Start-up smoke mitigation

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ChickenPinz
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Posts: 186
Joined: Tue Feb 11, 2020 7:16 pm

Start-up smoke mitigation

Post by ChickenPinz » Tue Aug 11, 2020 1:59 pm

Others have talked about this, but I'd like to collect the common wisdom on how to mitigate the smoke on start-up after a Pinz has not been started for awhile.

It's understood that the smoke is a function of the engine design that there are no oil seals on the exhaust valve stems. This thread isn't about how to change the engine, but how might we deal with the smoke cloud and oil mist that results.

I find the smoke is for maybe just a minute, so I'm brainstorming ideas here on how to minimize the smoke. One person mentioned using magnets to hold a rag over the tailpipe to capture the oil mist, but I suspect that doesn't address the smoke.

Some random [unvalidated] ideas, in the hopes of creating others from the field:
- A large bag, slightly permeable, to capture the exhaust. Dense canvas?
- A length of PVC pipe stuffed with fiberglass insulation?
- A box with multiple(?) furnace type filters?
- Electrostatic filter like used in bars as "smoke eaters"

Anyone tried something and had a success or failure to share?
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Texas710
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Location: San Antonio, TX

Re: Start-up smoke mitigation

Post by Texas710 » Thu Aug 13, 2020 8:23 am

When I first got the Pinz and up until a few years ago, the truck would smoke and spray oil at start up. Not every single time, but enough that I would either push it out of the garage to start it or put a cardboard box (or something) to soak up the oil spray. I have assumed it was due to excessive fuel/oil that wasn't fully combusted.

I always thought you could install a slight downturn on the exhaust to point the spray more towards the ground, or route the exhaust to the rear of the truck (more for exhaust getting in the cab during driving, window open)

I have since installed the SSI ignition system and really don't have the issue anymore. The exhaust is much less smoky, I don't tend to get the oil spray and overall the smell of the exhaust is much better with the SSI.

I would be curious to know if you have the SSI and are still having the issue, or if your still on stock or mechanical ignition.

ChickenPinz
United States of America
Posts: 186
Joined: Tue Feb 11, 2020 7:16 pm

Re: Start-up smoke mitigation

Post by ChickenPinz » Thu Aug 13, 2020 2:39 pm

In my particular case, I have the Pertronix ignition module. It's what I'm sticking with for now, and discussion of the pros/cons of alternatives is OT as I'm looking to better understand what my comrades have tried (or theorized) for the startup smoke. Given that it's an understood behavior due to no oil-seals on the exhaust valves, I don't see how an ignition swap would *eliminate* the condition that's limited to that first minute of operation.
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pinzinator
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Location: Indio, California

Re: Start-up smoke mitigation

Post by pinzinator » Sat Aug 15, 2020 9:27 am

To stop the oil spray, which is normal for a Pinzgauer, I drape a shop rag over the exhaust tip and hold it in place with a magnet.

ChickenPinz
United States of America
Posts: 186
Joined: Tue Feb 11, 2020 7:16 pm

Re: Start-up smoke mitigation

Post by ChickenPinz » Sat Aug 15, 2020 2:49 pm

pinzinator wrote:
Sat Aug 15, 2020 9:27 am
To stop the oil spray, which is normal for a Pinzgauer, I drape a shop rag over the exhaust tip and hold it in place with a magnet.
I really like that idea, and the magnet system is especially nice. I need the smoke mitigation version of that now.
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ChickenPinz
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Re: Start-up smoke mitigation

Post by ChickenPinz » Mon Aug 17, 2020 10:43 am

I've tested a solution that seems to work quite well. Know that it's not perfect, and I'm sure people are going to pick it apart for obvious limitations, but it's a starting point, and even possibly an endpoint. I hope others can use this and may improve upon it.

The solution is a 2x2x2 cardboard box filled with fiberglass insulation:
1, cut a hole in a box -- near the top center of the box so the box can rest on (or close to) the ground when on the tailpipe. Also multiple small holes on the opposite side near the bottom.
2, put your junk in that box -- Fill the box with fiberglass insulation (no paper, just insulation), and tape it closed
3, make her open the box -- Slide the box over the tailpipe, and start up your truck and run it for a few 10's of seconds.
And that's the way you do it!

The result was zero smoke on startup. The box became warm, but not hot -- it's not left on very long.

In an effort to head off some of the criticism I expect, here are some (but not all) of the obvious things recognized as limitations:
Yes, I expect oil will accumulate in the box and that may reach a point that it becomes hazardous. I don't expect that to happen very quickly, and the box&insulation can easily be swapped out at that time.
Yes, cardboard is flammable. You could also make the box out of something non-flammable.
Yes, that's a lot of insulation. I'm sure much less would also work.
Yes, the box is big. I believe a smaller box will work.
Yes, the box isn't very sexy. I believe it's about functionality, not looks. You could paint the box. :)
I'm also going to test the ABS pipe idea as well, with the goal being something that can be broken down into section for transport.
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whitesik
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Location: Indiana, U.S.A.

Re: Start-up smoke mitigation

Post by whitesik » Tue Aug 18, 2020 9:23 am

I find this interesting but I have no smoke on start up. Yes, a very small amount of oil splatter on the very initial start up. Do others really find this to be a big problem? I frequently start it up for a few minutes in the garage if I am not routinely driving with out giving smoke any thought. I now have the SSI but even with the petronix it was not bad.
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Not so new owner but still a novice

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