Rocky671 Posted January 23, 2015 Report Share Posted January 23, 2015 Wsup RATSUN..Ive been looking for some Doug Thorley headers for my 85 720 But kant find them anywhere....Kan anybody help PLEASE??? 1 Quote Link to comment
datzenmike Posted January 23, 2015 Report Share Posted January 23, 2015 Headers are alright if they improve over what's on there. It's strictly a 'racing' thing where any expence justifies any small advantage in a competition. The Z24... Has severe limitations as far as increasing the performance. It has a head design that limits good breathing above 4,500 RPMs. High lift and overlap cams are limited by the point where the valves touch. Port angles are very shallow with sharp bends before the valve. This is an excellent torque engine at low and highway revs but certainly not a screamer. As such, the stock exhaust manifold is way more than enough to handle it. No advantage to a header except weight savings. If you want bang for the buck... Swap in a 4.11 or 4.375 differential. (you probably have 3.545 or 3.70 now) This will increase acceleration by allowing the engine to be revving higher at the same speeds as it is now. Rev higher sooner= more power sooner. Speedo will need adjusting and mileage will drop some. Replace the somewhat smalll carb with a Redline weber 32/36 carb for under $300. Has everything for the conversion. Get a lower restriction turbo muffler. 1 Quote Link to comment
Z-train Posted January 23, 2015 Report Share Posted January 23, 2015 Un-less the engine will be LIVING above 5000 RPMs,the headers are a waste of time and a gigantic pain in the ass. 1 Quote Link to comment
_chiefjt Posted January 23, 2015 Report Share Posted January 23, 2015 Suprised Dmike didn't say something about "This is the wrong place to put this post" lol In my opinion if you come across Thorley headers jump on it because it doesn't come up often. But I wouldnt go out of my way for them because yes the stock manifold does flow just as good, just not in the top end. But for right now, that's all I'll say because Me and my dad are still testing the difference between Thorley headers and Stock exhaust (with thrush turbo). Right now it's about even cause I win the 1/8th mile and he wins the 1/4 mile. 1 Quote Link to comment
_chiefjt Posted January 23, 2015 Report Share Posted January 23, 2015 Un-less the engine will be LIVING above 5000 RPMs,the headers are a waste of time and a gigantic pain in the ass. Also, I'm gonna have to disagree with this. The headers surprisingly improved the gas mileage, made freeway cruising easier and not at 5k rpms, not a pain in the ass cause it was a very simple install and the exhaust shop couldn't have done a more perfect job on it. So there for I don't see why it's a gigantic pain in the ass. Exhaust shop charged $200 to do it and got the header for $250. Total is $450 but it came out every bit of perfect. 1 Quote Link to comment
Z-train Posted January 23, 2015 Report Share Posted January 23, 2015 Also, I'm gonna have to disagree with this. The headers surprisingly improved the gas mileage, made freeway cruising easier and not at 5k rpms, not a pain in the ass cause it was a very simple install and the exhaust shop couldn't have done a more perfect job on it. So there for I don't see why it's a gigantic pain in the ass. Exhaust shop charged $200 to do it and got the header for $250. Total is $450 but it came out every bit of perfect.Here's why it's a pain in the ass.First off you have to install them.No matter how easy/hard it is-it's still a pain in the ass.Non -pain in the ass headers haven't been invented yet-outside of "Zoomies". Exhaust/headers manifolds do NOT make cruising "easier" nor do they improve mileage on Datsuns unless something that was wrong gets corrected during the install. Header -$250 Shop labor-$200 Saying headers aren't a pain in the ass....PRICELESS! 2 Quote Link to comment
tr8er Posted January 23, 2015 Report Share Posted January 23, 2015 Also. They rust through over time. A non issue in some climates, but here they do. 1 Quote Link to comment
tr8er Posted January 23, 2015 Report Share Posted January 23, 2015 But as far as where to find them, I'm unfortunately unable to help. Good luck op. 1 Quote Link to comment
_chiefjt Posted January 24, 2015 Report Share Posted January 24, 2015 Everyone has there own opinion. "First you have to install them" lol Just how you install anything else right, I mean how else would you put something on your vehicle. Also, how's it a pain in the ass if it was easy. Removal of stock exhaust was simple and pretty straight forward. To put the header in requires removing the valve cover but its the same thing as removing a caliper to change the brake pads. Freeway cruising became easier because it is now breathing better. The stock exhaust piping is so skinny and the muffler is so restrictive so there for it is now corrected and can cruise better. :) Rusting header not a problem here in Vegas. I'm not arguing or saying your information is wrong I just disagree. Also, I'm no expert or a "Dataun Mechanic" this is just my experience and I thank you for your input. 1 Quote Link to comment
