Atomic Motors (Merged Topic).

[Ninka]

the rattle from the piston is due to the pistons having a less/more(cant remember which) silicone content in them, therefore they expand alot more than cast with heating up and cooling down hence the knock louder when cold 

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then why is it then, that nizpros bottom end dont rattle? is it that "you get what you pay for?" "you pay peanuts, you get monkeys?"

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I think you are spot on

Even though the discussed pistons are strong, they are not designed with street cars in mind, and thus the piston noise is not that important.

I know Nizpro have developed theirs specifically for use in the XR6T and with the least noise possible, so that's probably the difference.

[F6 RAPID]

mine runs a heap of power - loves it.

will do more shortly.

[Trough Lolly]

im with turbotrana on this... how many T with bent rods compared to holes in pistons do u see when over 300kw!

for proof look at the edited phoons.. running well over 350 and no probs due to better rods.

[turbotrana]

So for those who really feel they need forged pistons what is available and which forged pistons are the best.

CP Pistons - these are known to rattle around $1600

ACL Forged piston (These are Ross Pistons) - anyone had experience, around $1200

Arias Pistons (Marketed by Rocket industries) price ???

Special Piston Services Aust- good reputation, I think nizpro use, around $1700 Do these rattle????

At the moment only Ford have replacement oversize cast/hypereutectic pistons at over $1000 a set so if you do need to go oversize the forged option is not much more expensive.

Also on the rod side of things what are the options here

Argo H beam around 2k

Atomic H beam around 1800

Carillo I beam cast ???

[Guest]

the rattle from the piston is due to the pistons having a less/more(cant remember which) silicone content in them, therefore they expand alot more than cast with heating up and cooling down hence the knock louder when cold 

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then why is it then, that nizpros bottom end dont rattle? is it that "you get what you pay for?" "you pay peanuts, you get monkeys?"

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ok its not the silicon content that is the main factor its the manufacturing process!

forgings have a more dense contruction (more molecules per sq. inch) thus has a higher expansion rate thus requiring larger piston to bore clearances!!!!

high silicon content does effect the expansion rate but as silicon is a higher temp threshold than alloy its less likley to expand as much thus reducing the need for larger clearences effectivly quietening the engine down!

now to the main reason the skirt length this is the single most common reason for piston slap also the single most power robbing part of the piston

the longer the skirt the less piston slap and the more power loss due to friction

the shorter the less power loss but more noise

take your pick cp have the least restrictive pistons and when fitted correctly are quiet or

have the other brands (I have 2 others that I have used with success) still reducing power loss and making it easier to keep quiet or

stick to std pistons and just change rods

all three options are available through me!

[turbotrana]

Sorry forgot PAR conrods about $1800.

Its great to see heaps of choices straight off the shelf. It will only get better

[youngy]

my atomic engine is quiet as now its run in, just the loping idle from the cams.

[hsv eater]

my atomic engine is quiet as now its run in, just the loping idle from the cams.

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so then youngy,once its run in, it doesnt rattle anymore or does it rattle less?

[F6 UTE]

I have suggested to both the wog and Simon, why oh why do we NEED forged pistons?? Rods and oil pump gears. that's all..

Yes they are less prone to (damage from ) detonation, but if you guys (tuners in general ) can tune as well as your reps suggest you can, we shouldn't need them, should we?? I'm no idiot, and I can get off hte gas at any sign of det too.. We can run knock sensors to drop timing on a daily map, what's the issue??

I believe ( and I'm no expert ) that ceramic coated stock pistons will suffice for 80% of combinations out there.. Yes, high HP applications will be better served with forgies, but meh, I reckon save the coin for most of us..

Edited 10/10/06 12:13 PM by F6 UTE

[Guest]

I have suggested to both the wog and Simon, why oh why do we NEED forged pistons?? Rods and oil pump gears. that's all..

Yes they are less prone to (damage from ) detonation, but if you guys (tuners in general )  can tune as well as your reps suggest you can, we shouldn't need them, should we?? I'm no idiot, and I can get off hte gas at any sign of det too..  We can run knock sensors to drop timing on a daily map, what's the issue??

I believe ( and I'm no expert ) that ceramic coated stock pistons will suffice for 80% of combinations out there.. Yes, high HP applications will be better served with forgies, but meh, I reckon save the coin for most of us..

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well benjamin as I stated to you I'm happier with the casts!

and as to det damage well the forgies being of a more dense contruction like yourself \|/ than the cast is more prone to det damage so get your facts straight \|/

and last of all you dont save much $ over cast and os cast not being available hence the volume of forgies going out there