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Old 07-12-2007, 12:28 AM   #1
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Default Performance pistons alternatives

are there any other alternatives to getting some pistons that can put up with a little more abuse than stockers without going to the 400-600$ big boys forged units? like a piston that goes through a more quality casting process or somthing along those lines.
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Old 07-12-2007, 12:39 AM   #2
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are there any other alternatives to getting some pistons that can put up with a little more abuse than stockers without going to the 400-600$ big boys forged units? like a piston that goes through a more quality casting process or somthing along those lines.
Find out more about the 323 pistons. I know with 323 rods the 1.8 can handle 300hp. What are your power goals?
http://members.aol.com/solomiata/MX5Engine.html see this link. The 1.6 323 pistons are 7.8:1. 92-94 sohc 1.8 Protege is 8.2:1 when used on a dohc (miata) head.
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Old 07-12-2007, 12:42 AM   #3
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I'm not a fan of forged pistons myself due to their thermal expansion and wear characteristics.

Mazda makes overbore versions of stock pistons and you can get their domes ceramic coated and their skirts dry filmed. Lots of info available, use google.

Ben
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Old 07-12-2007, 12:58 AM   #4
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I'm not a fan of forged pistons myself due to their thermal expansion and wear characteristics.
I find that funny because so many people run them. Thermal expansion is of course taken into account in the design, that's why there are many different barrel-ity and oval-ity profiles. Then you got clearances, skirt lengths, etc etc etc.
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Old 07-12-2007, 12:48 PM   #5
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The tops of my stockers in my '90 looked surprisingly good after I took the motor apart after snapping a rod and shooting it through the block running 16 psi and a 50 shot (and knocking like hell). Not many people are killing stock pistons when their motors go.

I like Ben's idea.

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Old 07-12-2007, 12:54 PM   #6
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I find that funny because so many people run them. Thermal expansion is of course taken into account in the design, that's why there are many different barrel-ity and oval-ity profiles.
They all experience some degree of piston slap when cold. Piston slap = wear. A lot of these guys with forged pistons get to tear down their motors at regular intervals, say every 50k miles. Others just turn up the boost a little more to compensate.
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Old 07-12-2007, 01:14 PM   #7
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importperformanceparts.net, you can get oem equivalant pistons in any overbore. then get a good ring set for them.

Last edited by Braineack; 07-12-2007 at 05:33 PM.
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Old 07-12-2007, 05:32 PM   #8
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They all experience some degree of piston slap when cold. Piston slap = wear. A lot of these guys with forged pistons get to tear down their motors at regular intervals, say every 50k miles. Others just turn up the boost a little more to compensate.
how many of these people let the motor warm before driving every time?
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Old 07-12-2007, 05:33 PM   #9
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importperformanceparts.net, you can get oem equivalant pistons in any overbore. then get a good ring set for them.
the link does not work.
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Old 07-12-2007, 07:13 PM   #10
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thx guys
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Old 07-12-2007, 07:25 PM   #11
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how many of these people let the motor warm before driving every time?
What's appropriate warm up time? 1 minute, 3, 8, 20 minutes? Sitting idling or driving in 2nd at 2500 rpm?

The problem herein is that the motor is comprised of many different items each of its own metalurgy. So each item has its own heat transfer and expansion properties. Also all the parts of the motor aren't uniformly introduced to heat.

Piston slap is gonna happen. Your brand new forged pistons will strike your pretty freshly honded cylinders, slowly and eventually causing wear. It is going to take a long time before this wear is problematic, and at that point you may freshen the block, or you may just add a little boost.

Coincedintally, a few weeks ago I read an interesting article written by an injuneer explaining his theory that people who have crank issues get in and drive their cars hard before the motor came up to temp.
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Old 07-14-2007, 12:32 AM   #12
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my cp forged pistons slap on startup and sound like a desiel untill the engine gets up to temp and stays there for a min or two. after that its quiet and runs like a dream but on start up it runs a little rough and sounds like ***
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Old 07-14-2007, 02:47 AM   #13
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CP....eeew
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Old 07-14-2007, 01:33 PM   #14
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Where could you find a good ring set? I've been thinking bellfab rods + new OEM pistons and rings will be good for about 275 or so hp, would that be safe?

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importperformanceparts.net, you can get oem equivalant pistons in any overbore. then get a good ring set for them.
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