mini22

First I would like to say hello to everyone here at yotatech. I have been one of those looky loos over the past couple of years gaining valuable info. I am involved in dirt circle track racing in a 85 celica with the late 22r motor swap. Stock bottom end just a couple of upgraded hardware parts. lc stage 4 cam with intake and 500 keith dorton 2bbl. I have had much sucsess with the stock cast pistons but I have a new venture with the 22r. I am building up an identical motor to plant into a fullsize sprint car chassis. My question to the members is what are their experiences with switching to the forged pistons and how much difference the high comp pistons made in their ride? any input appreciated..

deviousKA

A cast piston is going to run a tighter tolerance and distort less irregularly than a forged piston. A cast or hypereutectic (high silicon cast piston) is always going to be better up to the point that it shatters due to high speed (6000+fps) or melts due to heat.

Forged pistons are stronger, but they expand a lot with heat and sometime irregularly. A wider cylinder>piston tolerance is required so there will be a loss of compression and piston slap when cold.

No 20r, 22r, 22re needs a forged piston unless its a high boost turbo application. Even in a race application I would advise against it. What you want is a piston that expands and distorts so little that you can run the tightest tolerance possible.

Although it should be said that piston technology is improving every day and some forged piston manufactures are able to run a tighter tolerance than they have in the past. I had been told once by a prominent piston engineer that it is not the forging process so much as the machining processes that dictates how the piston will distort and expand with heat. It was also mentioned that if the machining process is done on multiple machines or if the piston has to be set up multiple times, some inconsistencies can result, causing more need for a wide tolerance.

mini22

thanks for the input. i just cant bring myself to spend the 600 buck for 4 pistons from lce. i could get ahold of a forged set for about 400-500 but i just want to know its worth the investment. im looking towards the keith black 9.7's/1 hypereutectic. not sure what the stock's are rated at but for 200 bucks a set it seems like an ok deal.

jwilli

I have a 1988 toy. 4x4 . The engine i
Torn down and im about to go back together. I would like to get more low rpm horsepower for mud riding . I have 33" buckshot bias tires . What can I do to get more power at lower rpm

JasonYota

iTrader: (1)

Lower gears, either in the diffs or transfer case. don't waste your time on engine work.

wyoming9

iTrader: (1)

What Jason said!!!

These engines are not a good platform for building Horse Power it is very expensive for very little gain.

What your doing I would find the low end torque more benefit then Horsepower.