marks. Do the same thing on the head only leave the marks. Don't do anything on the ports where the turbo mounts. You want to have around 1/16" or a tad more smaller port in the head than the manifold. Going from the smaller to larger opening increases gas flow slightly and can improve spool response. It won't be night and day difference but every little bit helps. Even if you don't touch the head and just even up the ports in the manifold can help. This is very minor porting work because you're just doing the opening area and not going up inside.
 

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Discussion Starter #264 (Edited)
Just use a small drum type grinding wheel? Also, do you have a suggestion of where to drill the hole for the pyrometer? It seems this manifold divides the cylinders 1 & 4 from 2 & 3 (by looking at the pictures.) Not sure if this is true, but it leaves the pyrometer placement in question.
 

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On the porting you can use a grinding wheel. I used a carbide burr to lightly rough it out because those cut very fast. Just don't want to overdo it. Then finished with a grinding stone. Don't really have to polish these areas. I've done porting on gas heads and the final surface ended up looking like a mirror. Lot of difference in gas vs diesel. On the probe, in theory you want it in the #4 cylinder port which is the hottest. Might run a flexible wire into #4 port and see which one it exits in. There are a couple of theories as to the probe placement. Some say put it about 1.5" from the flange in the center of that port. I've seen others put the probe in the #4 channel near the head. Below is a link that says the best place is 2-4" from the head if practical. Near the turbo is by far more common. Near the head would probably be a bit higher reading. Now, if you follow Cummins recommendation, they say to put it in the exhaust pipe after the turbo. Their reasoning there is if the probe should happen to break it won't get into the turbine wheel and cause turbo damage. Probably doesn't happen all that often but Cummins is thinking the safest scenario. Only thing there is you must remember that readings after the turbo will be several hundred degrees lower than pre turbo. So if you want to set an upper limit of say 1100 deg you should think more like 900 deg after the turbo. If you ever see Cummins recommended temp levels they seem awfully low, but they are after turbo. The Sensor Connection EGT Probes Motorsports Sensors and Gauges
 

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Discussion Starter #266
Definitely something to think about. I was considering putting near number 4 cylinder but wouldn't the probe create some sort of a restriction for the cylinder measured? I like the porting idea as well. When you said "Lot of difference in gas vs diesel" what does that mean?
 

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The gas engines I was working on were carburetor equipped and no super charger or turbo. The smoother the passages are in the intake and exhaust the better the flow. I guess you could polish the exhaust ports in a diesel but must be careful as you can achieve negative results. We seldom see any porting work in the valve area on diesels. That's a different area and my little knowledge was just on gas engines for polishing. I balanced combustion head chambers within 1cc but that is in the pistons on the diesels. There was an engine shop beside my house for about 60 years. The part I mentioned is just evening up the exit ports on the head and inlet ports on the manifold. Factory castings are often a bit off. I don't think the EGT probe would prove much of a restriction in the #4 runner. Those things aren't big. There's another thing you can do to improve turbo performance if the bank account allows. That is ceramic coating the exhaust manifold and turbine housing. That heat is the energy that drives the turbo and keeping it in helps. Those coating come in all types and grades. Good ones are not cheap. Might cost near $1000 to do a manifold and turbine housing in the good stuff. There's a company in California that Jay Leno used on his Doble steam car that has some of the best. I think their heat rejection was like 6000 deg F. He showed putting an acetylene torch on a 1/8" steel panel and you could put your hand on the other side and it was cold. This is super space age stuff and I wouldn't even guess how much that costed.
 

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Discussion Starter #268
Thanks for the explanation. I don't think that ceramic coating is in my immediate or far future for that matter. This project is already over cost. I believe the engine is going together correctly and no reasonable expense was spared on the drive train. I am just learning as I go, but have the basics in hand.

I am looking at cutting up the pan a bit to clear the front differential. I purchased a 6bt oil pick up tube and will do what Johnpp77 did on his (see thread: 85 Chevy 4x4 4bt 4l80E) pan and pick up tube. I don't have a MIG welder though. I am a stick guy, but was reading the E6013 welding rod may to the trick. I can also braze. Should be interesting. that being said, I have a few seals and parts coming in to finish the engine. Hate to see this end. I have enjoyed it immensely. This also means I will dig into the areas which I am weak in, such as wiring and electronics (not to mention welding).
 

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My only welding experience has been stick as well. Welding something as thin as an oil pan isn't easy. Might need to find a good welder for that job. Brazing would probably be safer.
 

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Discussion Starter #271 (Edited)
Been watching welding videos :unsure:. I have stick welded before but my skills are sub-par at best. I will test out on other pieces of metal to see if this is doable. My welder can also TIG but I do not have much experience there either. So I will test my skills at the three processes (TIG, Stick and Braze) and go with what seems to work best. Otherwise, I will take the pan and oil pick-up tube to someone who welds professionally (y). I must admit I am looking forward to the challenge though.
 

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TIG welding is very much like gas welding, get some junk tin similar wall thickness to practice on.

Ed in CO.
 

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Discussion Starter #274
Thank you edpruss. I will try that. It seems to be a better solution than the rest. I will still attempt all three processes though. I have the welding rod and bronze rods for brazing.
 

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Discussion Starter #275
I received the fuel seals yesterday. I feel like I need to go to confession after the work I had to go through to get those buggers on. It was a colorful event to say the least, especially since the ends of the tubing is flared. Fitting a seal over a flared connection is challenging at best. They are on now. :D
 

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Discussion Starter #276 (Edited)
I received the new drive rivets to remount the label plate on the rear of the block. The screws I ordered were listed on the Cummins Website.
Cummins Part List.jpg


So I order 3908612 Drive Screws, Right?

3908612 Drive Rivet Screw (2).jpg


Turns out these things are miniscule. Way too small for the label plate.

4BT Drive Screw and Plate (2).jpg


Shown is the back of the label plate and the drive screw that it is supposed to be used. Not sure what screw to use now. Any ideas on the correct drive screw and where to get them?
 

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I checked another engine on Quick Serve and it shows those same rivets. The holes in your ID plates have gotten enlarged over time. Might want to put the plate on a piece of flat steel and hammer out some of those wrinkles. Could possibly attach it back with silicone. Do the hole sizes in the gear housing fit those little rivets? If you wanted to get fancy, you can get a new ID plate since you have the old one. No idea what one costs. Not even sure it comes with all the data stamped on it. May be a do it yourself job.
 

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Discussion Starter #278
The holes have enlarged probably due to vibration against the soft aluminum metal. These drive rivets are too small for the holes. One hole still has the old rivet inside of it. Look like it broke off at the machine shop. The plate was riveted on when delivered to them. The plate is okay, a bit hard to read, but readable in the right light and angle.
 

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Discussion Starter #280
Great idea. I will see if I can get the remnants of the old rivet out and start looking for those.
 
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