Guest reckless76 Posted October 15, 2004 Share Posted October 15, 2004 Hello all I just came up on a 1980 280ZX for $400. It's straight, only one ding in the back, only topical rust, and starts and runs great. And it comes with a second motor!! So after minutes of concideration, I decided to buy it and build it up. I found this place during my research and have read quite a bit.. But naturally, I've got a bunch of questions I was hoping you guys could help clear up.. So uh.. Sorry in advance for the length... Here are my goals: Street Legal, pump gas, get as close to 200HP as possible, stay smoggable in California, stay N/A The motor in the car has the N47 head, while the other motor has the N42. I'm figuring I'll use the N42 as I've heard good things about that, while I've heard nothing about the other. I'm assuming they both got the same blocks as I couldn't find the number... And I'm not worried about dished pistons or flat, cause I'll be replacing them. So after looking through the zcarparts catalogue and reading this site, I figured I'd have to take the entire motor apart.. I was looking at the new big bore kit, and upping displacement to 3.1, but I think it said compression would be too high for pump gas. I was wondering if a 2mm metal head gasket would fix that. I was also looking at the stage 2 cam kit, hoping that would be the best balace of drivability and performance. And of cource the port and polish of the head, but I'm not quite sure what I should tell the machinist to do. I've read about machining the exahust ports, combustion chambers, and intake, and also shaving (don't know what that is), but I'm not quite sure how much to do of any of it. As for fuel, I need to keep it FI... So I was going to go with a larger throttle body and injectors.. I read that a different O2 sensor might be needed.. And I heard that the zcarparts TB was crap, and the 60mm off the 240sx was recommended? So how close to my goals you guys think I can get with that?? Am I missing anything? I'm probably going to start this next summer, after I've saved all the money I'm going to need.. thanks in advance Quote Link to comment Share on other sites More sharing options...
Guest 240zt Posted October 15, 2004 Share Posted October 15, 2004 zx or zxt L28 or L28et? Quote Link to comment Share on other sites More sharing options...
Guest reckless76 Posted October 15, 2004 Share Posted October 15, 2004 Just the zx with the L28E no t It's the 2+2 I know it's not the ideal platform to start.. but i'm not really that picky.. Quote Link to comment Share on other sites More sharing options...
Guest 240zt Posted October 15, 2004 Share Posted October 15, 2004 sadley it takes lots o money to make a L28E go fast being as that T has lots of different parts .... your in the right place tho. But 200 hp isnt a hard target at all Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 15, 2004 Share Posted October 15, 2004 My opinion is that 200 WHEEL hp is going to be tough to come by and remain smog legal. I think realistically you're going to need a cam to get there which is going to make your HC's worse, and the extra compression might make it really tough to pass the NOx part of the emissions. I don't think it's that hard to build a 200 wheel hp FI NA L28, I just think the smog legal bit is going to be really tough. 200 bhp is no problem, I think Pete S is pretty close. He's putting 164 to the wheels with a flat top L28 and N47 head, and I believe no other mods. Quote Link to comment Share on other sites More sharing options...
Guest reckless76 Posted October 15, 2004 Share Posted October 15, 2004 Yeah thats what I'm worried about.. Puttin all that money into the engine only to find there's no way to pass smog.. But i'd be happy with 164 to the wheels.. I just need to know what is realistic here... But he's using an N47 head?? I was under the impression the N42 was concidered better.. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 16, 2004 Share Posted October 16, 2004 The N42 is better if you're going to port it. Out of the box the N47 flows just fine. The problem with his motor in your case is that it is very likely to ping on CA 91 octane gas, and I don't think you could pass smog because the increased compression is going to drive your NOx up. Quote Link to comment Share on other sites More sharing options...
Drftn280zxt Posted October 16, 2004 Share Posted October 16, 2004 Ah Crap ! Now a new engine will definitely be necessary for my goals. I have an L28E also(1979 2+2 ZX). I wasn't aware they had extremely different components, so now I'm eventually going to have to track down a P90a head and an L28ET (as well as all the other neccessary goodies that are different). What the diff between an L28ET and an ZXT L28? Sorry to get off subject. 200hp shouldn't be hard. Think about it stock=135HP. Intake, Exhuast, injectors (fuel rail), TB ,outta do it I'd think. Ten percent incresae from exhuast ~13.5hp =170.5hp. Ten percent increase from intake ~17.05hp = total 187.55hp. Thats a really free flowing exhuast 2.5" mandrel bent if done right, same goes for intake approx 2.5"pipe to a conical filter (K&N) down into the wind . Those increases is what exhuast companies claim (approx 10-15% increase in hp) my 0.02 Quote Link to comment Share on other sites More sharing options...
zguy95135 Posted October 17, 2004 Share Posted October 17, 2004 For the price of all the intake, exhaust, ect it would cost the same or less to get the turbo parts, plus with the turbo you can turn up the boost. Or you could go V8 Quote Link to comment Share on other sites More sharing options...
