Cummins 4BT & Diesel Conversions Forums banner

281 - 300 of 318 Posts

·
Registered
Joined
·
412 Posts
I'd say you could either go to a trophy shop and have another tag engraved if you are set on having the tag on the engine or just hand engrave the CPL on the engine. Mine was long gone on mine. No CPL was a bummer but I have managed without.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #282 (Edited)
Had to drill out one rivet on the rear of the block and a partial on the other. The side of the block with the exhaust manifold rivet hole for the data plate is short of 1/2 inch deep. Seemingly a rivet #9 x 1/2 inch should work (or self tapping screw). The other side is a different story. Nothing was behind the rivet. The drill bit fell in about 2 inches 😯 after I drilled throught the rivet. I wondered if the hole was intentionally that way or a previous owner drilled through to the tappet area. Now, i am not sure I went to the tappet area as I did hit something hard. That is scary at best when drilling through. I will seal this with a drive rivet or screw to be sure. 😁 5/18/20. I have positioned the engine with the flywheel up. I blew into rivet hole and it looks like the water side of the block. I will be able to tap and plug, hopefully with the data plate connected as well.

Elbonk, the tag is readable and reusable. I have to add a washing to one side as the hole is broken open at one side. I do like the additional information on the tag. If I could get another Cummins tag (blank with the categories) and have it engraved that would be cool.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #283 (Edited)
When installing the front seal, do you use sealant around the outside of the seal? I have watched Youtube videos which the installer states it is dry and others state RTV sealant goes around the outside.

Found a youtube video that explains it. The answer is sometimes you do and other times you do not. It depends on the seal.

Here is the Youtube video:
 

·
Registered
Joined
·
11,353 Posts
On the front crank seal, that just goes into the front housing dry. Not likely to leak where it contacts the housing. The one big issue is make sure the crank is totally clean and dry. There must be no oil or grease on that surface or the seal is guaranteed to leak. If the crank area is a bit worn or rough you'll need to install a sleeve and that will require a matching seal for that purpose.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #285
Thanks Charles, Got the seal and sleeve. I just received the install tool for both. Probably didn't need to, but they should (hopefully) guarantee success.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #286 (Edited)
In an effort to clear the front differential, I decided to modify the pan as Johnpp77 in his build thread: 85 Chevy 4x4 4bt 4l80E I did not finish the pan but got as far as cutting out the pan and fitting up what needs to be welded. Somehow ended up with a sprained right knee.
 

Attachments

·
Premium Member
Joined
·
221 Posts
Discussion Starter #287
I attempted my stick welder and found out that it wasn't a great choice on the practice welds. I picked up a flux core welder and will begin practicing using it before getting to the oil pan and pickup tube.

Switched gears due to the rain. Started working the fuse panel project. Still hoping it works out. I started by scanning the fuse panel to get an actual size. Pixel by pixel, I labeled the drawing. I finally printed it and cut out the sections I needed after laminating the whole panel. I do not recommend laminating the the fuse panel drawing. As soon as you cut it out the laminate comes off. I used DAP Rapid Fuse Glue which is better than super glue. I will spray some clear laquer on the panel to (hopefully) seal the new labels.

Not the greatest job, but it will be hidden from view. I was ultimately trying for functionality.
 

Attachments

·
Registered
Joined
·
11,353 Posts
Don't need a sprained knee. What are your plans for the drain plug? The 6bt had theirs in the bottom but I believe it was a flush mounted plug. If you don't plan on climbing over rocks and stumps you could mount your old plug down below. You mentioned the pickup so I guess this cut means it gets modified. On the welding, did you think about maybe taking it to a muffler shop? Those guys weld thin metal all the time and it needs to be leak free.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #289
Past the sprained knee. Now have a left shoulder issue. Not sure what is going on. I do like the idea of a muffler shop but do want the first crack at this. So far the engine has been all me save my neighbor who helped lay the head on the block and the machine shop who did the machining.... and the welder who welded my tappet cover vent together. As far as the oil pan, I have moved the drain caddy-corner. I am not a rock climber or anything else of the sort. This will be a daily driver and that is pretty much it. I have an issue with the rivet that I was dealing with earlier. It seems part of the old plug or rivet is still in the hole and I will need to drill, tap and plug. I was disappointed that the last person who worked on this engine tried to drill the rivet and drilled through to the water passage. It is what it is.
 

Attachments

·
Premium Member
Joined
·
221 Posts
Discussion Starter #290 (Edited)
Well I have given my best at welding the pan and learned a few things. If anyone will ever weld their pan, the stitch weld is the weld to do. The pan is 18 gauge metal and prone to burn through. Due to thickness you cannot run a bead. To accomplish the weld you will need to tack the cover or part to be welded several times around the perimeter. Then tack between the tacks and so on until it is welded around the perimeter. A MIG is preferrable with a 0.23 wire. I have flex core with a 0.30 wire. The weld is not pretty (nor should it be) so I used a 4-1/2 inch grinder wheel to grind the weld down. Once you look from the other side you will see the pin holes where the weld did not fill in. Luckily by that time you have enough thickness of the base metal to put a bead down and seal the pan. The first picture is the pan welded and the second is the flip side that shows the miniature holes that need to be welded afterwards. Now on to the oil pick up tube.
 

Attachments

·
Premium Member
Joined
·
221 Posts
Discussion Starter #291 (Edited)
Been busy since the COVID came out. I am working on the front pulley/harmonic balancer and engine mounts lately.


