I am going back and forth here.. trying to decide which pistons to get for my build.
Been doing alot of research etc..Are the Wiseco forged pistons 4032 or 2618? I know the CP are 2618.. and I know all the differences between the two materials. Since I am having a (highish) boost application.. (occasional n20 as well).. I will be planning on the 2618 material. I like the "anti-detonation" grooves that the wisecos offer.. but from the "research" I have done.. the CP seems to be a better machined product with stronger ringland design.. which would be very good for abuse from detonation during tuning etc. As for the piston to cylinder wall clearances.. I may be a little confused with this.. but so far I have found its.. .001" for every inch of bore size (4034 material) .003" for every inch of bore size (2618 material) IIRC.. They recommend going up to .004" for every inch of bore for anthing over 23psi of boost. Which seems kind of large to me. Stock 300zx bore is 87mm = ~3.43" I plan on doing a 87.5mm= ~3.44" (.020" over)
Possibly 88mm= ~3.46" depending on cylinder wall condition. (.040" over) I remember hearing something before ( I belive it was Ash when I met him).. That is somthing like recommended .0001" extra cylinder/piston clearance for EVERY extra ~100hp (on 2618 forged pistons) (whether that be high boost or n20). I may not recall this correctly, it has been about 4 yrs since I remembering talking about this.
Ash I apologize if it wasn't you I talked to about this before. For arguements sake.. If I plan on making 900-1000rwhp with my 150shot direct setup and ~28psi of boost.. If for example.. I went with a 87.5mm = ~3.44" bore.. And do plan on boosting more than 23psi (not daily) with the occasional 150direct shot of n20. Would it be a safe bet to machine.. lets say.. a .0038" piston/wall clearance? Kind of "middle of the road"? To alleviate possible problems of piston slap and still give ample room for expansion due to the boost levels? Also, Does anyone know the skirt taper of the CP.. I know the new wiseco design is .004" taper.. which is supposedly doing great. Experiences with piston slap vs your cylinder / piston clearance? (and which piston brand/material (4034 or 2618) you are using. I have a set of Eagle rods with Kyle@IPP.. but I am considering upgrading to the Pauter rods since I really liked how they are built when I saw them in person. Both Eagle and Pauter use ARP2000 hardware. I was thinking of running cometic metal head gaskets since I plan on running n20.. but may use stock since I know the MLS gaskets are very finicky when it comes to torquing/surfaces. What are your guy's opinions on all of this? Planning on running a stock UN-ground/machined, still nitride heat treated crank with stock rod, main bearings. ARP main/head studs.. I have assembled motors before (4G63, VG30DETT).. but I have never built a motor from scratch. I want to build this myself.. (except the machining of course). I just need some help with these details :) I have been going crazy spending hours looking around online and FSM. The heads... I have just opened up the exhaust runners/ports a little bit with a small lip to reduce exhaust reversion. I don't think I will be doing anything to the intake side of the head since its a boosted motor anyways.. Thanks for any of you guy's EDUCATED RESPONSES.
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AIM:Shawn300zxTT "-Any closeups on the nuts? - zboost(tx) 19:17:53 08/08/05
-Not really something you want to ask another man about... (n/m) - LordZ 19:24:00 08/08/05" "I just took 45 min and scrubbed the heck out of my rear"
teambushido(San Diego, CA) 19:24:51 12/11/04 -1991 Stage _ TT 5spd (Upgraded to hell and back)
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