RedEvilrps13 Posted October 28, 2008 Share Posted October 28, 2008 Howdy. While my 280Z is in the shop getting...erm....redone shall we say, I was interested in ditching the FI setup and going carb'd. I've been looking around the internet and here for an hour thus far and haven't found anything truly 100% useful on the matter. What intake/carb setup would I need? Would a setup off of a L26 work? Any and all info is greatly appreciated! Quote Link to comment Share on other sites More sharing options...
240swapped Posted October 29, 2008 Share Posted October 29, 2008 Hmmmm. Would the 260Z setup work? maybe....until the car warmed up. I made the mistake of going with these carbs and ended up with the thermolock issues everyone else has with these "boat anchors". Ditch the flat top carbs and get the nicer, rounder, bell top SU carbs. since it's a combined gasket, might as well get a header to throw onto the car too. don't froget to replace the fuel pump with a lower pressure unit.....like......I did. call dude from Z Therapy if you want bulletproof answers on the subject. Quote Link to comment Share on other sites More sharing options...
blue72 Posted October 29, 2008 Share Posted October 29, 2008 Early round top SU's or triple Weber/Dellorto/Mikuni sidedraft carbs. Those are the most common carb options. Then there are the less frequently used Holley/4 barrel manifold, and dual Weber DGV options. There are many performance options available for most of the choices listed above. To run the SU's you need the SU carb intake manifolds, heatshield, balance tube and throttle linkage. Usually people are selling these as a whole package. For the Weber carbs you need an intake manifold (a couple of different manufacturers out there), the carbs (40mm or more likely 44-45mm), the throttle linkages and correct jets and chokes. Then you need all the little stuff like hoses and a lower pressure fuel pump/ fuel pressure regulator. Alot of this information is here on the site, like the sticky on choosing Weber size, jets, chokes and emulsion tubes based on displacement and other engine mods: http://forums.hybridz.org/showthread.php?t=93343 There are plenty of resources for info on SU carbs, how they work and how to tune them. Just google Hitachi SU carbs. http://www.jetlink.net/~okayfine/sutech.html http://datsunzgarage.com/engine/ http://www.ztherapy.com/ - this one was already mentioned Here's some reading on the differences in SU intake manifolds: http://forums.hybridz.org/showthread.php?t=135702 I'm a bit biased toward the SU's because I still run them on my L28. Just remember that they were designed for a 2.4l engine. Though many people have great running cars with L28's and the SM needles in their SU's. I personally had mine overbored to keep up with the cam and head work on my car. Runs great and still gets acceptable gas mileage. Don't know why you are ditching the EFI, but now you've got some reading to keep you busy I guess. Quote Link to comment Share on other sites More sharing options...
Challenger Posted October 29, 2008 Share Posted October 29, 2008 I have a set of 260 carbs Im selling... pm me. Quote Link to comment Share on other sites More sharing options...
zuperair Posted October 31, 2008 Share Posted October 31, 2008 I had a 260 with the stock setup, and unlike many I had no problems with them. Lotsa crap on the manifolds though, so it's not a very attractive look and there are much better performance choices out there. I did end up ditching that setup, and going with the downdraft Weber dual setup. I've heard plenty of people trash them, but I had great luck with them. I used a 240 balance tube (no egr), ran them with a Hooker Super Comp set of headers and wow was it fun and effortless. I will say there's a cold start issue with the downdrafts due to the "uphill" climb that the fuel/air has to make up the manifold adapter to make it to the "level" ground of the intakes. When the mixture hits the cold aluminum, condensation can occur and look out for backfiring. Once it's warmed up, it's not an issue...and for me (this would change with jetting)....the break point would have been around 52-55 degrees. Anything lower than that and good luck, any temp above that and it's just a matter of how long will it take to warm up. Easy solution to this issue is just using heat on the manifold adapters. Back in the day after I figured this out....I used magnetic block heaters. Of course they don't stick to the aluminum, but you can set them in there on the top of the manifold adapter behind the carb and in about 5 minutes bang/zoom. Now, with so many heating options a small electric heating coil like that of a heated seat, or any type of line heater would solve this. The twin setup (weber) I think looks great compared to a Holly setup. Granted, you can't get much simpler than a Holly...but as a "semi purist" it just doesn't look right to me. And plenty of non Z stuff I think looks great....and alot on this site looks amazing...but that 4 barrel setup looks to me like my old Ford truck intake and I couldn't get myself to go that route even if it was the simplest. The triple setup I think "looks" the greatest (imo) and they're awesome when tuned right. But not for the faint of heart or the less applied z owner. The FI setup you have right now is about as bulletproof a daily driving setup as you'll find. To me, it just lacks the "passion" of the other more exotic choices. My rank given two categories: Appearence, and Performance considering popular carb choices and stock FI Appearance... Triples Su's (240z style) Dual webbers 260z Flattop Fuel Injection Holley 4 barrel (sorry, for me I really don't like this look) Performance... Triples Su's Holley 4 barrel (this could easily be no. 2 in this ranking) Dual Webbers Fuel Injection 260z Flattops Quote Link to comment Share on other sites More sharing options...
