Question about piston order.

[jimtash]

I have a full set of pistons and rods that I bought sometime ago off of Ebay that aren't in any order. I don't know which cylinders they came out of but they are out the same engine though. What would be the best way to fit these or to find out in which order they should go?

 

[BaySHO Performance]

Order doesn't matter as they are all the same and you will be installing them with new rings and rod bearings after honing the cylinder walls to give the new rings something to bed into. You need to make sure that they are installed the right way around: KOA (3.0) or KOB (3.2) on the rods should point towards the front (passenger side) of the engine.

 

[Ishodu]

The order matters r or l as the pistons are slightly off set for the correct side. I csn't remember if there marked or not. IIRC there were though

 

[jimtash]

Yeah I know which side they go in just not which order or if I'd run into any balancing problems. I have the crank that went with these pistons as well.

 

[zach44102]

The postons do have a offset in the pin location. You have 3 left bank pistons and 3 right bank.

 

[jimtash]

The postons do have a offset in the pin location. You have 3 left bank pistons and 3 right bank.

I know this. I should rephrase the question. How are the pistons located in relation to bank order and does it matter where each one goes? Will putting them in any order mess up the balance? These are loose piston and rods. They were not numbered when they came out of the engine so I don't know in what order they should be put back in. I know that there are 3 each that fit on each specific bank and that they have an arrow pointing to the front and an EX for exhaust. I know which way they go in but not the order in which they should. If I had taken the engine apart for example, the pistons would be in their order that they came out. These aren't and that's what I'm trying to figure out.

 

[Ishodu]

I know of a few people who have tossed in used pistons from random locations and had really no issue. I suppose if you wanted to you could weigh each one to see if there was much of a diff.

 

[jimtash]

Any idea if they all weigh even from Yamaha?

 

[Ishodu]

No idea but if they are all with in a few grams you have nothing to worry about.

 

[jimtash]

Thanks guys.

 

[msteiny]

I guess if you weigh them find the lightest one and then match the others to follow by removing some material. Ive done this a number of times on small and big blocks.