Dropping in forged pistons?

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Dropping in forged pistons?

Postby zero06 » Tue Apr 23, 2013 10:24 pm

I am currently upgrading to a metal head gasket with the engine in the car, I was thinking it might be worth while to drop in some forged pistons and rods while i have the head off. the motor is a jdm rc motor that had 30,000k on it. what do you guys think about dropping in stock sized forgies? my concern is blowby, but the engine is fairly new... has anyone done this?
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Re: Dropping in forged pistons?

Postby celicast184 » Fri Apr 26, 2013 3:45 am

dropping forgies are a plus. now one thing you should check before doing so is cylinder bores first! if they are out of round, then itll be best to over bore the cylinders! if they check out within specs, you should be good to go. then determine your ring gaps based on what your planning to do with the motor!
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Re: Dropping in forged pistons?

Postby gearhead313 » Fri Apr 26, 2013 10:41 am

I did the same thing to my JDM motor. I just honed them out and popped them in. Just be sure to de-glaze the cyl walls, not sit there for an hour and resize them! I left the stock rods b/c if you change rods, you should have the crank polished and sized for a new set of bearings. Stock rods hold a fair amount of power, if you retain the stock rev limit.
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Re: Dropping in forged pistons?

Postby zero06 » Sat Apr 27, 2013 7:48 pm

is it a bad idea to change the rods without polishing the crank? like i said the car only has 30,000k
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Re: Dropping in forged pistons?

Postby zero06 » Sun May 05, 2013 2:26 pm

head is off now, I can still see the factory crosshatch. what do you guys think?
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Re: Dropping in forged pistons?

Postby celicast184 » Mon May 06, 2013 6:01 pm

i would check the bores first!!! remember if the bores are egg shaped, rings are not gonna seal well. as far as factory cross hatchings, new rings need to seat well. think of it as a puzzle where the edges fit really well without spacing in between each piece. the rings need to wear to the walls at a microscopic level. the walls now are cut to work with ur old rings, now new rings need to seat to a new wall!
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Re: Dropping in forged pistons?

Postby celicast184 » Mon May 06, 2013 6:07 pm

also, by changing pistons, it throws off the weight of the rotating assembly. i def would have the assembly balanced again. these are some of the things i would do before dropping forgies as a saftly concern! all the motors i have built had the assembly checked for roundness, honed, and balanced at the very least!
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