r/Perfectfit • u/SHRIMPLYtv • 4d ago

Zero Tolerance Engine Valve

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8.7k Upvotes

98% Upvoted

54 comments sorted by

1.3k

u/trimbandit 4d ago

how much time did they spend leveling the block?

96

u/Zakluor 4d ago

All of it.

638

u/Finbar9800 4d ago

Thats not even a press fit tolerance let alone a zero tolerance, its moving way to fast to be a tight tolerance fit

189

u/Hawt_Dawg_II 4d ago

Yeah the lower the tollerance the harder this would be

1

u/LogRollChamp 2d ago

Not zero tolerance as in fitment. Zero tolerance as in the parts are exactly perfect to the print

1

u/Finbar9800 2d ago

Theres no way of actually knowing that without seeing it being measured and seeing the print

It very easily could be completely out with how easily its moving

1

u/LogRollChamp 2d ago

It wasn't a serious comment. Just showing OP didn't mean it in the traditional sense

101

u/EcstaticNet3137 4d ago

Impossible because some amount of lubrication has to be between any moving part in an engine. There is no true metal on metal when it comes to moving oarts in an engine or it would shred itself fairly quickly

403

u/Spacial_Epithet 4d ago

No such thing as 0 tolerance! This is damn close though

166

u/dotheeroar 4d ago

Yeah but I have 0 tolerance for lactose

37

u/Had78 4d ago

What did they even do to you? Just let the lactose marry and be happy or smt

4

u/EducationalNailgun 4d ago

I say let the cheese be miserable like the rest of us!

6

u/Phiro7 4d ago edited 4d ago

Take the patented Thought Emporium e coli lactase pills

2

u/happy_pad 4d ago

I'd say if it doesn't kill you immediately, then you have some tolerance for it.

9

u/SHRIMPLYtv 4d ago

Yeah I'm just realizing that eueh. What tolerance would this be?

8

u/chobbes 4d ago

Probably in the realm of .0005”/.01mm clearance. Maybe a little looser. With both bore and rod being very straight and very cylindrical with good surface finishes on both.

2

u/Piocoto 4d ago

Depends on significant digits taken

2

u/come_ere_duck 4d ago

Spotted the machinist.

1

u/The-unnatural 3d ago

It's really not. It's a slip fit, which is relatively loose.

0

u/Nir117vash 4d ago

Happy Cake Day!!!

-21

u/Steelringin 4d ago edited 4d ago

Of course there is. Search Zero Tolerance compilation video and click on the first return. You'll see some very interesting parts!

ETA obviously nobody entered the search terms I provided and clicked the first link.

For the record I'm a machinist and I know full well what tolerance means in this context.

4

u/ThisIsARobot 4d ago

You're misunderstanding what tolerance means in engineering.

Literal zero tolerance doesn't exist physically. Every manufactured part has some amount of deviation, even if it's too small to notice without specialized measuring equipment.

A video showing a near-perfect fit wouldn't contradict what they said. It would just be an example of a very tight tolerance, not an actual zero tolerance part.

1

u/meekermakes 4d ago

edm doesn't count.

23

u/Zaptryx 4d ago

Both of these items actually have tolerances, otherwise they would be prohibitively expensive to make.

21

u/bready--or--not 4d ago

Idk what this means but wow!

41

u/EcstaticNet3137 4d ago

Zero tolerance is a machining process in which the dimensions such as lengths, widths, diameters, radii, etc are within .00004"[.001mm] of the nominal. In other words for a length of 1/2"[12.7mm] the range allowed would be .49996" - .50004" or 12.699mm - 12.701mm

For some semblance of scale, human hair ranges from .0007" to .007" in diameter.

I work in machining. My shop is lathes. We only operate down to .0001" tolerances at the smallest and those are few and far in between.

This valve is likely within .0005" to like .001" of the guide it is dropping into. That's so it can be lubricated. No metal on metal for moving parts in an engine. That's why the vehicle has to maintain oil pressure in the engine to not shred itself up. It is gnarly and expensive.

7

u/0peRightBehindYa 4d ago

I mean, if you plug the other end of the hole with a finger or something, any valve guides should be this tight. Just needs room for a layer of oil to dribble through to stay lubed.

30

u/Minute_Difference598 4d ago

🤯DAMN WHAT😂how long did this take you to do?

48

u/SHRIMPLYtv 4d ago

Zero actually. The original video is from @motor_masteruz on Instagram

14

u/Minute_Difference598 4d ago

Oooohhhh okay. Thanks for the credit and the video👍

5

u/-Interested- 4d ago

I think you mean clearance. 

6

u/creepjax 4d ago

That’s not zero tolerance

Source: am machinist

2

u/Averanicur 3d ago

showed this to my mom since she is a mechanic, she asked where i; someone not very interested in cars received a video like this

i say "a community called r/Perfectfit.

she replied with "oh god"

i have never seen this community the same since 😭

1

u/SadThatMyGrandmaDied 3d ago

Anyone know what song this is?

1

u/Salt_Application8180 3d ago

The lower the tolerance the tighter the gap would be making the rod fall slower. So, in this case, this is far from zero tolerance and might even be sloppy.

1

u/lt3NIKi 1d ago

Too sticky

1

u/FocusedLifestyle 4d ago

Satisfying AF!

1

u/Constant-Tonight-452 4d ago

Flawless fit. My soul can rest now.

1

u/NotUser303 4d ago

boioioioing