pistons offset L - R bank

[Whitefinish]

I thought I remembered the pistons for the Front / Rear (or left/right) bank are different from another.

Especially the Diamond pistons groupbuy had an initial flaw. Although this was also related to a set for an 'inline' 6 cilinder and not a v6. However, it's all my memory and would like some other experts to chip in as well.

[branscoset]

I remember hearing/reading about this also. I have a set of pistons from the Diamond group buy and plan on using them someday. I looked at them last time this was posted and didn't notice a difference between the 6 pistons.

[Mud Flight]

You are talking about the pin offset. My set were good. 3 were offset to the exhaust side and 3 were offset to the inlet side.

[Whitefinish]

You are talking about the pin offset. My set were good. 3 were offset to the exhaust side and 3 were offset to the inlet side.

How can you check such a thing?

[branscoset]

How can you check such a thing?

I too would like to know. Probably should take my set to the machinist and have him check the "pin offset".

[KLZE Porsche]

You should be able to see the offset visibly by just looking at the pin end and noticing that it is not centered in the piston. Or -if you do not have a picture hanging eye -then you can measure the piston center to the end of the flat on each side. One edge of the flat face should be a closer distance to the pin than the other edge. But if you have a good eye -you should be able to see it without measuring.

Ref:
http://www.xtremethings.com/Piston_Offset.jpg

[sbeube02]

Thanks a lot KLZE Porsche for the detailed explanations.
How can these be mounted on our engines? Which side of the piston goes to which side on the head cylinder?

[branscoset]

Thanks Michael.

[Whitefinish]

People, please be warned when ordering pistons.

See the below example; leaving me with a beautifull set of 4 + 2
(Top right is same as left 3)

http://i292.photobucket.com/albums/m...psxdz8nnpa.jpg

[mac1]

so the new piston that I mailed you is a left or right? so confused.

[Whitefinish]

I don't know yet how to identify a L and R piston.

Now I have a set of 4-2 (either 4 left, 2 right, or 4 right, 2 left)

[SBPGT]

"On asymmetric piston designs, there is a wide skirt panel and a narrow skirt panel. The wide panel needs to be in the direction of major thrust. The major thrust direction is the side that is against rotation. For example, if the engine rotates clockwise when viewed from the front pulley the major thrust would be to the left (against rotation).” An asymmetric piston design has a wide and narrow skirt panel. The wide panel will always be placed on the major thrust side.



The last big area that plays into the importance of piston orientation is wrist pin location. This is primarily done to control piston noise. Different wrist pin offsets may require a specific direction when installed. Like the piston skirts, the correct installed location plays into the major thrust side of the engine.
"Some pistons have an offset wristpin and would need to be installed properly to have the desired effect of reducing piston noise."

Most pistons will come with an arrow or some sort of marking to illustrate the required piston orientation, but it is always good to verify this information, especially if you are using an asymmetrical piston configuration. These marking can differ depending on the application, piston design, and installed orientation of the engine. Either way, it is always a good idea to verify the correct location prior to installation.


Does this apply to the KL engine? I thought this was answered before, but I couldn't find it...

[RACERSNUT]

So, looking from the pulley side of the engine....the offset pin would be towards the firewall.

Is this correct?