wagon13 Posted January 23, 2011 Report Share Posted January 23, 2011 so im new here and ive been searching here for all the info i can get on the dual su set up i just bought from docsis510. i have never installed this set up and could use any info. im installing on my 71 510 wagon with L18 and would like all the info i can get please. Quote Link to comment
wayno Posted January 23, 2011 Report Share Posted January 23, 2011 so im new here and ive been searching here for all the info i can get on the dual su set up i just bought from docsis510. i have never installed this set up and could use any info. im installing on my 71 510 wagon with L18 and would like all the info i can get please. Welcome to ratsun. Your going to like them once you understand how to adjust them which is easy. To learn how to adjust them I would buy the chiltons manual part # 5790, datsun 1961 to 1972, it discribes in the tune up section how to adjust them. Keep in mind if either of the carbs is bad/worn out, it will make them impossible to adjust properly. wayno Quote Link to comment
wagon13 Posted January 23, 2011 Author Report Share Posted January 23, 2011 thanks man im hoping they are in good shape he said that they need oil? and read somewhere to use 10w30 not sure but thanks a lot for info Quote Link to comment
exit64 Posted January 23, 2011 Report Share Posted January 23, 2011 Use ATF in the dash pots. It works better than motor oil and stays more even through out the temp range. There is a very good SU section in the tech wiki at www.311s.org by Keith O. Read it and be enlightened. Quote Link to comment
wagon13 Posted January 23, 2011 Author Report Share Posted January 23, 2011 thanks exit64 i will go there now thanks for the info everyone here seems to be very helpful...glad i joined Quote Link to comment
wayno Posted January 23, 2011 Report Share Posted January 23, 2011 thanks man im hoping they are in good shape he said that they need oil? and read somewhere to use 10w30 not sure but thanks a lot for info I think it's automatic transmission oil, or power steering oil, I can't remember which now, but i know it's NOT motor oil. You could/should ask the roadster guys in the roadster section. It's easy enough to find out if there viable after the engine is started, if you close the jet and disable the other carb and it doesn't die, it's not viable/functioning properly. wayno Quote Link to comment
wagon13 Posted January 23, 2011 Author Report Share Posted January 23, 2011 i just printed tha tech sheet ...man good stuff it says a lot of people use marvel mystery oil. i will investigate further and thanks again Quote Link to comment
jun Posted January 23, 2011 Report Share Posted January 23, 2011 I'm not a pro at setting these things up, but this is what I can share from my experiences installing and running them. Thoroughly disassemble and clean them. Get some carb cleaner, clean rags, brushes, and go to town. A soft wire brush works wonders to clean and brighten everything up. If you can source a new linkage kit, I'd get it. Now would be the time to install them. I'd replace the bolts you stripped while you removed them, as long as you're at it. If you're running those older brass floats in them, go order some of the new Nissan units now. Trust me on this. The brass ones are cool but if they leak and fill up with gas, you will not like gas spewing out of the overflows, onto your header. It's $30 well spent. There are a few good threads on here about SU's, and some very knowledgeable SU owners. Namely a fella named "Zerow", who's threads and responses to SU questions have been extremely helpful to me. Speaking of overflows, do run some tubing out of them, and route them away from the manifold/header. I've made some using copper tubing and routed them to the other side of the block, away from heat sources. I've been running ATF in my dash pots and have been quite happy with it so far. Haven't tried Marvel Mystery or any other recommended fluids, so I can't speak for them. Also, make sure those "pistons" move freely up and down. If they get stuck in position while you're out driving, then come to a red light in traffic, embarrassing things happen. Trust me on this one as well! Print out all the manuals and such you can find online...read thoroughly, and get to know your carbs. They are pretty simple. If they aren't too worn out, they'll run good with a thorough cleaning and parts replacement. If you need filters, $100+ for some K&N's, or under $20 for some modified VW filters, as I've done. Again, good info about this mod from Zerow's thread. And polish your dash pots. It makes them faster ;) A shot after I worked out the bugs in mine. Still running strong! 1 Quote Link to comment
exit64 Posted January 23, 2011 Report Share Posted January 23, 2011 Clean su set up, Jun. I have tried the MMO in my pots before. I thought that it was too thin. Made the throttle response very on and off feeling. When you go to set these up for the first time use the caliper method described on 311s. It works great as a starting point but you will still have to fine tune from there. I also was having a lean spot show up halfway through the range so I put a pair of ADQ needles in. Problem solved. The British needles fit our carbs and have so many profiles available you can always find a needle that will fit your motor's needs. One other thing you need to do is make sure your timing is spot on before you take off the old carb. So many times it is an ignition problem that is causing grief but it gets misdiagnosed as carbs, and it will drive you crazy. Quote Link to comment