webster280z Posted October 31, 2008 Share Posted October 31, 2008 I have a complete SU set up off a 70 240z, manifold, heat sheilds etc, pm me you're interested Quote Link to comment Share on other sites More sharing options...
COmputoman Posted October 31, 2008 Share Posted October 31, 2008 I installed a set of SU's on my L28E from an 82' Check it out runs great after their warm! (which takes a good 5 minutes from completely cold) Quote Link to comment Share on other sites More sharing options...
RedEvilrps13 Posted October 31, 2008 Author Share Posted October 31, 2008 awesome info guys thank you very much! I think I'm going to pick up some L26 carbs to start out with, and move up after I'm used to them. Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 1, 2008 Share Posted November 1, 2008 Nice Bug! Quote Link to comment Share on other sites More sharing options...
city hunter Posted November 7, 2008 Share Posted November 7, 2008 I'm running a n42 with early 3 screw 44mm su's on a e88manifold with a 6-3-2 ehader. So far, I'm not real happy with them. The car is still setup for fuel injection, so I may end up going back, if I cant get any more power. Right now the car is pretty sluggish all around. I know there is a lot of tuning to do still, and possible modifying the needles. I dont think putting the carbs on will give you any more power, maybe even a loss? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 7, 2008 Share Posted November 7, 2008 I'm running a n42 with early 3 screw 44mm su's on a e88manifold with a 6-3-2 ehader. So far, I'm not real happy with them. The car is still setup for fuel injection, so I may end up going back, if I cant get any more power. Right now the car is pretty sluggish all around. I know there is a lot of tuning to do still, and possible modifying the needles. I dont think putting the carbs on will give you any more power, maybe even a loss? Sounds like you're doing something wrong. Quote Link to comment Share on other sites More sharing options...
Daeron Posted November 8, 2008 Share Posted November 8, 2008 it should open up some power, if not in real HP numbers then in "butt dyno" figures just because the manifold/carbs have more flow potential.. the stock EFI tends to run out of guts around 5500 or so where SUs can handle an engine pulling all the way to redline easier... but thats a rough statement to help let you know something isnt tuned right in the carbs. Quote Link to comment Share on other sites More sharing options...
city hunter Posted November 8, 2008 Share Posted November 8, 2008 I havent driven the car on the stock efi yet, but the car does make good power up top. From reading the articles, it sounds like I cant get enough fuel down below, but my carbs are also pretty worn out. I believe I cant get enough fuel down low with the stock needles. Quote Link to comment Share on other sites More sharing options...
misterZ Posted February 5, 2010 Share Posted February 5, 2010 After searching the forums I have not been able to find the answer I'm looking for so opted to revive this old thread in hopes for an answer. I bought a set of 3-screw SUs (round tops) to convert my 280Z but decided against and will install them on my son's l26 in his Fairlady after they're rebuilt. O'Reily's has the rebuild kits but I need to know if my carbs are 240Z or 260Z carbs... how do I tell? If it helps, they appear to be the same ones posted above in COmputoman's post (pic). Thanks, Quote Link to comment Share on other sites More sharing options...
zuperair Posted February 6, 2010 Share Posted February 6, 2010 260 Carbs are flat tops. Round tops are 240 carbs. Quote Link to comment Share on other sites More sharing options...
misterZ Posted February 7, 2010 Share Posted February 7, 2010 260 Carbs are flat tops. Round tops are 240 carbs. Awesome, thanks! Quote Link to comment Share on other sites More sharing options...
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