Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Lugging the motor

I read more and more references to "lugging the motor". Could someone please tell me what this means? Is it to do with the drive train not liking low revs or is there some reason which is purely engine related? I see references to this in bike applications as well. It is mentioned in the s&s running in procedure. What's it all about?

Engine strain at low revs. Not so common in modern engines...
http://www.roadandtrack.com/car-culture/videos/a30431/lugging-bad-for-engine/

If you go up a steep hill in high gear and the motor staining this is lugging. so right gear right speed no lugging. Thats how it was explained to me.hope it makes sense ...

Hmmm, I have long been aware of carbon deposits being the cause of pre ignition but to suggest that these come as a result of dilution of the oil by petrol is a bit far fetched. Such severe dilution would, I feel, bring about other serious problems as regards early engine failure to say nothing of the possibility of crankcase detonation!

A graph showing the spark occurring after top dead centre is worrying too.

I am not sure why low revs are seen to be the cause of all this, perhaps I am just a bit old fashioned?

The drivetrain makes some pretty frightening noises if you let the revs get low!

Our motors suffer below 3,000 RPM. They make maximum torque around 3,500. Unless I'm in first gear, I'm never below 2,800 and even that causes me consternation... she likes 3,000 as a minimum. 95% of the time I'm between 3,000 and 4,500, occasionally hitting about 5,250. My engine loves me.

You have a V twin with shared crankpin and individual cylinder capacity greater than any production car engine never mind motorcycle.

Its 56.25° cylinder angle gives poor mechanical and combustion balance, with no harmonic balancer as with HD engine.

It's never going to be a smooth at low revs, or anywhere above for that matter

We share the same experiences Richard, I too have a 1960 Venom. I like the way the s&s engine makes its presence known. I am merely concerned about not understanding the terminology - and I still don't.

S&S certainly suggest that running the motor under 2700 RPM constitutes lugging and is not a good idea. My assumption of what they actually mean is that below 2700 you really should not put any load on the engine; it may be okay to run at 2000 RPM at low speed on the barest whiff of throttle but when the traffic opens up then you need to change down, get the revs up and then open the throttle. Pulling away at 1000 RPM might seem like a wonderful thing but may well be knocking hell out of your engine even if the rest of the drive train may appear to be accepting it.

Go Ken!