Piston Bowl De-lipping

Countrycar · Jun 28, 2020

Just wondering guys if any of you know of, or have experience here to share about the de-lipping of the Piston Bowls. Basically I understand the process of de-lipping is done to keep the pistons from cracking under extreme heat and pressures. But my question is more to the de-lipping of the piston bowls causing idle haze as well as haze and or smoke under light throttle conditions. I have what to me is a little more idle haze and throttle tip in smoke than I'd like see. From reading and some research I've read where some builds run very clean, and others seem to run just as mine does, so I'm trying to gain some knowledge and understanding as to what is causing these problems. I've checked the compression and all are 410-420. I've done extensive visual checks for leaks in the system and it looks tight thru-out. I'm going to do a boost leak test next weekend when I get a bit more time to do so, but the system being tight and with no leaks, would the piston bowl de-lipping cause these issues. I was currently watching a guy named Brandon (The 7.3 Garage) from the Florida area who recently did a rebuild on his engine and he's basically running my same build. I don't know just yet if he did the piston bowl de-lipping but his truck runs very clean compared to mine.
I also currently watched an interview of another guy on Youtube that upon doing a second build on his truck, he mentions not doing the piston bowl de-lipping as it tends to cause idle haze as well as throttle tip in haze etc. So this is the only info I've managed to pull together in my effort to find out if the de-lipping can cause this problem. Thank you to anyone that can provide some info on this.
The following is my build.
300/200, BTS twins, HV-lpop, sxe 472 trubo, pistons bowls are de-lipped w valve reliefs cut in and ceramic coated, & dry film piston skirts and bearings, PP heads, Fass fuel system.

Magnum PD · Jun 28, 2020

200% nozzles don’t help either but I believe the bowl can affect the smoke issue.

Countrycar · Jun 28, 2020

Magnum PD said:
200% nozzles don’t help either but I believe the bowl can affect the smoke issue.

From what I'm reading across the Internet the delipping does seem to have an affect on the issue of idle haze and tip in smoke. I'm going to keep searching on this, and hopefully and I can figure it out. I recently had this conversation with Carson a few weeks back, and he did mention to me that he's got a couple of buddies that are running 3/2 and 4/4's or 4/2s, but that they all run extremely clean in a DD tune. Something I thought I was going have on my own build, but as you can see no so much. In hind sight, I wish I'd of known this before I did my build. I don't think it'll to long before I pull the engine and make the necessary changes to fix this issue. At this point I'm just gathering information. It'll also give me the opportunity to change out my cracked block as well. :toast: Thank you Magnum.

sootie · Jun 28, 2020

Tuning.

lincolnlocker · Jun 28, 2020

Yep. What sootie said. Tuning plays a big part of the entire equation. Always has. Always will.

live life full throttle

Countrycar · Jun 28, 2020

I agree fellas that Tuning plays a very important part in the equation, but if there's a mechanical issue, NO amount of tuning is going fix it. I get it I'm running 3/2 injectors and they tend to haze and or smoke some. But when I hear of others running my same set up, and or bigger injectors than I run and running cleaner than my setup, then I feel I need to do further investigation as to where my issue might be. I had my truck live tuned by Matt, so in my opinion it doesn't get much better this. I hope to get my truck on his dyno this year, to do further testing and adjustments to the tuning itself and see what more we can do. I was just wondering if anyone had any relative experience with piston bowl de-lipping.
I've also ran other tunes just to verify, and the truck either smoked worse, or ran like a neutered turd.

Garbage_Mechanic · Jun 30, 2020

According to Swamps back in late 2017 when they built my engine, there was no negative effect of delipping. Don’t have I running yet so we will see. With 160/30’s and ported heads I expect very clean exhaust.

Countrycar · Jun 30, 2020

Garbage_Mechanic said:
According to Swamps back in late 2017 when they built my engine, there was no negative effect of delipping. Don’t have I running yet so we will see. With 160/30’s and ported heads I expect very clean exhaust.

Thats the kind of info I was looking for. Very Helpful, Thank you sir. PM sent.

lincolnlocker · Jul 3, 2020

Exactly. Delipped pistons arent the issue. Its tuning or something else. Probably just needs a hair more timing.

live life full throttle

turbodiesel_02 · Jul 4, 2020

Just put my truck back together 02 7.3 after a cracked piston situation after 10 years of abuse.went with delipped and coated pistons to help with the heat.I have not seen any haze at idle whatsoever,it now idles smoother than it ever has and tuning hasn’t been messed with since 2010.injectors are 238/80’s that unlimited diesel just went through while the truck was apart. Just throwing that out there...

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Countrycar · Jul 5, 2020

Well we'll see later this year how this all plays out. I hope to be able to get the truck on Matt's dyno this year and make some adjustments to the tuning. Hopefully this is just all it is. I had 238/80's for about 14 yrs and they did run very clean as well. I'm now running 3/2s so the tuning needs to be spot on. I also run Nates injectors, and he's always been great to deal with.

superpsd · Jul 5, 2020

Yep I would have the tuning dialed in. Many parameters are critical to a clean burning engine. Timing being one that is critical. A few degrees too advanced or retarded can be the difference between a clean exhaust flow or haze and heavy opacity under load etc.

This is my 7.3 idling at 400rpm on a cold engine with 200% nozzles. I also could have refined the tuning further but it was just a simple test.
https://youtu.be/e_xCe2caUY4

Countrycar · Jul 8, 2020

superpsd said:
Yep I would have the tuning dialed in. Many parameters are critical to a clean burning engine. Timing being one that is critical. A few degrees too advanced or retarded can be the difference between a clean exhaust flow or haze and heavy opacity under load etc.

This is my 7.3 idling at 400rpm on a cold engine with 200% nozzles. I also could have refined the tuning further but it was just a simple test.
https://youtu.be/e_xCe2caUY4

Appreciate it, thank you sir. Unfortunately it won't be until later this year before I can get the live tuning done. I'm very tempted to pick up the minotaur software and train myself and make the changes I need. :rockon: