Guest scarab73 Posted June 3, 2005 Share Posted June 3, 2005 I have recently aquired another z! And a former scca car at that! But I have to admit I'm new to the whole six cylinder thing (I'm a v8 guy) and I wanted to know if anybody had any suggestions for syncronizing a set of weber 32/36's? my buddy has a sync tool, but dgv's don't have circular tops (to put sync tool on). I'm sure someone out there has knowledge of dual downdrafts. any and all info greatly appreciated. Quote Link to comment Share on other sites More sharing options...
bjhines Posted June 3, 2005 Share Posted June 3, 2005 Motorsport Auto sells an adaptor to fit those carbys.... Quote Link to comment Share on other sites More sharing options...
fischer183 Posted June 5, 2005 Share Posted June 5, 2005 Get the adaptor and unhook all of the linkages to both carbs. Don't worry about tuning until after synched. Try to (by ear) keep both carbs at about the same idle setting while moving the idle mainly on one towards your destined point. Put on the synchronizer and screw in the middle section until the little red piece gets to the line (hopefully you have the same type as me). Now move the synchronizer to the other carb, not changing anything on the synch, and tune its position until the red piece reaches the same spot. Now you're synched up. Put back on the linkages and make sure you're still at the desired RPM. If not start over. Pat yourself on the back. Quote Link to comment Share on other sites More sharing options...
Guest billyzbear Posted June 9, 2005 Share Posted June 9, 2005 I don't want to be the bad guy. Those down draft carbs don't work well with Z's. The older round top 240 carbs or the side draft webers for more HP. Quote Link to comment Share on other sites More sharing options...
flashstang04 Posted June 9, 2005 Share Posted June 9, 2005 Wow, I had heard that they are far superior to my stock flat tops...hmmm. maybe I will hold off on them. Anyone else got any testimonials or know if they are hard to sync?? Quote Link to comment Share on other sites More sharing options...
Guest scarab73 Posted June 10, 2005 Share Posted June 10, 2005 I don't want to be the bad guy. Those down draft carbs don't work well with Z's. The older round top 240 carbs or the side draft webers for more HP. what specificly is their downfall? I'm pretty new to webers, I'm a holley guy. I have noticed a sputter under hard cornering, but thats about it. what advantage would I have with a sidedraft? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 10, 2005 Share Posted June 10, 2005 The flat top SU's were OK when they were new, but they can't be tuned easily, so most people run them until they start functioning poorly, then take them off and either put on the earlier round top SU's (good) or the dual Webers (less bad than the flat tops) or the four barrel manifold (search for this one, I'm tired of that argument). All you have to do to understand why they are less than ideal is look at the manifold. The air/fuel mix has to go through this question mark shaped manifold adapter thingy to get into the stock manifold. The fuel is heavier than the air, so it tries to separate and pool at the bottom of the curve. The solution was to put a bunch of bumps in the bottom of the curve to keep the fuel mixed with the air, but now you have a bunch of turbulence in the manifold which hurts its ability to flow. The advantage of a sidedraft carb is that the incoming air/fuel doesn't have to change direction (drastically) to get to the head, so I believe that they will flow more than a downdraft carburetor. A downdraft carb works well on a V engine, where the flow is mostly down. A sidedraft carburetor works well on an inline engine, where the flow is mostly sideways. Sputtering around corners is usually a sign of incorrect float level. Quote Link to comment Share on other sites More sharing options...
flashstang04 Posted June 10, 2005 Share Posted June 10, 2005 The flat top SU's were OK when they were new' date=' but they can't be tuned easily, so most people run them until they start functioning poorly, then take them off and either put on the earlier round top SU's (good) or the dual Webers (less bad than the flat tops) or the four barrel manifold (search for this one, I'm tired of that argument). All you have to do to understand why they are less than ideal is look at the manifold. The air/fuel mix has to go through this question mark shaped manifold adapter thingy to get into the stock manifold. The fuel is heavier than the air, so it tries to separate and pool at the bottom of the curve. The solution was to put a bunch of bumps in the bottom of the curve to keep the fuel mixed with the air, but now you have a bunch of turbulence in the manifold which hurts its ability to flow. The advantage of a sidedraft carb is that the incoming air/fuel doesn't have to change direction (drastically) to get to the head, so I believe that they will flow more than a downdraft carburetor. A downdraft carb works well on a V engine, where the flow is mostly down. A sidedraft carburetor works well on an inline engine, where the flow is mostly sideways. Sputtering around corners is usually a sign of incorrect float level.[/quote'] So the 32/36 although it is a good carb setup, is better used in something that is not "inline"? How are the mechanics of the roundtops compared to the mechanics of the downdrafts...(Not which one is better, just internally, what is different) Btw, in my previous post I accidentally said that I had flat tops, but actually have the 240 carbs. So again, maybe I will hold off on a downdraft conversion8-) Quote Link to comment Share on other sites More sharing options...
Guest scarab73 Posted June 13, 2005 Share Posted June 13, 2005 how can I check that my float level is correct? I'm used to external adjustments and sight plugs to check, is there any way I can adjust without bending my float tab? Quote Link to comment Share on other sites More sharing options...
Guest billyzbear Posted June 14, 2005 Share Posted June 14, 2005 What year is your 240z carbs? 73's where bad flat tops. The 70-72 have a more rounded top. It has been 10+ years for me, I switched to 3 40mm dcoe webers and then to 45mm. I'm sure if you search here or google you can find the float level measurement. Take the top off and at a 90, measure how far the float is from top. You will need to bend tab at float seat. give everything a good cleaning while you are there. I remember a video clip on how to rebuild and adjust 240 carbs somewhere. The early 240 carbs are very easy to adjust, rebuild and performance is good. 12secNorm uses them. The only reason I changed is way back I put in a monster cam and needed more adjustability. The sidedraft webers are good but not the downdrafts. Quote Link to comment Share on other sites More sharing options...
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