Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - 89 6.2 Diesel is geared to smoke point, need smoke detector :)

JohnAh · 08-11-2012, 11:04 AM

Sorry, I´m not sure I hava a clever solution but I´m interested in diesels and like to learn how they work in detail.

If I understand it right, you are running on very low rpm to minimise losses in the engine. To get maximum torque the IP have to be set as close as possible to the smoking point? Is there a non-linear function between injected ammount of fuel for each piston stroke and the engine speed? With a turbo I can immagine that to be the case but is it also valid for a suction engine?

I read somewhere that many average diesels may have around 50% more air than is needed for smokeless combustion. If the IP can be made to increase the ammount of fuel the power will increase up to the smoking point.

I guess a turbo conversion of a suction diesel can easily result in heavy smoking at lowrpm if the IP can´t be made to compensate for the lack of boost pressure.

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Concerning the problem to see when the engine begins to smoke, how about an optic system like infrared smoke-alarms? I´m not sure how they work but I guess they have an LED and a photo-sensor in the open air, a identical setup in a closed chamber as reference and a bridge-circuit sencing the slightest difference.

My idea here is to arrange the LED and photodiode with lenses in such a way that the distance between them can be more at least a few inches. The reference should be placed in exactly the same way close to the meassuring device to get the same temperature. There must be total darkness offcourse, and a clever solution to keep soot away from the surface of the optical components. Perhaps injection of a clean airstream around the sensor and LED can be arranged? The speed of the exhaust gases may take care of this air injection.

08-11-2012, 11:04 AM	#2 (permalink)
JohnAh EcoModding Apprentice Join Date: May 2012 Location: Vallentuna, Sweden Posts: 129 Phantom Blot (Spökplumpen in swedish) - '75 Saab 96 V4 90 day: 52.77 mpg (US) Thanks: 17 Thanked 55 Times in 30 Posts	Sorry, I´m not sure I hava a clever solution but I´m interested in diesels and like to learn how they work in detail. If I understand it right, you are running on very low rpm to minimise losses in the engine. To get maximum torque the IP have to be set as close as possible to the smoking point? Is there a non-linear function between injected ammount of fuel for each piston stroke and the engine speed? With a turbo I can immagine that to be the case but is it also valid for a suction engine? I read somewhere that many average diesels may have around 50% more air than is needed for smokeless combustion. If the IP can be made to increase the ammount of fuel the power will increase up to the smoking point. I guess a turbo conversion of a suction diesel can easily result in heavy smoking at lowrpm if the IP can´t be made to compensate for the lack of boost pressure. ------- Concerning the problem to see when the engine begins to smoke, how about an optic system like infrared smoke-alarms? I´m not sure how they work but I guess they have an LED and a photo-sensor in the open air, a identical setup in a closed chamber as reference and a bridge-circuit sencing the slightest difference. My idea here is to arrange the LED and photodiode with lenses in such a way that the distance between them can be more at least a few inches. The reference should be placed in exactly the same way close to the meassuring device to get the same temperature. There must be total darkness offcourse, and a clever solution to keep soot away from the surface of the optical components. Perhaps injection of a clean airstream around the sensor and LED can be arranged? The speed of the exhaust gases may take care of this air injection.