What's the point of aftermarket forged pistons/ rods on a mild N/A setup?

 

I would say just quality parts. You may not need something that strong for a mild setup but some people just want to put the best parts into their car. Its better to have forged than cast and always leaves the door open for a bigger setup like maybe if sometime down the road you decided you wanted to spray or something

 

A good aftermarket forged piston will take a ton more abuse than the stock cast piston. They are more important in boosted engines, but like he said above, it's nice to have them now if you're NA because someday you might wanna boost.

The drawback to good forged pistons is that like any quality part, they are expensive and because they tend to be noisy compared to stock pistons.

Sonny

 

Has anyone heard of decreased engine life being an issue with forged pistons?

 

no i haven"t heard anything like that but i think forged parts tend to get a lot harder than cast parts which may account for something like that if its true. btw i guess i would fall into this catagory. I have forged pistons in my car with mid compression(11.5:1) car still isn't running yet need a new oil pump should be up this week. I really didn't have much of a choice tho thats all that was available, not that i looked into getting cast pistons but i think the only companies that really make pistons for a b20 and je, weisco, and endyn. I got the endyn's cause that was all i could get mid compression bsides je and they where on some sort of nationwide backorder for rings

 

Is anyone aware of the fact that the Honda OEM parts are forged? Just because its weak is ignorant to assume that is cast. Take a look at the parts, they're forged. I swear, everyone is..... nevermind.

In a high compression n/a application, cylinder pressures can be higher than in a turbo car, so upgrading the parts to stand the abuse isnt a bad idea. Plus what good is an n/a engine with stock pistons. N/a should be more than just bolt-ons. With aftermarket, you can raise compression or even rod length. Move the ring pack and wrist pin higher on the piston and use a longer rod.

 

Actually, Honda pistons are hypereutectic cast pistons. Not forged. I think you are thinking of the rods and crank (which are forged, while many domestic automakers use cast rods and a cast crank).

 

Actually, this depends on what type of forged pistons you use. There are actually two types of forged pistons. There are racing pistons (low silicon) and street forged pistons (high silicon). Silicon tends to lower the thermal coefficient of expansion of aluminum. So low silicon pistons expand more when they heat up than high silicon pistons. As a result, low silicon pistons must run a larger piston to cylinder clearance. So they rattle more. But since low silicon pistons are stronger than high silicon pistons and since longevity is not too important for all-out racing, low silicon pistons are the pistons of choice for racing. High silicon pistons may not be as strong as low silicon pistons. But they are still MUCH stronger than stock cast pistons. And since they expand less than low silicon pistons, they can run piston to cylinder clearances similar to cast pistons. Therefore, they run quiet.

But back to the original question of why people use forged pistons in N/A applications. There are a couple of reasons why people do. One is resleeving. When an engine is resleeved, it is frequently to some non-standard size. An OEM cast piston is not likely available in the diameter required. The other is compression. If you wish to run a higher compression piston, an OEM piston is also not likely available.