Guest 240Rob Posted February 3, 2004 Share Posted February 3, 2004 I have a 80 280zx and i need a little direction. I plan on proably road race or drag race but mostly to drive on the street to terrorize local Honda and such when I'm not driving the 240(SX). It has about 120 k miles on it, doesn't burn oil or leak oil for that matter. 1 Should I rebuild the motor or just freshen it up new gaskets 2 How much would a Nismo .6mm headgasket bump up compression and what is a safe amount to get the head decked? 3 Would it still run alight if I remove and blocked off the EGR? 4 Also I have a junk 85 300zx non turbo 5 speed that I'm about to get rid of is there anything use full on that car that could be used on my Z? 5 Is there a short throw shifter for the 5-speed Z or another model work? any info will be helpful thanks Quote Link to comment Share on other sites More sharing options...
akeizm Posted February 3, 2004 Share Posted February 3, 2004 I can only answer no1. If it ain't broke. don't fix it heh. But replacing the gaskets wouldn't hurt (prolly better off you do, just to make sure its not leaking etc) Quote Link to comment Share on other sites More sharing options...
Guest smoov280zx Posted February 3, 2004 Share Posted February 3, 2004 That's pretty low miles considering how long L6's last when taken care of. I'm on 231K myself and it runs faster than stock with the exhaust and swapped dizzy, even though the compression is about 10-15 lbs lower than optimal. I'd say do a compression test, and if it's good numbers then dont mess with the internals. Get the cooling system flushed for sure before your auto-x, just to be sure. Do a search for the L engine calculator or download it from zcar.com, it lets you check out mucho numbers for different engine configurations, compression, bore, stroke, chamber vol etc. If you cant find it, email me and ill send it to you. Me, if i changed the head gasket, i would probably rebuild the head while it was off since youll be racing it. I dont know about classes in auto-x so i dont know if shaving the head would put you in another class. You can shave yours if you want, but if you have an n47 you can just switch the pistons to the later flattops and you'll bump your compression from about 8.3 to about 9.8, more if you get the thinner head gasket. If you do that you've got a factory spec head you can level later if you need to. I think the search is down on this site right now, but zcar.com also has tons of info about "n47 with flattops". If you know this already, sorry for droning on. Dont know about the last 3. Quote Link to comment Share on other sites More sharing options...
Warren Posted February 3, 2004 Share Posted February 3, 2004 In reference to #2, if you're referring to the stock head gasket, it is not 0.6mm thick...it's 1.25mm thick. If you DO deck the head, plan on shimming the cam towers the same amount or you'll throw your cam timing off slightly. I hope I read your post correctly. Warren Quote Link to comment Share on other sites More sharing options...
Guest 240Rob Posted February 4, 2004 Share Posted February 4, 2004 thanks for the info .6mm is compressed thickness, but I think I found out what I'm going to do Header with 2 1/2 in exhaust with a free flow muffler Mild Port and polish with gasket matching Cam don't know which one yet with heavier springs and titanium retainers Underdrive crank pulley Remove and block off egr passages Bump up oil pressure a little with springs(already got them) Alum flywheel and Dual Friction clutch Maybe deck the head .020 I think? I have a mallory ing box but have yet to hook it up what do you think? thanks Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted February 4, 2004 Share Posted February 4, 2004 Your biggest increase in performance will be a boost in compression. If you plan on pulling the head and doing work there, you may wish to consider a set of flat top pistons or an 81-83 n/a short block (already has flat-tops) with your head. Then you won't have to spring for the .6mm gasket or shaving your head, and either a stock or a good ole felpro headgasket will yield 10:1 compression. Quote Link to comment Share on other sites More sharing options...
Guest 240Rob Posted February 5, 2004 Share Posted February 5, 2004 Orlando huh live about 45min from there race my S-14 at the track about once a month. Thanks for the info something i'm going to check into if I could get a block with fairly low miles and pretty cheap most of my money goes to my 30 over KA turbo block on the stand Also was reading about stroker cranks what diesel motor did they come out of? At the Nissan dealership I work at there is a diesel Maxima wagon don't know what year or engine model yet they are proably going to haul it off this week to start building the new dealership Thanks Quote Link to comment Share on other sites More sharing options...
Mack Posted February 5, 2004 Share Posted February 5, 2004 yup, that old P.O.S. maxima deisel wagon has the heart of the stroker motor, the crankshaft. 81 to 84 maxima desiels. as long as its got a deisel and its an L6, pull it! and if you want to get rid of the rods after your done, I'd be glad to take em off your hand for ya! its a little pet project..... be forewarned, a stroker project is by no means cheap or easy. just ask around. You'll need some L24 rods and I am sure you already have a line on some KA pistons, lol! also, if you dont want to go thru all the hassle of switching pistons, you can get a head from a gas powered maxima of the same vintage and put your heads intake valves in it and pick up a similar boost in compression, without shaving or shimming. McAdam Quote Link to comment Share on other sites More sharing options...
Guest 240Rob Posted February 5, 2004 Share Posted February 5, 2004 cool thanks for the info will look around for a head thanks Quote Link to comment Share on other sites More sharing options...
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