Moderators PB260Z Posted December 30, 2014 Moderators Share Posted December 30, 2014 Looks like I have a pair of "SR stamped needles" in my glove box. I think they came with the car many years ago. They seem to be unused and a quick Google search it looks like they might be the profile for a Jaguar XK140. Which is a 3.4 ltr motor. Probably would run too rich I'd assume. They most likely would , but why not give them a try ? It doesn't take long to fit them and costs you nothing. Quote Link to comment Share on other sites More sharing options...
WogsRus Posted December 30, 2014 Author Share Posted December 30, 2014 go to here and have a look against SM needles which are a good base line start https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=15&cad=rja&uact=8&ved=0CDEQFjAEOAo&url=http%3A%2F%2Fhome.comcast.net%2F~rhodes%2FPDF%2FSU_Needles.xls&ei=duOfVNb9DpO78gWbv4GIBg&usg=AFQjCNEsDxM5cLMEf1XbD66CgA7Dm98joA&sig2=qP1KgmDjONW2aCgihXo7Kg looking at is, the SR fall between SM and SH needles with leaner top end. Worth a try its only a 5 minute job. 44071_cb73bafeb4d51a74e2732cf4755c623c3bc551cb.pdf Quote Link to comment Share on other sites More sharing options...
Administrators gav240z Posted December 30, 2014 Administrators Share Posted December 30, 2014 I guess the first thing to find out is what needles I have in the car currently. I was looking to buy this book. http://www.amazon.com/Carburettor-High-Performance-Manual-SpeedPro-Series/dp/1845840739 SU Carburettor High-Performance Manual (SpeedPro Series) by Des Hammill I was wondering if it was of any use? I have the ZTherapy DVD at home in Sydney but am currently in Melbourne and don't have access to it. Quote Link to comment Share on other sites More sharing options...
WogsRus Posted December 30, 2014 Author Share Posted December 30, 2014 if you download the link i posted, it is software that allows you to see what needels you have. You dont really need to know what they are from more if they will work Quote Link to comment Share on other sites More sharing options...
1600dave Posted December 30, 2014 Share Posted December 30, 2014 Hammill's book isn't bad, gives a reasonably simple explanation of how SU's work and what can be done to get them running right. Explains stuff like selecting / upgrading needles and modifying SU's for performance (ie racing). Quote Link to comment Share on other sites More sharing options...
wildy55 Posted January 16, 2015 Share Posted January 16, 2015 Does this needle swapping work for the Hitachi SU's also? I need to find out what needles are in mine, but I suspect my L28 is running out of fuel higher up in the rev range due to the L24 size needles in it and hence feeling flat. [/hey gav/anybody anyupdate on which needles to put in 240 hitachi carbs when theyre on an L28? Just pulled mine out but needles have no id on them. quote] Quote Link to comment Share on other sites More sharing options...
WogsRus Posted January 16, 2015 Author Share Posted January 16, 2015 If needles have no id on them, they are hitachi carbs not SU. SU needles will however fit in there. Quote Link to comment Share on other sites More sharing options...
wildy55 Posted January 16, 2015 Share Posted January 16, 2015 Yup, they're Hitacis alright. So are you saying that those BAX needles will fit and are the right upgrade on an L28? If not, which are?? Quote Link to comment Share on other sites More sharing options...
WogsRus Posted January 16, 2015 Author Share Posted January 16, 2015 sorry. For Datsun Hitachi carburettors, you need fixed needles, these have two letters on them, such as SM, SH etc. For SU carburettors, you have two types of needles, swing and fixed. The swing needles use a small spring to apply pressure to one side of the jet, this was done for emissions and low throttle response. All Hitachi carburettors, standard on datsun, have a fixed needle, so it fits in direct to the based of the piston. From what i have researched and found, L28 running Hitachi, try SM or SH needles. Use this tool to play around with https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=15&cad=rja&uact=8&ved=0CDEQFjAEOAo&url=http%3A%2F%2Fhome.comcast.net%2F~rhodes%2FPDF%2FSU_Needles.xls&ei=duOfVNb9DpO78gWbv4GIBg&usg=AFQjCNEsDxM5cLMEf1XbD66CgA7Dm98joA&sig2=qP1KgmDjONW2aCgihXo7Kg Quote Link to comment Share on other sites More sharing options...
