Forged vs Cast pistons...

Reign_Maker

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Aug 31, 2005
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Anyone feel like learnin me the difference? :biglaugh:

Im wondering because I didnt know that JE makes a cast and a forged piston for the 7M... Why would you get a cast piston from JE? Why not just use your stockers? Arent stockers cast?

jake
 

NashMan

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Aug 5, 2005
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there alot fo diffent way's of casting and the type of content in the mealt that they use

just like some forged stuff is junk and the other are god like

hope this answer your qestion wiht out me trying to type alot fo words that you will most likly not bebale ot read
 

Reign_Maker

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Dont worry Nash man, I understand you... :D Thanks bro...

I just think its wierd that someone would buy cast pistons for a "built" motor instead of buying forged...
 

IJ.

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Mar 30, 2005
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Some types of cast pistons can be ran very tight in the bores so you get less slap/piston rock and can provide better ring seal.

Hypereutectic pistons fall into this group but as they're brittle can't stand much detonation so again tune is king!
 

Reign_Maker

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IJ. said:
Some types of cast pistons can be ran very tight in the bores so you get less slap/piston rock and can provide better ring seal.

Hypereutectic pistons fall into this group but as they're brittle can't stand much detonation so again tune is king!

IM THE KING!
rrksbo.jpg
meow
 

Reign_Maker

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IJ...

You said tuning is king... I said I am king... And a pic of a lion, who is king of the jungle... Im a LION! *meow*

get it?

blaaaaaaaaaaaaaaaaaaaaaaah... :D
 

souprat

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lets all say it together:

"i'm sofa king wee tard ed"

are there any aftermarket cast pistons that are capable of handaling more power than the stock pistons yet less expencive than forged ones? or is it just best to put up the money and go with forged pistons.(bringing it back on topic, lets see if i'm successful)
 
Mar 30, 2005
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hi jake :)

the only real difference between forged and cast is forged can withstand about 100c more. Forged pistons can break just as easy as cast if you really screw up. If you keep the heat under control you can make alot of power on the stock 7mgte pistons. The only problem with the 7mgte is the rings are gapped pretty tight, and when you bring the heat up they will expand to the point where the ring lands will pop off.

If your planning to build a real power plant, forged ROSS or CP pistons are the top forged stuff and use the rings that come with them ( NEVER GET TOTAL-SEAL RINGS ) with a slightly higher ring and piston/cylinder gap then OEM will give you some extra protection.


oh btw, im using stock pistons, and hastings rings. Piston to cylinder gap is .004", and my compression ring gaps are around .018". The car doesnt smoke on cold starts at all, and I dyno'd 350whp/330wtq on 10psi with 1000 miles on the engine. So there is proof that fairly high ring gap and slightly higher cylinder/piston gap wont lose compression/power =/
 
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IJ.

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NegativeGeForce said:
oh btw, im using stock pistons, and hastings rings. Piston to cylinder gap is .004", and my compression ring gaps are around .018". The car doesnt smoke on cold starts at all, and I dyno'd 350whp/330wtq on 10psi with 1000 miles on the engine. So there is proof that fairly high ring gap and slightly higher cylinder/piston gap wont lose compression/power =/
Not being a Cock or anything but how does that "prove" anything?

Unless you've tested with tight clearances V's loose you only have 1 data set and have no idea if there's a difference.....
 
Mar 30, 2005
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IJ. said:
Not being a Cock or anything but how does that "prove" anything?

Unless you've tested with tight clearances V's loose you only have 1 data set and have no idea if there's a difference.....

my point is there is no difference. I am just stating I am having no issues with the fitment specs im using. Just trying to make a point that its ok to go bigger.
 

IJ.

Grumpy Old Man
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How do you know there's no difference if you haven't ran the motor with tight clearances?

Again I'm NOT trying to be a Cock it's just that to make a statement like that you'd have to have solid comparative data to back it up...
(I happen to agree that High Out put motors should have slightly looser end gaps to prevent them nipping up)
 

souprat

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i had a thought at lunch today:

if you buy a new set of pistons from toyota and get them cryogenically treated the pistons will grow and get bigger right? so then you bore your block out to the right size so you get the right clearances right? what do you do for your ring gaps? because the cryo treatment would make the ringlands smaller right? i'm not an expiriaced engine builder so i dont know if they make rings that are different thicknesses so you could maintain the right gap, or do you get the pistons machined after they are treated?