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Discussion Starter #1
OK so ive got my new race engine together and ready to go but im just wondering what sort of rpm people are running nippon racing pistons at? im a bit dubios about running them past 8500 because theyr jsut so damn light im afraid they will break , i can remember when i put them in but they do have a relativly heavy crown and lgith skirt correct? in which case i may end up seperating the crown from the skirt and sending a rod through the block. Is there anyone out there that ahs experience with these pistons? this is a circuit racer so it will see high rpm from long stints not just a quick run down the strip.

-hamish
 

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8500rpm+ I would recommend a balance of the drive train for that rpm, forged pistons tend to be much more reliable than cast units, not only the crack, rods, and pistons, but the flywheel too, I've seen them shred before, its not very pretty...

As far as Nippon, i dont know too much about those pistons but Nippon is also known as Nippondenso, which makes OEM parts for Honda and Acura, you can judge on your own from there.

How heavy are those pistons compared to stock?
 

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Discussion Starter #5
transzex said:
unless you have a HUGE cam and tuned length ITB's, no need to go beyond 8000 rpm.....no power up there.
im not really spose to give particulars of the cam grind since its taken a few years and a few dead engines to develop them but they are over 300 degree , ITB's are on there way next off season and im considering if i should just pull it and drop some forged pistons in at that time aswell , i brought the nippons on a spur of the moment thing and now i regret it. Everything else is well up to the task but these i think are gonna be the weak point and i really dont wanna destroy an engine ive invested 20k+ nz dollars into.
 

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Brokedick Millionaire
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you understand the piston acceleration speeds your trying to reach, the ONE reason B series are better..........

over 300 is not much, as likely it was measured at .001"......

Toss out some 280-282 @ .050" valve and .490" valve lift numbers.

You asking too much, esp. if rpms will be sustained.
 

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Discussion Starter #7
NO that is at 40 thou , i do understand its a very large cam for and engine that has such an out of square bore but hey thats the challenge in it , its too easy to build a high rpm b-series. I cant remember lift figures off hand but they are not extreme since the more lift the higher the rpm you need to make them work so thats why we have opted for alot more duration only problem was stopping the bastard oversized valves from hitting the pistons or hitting eachother. I really should of gone for a forged piston from the get go but ah well i will run with what i have for now and then strip it down next off season.
 

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Brokedick Millionaire
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bottom end cannot sustain the high rpm and piston speeds that a cam like that needs to work at.

How many engines have you killed try to get that cam to work?
 

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Discussion Starter #11
Ah i see what you mean i thought you were talking about valve interference , yes we do understand that those sort of speeds is just crazy , this will be the second engine to try these cams on , the first one went well until it spun a bottom end so this time we have payed better attention to the oiling to help remedy this , also this crank we are using is a custom forged job that is light as hell so hopefully that will make a sizeable difference. We have run the specs through a pro simulator and it seems to think it will survive but then again how accurate is a computer program when compared to real life.
 

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Discussion Starter #12
oh i forgot to mention im not paying the bill on this engine its my sponsors little pet project so if it pops it pops but if it lives then its going to be alot of fun
 
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