No updates on the teardown yet, but I'm pretty sure I was being a bit dense when I pulled the original built engine. I'm hoping that I was just being over sensitive, but I think what I may have been hearing was something exhaust related. The 5.3 went in and made the exact same sound.

 

Mazda's actually doing closed loop combustion control in their SkyactiveX engines - I've been looking for sources on where to buy the sensors, but the only place I've been able to find them quotes them at around $600. Might be worth keeping an eye on junkyards to see if I can pick one from a scrap rig.
Beru/Federal Mogul also has a pressure sensing glow plug that gets used in some diesel applications too - take a look here: They're cheap too. Looks like about $100 per sensor. I bet they could be used in gasoline applications if the glow element was disabled/disconnected.

 

Not the highest quality post, but found this interesting. Here's some pics of the internals of a spark plug. I hacked a few apart to see if I'll be able to stuff the ceramic into a different housing to give the pressure sensor a bit better path for the pressure to travel similar to how the Kistler transducers offset the ceramic to the side of the plug hole and the pressure port gets bored directly down into the chamber side of the plug. It might not be worth the effort but I'll probably consider it at some point if the signal quality isn't great with the side port.
Pics: Hot, GTO OE Denso vs BR7EF. Interesting to see the difference between a hot and cold plug.

 

What transducer is that?

 

That's the Optrand PSI plug. 0-200 bar, M3.5 fiber optic sensor piggybacked on a standard plug. Should be more portable than the Kistler piezo one I had before.

 

Ah, interesting. I wonder if they don't have the same sooting issues as the Kistlers do. Those are pretty different all around.

 

I'm honestly not sure. I haven't ran the Optrands long enough in the past to check soot accumulation, but this time around should be a little different. I'll keep an eye on it every time it comes out - should be an easy check.


In other news...a somewhat shameful picture, but kind of a big sigh of relief.... I found the knocking in the 6 liter. Oops. The good news is that it didn't rattle around the engine and just stuck in the windage tray. It would barely graze the rod cap every revolution and that was the sound I heard. I got really lucky.

 

Oops!!

back in my Saturn days someone left a 15mm socket in a transmission they took apart. For weeks they posted about this noise and all of us said "oh it's just common diff pin noise"

about a thousand miles later; a 15mm socket spit out the side of the case and wrecked everything inside on its way out

sometimes we gotta learn the expensive way 😖

 

Hey Ckirley just checking if you have made any more progress and wanted to express my interest as I think we can learn some stuff here.

Also if you need any FEA done I can help, or maybe making simulink models as well, although its something I struggle with I am always trying to learn but I have done some basic things like timed reservoir blowdown and selected choke sizes and stuff like that that you can back up with empirical hand calc formulas.

Also checking to see if you need anything maybe I could donate to the cause? I can't really think of much I have now that would be of any use though.

 

Hey all,
Sorry for the lack of replies - life has been really busy lately. Between moto and work, I haven't had much time to work on this project lately. The good news is that things are starting to calm down a bit so I can start to get things back on track.
In the last couple months, I've hit a couple speed bumps with the indicating system. The Optrand had some issues with the electronics and had to get sent back to the manufacturer for diagnostics and repair. Hopefully it's something small.
I've also been working with a start up company called BDN Automotive to evaluate their CA-6 combustion analyzer on the Gen 3 LS. They were able to get the 24X trigger wheel pattern built up and functional but I'm waiting on the return of my Optrand for beta testing to begin. I'm hopeful that this thing will work out well - for 1900 Euro it's pretty close to unbeatable as far as price goes and would save me a massive amount of time in developing my own indicating system. The guys at BDN have been pleasant to work with and have been able to develop additional functionality when needed. Apparently the 24X trigger wheel was a big tear up to their angle calculations in the software but they didn't hesitate to support it. I'm hoping the accuracy is there too - I'm benchmarking it against some AVL stuff at work to back up their claims (within 2-3% of the really expensive blue stuff). If things work out I'll probably end up picking one up and doing some contract calibration work on the side to pay for the equipment.
Link for those who are interested: https://bdn-automotive.com/products/combustion-analyser

Jclark, thanks for checking in and the offer for help. I may take you up on some of the Simulink stuff at some point, but I need to finish up some of the stuff I started before I proceed with new stuff. I figure that troubleshooting code or PCB issues aren't much added value to this forum but I'll try to keep things better updated with truck related stuff as I finish it.

Hopefully I'll have more updates in the next couple months. If you don't hear from me, I'm still working on the project

-Cal