Author Topic: Smoking trait of the petteroid, can it be reduced/eliminated?  (Read 24284 times)

mkdutchman

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We have a petteroid 3.5 that we purchased recently, after cleaning the sand out of the crankcase, overhauling etc we tried to fire it up and couldn't be started without starting fluid. After lots of fiddling and expermentation we retarded the the whole camshaft a notch, which works out to about 6-7 degrees. Now it starts and runs nicely but smokes, not an awful lot, but enough that it's bothersome. We fiddled with the valve lash, it made a little difference,  but not much. We thought it might be a lack of oxygen in the cylinder (e.g. intake timing?) but that doesn't seem to be the case. We even put a new camshaft in but that didn't help any either. Now just lately I was told by someone that the injector squirts fuel too close to the cylinder, or on the piston/cylinder walls, where it just sits and smoulders instead of burning like it should, therefore the smoke.

Are there more people with this problem? I heard it's just how they do, you can't fix it. It seems to me there has to be a way to make them burn cleaner, all that smoke and unburnt fuel going out the stack goes against my grain!

I also saw that fattywagonman modified a piston (on the 6/1?) to make it burn cleaner, did anyone else do this too? If so, what results did you get? IMHO it seems to me that might be worth looking at.

I was checking out fatty's EGR setup, very interesting, where are you with that by now, fatty?

fattywagonman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #1 on: June 14, 2006, 04:14:04 PM »
Hi Dutchman,
Check out these mods I made to the piston... It helps a bit with the smoke...

you are correct about the fuel making it's way onto the inside of the cup... not good for complete combustion... I also have been working on some injector ideas like squiting the fuel onto a deflector for better atomization ... Here's a pic

Also considering a pin in the center of the combustion cup... If I do this I'll  squirt the fuel onto the head of the hot pin..   

Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #2 on: June 14, 2006, 04:19:19 PM »
There are several folks with that engine here.  One or more will be along soon.  I don't know that engine, so won't attempt to diagnose the problem further, but I wonder about the smoke.  What color is it?  Black?  White?  Blue?   Since your valve timing was off from the factory, maybe the fuel injection timing is, too.  

Halfnuts

fattywagonman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #3 on: June 14, 2006, 04:37:44 PM »
I forgot to add that I'm also working on a prechamber for the injector... This could also help with the combustion..

mkdutchman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #4 on: June 14, 2006, 05:20:02 PM »
Thanks for the pics, fatty, gives me some ideas to work on. How hard would it be to modify the injector itself, do you think? Probably micro machining, etc.

And yes, our injection timing was overadvanced at the factory, that was probably why it started so hard. The smoke color? light grey. Unburnt fuel perhaps?

Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #5 on: June 14, 2006, 05:26:16 PM »
White smoke indicates unburned fuel, black indicates too little oxygen/too much load/too much fuel.  Light gray doesn't sound so bad, but if it's really dense, then something still is wrong.  I'd still suspect injection timing, but if you've already done that . . .

You might try pulling the injector, hooking it up to the fuel line and watching to see how the fuel is sprayed.  It should be a very fine and even spray with no dripping before or after the main spray event.  It's entirely possible one of our Indian friends dropped the injector prior to installing it.

Halfnuts

ronsmith

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #6 on: June 14, 2006, 05:57:44 PM »
my 3.5 petter also smokes grey smoke a lot. I de carboned it about a month ago and that seemed to help for a little while. Now its back to smoking rather heavily. I dumped the exhaust into a barrel of water w/ dish liguid to try and take out some of the carbon. It removes some of it but still smokes heavy. I am going to pull my injector and check the spray pattern and then I will run a copper fuel coil around the exhaust to heat my fuel. I am burning hydraulic oil in it. Hope it helps.

mobile_bob

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #7 on: June 14, 2006, 06:27:08 PM »
it occures to me perhaps the engine is running too cold?

are these mini's tstat controlled?

if not how hot do they run, water temp?

if they arent getting up to around 190 degree F. they will probably smoke some.

a cold running engine will smoke more, build carbon faster, and be shorter lived.

by cold running i don't mean room temp,  an engine running under 180-190 is classed as cold running, in my books.

just something simple to check, alot easier than rebuilding and changing timing i would think.

