Author Topic: HA6 Smoke after full rebuild  (Read 72 times)

dgordillo66

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HA6 Smoke after full rebuild
« on: November 07, 2021, 10:56:45 PM »
Hi Everyone,

I have a lister HA6 which was just overhauled, I'm a little concern about the amount of smoke it's producing. I'm not very familiar with old diesel engines and I haven't ran this one for longer than 10 minutes after receiving it from the shop, can anyone tell me if this is normal?

https://youtu.be/lf_qvjIwbqI

Ambient temperature was about 15 to 17 celsius, at the time of this video the generator had been running for about 5 minutes with no load on the generator.

dkmc

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Re: HA6 Smoke after full rebuild
« Reply #1 on: November 07, 2021, 11:45:49 PM »

The rings need to seat....if that's what is causing the smoke. Warm it up again, then apply a 50% load to it for  15 minutes.
Then go to 70% load for 30-45 minutes and see if the smoke diminishes. Let it cool down cold, and do another 30 minute run at 70%. Might take longer but running new rings on new cylinder wall unloaded is asking for glazed cylinder that may always smoke. 

Of course there are other questions:
Is the piston/cylinder clearance correct?
Ring gap right and gaps staggered?
Cylinder round and no taper?
Correct cross hatch pattern from the hone?


dgordillo66

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Re: HA6 Smoke after full rebuild
« Reply #2 on: November 08, 2021, 02:09:15 AM »
Hi DKMC, I'll try the ring seating procedure as suggested and see what happens. So far I've checked the piston/cylinder clearance and the ring gap before assembly, the hone was done by reputable shop so I didn't think of checking it until now, I guess that would be my next step if the seating procedure doesn't help.

Thank you very much, I'll update the post with results.

dkmc

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Re: HA6 Smoke after full rebuild
« Reply #3 on: November 08, 2021, 02:27:28 AM »

Be sure it's warmed up before applying load. Oil should be warm as well as water.
Good luck! 

mobile_bob

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Re: HA6 Smoke after full rebuild
« Reply #4 on: November 08, 2021, 04:26:57 AM »
+1 for getting a load on it!

i am a bit more aggressive in my approach

i want a load on my engine as quickly as the oil pressure is up and stable, that usually in a few seconds

i start at about half load and run it there until the coolant is warmed up, the engine is running at stable temps and then i load the coals to it!

i raise the load and watch the crankcase breather for blowby, and increase power until i get some increase in blowby and then i back off a bit and run it there for perhaps 15minutes, then increase load again until the blowby increases, back off a bit, run there, wash rinse and repeat until the engine runs at full load.

my changfa's are fully broken in, in under an hour or run time.  and there is no visible smoke right up to full rated power where there might be just a touch of gray smoke.

i come from the old days, '70's and specialized in 71 and 92 series detroit 2 strokes
those engines could be ruined after an overhaul in just over 15 minutes of no load operation. 

and i learned from the old mack truck engine manuals their break in procedures, and it is as i described. i have used it on all sorts of engines since and have had no issues with smoke or oil consumption.

an engine that is built to spec's, clean, and assembled properly should not take long to break in, that is if it is done right.

those old days of long time to break in, comes from poor tolerances on the assembly lines, where the cylinder finish was not so good, things were not so clean, and assembly was fast and furious.

remember what break in really means, it is wearing down the high spots, and the crosshatch is like a file that wears away at the rings, seating them.  if you don't have enough load on the engine, the engine never gets up to proper temperatures, and the dynamic cylinder pressures are not as high as they should be to force the rings against the cylinder walls.  so you often times get glazed cylinders that have the high spot worn down but they didn't have a chance to get the rings worn to match.

one other thing i am a stickler about that is cleanliness when assembling the cylinder kit
bore and  hone is fine, but don't depend on them to get the thing as clean as it should be even if it looks good. hot soapy water, blow dry, and follow up with white paper towels and atf, wipe them down with the atf until the towels come back with nothing put the red color of the oil, no signs of gray color.  its amazing how much crap can be cleaned out of what appears to be clean parts.  try it sometime.

i see lots of guys thinking that cleaning the parts in solvent is clean, bull crap!  i have shown many mechanics just how dirty their cylinder liners were after they cleaned them in clean solvent.

that gray stuff that comes out on the towels is a combination of fine iron particles of the liner and fine abrasive compounds from the honing operation, neither of which are good for an engine.  you don't want that stuff however minute to be making a lap and scrubbing down your cylinder walls, rings and piston.

anyway i digress

get some load on it, don't run it anymore until such time that you can load the thing up.

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info