1600dave Posted January 16, 2015 Share Posted January 16, 2015 If you need to, you can run swing needles in a "fixed" needle type carb (ie hitachi carbs). The flange for the spring just presses off, you may possibly need to smooth some knurling on the needle that is under the flange so it will fit neatly into the piston. If so, whack it in a drill or lathe and carefully use wet & dry to smooth it down. Knurling doesn't hurt, but if it is raised a little, it can cause the needle to no longer fit in its hole. Quote Link to comment Share on other sites More sharing options...
WogsRus Posted January 30, 2015 Author Share Posted January 30, 2015 WOP WOOP,just installed leaner needles, went from BAX to BCH. Much better top end pull so close to where it needs to be. Need to check AF on a dyno but my seat of your pants dyno says yessss. Quote Link to comment Share on other sites More sharing options...
Clockwork Posted April 26, 2015 Share Posted April 26, 2015 Where are you getting needkes from WogsRus? Quote Link to comment Share on other sites More sharing options...
WogsRus Posted April 27, 2015 Author Share Posted April 27, 2015 these guys http://www.ebay.com.au/itm/NEW-EACH-SU-CARBURETOR-METERING-NEEDLE-NUMBER-BAX-CUD1121-/281281340502?pt=LH_DefaultDomain_15&hash=item417daca456 near on over night postage and good pricing. Quote Link to comment Share on other sites More sharing options...
Clockwork Posted June 6, 2015 Share Posted June 6, 2015 Humm, I was just comparing your needle tests (SM, BAX, BCH) to the needles currently in my l26 - HS6's with BBK needles. Im not totally sure what to make of the comparison, considering the differences in engines, however, Mine start leaning out at about station 7, which is probably having a negative impact at higher revs. I just replaced my sparks, which to my inexperienced eyes looks to be either quite normal or maybe a bit of high speed glazing (according to that picture scale in the haynes manual and posted on this site in colour). This is the part that confuses me somewhat, as the car is running quite rich (smell and sound), yet seems to drop power at high accel, but the plugs dont appear to be burning overly hot (NGK BP6ES). Who else has some SU HS6 Carbs on a stock l26, and what needles are you running? I also cleaned my carbs up somewhat a few days ago, turns out my rear dashpot cover is a "front" cover (turned 90 degrees to make screw holes line up) - doesnt seem to be an issue as it doesnt really do much, unless it affects suction. biggest issue I found is that my springs are different lengths, which is the reason my rear piston falls back more slowly (carby cleaner has fixed this somewhat though, it was sticking a bit). Quote Link to comment Share on other sites More sharing options...
WogsRus Posted June 22, 2015 Author Share Posted June 22, 2015 you will find that if you can smell fuel its likely to be lower rpm running, at high rpm its hard to tell mixtures. I have the old BAX i would be happy to send for you to test, i think they arnt best shape but wouldgive you a good indication. Quote Link to comment Share on other sites More sharing options...
Clockwork Posted September 25, 2015 Share Posted September 25, 2015 ugh, just sent away for some BCH to test em out, accidentaly ordered BAX, but what turns up - BAW :S BAW sit in between BBK and BCH so will stick em in anyway and have a feel. Quote Link to comment Share on other sites More sharing options...
WogsRus Posted September 25, 2015 Author Share Posted September 25, 2015 let us know how you went i wander why they stuffed up the order anyhow. I need to get mine to a dyno to see the fueling might need to lean it out at part throttle a bit Quote Link to comment Share on other sites More sharing options...
Clockwork Posted September 26, 2015 Share Posted September 26, 2015 Ah, one of my carbs looks like it needs a bit of rekitting, float definitely, started spurting fuel everywhere, couldn't seem to adjust fuel mixture to get it to stop. Noticed a couple of missing springs on one of the chokes to, and a couple of random bitsa screws instead of the real deal. Think I'll send em up to that guy in launnie to get a full work over. Hate the idea of fuel falling directly onto a hot exhaust... Quote Link to comment Share on other sites More sharing options...
WogsRus Posted September 26, 2015 Author Share Posted September 26, 2015 cheaper to get a new set of carbs, the guys in lton are great but ridiculously expensive. I recently rebuilt my dads carbs with a full SU kit and it was only $180 Quote Link to comment Share on other sites More sharing options...
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