# Looking for piston details explained...

by 5.0stang
Tags: explained, piston
 P: 63 I'm trying to find an article or something similar online that has a diagram of a piston and explains the different parts of the piston. For example, trying to find out what the piston's compression height, ringland, deck thickness, ring grooves, etc. I would like to know what all of these mean. A particular piston I'm looking at says: Compression Height: 1.090 Ringland: .220, .140, 075. Deck Thick: .325 Ring Grooves: 1/16,1/16,3/16 What do those numbers mean? Thanks from a newbie:)
 PF Patron Sci Advisor P: 2,792 Compression height is the distance from the centre of the gudgeon pin to the crown of the piston (the flat bit on the top). Ring land is the distance between the rings; hence top ring land is the distance between the top ring and the crown. Ring grooves are the grooves into which the piston rings sit. I'm not sure about 'deck thick', I imagine it to be the thickness of the top deck taken at its thinnest point.
 P: 63 Your always a helpful one Anyone got a piston diagram that is labeled?
P: 5,096

## Looking for piston details explained...

These might help:

 Piston/Deck height volume is the small volume at the top of the cylinder that is not swept by the piston.
http://www.mre-books.com/smallblockf...blockfrd7.html

http://www.ajdesigner.com/phpengine/...eck_volume.php
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P: 2,792
 Quote by Fred's link Piston/Deck height volume is the small volume at the top of the cylinder that is not swept by the piston.
That's what I was going to suggest too, but it's not actually a piston parameter because it's dependent on other components, whereas all the others are piston-specific. I think there's a subtle difference between piston/deck height volume and deck thickness.

I'll try and remember to ask next time my piston man is around.

I've got a labelled piston diagram but it's in a book and doesn't have all the parameters you were after. I'll see what I can find at work, failing that I'm certain you'll find something on the Federal Mogul or Mahle websites.
P: 5,096
 Quote by brewnog That's what I was going to suggest too, but it's not actually a piston parameter because it's dependent on other components, whereas all the others are piston-specific. I think there's a subtle difference between piston/deck height volume and deck thickness.
I was thinking the same thing when I saw that. However, couldn't that parameter be changed simply by changing the height of the piston? I honestly have no idea why one would do that other than increased pressure. Is that usually an option with pistons?
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