Guest reckless76 Posted October 18, 2004 Share Posted October 18, 2004 Yeah..... The manufacturers always claim huge horsepower increases... Don't know if it's different with these engines, but when I was buildin up a civic, I was lucky to get 2HP off an exhuast if 10 was claimed... I'm planning on getting Intake, Headers, Exhuast, and fuel upgrades cause I don't want any bottlenecks after the cam upgrade. But with the big bore and stroke upgrade.. Can I lower the compression enough with a larger head gasket?? Or would I need dished pistons.. There has to be some ratio I can hit with the larger displacement that would let me pass smog and still take advantage of the cam.. Any ideas?? And I do plan on porting the head... I want to get everything machined.. Just don't know how much to do... Anyone know a good machinist near Sacramento?? Quote Link to comment Share on other sites More sharing options...
Guest blusty Posted October 18, 2004 Share Posted October 18, 2004 maybe you could sell the extra engine and make room in your work area for a L28et? eric Quote Link to comment Share on other sites More sharing options...
BleachZee Posted October 18, 2004 Share Posted October 18, 2004 Same applies here. If you get the K&N filter, a larger throttle and port out the intake manifold, you'll be lucky to see +6hp. Larger injectors will run more rich, so you'll lose power. You need more air at higher rpms, not fuel. First port the head and put a bigger cam in there. Once that is done you can start worrying about running lean at 7000rpm if the bottom end is balanced to even go that fast. A full exhaust adds 8-13hp but only if all the intake and cam work is done. Bolt-ons really don't do a whole lot by themselves. Quote Link to comment Share on other sites More sharing options...
Guest reckless76 Posted October 18, 2004 Share Posted October 18, 2004 So i guess there are a lot of problems associated with the stroker kit.. (did some more reading) and the stock internals are forged anyway... Guess I'll just do a plain ol' rebuild on the bottom end and just get new pistons if I have too... Just seems like a waste sending the block while it's out to the machinist for cleaning and polishing, then not getting it bored out while its there... Anyone ever just do a small overbore and add oversided rings?? Or do you really need larger pistons?? Can the stock rods handle em?? Wait .......forged oversized pistons would actually be lighter than stock, wouldn't they?? Oh and i figured out what to do about the smog issue.... But I have doubts about it's legality, so I'll just say it involves both my engines and a little work every couple years.. Quote Link to comment Share on other sites More sharing options...
Gollum Posted October 19, 2004 Share Posted October 19, 2004 well, i was just going over my 81 L28 Nox numbers. the 25 mph is kinda close. But it's also got 150k on it. I want to see what my 26k motor put out when i smog it this month. I'd recomend buying a L28et. More power off the bat, and you could probly smog over 300bhp easy. Turbo motors are much more forgiving with smog. Just make sure what's visible is leagal. If you change the turbo get polished aluminum instead of chrome. And if you buy a new intercooler i'd recomend cleaning the whole engine so you could eat off it. You don't want a couple of shiny parts and a grimy engine to may the test station say "wow, that intercooler looks clean. That turbo looks clean too. I'm gonna go check the part number on these." Put in a boost controler and hide it well. Make sure you have a setting with no turbo boost. This will alow you to basically be smoging a low compression all engine vehicle. And the CO & 02 is just a balance of air to fuel. So make sure it's tuned well. Oh yea, and only manufacture approved ECUs are leagal in california. Once again, i hate california smog. Hope i've helped. Just my .02 cents. Quote Link to comment Share on other sites More sharing options...
Guest reckless76 Posted October 20, 2004 Share Posted October 20, 2004 You're right.. I give up on the N/A thing... Plus I read a post from Bastaad525 that pretty much answered all my questions... Guess searching really does work.. Gotta go find an L28ET now... I'll let you guys know when I'm sellin the other two engines... Quote Link to comment Share on other sites More sharing options...
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