I recently sent my head out to get machined and assembled. I got it back a day ago and found #1 cylinder to have some knicks/pitting. I contacted them, asking about pre-ignition and hot spots, and they said it was from detonation and they cleaned it up the best they could without porting. They also said that it will be fine to run and that the small spots will fill with carbon. They are a very reputable shop and I don't wish to mention their name because its nothing that they did wrong.

I just wanted a second opinion to ease my ocd. With that said here is a picture.

 

That's a little detonation or some debris going through the engine. It will fill with carbon in under a minute & do absolutely nothing.

 

I think it might be a bit of both. Back when I ran it n/a it developed a missfire under load. Upon replacing the plugs I found the electrodes to be badly worn. After replacing them it ran like a champ. I also had the lead tech in my shop read the new plugs and he said it looked to be burning oil and possible detonation.

Thanks for your reply.

 

Unless you have marks on your slugs n jugs id say it was just slight detonation as well, if it was debris everything would have marks most likely

 

make sure there are no high spots or sharp edges
just check that and then like mentioned they will fill up with carbon without risk

 

the bigger divots look like foreign material that passed through that cylinder.

 

Question was answered after the first post. Thats not to common.

 

Thanks guys.

I sold the block awhile ago, so I have no idea what the pistons look like. Didn't notice any damage until I got the head back all cleaned up. I now have a semi built b16 block with wiesco 9.0:1 pistons.