engine hour analysis and idling

[6balls]

We know our boats idle a lot, we write about it when discussing how many hours is too high. Was reading an article in Car and Driver and I thought this was interesting:

 

(Fun fact: Chevy says it equates the wear of one hour of idling to 33 miles of civilian driving.)

 

This was a police interceptor vehicle article...and they were discussing how much time a police car spends idling.

 

So idling is roughly half the wear of a use-hour if that is true, according to Chevy.

[BraceMaker]

You wonder about those things, what's worse 1 hour of idle or 10 starts/hour.

I have been shopping for new vehicles and so many of them now turn off when you reach a full stop and then restart when you come off the brake pedal. Presumably better for fuel econ and the environment - but what about for the engine?

 

The hybrid version of this in a ski boat would probably shut off the engine when you came to idle and use battery power to maneuver the boat then start when you pulled the skier out.

 

My theory is that I don't like to kill the engine until I've idled for at least a few minutes after pulling the skier, mostly because at restart often you'll have the high heat buzzer for a few seconds - but what's the wear and tear?

[Wish]

My brother just purchased a 2018 F150. It shuts off at stop lights. Ford must think fuel economy out ways frequent starts by a wide margin I would think.

[MISkier]

I doubt any of them are considering the wear and tear issue of stop/start. They are just trying to meet CAFE, while still providing the consumer with the vehicles and horsepower the market demands (i.e. SUVs and Trucks).

[DW]

Warm starts won't add to internal engine parts, it will add some wear and tear on the starting system (starter / flywheel). There is a lot of dyno development work being done on start stop systems and total impact to system.

[Jody_Seal]

Which would you rather have, A 300 hour engine utilized in a heavy wake boat or a 1000 hour engine utilized in a slalom boat??

Ill take the 1000 engine all day long!

[Chef23]

@Wish a lot of the newer cars shut off at traffic lights. My wife and I both have 2014 vehicles with it (an Audi and a Jeep). I hate that feature and always turn it off. I am sure it saves some fuel but I hate the fact that there is a lag when you step on the gas to begin acceleration.

[Moved2ski]

The postal service trucks in my neighborhood shut off at each house. must be hundreds of starts per day.

[Jmoski]

For cars that idle for hours everyday it’s important to account for it in the oil change interval given its odometer based.

 

But for us, the change interval is already based on run hours, so the idle time is accounted for.

 

On the auto stop/start - it was pretty seamless on my boxster, but I still disabled it (there is an off switch)

[oldjeep]

Some of the new start/stop engines are now using a belt/electric motor to start the engine when in start/stop mode. Supposedly taking care of the issue of wear and tear on a conventional starter/flywheel. The Ram eTorque is an example of this, it uses the regular 12 bolt starter to fire the engine up first thing in the morning but spins the engine to start when in start/stop.

 

Lot of extra junk to fail, but neat technology

[BrennanKMN]

Personally I don't really care either way for myself. I leave my engine idle for the 20-40 seconds at each end of the lake because it is convenient. When we change skiers for 2-8 minutes I shut it off.

 

My boat is a tool to ski with. I do what is the most convenient and conducive to skiing.

 

I am in the camp that if you want to reduce hours and fuel consumption do the stop start method. If you happen to have a starter fail because of the excess wear (unlikely) you will have long paid for the new starter in the fuel saved by the time it fails.

[LeonL]

I recently heard that boats only accumulate hours if its in gear. I don't believe that, but I think it was on BOS that someone made that comment.

[shansen345]

@LeonL The hour meter will record if the engine is running regardless of being in or out of gear.

[skiinxs]

Funny, I was just about to post this when I saw the @Gloersen post above. I will post anyway but this simply corroborates his data. This is from a Diacom report I pulled from my '17 in early July. Bottom line, used as a ski boat and shutting down when possible, still almost two thirds of the time was spent at idle (notice the 1,072 starts, or on average every 6 minutes showing that I do shut down frequently in slalom, less frequently in trick / jump)

 

4. SYSTEM INFORMATION

 

Customer configuration Information:

 

Engine Part Number: K2163357GC30815

Engine Serial Number: 567538

Customer Hardware PN: R116029-2D07

Customer Emission File Name: 4G120_62DI_PCM_SENTFP_AX50_PROD.001

 

ECM Software and Hardware Information:

 

ECM Serial Number: 4656

ECM Hardware Number: 2490004-A

ECM Manufacture Date: 2016/11/15

ECM Sofware Number: 9999000-1

Current CAL Model: 9999000-1

Current CAL Date: 2016/11/30

Total Calibration CS: 97A457B0

Emissions Calibration CS: 425F50BC

Total Number of Cylinders: 8

Engine Displacement: 6.2

Cylinder Firing Order: 1-8-7-2-6-5-4-3

 

 

 

Engine Operating Hour Summary (RPM vs MAP psia)

_____________________________________________________________

RPM\MAP 4.0 6.0 8.0 10.0 12.0 15.0 TOTALS

_____________________________________________________________

700 52.78 10.49 0.14 0.04 0.07 0.01 63.53

1800 0.54 1.08 1.73 0.16 0.01 0.00 3.53

2500 0.13 1.46 14.50 2.22 0.29 0.00 18.60

3500 0.02 0.24 6.16 8.73 1.02 0.03 16.20

4500 0.00 0.01 0.07 0.38 0.22 0.10 0.78

5600 0.00 0.00 0.00 0.01 0.03 0.00 0.03

 

Total Histogram Hours = 102.67

 

Miscellaneous Information

_____________________________________

Master/Slave Configuration : Master

Total Engine Starts : 1072

 

[JackQ]

Shutting off the ngine after each pass can be problematic for newer boats with catalytic converters as the need water flow to cool off, constant shutdowns may/will cause premature failures.

[jpwhit]

If a boat were designed to implement the same style of auto start/stop that is becoming common in the automobile industry, it would have to follow a similar strategy that is being used in cars. It would have to switch over to electric coolant and/or oil pumps such that cooling and/or oil flow continued during the shutoff periods. That's how many cars avoid the wear issues of start/stop cycles mentioned here. This is very true and common in any car that has a turbo. Which is a very similar issue as the catalytic converters that are now standard in boats. These type of components simply must have some form of cooling during the shutoff periods.

 

Also as previously mentioned, some form of electrical maneuvering thrust would make such a system much more beneficial in my opinion.

 

I'm involved in the development of these types of systems via my work. And there is a lot of this technology in the development pipelines right now. And as mentioned earlier, a lot of these designs are based around belt driven electric machines. The systems in the development pipeline right now combine engine starting, power generation, and engine power augmentation in the form of mild electric hybrid capabilities into one system. Most of based on a DC power system that is independent of the typical 12v system. Many are 48V DC.

 

It seem inevitable to me, that this technology will trickle down into the marine engine business.

 

[swc5150]

@LeonL Our 80's MC's would accumulate hours by just turn the key to the "run" position. Had a buddy put a few days worth of hours on his Tristar until the battery died. Glad that has long since been remedied.

[Jody_Seal]

shutting down at each end and re-start would chew up starters and ring gears. depleting the service life of those components at a far faster rate.

Wait!! what am i saying I am in the parts business!! Yea! shut em down at each end!!

[ski6jones]

Please don't put auto stop/start in boats. Imagine the price bump for that tech which literally adds zero value for the skier.