piston pitting

[Keith Williams]

can this be removed enough to still be useable i can remove with a red then scotchbrite with my dotco wheel i know about the snap ring thanks for alls help

 

[giantpune]

I think that pitting is bad enough, if you try to remove material to the point of making that smooth, you will be making measurable changes to the chamber volume and the piston weight.

 

[Aus73Mach1]

Scrap that one and others like it. Piston lands are gone in places as well. The cir-clip is also bent out of shape. Even some good second hand ones would be a better option if your budget is tight. What do the cylinders look like?

 

[Keith Williams]

Scrap that one and others like it. Piston lands are gone in places as well. The cir-clip is also bent out of shape. Even some good second hand ones would be a better option if your budget is tight. What do the cylinders look like?

i said i knew about snap ring

 

[mrgmhale]

I would replace the pistons. I would then look for a nice forged aluminum piston. Not racing pistons as you will find they are not as durable for many thousands of miles of street driving. Unless you have non-ethanol gasoline with over 90 octane I suggest going for 9.5:1 compression, as opposed to 10:1 or higher. This means a balancing of the engine is called for. Before putting much into the engine rebuild I would want to identify the cause of that pitting.

 

[Keith Williams]

Scrap that one and others like it. Piston lands are gone in places as well. The cir-clip is also bent out of shape. Even some good second hand ones would be a better option if your budget is tight. What do the cylinders look like?

the block cylindres need honeing the motor sat out side a while when i purchased it i was suprized cylinders were to bad i cleaned up rust whit pacid cleaned up good i was just hopeind i could save pistons who likes to spend 500 .00 if you dont need to thank you

 

[Keith Williams]

I would replace the pistons. I would then look for a nice forged aluminum piston. Not racing pistons as you will find they are not as durable for many thousands of miles of street driving. Unless you have non-ethanol gasoline with over 90 octane I suggest going for 9.5:1 compression, as opposed to 10:1 or higher. This means a balancing of the engine is called for. Before putting much into the engine rebuild I would want to identify the cause of that pitting.

thank you it was sitting out side a while i got it for 100 dollars a 4 bolt main the closed chamber heads are worth more than i paid i was just hopeing it would work one cleaned up nicely but the volume my be slightly different as far as balanceing that could be done ill look for some new ones flat tops the rods have been converted to flosating pins i dont want to buy new rods tioo i just sold two new sets of l2348 pistons one had the rods thats how it always goes thank you all

 

[Stanglover]

My penny's worth, in other words, not much.
With todays crappy gas, you might want to consider dish top pistons with those CC heads.
Here I speak from my own experience. My motor is a 71 M code. I had it rebuilt several years ago and with flat top pistons, deck and head truing, the compression ratio was above 11:1 and that caused major spark knock with 91 octane gas, no ethanol at that time. Move forward to another unrelated problem when the motor was rebuilt again (under warranty), but this time I had 13cc dish top pistons put in. That lowered the static comp ratio to just under 10:1. It still had some spark knock, but I was able to tune that out with a recurve of the distributor, not going into that here.
The pistons I chose were Keith Black hyperutectic KB148. see chart below, but these numbers for comp ratio are slightly lower due to head plaining on my engine.
These pistons are ok for a street driving car. If you're into drag or other hard driving, then billet pistons would be best.