Dimerforlife13 Posted January 10, 2010 Report Share Posted January 10, 2010 What are you guys running for jets on your weber downdrafts? I haven't been able to put mine on the dyno yet but I am just curious about everyone else. Thanks -Brett Quote Link to comment
Loren Posted March 6, 2011 Report Share Posted March 6, 2011 i'm currently using a 135 primary main jet,& a 110 secondary main jet. the pump jet is a 50. i am not having good luck getting jets for my dgav so i haven't been able to change the air corrector jets,or the emulsion tubes yet. currently it has 170 air corrector jets for the primary,& 160 air corrector jet for the secondary. both are using f 50 emulsion tubes. it pops through the carb when i give it gas,especially when cold. it was jetted WAY to rich( leaing a black spot on the ground during start-up, but i think it's too lean now. dime quarterly had a really good article on this,& someone here was good enough to post a link,that's how i found it. now if i could only find the jets i need! Quote Link to comment
ggzilla Posted March 6, 2011 Report Share Posted March 6, 2011 Here is the Weber DGV (32/36) jetting for a stock 510 with L16 engine: Main Venturi: 26/27 Aux Venturi: 3.5/3.5 Main Jet: 140/135 Em Tube: F50/F6 Air Corr Jet: 165/160 Idle Jet: 55/50 Pump Jet: 50 Needle Valve: 2.00 Weber 38/38, DCD or other Downdraft will be different. This jetting is the baseline for any L16, even in the 521 or 620, 510 etc. I ran it with my A12 and it had great performance and idle, with only a slight flat spot just off-idle. Quote Link to comment
WAGON JON Posted March 11, 2011 Report Share Posted March 11, 2011 What engine are you running? It makes a difference in the jetting. I got specs. Quote Link to comment
banzai510(hainz) Posted March 11, 2011 Report Share Posted March 11, 2011 Loren How can you say over jetted? 135 on a L16 is about right. ck your dizzy mixture retime and try again. Quote Link to comment
Loren Posted March 11, 2011 Report Share Posted March 11, 2011 what I meant to say is that it WAS jetted way to rich,before I changed the jets the first time. 155 primary main jet, 140 secondary main jet. you could smell how rich it was running,and it left a big black spot on the ground at startup,and wherever it sat & idled for any length of time. I have since changed the main jets again to 140 primary, & 130 secondary. it seems better,but still seems to lack some power,& still pops through the carb at about 3/4 throttle. it also still pops through the carb alot until it warms up. i've got some work left to do on it i'm sure,& need to check the timing too. it's an L20 by the way. thanks for the advice everyone! Quote Link to comment
fivetenguy Posted March 11, 2011 Report Share Posted March 11, 2011 anyone have the jetting specs for an L18 and L20b? Quote Link to comment
ggzilla Posted March 12, 2011 Report Share Posted March 12, 2011 The baseline jetting is the same as for the L16 -- it will run fine on any stock engine. The final jetting depends on your engine. Quote Link to comment
Guest kamakazi620 Posted April 24, 2011 Report Share Posted April 24, 2011 what I meant to say is that it WAS jetted way to rich,before I changed the jets the first time. 155 primary main jet, 140 secondary main jet. you could smell how rich it was running,and it left a big black spot on the ground at startup,and wherever it sat & idled for any length of time. I have since changed the main jets again to 140 primary, & 130 secondary. it seems better,but still seems to lack some power,& still pops through the carb at about 3/4 throttle. it also still pops through the carb alot until it warms up. i've got some work left to do on it i'm sure,& need to check the timing too. it's an L20 by the way. thanks for the advice everyone! If thats the same weber you took off the620 you sold me it was jetted perfect for a hopped up l16.if your carbs "pops"then its your timing, carbs dont pope or backfire unless timing is "fucked" whats a dgav? I'll I know is a dgv (manual choke) and the dgev (auto/electric choke) Quote Link to comment
Dimerforlife13 Posted April 24, 2011 Author Report Share Posted April 24, 2011 Carbs will pop out of the carb if they are lean... Quote Link to comment
Guest kamakazi620 Posted April 25, 2011 Report Share Posted April 25, 2011 Carbs will pop out of the carb if they are lean... guess i've never been lucky enough to have a "lean" carb,every time I set up a downdraft carb be it a 2 barrel 1 barrel 4 barrel,i set the mixture screw 1 1/4 -1 1/2 turns from closed set timing then go back and set mixture again Quote Link to comment
BRE_dAtSuN Posted April 25, 2011 Report Share Posted April 25, 2011 what would be a good setup for an l20 with cam and flattops Quote Link to comment
