lugging question
Stellar HDF Member
Joined: May 2009
Posts: 2,856
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From: Middle of Kansas
I think there is a difference in engines, and my 99 Softail Classic is stock, except for the K&N filter, and drag pipes. I can run mine through the park in 3rd, at 18 to 20 mph with no problem. It is just a put put, but I am also not accelerating. The engine is very smooth, and not working at all. If I want to get up and go from there, I go to 2nd. That twist grip makes all the difference. I have ridden for years, and do have a feel for engine performance, but I can tell when it is lugging, and when it is not. Some people like to grab a handfull of throttle when they want to go, and others like myself, normally just twist it gradually. You also have to take into consideration that the EVO is a fairly low compression engine, with fairly retarded timing at low RPM.
Outstanding HDF Member
Joined: May 2008
Posts: 2,230
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From: Mount Holly, NC
if the flame-front can't expand because of load, you get incomplete combustion. unspent fuel collects on the cylinder walls and washes down. dirty incomplete combustion makes for dirty filthy oil. dirty filthy oil deposits carbon everywhere and adds to the problem.
Road Master
Joined: Dec 2006
Posts: 1,058
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From: Omaha Nebraska
Sorry, I don't buy that. Quite the opposite, due to more load it is more difficult for the combustion cycle to push the piston down and the flame front has more time to spread, detonation is at risk here meaning possible multiple flame fronts. However a good engine management system takes this into consideration and as load increases at a given RPM, it properly retards the spark advance to compensate for this to prevent detonation and engine damage. Lugging increases stresses on an engine's bottom end, mainly rod and crank bearings. But I have never seen or heard of many problems in this area either, even from luggers.
Ultimate HDF Member
Joined: Nov 2008
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If its making your motor have a chugging sound or a loping like your bike has a long duration cam as you say you like. YOU ARE LUGGING THE MOTOR.....Not good.
Last edited by 1931jamesw; Nov 2, 2009 at 09:10 PM.
Road Master
Joined: Oct 2009
Posts: 1,074
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From: Baltimore, MD
FWIW the newer twin cam engines don't seem to make the potato potato sound that I remember the HD's used to make when I was younger, like in the 70's. I mean, they sound like Harleys, but not the same. If that is what you are trying to achieve, I don't think it's gonna happen at any RPM. I claim no technical knowledge other than having ears which can hear an engine.
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Outstanding HDF Member
Joined: May 2008
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From: Mount Holly, NC
Sorry, I don't buy that. Quite the opposite, due to more load it is more difficult for the combustion cycle to push the piston down and the flame front has more time to spread, detonation is at risk here meaning possible multiple flame fronts. However a good engine management system takes this into consideration and as load increases at a given RPM, it properly retards the spark advance to compensate for this to prevent detonation and engine damage. Lugging increases stresses on an engine's bottom end, mainly rod and crank bearings. But I have never seen or heard of many problems in this area either, even from luggers.
if an engine was efficient at low rpm lugging wouldn't be an issue (EDIT: except in the case loads on rods and bearings, but my whole point is to show how lugging ruins oil and rings). the time allowed for flame front development would be as you say. however, since engines don't make power for sht at low rpm, you must conclude that time has nothing to do with complete combustion. it has to do with flow and velocity, and an engine at low rpm produces little of either. when you lug, you get precipitation of unspent fuel and washdown. no engine management system can make this fuel burn after a firing event. it simply isn't possible.
Last edited by Certainteed; Nov 2, 2009 at 10:51 PM.
Outstanding HDF Member
Joined: Feb 2006
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From: Boca Raton, Florida
Well, whether in a 3 litre Healey or on a Harley, I've always like that "contented Gurgle" sound of a slow-turning engine. The "sweet spot" on a tennis racket or the well placed power stroke of a canoe paddle. I get the same satisfaction from "Happy Engine" exhaust note! Sort of like a Purr from a VERY large cat!
A "Gurgle" seems to be ok on my '01 WG, though at much lower rpm the engine will "clank" and that's rather embarrassing as well as probably not so good for the engine.
Overall, my engine seems to be at too high an rpm (for my tastes) at highway speeds, and I might consider changing sprocket ratios some time in the future to get lower rpm at higher speed (reducing noise and fuel consumption).
Jim aka kiltiemon (My ex-wife used to refer to the Healey exhaust as a "'contented' note".)
A "Gurgle" seems to be ok on my '01 WG, though at much lower rpm the engine will "clank" and that's rather embarrassing as well as probably not so good for the engine.
Overall, my engine seems to be at too high an rpm (for my tastes) at highway speeds, and I might consider changing sprocket ratios some time in the future to get lower rpm at higher speed (reducing noise and fuel consumption).
Jim aka kiltiemon (My ex-wife used to refer to the Healey exhaust as a "'contented' note".)