Turbo

showcrop · Mar 20, 2014

How easily is a turbo supposed to spin? A good breeze should make one turn shouldn't it?

buzzinduzzin · Mar 20, 2014

should be able to spin it with your fingertip, also make sure it is not rubbing the housing

G1355 · Mar 20, 2014

Yeah they turn easy, that's why your suppose to cover up the
exhaust when hauling turbocharged equipment so the wind and air
don't get in there and spin it backwards and take it out.

Bob · Mar 20, 2014

The turbo on a cooled-down diesel with 15-40 oil in it (and, of course in the turbo bearings) will turn easily, NOT quite as freely as a pinwheel in a slight breeze.

Anonymous-0 · Mar 20, 2014

Cover the exhaust! Ha! According to what authority????
Some guillable wet behind the ears boy?!

VicS · Mar 20, 2014

You don't have to cover yours, but I will cover mine when I haul it , or leave it out at night. Maybe it is a old wives tale. I'm not going to take a chance. And besides it might rain! Vic

k6zrx · Mar 20, 2014

I would agree with you. For the turbo to spin, there must be a flow of gases through it. The only chance for air flow in a stopped engine would be from intake-exhaust overlap. Not enough air flow to spin anything up.

I could see spinning a turbo without proper lubrication would be bad, like if someone blew compressed air into it.

Josh

Anonymous-0 · Mar 20, 2014

Actually on some machines mechanics recommend covering the exhaust so the turbo won't spin or loading a machine the other direction. Going down the highway at 60 MPH with the wind going into the exhaust could spin a turbo. Pretty cheap way to prevent it from spinning.

Anonymous-0 · Mar 20, 2014

Larry Hopefully this will be a very good season this year and you can make a lot of money. I know you will be up in Pa. as much as you can, and hope that's a lot. If you ever get up north in Pa. toot your horn and maybe I'll hear it. Good Luck and keep up those pics.

G1355 · Mar 20, 2014

Why would i make that up. Where I work it took the turbo out of a d6 cat dozer, then we learned after we couldn't figure out why it had no power, when you ever see equipment with rain cap open if it has one, you better believe its spinning the turbo, if you park them on a trailer backwards you shouldn't have to worry as much about that.

Steve@Advance · Mar 20, 2014

I would think you'd need to use your experience and
judgement, considering it has cold thick oil in the
bearings, it's going to have some resistance.

I would be feeling more for dragging, as in turning
and pushing sideways to check for side or end play,
tight spots, runout.

Jack in Colo · Mar 20, 2014

Haven't heard that old wives tale in 20 years or more, if a real mechanic tells you that he's probably pulling your leg for a laugh, think about it, where's the air coming into the exhaust going to go?? maybe through the turbo and into the cylinder through an open exhaust valve but then there's no where else for it to go which means NO FLOW to turn anything. and just a breeze blowing through a turbo probably wouldn't be strong enough to hurt it anyway, thats not the way a turbo works.

RBnSC · Mar 21, 2014

I agree the only way there can be flow is if both valves are open, like you say overlap.
Ron

Dick2 · Mar 21, 2014

Allis Chalmers manufactured turbo chargers during WWII for B17 engines so the bombers could fly above the flack of the anti-aircraft guns. After the war, AC used their turbo experience and started using turbo's on their own engines.

We were advised in meetings and bulletins that the turbos were lubricated by the engine's oil pump. Therefore, we were to advise everyone that when hauling a tractor with a turbo that the exhaust needed to be capped off so the turbo didn't spin from the vacuum that was created - because there was no oil being pumped to the turbo.

A turbo is a precise piece of equipment, with small precision bearings that spin at high speed. Without oil, those bearings will fail quickly.

But if you want to ruin your turbo and create a big repair bill, it's alright with me.

Dick2 · Mar 21, 2014

Air moving across the open end of a pipe creates a VACUUM, which will cause the turbo to spin.

That is basic physics.

