Cover the exhaust when transporting machine to protect turbo???

[Truck Shop]

I don't know what the area of the opening of a partially open valve is, I just guesstimated that number. Doesn't seem like enough pressure or flow to do muc

Probably .070. But overlap in a gas engine is measured at .050 and how much lobe separation
110 or 112. Either way it wouldn't matter--just isn't enough air flow.

 

[Acoals]

I have never covered the exhaust, and have yet to have a turbo failure. You need flow to make a turbine wheel spin. On my excavator there did not appear to be any point where there were both intake and exhaust valves open at the same time, but even if there were, that is one long tortured path for the air to try to push though.

 

[Truck Shop]

any point where there were both intake and exhaust valves open at the same time,

Engines have tendency of always stopping in a few spots, it would be rare for one to stop
at tdc and overlap.

 

[big ben]

my 2 cents.

- I would assume it is not that uncommon to stop on TDC because as the piston comes up to TDC compression stroke it is under max load and the point when the engine would want to stop turning resulting in the running mate being on valve overlap

-A lot of the time on Cat equipment the exhaust stack is bigger than the exhaust pipe (Venturi effect) so the air would naturally push into the engine bay and out not down the actual exhaust (path of least resistance)

And just to be clear for non T4 engines the path the air would have to go while creating enough flow to spin the turbo

-down exhaust
-through muffler baffles
-past exhaust side of turbo
-into exhaust manifold and find a valve
on overlap
-out intake manifold
-through aftercooler
-through turbo compressor side
-reverse through the air filters
…..not likely

 

[Truck Shop]

I would assume it is not that uncommon to stop on TDC because as the piston comes up to TDC compression stroke it is under max load and the point when the engine would want to stop turning resulting in the running mate being on valve overlap

It would seem that way--but it aint.

 

[skyking1]

^ trying to bump starter around to set valves is a losing proposition for that reason.

 

[jonno634]

I cover mine, unless it has a rain cap that will be closed the direction I am driving. I’ve heard the oil thing, but was told rocks, kicked up or a bird in there could be an issue. I’ve never seen it, but it only takes a minute or two, so I do it.

 

[56wrench]

I think its not so much the risk of air pushing into the exhaust as the possible venturi effect of the air rushing past the top of the exhaust pulling air out of the exhaust at todays highway speeds combined with pushing into a strong headwind

 

[Oxbow]

Back in my heavy towing days in the eighties, whenever we towed a truck into the dealership they would verify that we had the stacks covered. Probably just CYA, for us and them, but the habit stuck with me.

After all, what happens when a machine is parked on a jobsite during a 60 mph wind? Really no difference in my mind.

 

[8V71]

Don’t know if it ever helped but I always did it just so some guy would look at it and say wow that’s a good idea I never thought of that

 

[Truck Shop]

Well lets see--first off I'm not going to carry a fruit ladder acting like a fruit bum to climb
to the top of stacks 13,6. Never happened not going to happen. I tow damn near every
thing from the back because I'm not going to lay in water or a truck stop where people
have been pi$$ing in the lot to pull a driveline if I don't have to. I tow at 65 mph when
I can, given wind conditions, sometimes only 55. Just not going to worry about some
damn turbo compressor wheel spinning out of control.

 

[.RC.]

So I am a bit confused. I would have thought, for the turbo to spin it requires airflow. So where exactly is the air flowing through the turbo when the engine is stopped going to?

Is the train of thought, air is going to enter the exhaust outlet, go through the muffler, through the turbo, and then go where exactly?

 

[OzDozer]

RC, the air potentially goes through the engine via partly open, overlapped valves, then back up the intake and out through the air cleaner.

As I said above, in the days of oil bath air cleaners, there was a lot less resistance in the air cleaner for air to take that path - but with dual dry elements, there's nowhere near the same ability to allow volumes of air through.

 

[Vetech63]

I believe the odds of catching a bird into the exhaust stack while going down the road is much greater.

 

[1693TA]

I believe the odds of catching a bird into the exhaust stack while going down the road is much greater.

I've done that. Not into the stack but smashed against it at highway speed. Bent the damned thing too. Brand new tractor and a hawk eating road kill which is common around here.

 

[skyking1]

It reminds of the mechanic/wives tail-----{Don't touch the bearing surface of new main & rod
bearings because the oil in your hands will etch the bearing}.. Peeeewwwwwwwwwwww.

My fave is the battery on the concrete thing. The science is just amazing!!
How about keep it warm or charged or both?

 

[Oxbow]

My fave is the battery on the concrete thing. The science is just amazing!!
How about keep it warm or charged or both?

Dangit Skyking, another myth busted.........I still set mine on a board just cuz!

 

[1693TA]

The discharge thing used to be true but that was back in the days of "bakelite" cases which were not always a perfect insulator. The plastic cases replacing these in the 1940's did away with that but old habits die hard sometimes.

I do keep batteries on a float maintainer as do believe they work. Just put a new group 31 in my skid steer yesterday replacing one that was new in August 2016 according to the receipt. The one prior to that battery was an Interstate and new in 2008, and the one prior to that was new in 2000 when I purchased the machine with a bad battery. I don't think with the vibration these things take that is too bad of service life but I do feel the maintainers help to extend this life.

 

[skyking1]

Dangit Skyking, another myth busted.........I still set mine on a board just cuz!

It is that much further up to lift. as you get older use bigger boards. Eventually set it on a chopping block so you don't bend over at all, and for sure get those batteries with the handles on them.

 

[Truck Shop]

and for sure get those batteries with the handles on them.

Well the older a boomer gets the handles grow above the belt line and the buckle starts staring
at the ground.