Z-train Posted January 24, 2015 Report Share Posted January 24, 2015 " Freeway cruising became easier because it is now breathing better." This is categorically false, un-less the installation has alleviated a prior existing "problem". "The stock exhaust piping is so skinny and the muffler is so restrictive so there for it is now corrected and can cruise better". So now YOU know better than the factory engineers that designed the thing? This is your imagination and/or butt dyno.....which is always wrong. Headers leak. Every last (*^&ing one of them. Stock up on gaskets as you WILL be changing them. By DatsunMike: "Has severe limitations as far as increasing the performance. It has a head design that limits good breathing above 4,500 RPMs. High lift and overlap cams are limited by the point where the valves touch. Port angles are very shallow with sharp bends before the valve. This is an excellent torque engine at low and highway revs but certainly not a screamer. As such, the stock exhaust manifold is way more than enough to handle it. No advantage to a header except weight savings." Read this. Read it again. Think about it. Then read it a third time. Every word is true.Your head stops flowing LONG BEFORE ANY header will give an advantage. 1 Quote Link to comment
_chiefjt Posted January 24, 2015 Report Share Posted January 24, 2015 I'm not saying I know better than the Factory engineers. But I'm not gonna waste my time bickering back and forth if your just gonna throw everything I say back at me. My opinion doesn't matter to you so why do you keep insisting all the shit you have to say. Cause right now anything you have to say anymore I don't give a fuck. I'm trying not to make this an argument but you keep downing everything I have to say and coming back at me with an attitude. So fuck this and fuck you. 1 Quote Link to comment
Dean720Ada Posted January 24, 2015 Report Share Posted January 24, 2015 I know to many people on Guam and guamanians that are stateside trying so hard to beef up the z24 to race. Like mike said the z24 motor has its limitations. It's a torque montser but no screamer. To me headers are headers don't matter of Doug thorleys or pacesetters. A good mild cam, port and polish head, side drafts, some msd coils are just as good as it gets to make the z24 boogie. As far as for racing you won't see these motors hitting below 13s. Never seen it done. My fellow guamanians have to much pride in the z24 motor to race. My opinion these days is to motor swap with way more limitations. A v8 or a jdm motor where building a motor sky is the limit on what you can do. As far as Doug thorleys I don't think thorleys make it for z24 motors anymore. Very hard to find. Other than that you can only do so much to the z24. Basic set up like the side drafts, mild cam port and polish, clutch pretty much all you can do to that motor. Or find a way like Patrick smith did to his z22et. His motor is pretty bad ass for a napsz. 1 Quote Link to comment
Rocky671 Posted January 24, 2015 Author Report Share Posted January 24, 2015 Hahaha thanks everybody for the opinion i didnt mean to start all the debates lol im just tryin ta get my NAPZ runnin cherry with sum speed...Dean720ada yea i moved from guam to washington back in 99.My family always been into napz now i got my own and im trying to learn everything about it.guam671 thanx primo for the input i was think bout that thrush turbo too. 1 Quote Link to comment
datzenmike Posted January 24, 2015 Report Share Posted January 24, 2015 Long as it's reasonably civil information and ideas get passed around. I think the Z head is perfect for a turbo application just not normally aspirated. It has to work much too hard to suck air in. It's cross flow keeps exhaust heat from the intake ports, it has near HEMI combustion chambers and dual plug design allowing minimal timing advance. Yes the port angles are not good for flow but let the turbo do the work by cranking up the boost. For 7 lb of perceived power you may need 10 lb of boost, so just dial it up. Nissan makes powerful engines, but the turbo made then equal. Any engine will breathe with enough boost. 1 Quote Link to comment
