I would like to hear others thoughts on these 2 alloys.

Most aftermarket pistons use the 2618 alloy (low silicone alloy <1%). this alloy has a higher overall strength and can untimately take a bit more abuse, but you have to run higher piston-to-wall clearances...usually .003" to .004" and will likely have more cylinder wall wear.

The 4032 allow has a higher silcone content which allows for less piston expansion...hence you can run tighter wall clearances. More like .002 - .0025." My understanding is that this alloy also has greater "durability" than the 2618 alloy.

So, for a true "street/strip" forced induction truck thats DD. The goal is to make around 700 rear wheel hp on boost on 15lb. I have 2618 probe piston and want to insure my self that I bought right piston.

 

It's my understanding that the 2618 is the stronger piston. Don't worry about the higher clearance at cold(room) temps. They warm up quickly and the piston slap quits. You shouldn't notice any crazy wear on the pistons or the cylinder walls if you let it warm up a bit before you start beating on it. Most of the time, if you see scored walls & pistons with a 2618 piston, it was either overheated, or not set up properly from the original build(meaning improper clearance).

 

AKlowriderZ71 so mean like you see in this picture. The wear marks are perfectly smooth and this little over 2k. All the cylinders were like this.

 

That goes without saying for any vehicle. When I lived up north we drove these 6L crew cab 3500HD trucks and none of them lasted over 100k. People would beat the **** out of them at -40. Even with stock hypereutectic stuff its good to take it easy until it reaches operating temp.

 

i have wiseco's (2618) i can't say anything about cylinder wear because i only have about 2k on them. i read some crazy stuff about how loud 2618 pistons can be but mine are super quiet, alot quieter than alot of early gen III piston slap that i have heard.

 

What is your piston to wall clearance?

 

I run 4032 pistons in most of my builds including the 370 I ran 9.6 with. Main reason I run them is they seal up better cold, and hold their ring seal longer along with less noise. The 4032 alloy is harder and more wear resistant, but in turn it is more brittle. A 2618 piston is softer but will take more abuse it just grows, and wears more. The reason the wiseco's are quiet is they have longer skirts, and offset pins. Only problem I with the wiseco is the low CR height, and they're heavy.

 

Maybe ask Kurt which piston he used?

107,000 boosted miles comes to an end! - LS1TECH

 

4032's here, daily driver, 650rwhp on only 13 psi, will run up around 18 with bigger injectors. Winters here can get -30f for days at a time. It's quiet, even when cold. I have no complaints about them.

 

not quite sure, the machine shop should have set them to wiseco specs. think its around 4-5 thou.