if you were to build an engine, would you use the stock cast iron pistons or the forged if they yielded the same compression ratio? it seems like everybody likes the integra and civic typer pistons. yes they are sort of inexpensive, but arent they overated? why wouldnt you pay a little more for forged ones?

 

cast ALUMINUM...not cast iron pistons.....Sheesh,those would be some heavy *** pistons!Just depends on how much you wanna spend and how strong you want the motor to be.

 

$200 vs $500 is a big difference.
The fact is forged will be stronger and lighter, better balanced. But will also require aftermarket rods. Me personally, I would go with CTR, .25 overs but thats cause I'm about the all motor baby.

 

it's fine to use forged pistons on stock rods. If you're going all motor, it'd really just depend on your budget.

 

What is the compression ratio on the CTR pistons?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BME1986 &raquo;</TD></TR><TR><TD CLASS="quote">What is the compression ratio on the CTR pistons?</TD></TR></TABLE>
depend on what motor its being put in

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by whiteinteg95 &raquo;</TD></TR><TR><TD CLASS="quote">if you were to build an engine, would you use the stock cast iron pistons or the forged if they yielded the same compression ratio? it seems like everybody likes the integra and civic typer pistons. yes they are sort of inexpensive, but arent they overated? why wouldnt you pay a little more for forged ones?</TD></TR></TABLE>

same question im thinking of also. I always see everyone with CTR/ITR stock pistons but i hardly see anyone with Toda's or the like. Im also in the same boat cause i wanna rebuild also, i guess i will start a thread myself. I wanna take my **** to the track so i might go with Toda's high compression forged pistons.

 

I love my CTR pistons, they're a bit heavy though.

 

I'd go with the Type R pistons because I don't believe aftermarket forged pistons are designed to last as long as factory pistons. They might be stronger (which I don't see as being necessary in an N/A motor), but they won't last as long.

 

i dont understand what you mean by last as long. How can the forged pistons not last longer if they are stronger.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by whiteinteg95 &raquo;</TD></TR><TR><TD CLASS="quote">i dont understand what you mean by last as long. How can the forged pistons not last longer if they are stronger.</TD></TR></TABLE>

The same way titanium retainers wear out after a couple thousand miles, despite being stronger.

Strength and durability are two completely different things, and don't necessarily go hand in hand.

 

its because the piston to wall clearances on forged pistons are a lot higher. Cast pistons expand (when heated) at a more predictable rate than forged pistons, so you can run tighter clearances....
Why are forged pistons lighter, becuase of the finishing process? I mean, compressing a large piece of metal down to a small piece shouldn't be lighter than just casting a small piece, no?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lsos &raquo;</TD></TR><TR><TD CLASS="quote">I don't believe aftermarket forged pistons are designed to last as long as factory pistons. They might be stronger (which I don't see as being necessary in an N/A motor), but they won't last as long.</TD></TR></TABLE>
Especially if you don't clearance them correctly.

I'll post some pics and notes up of a set of JUN Cosworth pistons [std bore] that came out a R block. It wasn't pretty, especially with only 9k miles on those pistons/block.

 

Pistons 1 and 4 suffered detonation. You can see the knicks where it looks like somebody jabbed it with a steak knife.

The pistons were never clearanced when they were initially put in.

Bore's all look like this. After the machine shop honed the bores out, they found a vertical 3/4" crack in the #1 cylinder wall. They're going to resleeve the cylinder.




Chunk missing out of the valve pocket edge.


Piston #4.


I forgot how big that feeler gauge was, but it was something around .010".




After the pistons were taken off the rods and cleaned.










I want to say that the JUN Cosworth pistons are 2618 alloy. Compared to 4032 alloy, 2618 has less silicone content, is less brittle, more dense in aluminum, and handles heat better. There's numerical data I have referenced that I can put if anybody asks for it. It's on the other computer right now.

They're pretty light tho. With the rings and wrist pins still on there, each one only weighed around 300g. Wrist pin typically weighs 88g, and rings usually weigh 16g. That's about 200g per piston, compared to 333g for a PCTX .25OS piston.