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Whats the engine condition like?

Still like new upon start up no extra noises or loss of compression?

Thanx peoples. I'm in the process of a engine rebuild and would like to know if the benifits out weight the negatives for a daily driven 25-30,000km a year driven car. I need the car/engine to last at least another 3 years.

So basically what I'm asking is will forged pistons last 100,000km's and still have near perfect compression and oil usage?

Joel Joel Joel, mate you're gunna' research youself into an early grave! :D

I'm sure if you talk to enough people & read enough web info you'll get answers/opinons that vary wildly.

I can honestly say I have never heard anyone complain about the life of a forged piston equiped engine.

Edit - Cold starts - no change from when it was stock internals. Basically the engine is as smooth (if not smoother) than it use to be! The choice of pistons is one thing but the quality of the build is the big one (ie tolerances)

hahah lol.. I've just been down to speak to the blokes at RPM. There's no long term reliability issues due to forged pistons IF the bore is machined to suit the pistons and clearances are set correctly.

They mentioned that black CA18 180sx that is making 310rwkw at the wheels. Thats been running for around 3years with no drama's at all, and several VL Turbos.

They also mentioned.. Porsche, BMW etc. run forged pistons in their HP engines with no problems.

I think its a bit of a wives tale from the old days where forged pistons required large clearances hence sloppy bores that caused lots of wear on start-up eventually causing an early retirement.

I was out at AIR with James & Shaun @ the last AIR comp/street meet & James was talking about how poor it is to see freshly rebuilt engines in this day & age that burn oil.

4AGZEs use forged pistons from the factory also. The old loose pistons are long gone. Piston technology has advanced alot since those days and a car with forged pistons should be nice and smooth these days as long as they are installed with the right tollerances.

Geoff.

Didn't know that pistons wore out, my understanding is the rings that wear out, think about it! So rings are just as important if not so more, and yes, the higher the silicon content in the metal composition of a piston, means it will require more clearance, if nec, just warm it up nicely. If they were a prob. big dollars exotics would not use them instead of hypo pistons.

Thanx ppls.. :cheers: Makes me feel better.

I'm going Wiseco as they have been around for many years and are avaliable at a snap of the fingers for $1400 with rings.. Also little bit of trivia.. Did you know Wiseco make the rings for a lot of the top brand pistons.. CP, JE etc was in the list.. :)

Just as a matter of interest, what piston bore clearances are you guys running ?

With my Arias forgies the bores were finished oversize to give seven thou clearance, that was with a turbo Ford six cylinder motor that has a 94 mm bore. It lasted about 30,000 Km and had some serious ring sealing problems.

I still have these pistons attached to Crower rods, but no digital camera here unfortunately.

Warpspeed... 7 thou is a lot, over double what wiseco recommend.

Wiseco recommend 3 thou for a street car or up to 24psi and 4 thou for 24psi+ & if the car is being used for race.

Warpspeed.. That wasn't an older 250 ford motor was it?

I had a TE cortina that I had a little bit of work done to when I was younger.

I found after 200,000km's (probably had the clock wound back though) the bores were glazed and had a huge lip that required the bore to be bored out 1.5mm. Maybe the reliability of forged pistons in some motors is greater than others. The RB's are known for having very clean new looking bores even after hundreds of thousands of kays.

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