First the mounts. I found a G-Force adapter which turned out to be from an estate sale. Since the engine will now be upright, I needed to make new engine mounts. These are not complete, but they are close.
128662

I modeled them after the original engine mounts. I have to get the passenger mount straightened out and weld both. Progress is being made.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #292
Next was the front pulley. I decided to purchase a balancer/pulley from a 6BT to help smooth out the engine. I then had an idea to add a tone ring to pick up a tach signal. I couldn't fit the tone ring on the back of the balancer/pulley, so I put it on the front of the pulley. I had to design a 3/4 spacer to bring the outside circumference of the tone ring off of the balancer.
128664
128665
128666
128667
128668
128669
II topped it off with a barring tool.
 

·
Registered
Joined
·
630 Posts
Yep. that barring tool is pricey, but it sure is handy. You'll find out the first time you adjust the valves. I'm glad I have one on my 12 valve.
 

·
Registered
Joined
·
11,353 Posts
Don't feel too disappointed if that harmonic balancer has little improvement over the stock. A 6bt balancer for a better word is tuned differently. A 4bt doesn't have harmonics like a 6bt. There is a specific balancer made for a 4bt that does help. These were found on marine engines. They are a fluid type balancer rather than the rubber type with a metal ring. One of the big differences is weight. The unit weighs around 26 lbs and mounts in front of the factory pulley with an adapter. The company Fluidampr makes an identical unit called their competition model. They also have one with the pulley attached that is specified for the 4bt. We have several members who use the factory 4bt unit but the main hold back is cost. The factory units is in the $600 range and the Fluidampr units maybe $100 cheaper. The Cummins part # for theirs is 3925233. The adapter plate is 3968954 (old part # 3924579) and the bolts are part # 3924584. Here's a photo of what the kit looks like.
 

Attachments

·
Registered
Joined
·
630 Posts
While the 6BT dampener may not be ideal for the 4BT, here's testimony from Randy that it does help reduce vibrations.


Based on his testimony (and the ridiculously low price I paid), I purchased a used balancer from a 1995 12 valve for my upcoming 4BT conversion. T_Swindler, I see your dampener doesn't have notches. Is it from a 24 valve engine?
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #296
95Z28A4, I am not sure. If I remember right, the advertisement just stated 5.9L. It was $100.00 so I wasn't expecting too much. Thanks, Charles. The price of the fluid damper is out of my league at this point. I am just hoping this does something. Admittedly, I was just trying to pitch the tone ring idea. Finding a way to mount it to a 4BT solves the issue of the tach signal. I would have been much cheaper to go with an alternator signal, but just did not want to go there.
 

·
Registered
Joined
·
11,353 Posts
The 6.7 damper is a fluid type and has a tone ring built in. However, there are clearance issues with that one on a regular B series engine. The main improvement will come from adding mass to the crankshaft. Those extra pounds do have some effect, just not as much as the fluid type.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #298
Thanks again Charles, that is probably close to what I picked up. The damper and the tone ring were a used set I picked up on eBay. Per the original design, the tone ring fits on the back of the damper and both bolt to the crankshaft. Clearance was in the issue. The damper/tone ring would need a spacer behind it to work but then the belt alignment would be an issue. That is why I am using a 5.9 damper with the tone ring on the front. I just had to do a quick design of the spacer to accommodate the tone ring to mount it on the front. Saying that I agree that weight on the damper will have some effect on the engine.
 

·
Registered
Joined
·
11,353 Posts
Sort of curious where you got the bolts for the new setup. Those bolts are a special thread and extremely high grade. On the Cummins 4bt damper the only source I ever found for those was Cummins. Yours may actually be about the same length as those since you had that adapter on the front. Those 3924584 bolts are M12x1.25x60 mm flange head grade 12.9 or higher. Also probably one of the 2 places on the engine where red Loctite is recommended. The other is the flywheel bolts.
 

·
Premium Member
Joined
·
221 Posts
Discussion Starter #300 (Edited)
Sort of curious where you got the bolts for the new setup. Those bolts are a special thread and extremely high grade. On the Cummins 4bt damper the only source I ever found for those was Cummins. Yours may actually be about the same length as those since you had that adapter on the front. Those 3924584 bolts are M12x1.25x60 mm flange head grade 12.9 or higher. Also probably one of the 2 places on the engine where red Loctite is recommended. The other is the flywheel bolts.
I believe I have M12x1.25x50. The bolts are 10.9 grade. But after comparing the old bolt
128681
...


128680


To the new bolt...
128683

128684


128685


It looks like I will be re-thinking this a bit.

After measuring I will need an M12x1.25x70mm Bolt. The only issue is strength. I cannot find a 12.9 so you are correct. I don't believe there is anything higher than a 12.9 as it exceeds a grade 8 bolt. The 10.9 is comparable to a grade 8. Looking at torque values the front pulley bolt torque is 92ft lbs or 125 Nm. The recommended torque for a 10.9 M12 fastener is 135 so it is within the limits of the bolt. The 12.9 M12 recommended torque is 160 Nm. "There is no technical advantage in using a property class 12.9 fastener when it is tightened to a level that a lower strength fastener could sustain." Technically, a 10.9 will do the job and in the absence of a comparable 12.9, I will have to use the 10.9. Great question as it made me think it through, measure, research, and order the correct bolts.
 
281 - 300 of 318 Posts
Top