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europachris

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #8 on: June 14, 2006, 06:30:40 PM »
My Changfa smokes a bit until the water temp in the hopper comes up.  Once she's up to 170F or so, it runs extremely clean at any setting up to full load.  Once you overload it, it starts to smoke like an old Mack.

Temp is critical for clean combustion on a diesel.

Chris

bitsnpieces1

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #9 on: June 15, 2006, 04:11:19 PM »
mkdutchman:

  I would tend to agree with damage to tip of injector, preventing good spray pattern.  Hence some unburnt/slightly burnt fuel.
  This will seem a bit elementary, but, while working with injector DON"T EVER get any part of your anatomy in front of it.  Diesel fuel injected into your body does terrible things to your health.  PSI will be in thousands of pounds.  
Lister Petter AC1, Listeroid 12/1, Briggs & Stratton ZZ, various US Mil. surplus engines. Crosley (American) 4cyl marine engine(26hp).

mkdutchman

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #10 on: June 15, 2006, 08:43:00 PM »
if it's really dense, then something still is wrong.  I'd still suspect injection timing, but if you've already done that . . .

You might try pulling the injector, hooking it up to the fuel line and watching to see how the fuel is sprayed.  It should be a very fine and even spray with no dripping before or after the main spray event.  It's entirely possible one of our Indian friends dropped the injector prior to installing it.

Yes, our Indian friend Mr. Ashok Tank was kind enough to send us another injector, piston rings, seals, and camshaft, via Air! The service we got can't be complained about. But the new injector made no difference.....and the old one's spray pattern was good, nice and even, misty, etc. We usually run at about 190 degrees or so, judging from appearence it doesn't seem to make much difference, I think maybe I should look at the injector timing perhaps? Where should the timing be?

Hi Dutchman,
Check out these mods I made to the piston... It helps a bit with the smoke...
you are correct about the fuel making it's way onto the inside of the cup... not good for complete combustion... I also have been working on some injector ideas like squiting the fuel onto a deflector for better atomization ...
this article I find extremely interesting, just check out that combustion chamber shape! http://www.sonexresearch.com/prod.html

Also, here's a video of the thing running, you will doubtless notice that it's not under load, but here again even under medium load it reduced just to the point of where you could see the difference.
http://video.google.com/videoplay?docid=-8125627003936673255

Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #11 on: June 15, 2006, 09:22:26 PM »
I have no problem saying, "That's a smoky engine."

It sounds like it's running OK.  Wonder if it's just that the rings aren't seated yet and it's doing the oil-slobber thing.

[edit]  On second thought, it sounds like maybe the engine is missing, and immediately after each miss there's a puff of smoke.  Sticking intake valve?  Hmmm...

Halfnuts
« Last Edit: June 15, 2006, 09:33:44 PM by Halfnuts »

GuyFawkes

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #12 on: June 15, 2006, 10:15:12 PM »
I have no problem saying, "That's a smoky engine."

It sounds like it's running OK.  Wonder if it's just that the rings aren't seated yet and it's doing the oil-slobber thing.

[edit]  On second thought, it sounds like maybe the engine is missing, and immediately after each miss there's a puff of smoke.  Sticking intake valve?  Hmmm...

Halfnuts


yeah, there is a definite "blown valve" sound coming out of it, as you say, bent or sticky, broken spring, bent pushrod, lots of possibilities there, but it is missing a lot of power strokes, which could also be down to the pump / governor, but that blowy valve sound is where I'd start.
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emerald

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #13 on: June 15, 2006, 11:35:30 PM »
Do all Indian petter types smoke like this one?

I find it hard to believe that they are all that bad.


Halfnuts

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Re: Smoking trait of the petteroid, can it be reduced/eliminated?
« Reply #14 on: June 16, 2006, 01:01:21 AM »
Where's that Hotater guy when you need him?  He's supposed to have a whole stable of them.

Halfnuts