NA Diesel No Smoke Timing???

[CareyWeber]

Dr Lee,

I have a small diesel in my IHC Scout it is a Nissan NA SD-33 IDI 6 cylinder engine.

I make exactly ZERO black smoke when running down the road no matter what the postion of the throttle is (this includes going up hills). This includes at night watching my exhaust with another cars headlights right behind me. My 97 6.5TD makes smoke that is only visible at night when someone is behind me.

My question is could the timing be advanced to much or could it be retarded to much.

How does; or does the timing of a NA diesel effect how much black smoke it produces.

Another thought is it just needs more fuel???

Thanks
Carey

[CleviteKid]

Hi Carey,

Theoretically, advancing the timing will give you a more complete burn, but at the cost of power if you go too far, and also the rate of pressure rise could give you a dangerous level of diesel rattle (broken rings, wiped bearings, etc.) If the engine is not noisy, it is not advanced too much. Retarding the advance substantially will give some white smoke from incomplete ignition of the fuel charge.

Yes, you could (should?) add more fuel. The headlights-of-a-following-car test is quite sensitive to low levels of smoke.

Dr. Lee

[CareyWeber]

Dr Lee,

I forgot to give you some EGT info.

Running on the level at 55mph gives about 500