Traditional Farmer · Mar 21, 2014

Yep take an air hose and stick it down the exhaust pipe it won't spin the turbo because to spin the turbo it need an air flow which it won't have in the engine.Even if the exhaust and intake valves were open the air would have to exit back thru the air cleaner which I'd assume is also picking up the air from being transported so that and the exhaust would be an equalizing pressure.

Sean Feeney · Mar 21, 2014

I agree %100 they even sell covers
cover

JMOR · Mar 21, 2014

the late Rolls-Royce Master, John Bamberg stated many times that "there are a lot of products on the market to sell, but not to buy!"

Anonymous-0 · Mar 21, 2014

State DOT requires thier lowboy drivers to cover and tape stacks before moving equipment and dealers cover stacks when delivering so I believe the gullible wet behind the ears kid and not the grouchy old man.

Russ from MN · Mar 21, 2014

Interesting note, thank you! When I worked in a JD shop in the 70's they had just started putting turbo's on skidders. The mechanic told me it was so they could maintain reasonable horsepower at high altitude, where the best timber grows!
We had a Ford Thunderbird turbo coup for awhile, basically a pinto engine with a turbo, too much power for the torque converter, had to change it once. I read a turbo can spin up to 180,000 rpm!

Jack in Colo · Mar 21, 2014

you are correct that air moving across an open pipe will in fact cause a vacuum but a flow of air is only possible if the opposite end of the pipe is also open, in this case the opposite end of the pipe is closed by the engine itself. This is also basic physics.

Case Nutty 1660 · Mar 21, 2014

I have hauled equipment for 40 years and we always covered the exhaust on turboed engine, it is even in the ops books on equipment such as CAT/CASE ect, now days the manufactures build a flap in the exhaust system to prevent it from happening

Dick2 · Mar 21, 2014

A flow of air from the opposite end is not necessary. The vacuum will create a turbulance and suction in the pipe that will spin the turbo at high speed. Without the engine running to pump oil, those small bearings can't last long without oil.

guido · Mar 21, 2014

Hello showcrop,

It should turn pretty easy, in other words no resistance if you spin the wheel. Stack caps are not just to keep the rain out. A stiff breeze will spin the turbo, and ruin the bearings surface,

Guido.

oldtanker · Mar 21, 2014

(quoted from post at 11:53:42 03/21/14) Hello showcrop,

It should turn pretty easy, in other words no resistance if you spin the wheel. Stack caps are not just to keep the rain out. A stiff breeze will spin the turbo, and ruin the bearings surface,

Guido.

Well I just got off the phone. I talked to 2 different guys, a SIL in ND, early 30's and a school trained diesel tech and a guy about 28 also a school trained diesel tech. 2 different schools, both of them laughed at that question. They have never heard of it. The 28 YO works in his dad's shop and ask his dad. His dad had heard of it but it was always as a joke.

I really can't see how 2 half open valves on one cylinder would pass enough air to snip up a turbo enough to damage it.

Rick

JMOR · Mar 21, 2014

(quoted from post at 17:09:40 03/21/14)

(quoted from post at 11:53:42 03/21/14) Hello showcrop,

It should turn pretty easy, in other words no resistance if you spin the wheel. Stack caps are not just to keep the rain out. A stiff breeze will spin the turbo, and ruin the bearings surface,

Guido.

Click to expand...

Well I just got off the phone. I talked to 2 different guys, a SIL in ND, early 30's and a school trained diesel tech and a guy about 28 also a school trained diesel tech. 2 different schools, both of them laughed at that question. They have never heard of it. The 28 YO works in his dad's shop and ask his dad. His dad had heard of it but it was always as a joke.

I really can't see how 2 half open valves on one cylinder would pass enough air to snip up a turbo enough to damage it.

Rick

'll believe it when someone installs a window in the housing & I see it spinning as it is towed down the highway. Skeptic, too.

RandyB(MI) · Mar 21, 2014

It only takes one customer law suit against a trucker over a burned up turbo bearing that was already burned up before ever loaded on truck to get a rumor like this going. SO! If you tape it up , which is a good idea, do so to protect yourself from the a-hole law suit happy slime trying to get something for nothing. I'd love to see test data showing a healthy turbo being damaged by hauling with exhaust uncovered.

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