Mercruiser 496mag pistons replacement

[Radek Kobliha]

Hey guys, did you ever replace an oem pistons with some aftermarket ones? I have low compression on 4 cylinders. We completely took apart the short block and found these 4 piston rings stuck, rusted, broken and we are not even able to take them out. Cylinder wall looks good with no obvious damage. Just decided to replace all 8 of them and go from there. I found a brand Diamond pistons where they are saying it's a direct replacement. Is it true or is there anything else what I should take care of? Can you recommend any other brand what would directly fit? Thank you!

 

[PlayDate]

1) Did you find the source of the water intrusion into the cylinders?
2) Were all the rusted ones on the same side or on both sides of the block?
3) Assuming you got the rusted ones out.....there is no damage to the cylinder walls?


Diamond makes great pistons. The question really comes down to whether you are boring the block.