Engine Assembly Question, Which way do the pistons face? |
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Engine Assembly Question, Which way do the pistons face? |
ThinAir |
Mar 27 2005, 06:10 PM
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#1
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Best friends Group: Members Posts: 2,543 Joined: 4-February 03 From: Flagstaff, AZ Member No.: 231 Region Association: Southwest Region |
I'm about to install the Mahle Euro (flat top) pistons and cylinders. I know that it is critical to have the pistons facing the correct direction relative to the flywheel. I'm used to seeing an arrow on top of the piston that is supposed to be pointed toward the flywheel. These Mahle pistons have no such marking.
This picture shows the top of the piston. Is that funny little symbol supposed to represent a crankshaft & flywheel? Is it critical which side faces the flywheel end or just that all the pistons are the same? I'm hoping someone answers quick - I'd love to get the heads on tonight! Attached image(s) |
Dave_Darling |
Mar 27 2005, 07:19 PM
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#2
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914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
The funny symbol, in this case, is a crankshaft and a flywheel. Squint a little bit--see it? The flywheel is on the very right-most side of the glyph, which means that the right side of the piston (when viewed from the "top") should be closer to the flywheel.
The reason the symbol is there is because the pistons have very slightly offset wrist-pin holes. This keeps the forces going from piston through connecting rod to crankshaft (and back the other way) lined up a little bit better, which reduces the "piston slap" and the piston rocking in the cylinder bore. It's not critical, but it's a good thing to do correctly if you can. --DD |
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