81SVN20 Posted January 25, 2015 Report Share Posted January 25, 2015 I know to many people on Guam and guamanians that are stateside trying so hard to beef up the z24 to race. Like mike said the z24 motor has its limitations. It's a torque montser but no screamer. To me headers are headers don't matter of Doug thorleys or pacesetters. A good mild cam, port and polish head, side drafts, some msd coils are just as good as it gets to make the z24 boogie. As far as for racing you won't see these motors hitting below 13s. Never seen it done. My fellow guamanians have to much pride in the z24 motor to race. My opinion these days is to motor swap with way more limitations. A v8 or a jdm motor where building a motor sky is the limit on what you can do. As far as Doug thorleys I don't think thorleys make it for z24 motors anymore. Very hard to find. Other than that you can only do so much to the z24. Basic set up like the side drafts, mild cam port and polish, clutch pretty much all you can do to that motor. Or find a way like Patrick smith did to his z22et. His motor is pretty bad ass for a napsz.Prim you have been away from Guahan too long.... Won't see the NAPZ motor hitting below 13s? That's an under statement prim all day long! Theres motors out here that hit 11s and 12s all day long run after run.... Naturally aspirated and built at home in the 671.To primu guam671 munga ma atende I man inosente! To primu rocky this is ton from 720world message me on 720world and I will let you know where to get Doug's! Also pat has a shop and his motor was built from top to bottom not just adding headers, etc. Keep ratsun informational fella's and respetu umbre! Esta! 1 Quote Link to comment
datzenmike Posted January 25, 2015 Report Share Posted January 25, 2015 You sure that's not a 1/8 mile track??? :lol: 1 Quote Link to comment
_chiefjt Posted January 25, 2015 Report Share Posted January 25, 2015 Don't forget elevation makes a difference. 1 Quote Link to comment
datzenmike Posted January 25, 2015 Report Share Posted January 25, 2015 Surely you aren't below sea level??? 1 Quote Link to comment
_chiefjt Posted January 25, 2015 Report Share Posted January 25, 2015 Don't forget elevation makes a difference. If you were to run a 12 on Guam you most likely will not run that here in the states. Quote Link to comment
datzenmike Posted January 25, 2015 Report Share Posted January 25, 2015 Highest point is 1,300 feet so much of it is close to sea level.... so is much of the US. All of Florida is under350 feet. I am sitting about 10-15 feet above high tide. Quote Link to comment
84720FourWheel Posted January 25, 2015 Report Share Posted January 25, 2015 Unless you are near the Rockies you probably aren't more that 2000 ft above sea level. I would guess that 65 percent of the U.S. is below 3,000. I don't think you'd even need to rejet the carb unless the altitude change was greater than 5-6,000 ft. Quote Link to comment
_chiefjt Posted January 25, 2015 Report Share Posted January 25, 2015 I guess it doesn't make that big of a difference but if you run 11s in Vegas, you run 10s in Cali. I know this because my dads co worker runs a Vega and that's the results he gets. 1 Quote Link to comment
petercscherer Posted January 25, 2015 Report Share Posted January 25, 2015 Unless you are near the Rockies you probably aren't more that 2000 ft above sea level. I would guess that 65 percent of the U.S. is below 3,000. Out here in Lubbock, Texas it is as flat as a grid-iron but we are at 3,256ft. There's such a thing as the "high-desert" and it DOES have an impact on performance. I cannot testify to the issue of headers and HP, but I know I had to refine the mixture on ALL of my old cars when I moved here from North Dakota (1,600ft). ~Peter 1 Quote Link to comment
84720FourWheel Posted January 25, 2015 Report Share Posted January 25, 2015 I also had to adjust my mixture, but that's just adjusting a screw. I moved from western Colorado to Minnesota. 4640ft to 800 ft above sea level.For racing, elevation is a factor, fractions of seconds can mean a win or a loss. But the average person probably won't notice unless it's a significant altitude change. Quote Link to comment
datzenmike Posted January 25, 2015 Report Share Posted January 25, 2015 Adjusting a screw? That only changes the idle mixture. To affect performance and mileage the main jets would need changing but for a few hundred feet not worth the bother.. At 5,000 feet there is 15% less oxygen and you will be making at least 15% less power but burning the same amount of gas. If living in Denver smaller main and secondary jets would be a very good idea to save gas. Have a care though if driving to the ocean. You will be running very lean mixtures if you do. Quote Link to comment
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