7mgte reliability

[Miguel]

Hey guys ive been reading that forged pistons arent good for a daily, what do you think?
I have the following
-probe forged pistons
-stock rods
-king bearings
-brand new oil pump with steel braided hoses
-machined/honed
would the forged pistons wear out fast or whats the deal? :1zhelp:

 

[Nick M]

Wear out fast? That would defeat the purpose of forged if it is on the losing end of entropy on the cycle. They contract when they cool and as such are noisy at start up.

 

[emericaskater285]

Why would OEM's use forged pistons in many many applications if it were going to wear out quicker? if its a daily driver and not making over 500hp, and has a half ass decent tune on it, you will have bearing/rod issues before you will have pistons fail. (as long as you don't have an injector failing, or some other issue like that the pistons will outlast the bearings, and most likely rods)

 

[emericaskater285]

Wear out fast? That would defeat the purpose of forged if it is on the losing end of entropy on the cycle. They contract when they cool and as such are noisy at start up.

I'm not disagreeing when I say this, but my wiseco's are quieter than the factory cast pistons in all 3 of my engines that have had them vs my factory engine, and others I've heard. I know there was a brand out there that had shorter skirts (je or cp iirc) and they made some noise upon startup.

Idk what the first engine had for ring gap (I bought the car with the engine already built), but the two latest built engines I've opened up the ring gap to the larger end of the spec.

 

[Miguel]

Thanks guys! People i know swap their 7m for a 2jz And i decided to keep mine. so itll last as a daily, im aiming at 450hp with 550rc injectors. And the forged pistons have shorter side skirts than oem cast ones.

 

[Miguel]

are my pistons supposed to be a loose fit or tight fit ?

 

[emericaskater285]

are my pistons supposed to be a loose fit or tight fit ?

Do you have rings on? what do you mean by loose/tight fit? that question is vague.

the sideskirts on some of the pistons were short that it would cause a bit of slap at idle, but its not always going to mean its going to make noise because they're shorter.

 

[Miguel]

I took the rings off to measure the clearance from the cylinder wall and its pretty loose, ahhh got it.

 

[supraguy@aol]

There needs to be a bit of a gap for heat expansion. The specs should have been included with the pistons, as well as ring gap.
If not, call Probe and they will give you the info.

 

[Miguel]

Alright I measured the piston to wall clearance and for probe pistons the max .006 in and my measurement is .008, would that affect it?