Mike Posted April 27, 2000 Share #1 Posted April 27, 2000 -- Group Message from "Dan Baldwin" <danbaldwin@hotmail.com> -->I was thinking of building a 3.1 liter.A fine ideer! I already have a 2.8 with a P79>head. I was wondering if this is a good head to ues or not.Not the best head for performance. Low compression and poor exhaustport design. N42 is what I'm using. Higher compression and thepreferred square exhaust ports. Others prefer the P90 turbo head,which also has square exhaust ports.I would like to>be able to drive this car on the street and be able to use pump gas.With the N42 head and a 2mm HKS head gasket, I'm at 10.14:1. somewhatsteep, but I ran mine like this with the stock cam (hotter cam allowsmore compression) at something like 10-12 degrees ignition advance atidle and had no pinging problems using 93 octane pump. With a hottercam, I now run more ignition advance, ~17 or so.With a P90 head and 1mm HKS gasket, you'd be at 9.75:1. Shouldn'tbe a problem. Also>any suggestions on where to get the crank, rods, and pistons besides Nismo>and MSA would be appreciated, they are kind of expensive($1800)Time to scour the junkyards, or post to this list and the big list(go to www.zhome.com to find out how to join it) for the desiredparts. 240Z rods, diesel crank from a diesel Maxima, and get newKA24 pistons. If you're gonna be racing or doing a lot of high-rpmusage, you might consider having the rods shot-peened and havingthe pistons cryo treated or something. If you're breathing throughstock FI or SU carbs, you won't be revving high enough to worry withit.FWIW, my 3.1 breathes through 240Z SU carbs which, in spite of a290/.503" cam, limits my rpm to 6500 or less (6500+ in lower gears,just over 6000 in 4th). before the cam, I was limited to 5000-5500.I don't know how much more the stock FI flows than SUs.BTW, I didn't have my rods shot-peened or pistons treated when mymotor was built. If I was doing it again I probably would.3.1 with SUs (or with FI) is a KILLER street setup. I do a fairamount of track work, though, and find myself in need of more.Still, even at the track it's great to have a ton of low-end, and atthe high end even though torque falls off, it's still aheadof a stock L24, and monster torque is only an upshift away.I really need 3X2 44mm or 45mm carburetion to take full advantage ofthe motor, though.Dan Baldwin'71 240Z 3.1________________________________________________________________________Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com --------------------------------------------------------------©The Internet 240z-Club - Our Web Site: http://www.240z.org Our Bulletin Board: http://www.240z.org/forums.htm Send your Email messages to: mailto:240z-club@peak.org-------------------------------------------------------------- Link to comment Share on other sites More sharing options...
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