IrocManiac

Guys I just read in another post that lugging the engine is hard on bearings...I haven't ever heard this and have been around the car thing since I was a wee lad....can someone or everyone please explain?

Mikey97Z

That was me that mentioned lugging the engine! Lugging is when the engine has high load and low rpms and it is really straining to push the crank around. This can be like flooring it in 6th gear at 1200 rpms or something smilar. The pistons are pushing hard on the rods but they're not able to accelerate.

Another thing to remember is that low gear ratios in the tranny will transmit much of the engine's torque to the BACK of the drivetrain (the tires, rear gears, and driveshaft), and the high gear ratios will place more strain on the FRONT of the drivetrain (pistons, rods, crank, clutch, ... and bearings).

IrocManiac

So basically when I'm rolling to a stop and put it into second at about 2mph and ease out on the clutch and back into the gas there's about 2 seconds where it's kinda luggin' a bit, thats gonna hurt my baby? If so I'm going to first everytime.

Z28SORR

Well, I've also been around a long time and I have heard this for years. And like so much of this kind of info I believe it's an "old wives tale".

To the best of my knowledge, which is limited, lugging your engine does absolutely no harm what so ever.

There is a lot of, "I heard and some one said", responces on these boards. So if you know of one, please link to an engineering or science paper on this subject.

Mikey97Z

According to the Clevite Bearings website, overloading is responsible for 9.5% of bearing failures.
http://www.engineparts.com/products/...iles/frame.htm

Mikey97Z

Also according to How to Rebuild Small Block Chevy LT-1/LT-4 Engines by Mike Mavrigian

page 66
"Inspecting Main and Rod Bearings"
"Bearing Overload - If the bearings exhibit surface spalling and/or fatigue cracking, this may be a sign of engine over-revving or lugging the engine under heavy loads."

Mikey97Z

Generally, if the car is in motion, second gear will be okay. Just don't floor it when the rpms are so low. Just ease onto the gas until the rpms get up there. But if you want to jam on it then you should shift into first.

IrocManiac

I don't floor it in a specific gear (except first) when I'm below 3000 or so rpm.

OldSStroker

Here's an interiesting thread on this subject:


http://web.camaross.com/forums/showt...g&pagenumber=1