Is the trend now to go with lighter viscosity oils in equipment.

[RickB]

So maybe they have to make them looser! A 70s/80s Diesel engine would use 15w/40 and would run for 10,000 hours without attention and only oil changes. That's what DIESELS were all about! This new technology belongs in the garbage!

Bull. Most any 70s-80s wet sleeve Diesel was good for MAYBE 4000 hours before the first inframe. And just about everyone except Perkins and Ford Tractor Operations built predominantly wet sleeved Diesel engines.

 

[Quickster2]

Be careful in these discussions that you don't confuse tolerances with clearances.

Good point and agree.

 

[WM75Guy]

I go by the manual and use NH products. For the little I use it is a small price difference and gives me peace of mind. My TC40DA came with 10W-30 from the factory, according to the manual, and is good for -10 to 120 F. In Texas I could use 15W-40, which is rated from +10 to 120 F. The new Workmaster 75 calls for 10W-40 or 0W-40. It does not give a temp range for either.

 

[MechanicalGuy]

Having to crack into an engine before a hundred thousand miles or even at a hundred thousand miles to change a timing belt is a fail in Engineering in my opinion.

My car has a timing chain and 177k and chains are vastly superior imo.

 

[combustor]

My car has a timing chain and 177k and chains are vastly superior imo.

...and timing gears are vastly superior to timing chains.

 

[MechanicalGuy]

...and timing gears are vastly superior to timing chains.

Maybe not in overhead cam situations where the chain has a really long run to make, but in concept you're right. The point was that Honda engines use a dated and far inferior method of timing.

 

[deserteagle71]

My car has a timing chain and 177k and chains are vastly superior imo.

What you all need is one of GM's new 3.0 Duramax diesels...where you have to drop the transmission to access the timing chain and the belt that drives the oil pump......New GM 3.L Dmax | Bob Is The Oil Guy

 

[MHarryE]

It is the bearing clearance that has changed, made possible by improved machining processes. Reduced clearances required lower viscosity oils. Bearing diameter closer to journal diameter results in higher bearing load capacity provided there is sufficient room for hydrodynamic oil film. Clearance of .0025 to .0030 would dictate 10W-40 or 15W-40 oil. Clearance of .0015 to .0020 would mean using 0W-20 or 5W-20 oil. With the reduced clearance comes greater load capacity allowing higher engine power plus reduced friction with the lighter oil. Using higher viscosity oil in engines designed with tighter clearances can damage the engine. The engine is designed for oil to feed in on the unloaded side. Under load the minimum film may be only .0002. Using .002 as the starting total clearance, that leaves only .0018 gap for oil to enter so using the proper viscosity for the design is important.

 

[Grumpycat]

Honda has a failed philosophy in their continued use of timing belts on their engines. Having to break into the engine to replace timing belts so early in an engines life is poor engineering practice.

Gee, by that logic using a belt to drive the alternator, A/C compressor, power steering pump, etc, is "poor engineering practice."

Believe MechanicalGuy has a poor grasp of what good engineers actually do. Timing belts are actually a very good elegant solution. But making timing belts difficult to service is a bad thing. Just because some are difficult doesn't mean all are, or have to be difficult.

Timing belts are quieter and more efficient than chains, gears, or bevel shaft drive. Timing belts are lighter so less power is needed to accelerate or decelerate the valve train. Light is not much of an advantage for a tractor engine but matters greatly for automobile engines.

Who says a belt has to be replaced at 100,000 miles? That a belt could not be designed to last longer? I remember GM V8's of 20 years or so ago requiring timing chains (and sprockets) at 30,000 miles if one was "having too much fun." And the two sprockets were not 10" apart.

 

[combustor]

Gee, by that logic using a belt to drive the alternator, A/C compressor, power steering pump, etc, is "poor engineering practice."

Believe MechanicalGuy has a poor grasp of what good engineers actually do. Timing belts are actually a very good elegant solution. But making timing belts difficult to service is a bad thing. Just because some are difficult doesn't mean all are, or have to be difficult.

Timing belts are quieter and more efficient than chains, gears, or bevel shaft drive. Timing belts are lighter so less power is needed to accelerate or decelerate the valve train. Light is not much of an advantage for a tractor engine but matters greatly for automobile engines.

Who says a belt has to be replaced at 100,000 miles? That a belt could not be designed to last longer? I remember GM V8's of 20 years or so ago requiring timing chains (and sprockets) at 30,000 miles if one was "having too much fun." And the two sprockets were not 10" apart.

The 3 cyl Ford 1.0 ecoboost had an interesting solution of running the belt in oil, lowered friction even further and extended service life, supposedly good for the life of the engine.

On almost all aircraft engines the accessories are gear driven, no belts or chains (a few older, very simple designs have a belt driven generator or alternator though). Weight is orders of magnitude more important on an aircraft than a car, yet they went with gears instead of belts. Durability and reliability are obviously high priority on aircraft powerplants. The reason for belts/chains is a cost one (and overhead cam as mentioned, but I'm not sure how many models of 'equipment' employ that)