Guest kamakazi620 Posted April 25, 2011 Report Share Posted April 25, 2011 what would be a good setup for an l20 with cam and flattops How much money ya got???? cheap would be weber dgv out the box next step would be su's next step would be weber/mukuni sidedrafts.take into account every step up would require porting and bigger valves to get max power,+ i'd balance the bottom end Quote Link to comment
BRE_dAtSuN Posted April 25, 2011 Report Share Posted April 25, 2011 i meant jetting setups... i sold my mikuni 44's and got the 32/26 and i beleve its jetted for an l16 ill check what jets are in there now but im asking a good setup Quote Link to comment
Guest kamakazi620 Posted April 25, 2011 Report Share Posted April 25, 2011 i meant jetting setups... i sold my mikuni 44's and got the 32/26 and i beleve its jetted for an l16 ill check what jets are in there now but im asking a good setup Well wtf else has been done to the motor????? Der Der cam and flat tops tell me nothing,ported head??? bigger valves???? Big cam??? compression ratio??? cam and flat tops means to me 8.5-9.0-1 compression cam means little bigger than l20b cam Whatcha got???? Quote Link to comment
BRE_dAtSuN Posted April 25, 2011 Report Share Posted April 25, 2011 basicly 10.3:1 compression... 510 lift cam.. port matched.. dual valve springs.. electronic ignition... im guessing i should just put the biggest jets since its such a smaller carb than my mikunis i would just like to know #'s Quote Link to comment
Guest kamakazi620 Posted April 25, 2011 Report Share Posted April 25, 2011 basicly 10.3:1 compression... 510 lift cam.. port matched.. dual valve springs.. electronic ignition... im guessing i should just put the biggest jets since its such a smaller carb than my mikunis i would just like to know #'s Jet it like the first jets Loren had in his weber,it ran PERFECT on my Flattop L16 w/peanut head,i put a stock weber on and it still pulls hard but not as hard as that jetting,also with all yer mods you should step up to a 38 weber outlaw,if it ran good with the mikunis you took a step BACKWARDS with the 32/36 weber Quote Link to comment
BRE_dAtSuN Posted April 25, 2011 Report Share Posted April 25, 2011 Jet it like the first jets Loren had in his weber,it ran PERFECT on my Flattop L16 w/peanut head,i put a stock weber on and it still pulls hard but not as hard as that jetting,also with all yer mods you should step up to a 38 weber outlaw,if it ran good with the mikunis you took a step BACKWARDS with the 32/36 weber yea i know money issues... not preference... im not looking for best performance i realize just something that will run fine with no lean points or struggle spots as i have read is an issue running wrong sized jets Quote Link to comment
Guest kamakazi620 Posted April 25, 2011 Report Share Posted April 25, 2011 yea i know money issues... not preference... im not looking for best performance i realize just something that will run fine with no lean points or struggle spots as i have read is an issue running wrong sized jets Then run 155 primary 140 secondary jets it ran ma mystery l16 PERFECT,sould be a starting point for your killer motor Quote Link to comment
BRE_dAtSuN Posted April 26, 2011 Report Share Posted April 26, 2011 Then run 155 primary 140 secondary jets it ran ma mystery l16 PERFECT,sould be a starting point for your killer motor thanks man ill check today whats in there Quote Link to comment
banzai510(hainz) Posted April 26, 2011 Report Share Posted April 26, 2011 Bre Datsun Why sell the Mikunis? A DGV isnt really for your motor w 510" lift Am I missing something? besides less power Quote Link to comment
BRE_dAtSuN Posted April 27, 2011 Report Share Posted April 27, 2011 heres whats currently in there primary air jet 165 secondary 160 primary fuel 135 secondary jet 140 i think they are backwards from what i read so im flipping them primary idle jet 55 secondary 50... so im guessing its got stock jets besides on being flipped.. so i should order 155 primary fuel jet and leave the 140 at secondary??..what about air jets is that ok or should i go bigger?? Quote Link to comment
Loren Posted April 28, 2011 Report Share Posted April 28, 2011 yeah that l16 ran real strong with the weber i have,but my l20 never has run right with it. it wouldn't idle,left a black mark on the ground under the tailpipe,and smelled like raw fuel. my guess is it ran better on your l16 because of the peanut head,& i thought it had some other stuff done to it also. my l20 is stock,except for the later electronic dist. and that weber. i'm still not happy with the jetting,but at least it idles,doesn't leave a mark,gets a bit better mpg now. Quote Link to comment
BRE_dAtSuN Posted April 28, 2011 Report Share Posted April 28, 2011 hey ur running too rich and im running too lean...lets swap jets this one is setup for stock wat do u say Quote Link to comment
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