wagon13 Posted January 24, 2011 Author Report Share Posted January 24, 2011 man thanks to everyone this is cool all the info you guys have its sooo helpful and really thanks a lot.:D by the way jun your wagon is super nice man good job... Quote Link to comment
ggzilla Posted January 24, 2011 Report Share Posted January 24, 2011 Nissan recommends 10W30 weight or 20W motor oil in the factory Hitachi twin carbs. Or are you using non-Datsun versions (british S.U. carbs)? Quote Link to comment
wagon13 Posted January 24, 2011 Author Report Share Posted January 24, 2011 im not sure yet i hvent recieved them,but i believe they are hitachi's. i also have heard of the 20w.are you running su's? Quote Link to comment
ggzilla Posted January 24, 2011 Report Share Posted January 24, 2011 Nope, i have genuine factory Datsun twin Hitachi carburetors. They are nearly identical to british S.U. type "H" carbs, but with japanese quality. Quote Link to comment
wagon13 Posted January 24, 2011 Author Report Share Posted January 24, 2011 i believe these are hitachi's thats what i was askink im sorry for calling them su's.. they are su style hitachi my oppologies for the confusion Quote Link to comment
zerow Posted January 24, 2011 Report Share Posted January 24, 2011 ...Namely a fella named "Zerow", who's threads and responses to SU questions have been extremely helpful to me. ...If you need filters, $100+ for some K&N's, or under $20 for some modified VW filters, as I've done. Again, good info about this mod from Zerow's thread. Thanks for the shout out, jun! I found and copied this from an old thread... I recommend the websites: http://www.jetlink.net/~okayfine/su/sumain.html (credit to the webmaster) http://www.sportsimports.ca/archive/technicaltips/att06.htm (credit to the webmaster) Carburetor Type: Hitachi HJL38W6 (roadster is similar, but not the same) Parts for rebuild: (IMHO best place for parts found thus far) http://www.ztherapy.com/products/masterprices/master_price_list.htm (Scroll down 3/4 way down page to Datsun 510 SSS) What I have bought: (From Z Therapy) ZT31-608 Needles and seats (pair) ZT097 Float Bowl Gaskets (From Nissan) 99996-D1110 Linkage Kit 16174-15801 Phenolic Spacers with Gaskets 16061-K1407 Float (X2) (BTW: If your counter guy says these numbers are not valid, tell him to check the Motorsports catalog; trust me, I have the boxes to prove these numbers are correct) Cleaned sliding portion of nozzles with 0000 steel wool with a very small amount of metal polish (Brasso or eqivalent) Replaced throttle return springs (Home Depot) Refinished heat shield (heat resistant paint) Replaced Fuel lines (Stainless steel intake lines, flexible rubber fuel bowl lines) Replaced Hardware at Float Bowls (M5x12mm) and Domes (M5x16mm) I recommend Stainless Allen Head fasteners, looks nicer and easier to ensure tight fit without stripping And for the filters: http://community.ratsun.net/topic/5294-su-air-cleaners-for-a-ratsun-price/ (also a great shot of the carbs as finished...) Hopefully this all helps Quote Link to comment
wagon13 Posted January 24, 2011 Author Report Share Posted January 24, 2011 thanks zerow this site is great and thanks to everyone again info is sooo helpful. thanks ratsun members you people are awesome Quote Link to comment
qwik510 Posted January 24, 2011 Report Share Posted January 24, 2011 Here is some more. You may have seen it but just in case. http://dimequarterly.tierranet.com/tech/SUTech/su/references.html The Dime Quarterly back issues is a great place for technical info. www.dimequarterly.com The dime quarterly had a great writeup in a two part article. Volume 3 Issue 1 Everything you ever wanted to know about SUs and more - Part One Volume 3 Issue 2 Everything you ever wanted to know about SUs and more - Part Two - In this installment we'll cover installing the SU intake manifold and carbs, getting the carbs to run, and fine tuning them. Volume 4 Issue 1 SU Carburetor Modification Guide - Looking for more performance from your SU carburetors? Look no further. We’ll show you how to squeeze the last bit of performance and efficiency from these carbs, one modification at a time. Quote Link to comment
wagon13 Posted January 24, 2011 Author Report Share Posted January 24, 2011 great info qwik510 thanks now i have a lot of reading to do Quote Link to comment
wagon13 Posted January 27, 2011 Author Report Share Posted January 27, 2011 so i received set up today was soo excited the found out one float is full of gas:( . where do i get some plastic ones and how do i tell what carbs these are? Quote Link to comment
zerow Posted January 27, 2011 Report Share Posted January 27, 2011 so i received set up today was soo excited the found out one float is full of gas:( . where do i get some plastic ones and how do i tell what carbs these are? Take the part number from above 16061-K1407 Float (X2) and head down to the Nissan dealer. Now, be warned: They will be a special order item. And there is the off chance that a brass one may end up in a plastic float box. Quote Link to comment
wagon13 Posted January 27, 2011 Author Report Share Posted January 27, 2011 man thanks again i feel kinda dumb but i want to learn all i can so thanks for letting me know all this its great Quote Link to comment
67411sss Posted January 27, 2011 Report Share Posted January 27, 2011 I just posted some schematics in the "how to" section braking down the carbs and manifold with parts # if that helps. Quote Link to comment
wagon13 Posted January 27, 2011 Author Report Share Posted January 27, 2011 that helps man thanks Quote Link to comment
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