Here's some useful information from the Pierce Manifolds site...
exploded Diagram with part numbers!
Weber DGV 32/36 5A
And this is off the DQ site:
[quote]
So what can you do on your own? Well, you could buy a box of spiffy jets and other hardware, then spend about 100 years trying all the combinations to find the ultimate results. This is done commonly and is generally called racing. Or you could listen to what others have done with similar applications and buy a much smaller box of spiffy jets and things and probably achieve the same results. Or you could go to someone who has already done this enough times to know how and is willing to do it for you. In the end, you will have a simple little carburetor that performs great and that you understand a bit better.
The good news is that the Webers, as you buy them, are set up very close to what you need. (Caution: if you are the junkyard dog insisting that the $10 DFV off the old Renault you found is right for you, you have your work cut out for you, I promise. I intend to try to save you some of the joy of that tuning exercise here.) This data is for rather mild, more or less stock-type motors. If you really want some unique, high-power motor, you probably aren't going to use the DGV anyway. You may elect to challenge my advice and, if you add to it, I'll be pleased. What I just promised is to lay out a tuning procedure using the small box of spiffy jets. To begin, you must have a solid engine and fully functional electrical system. It sounds silly, but most of the time a carburetor is replaced because another part is malfunctioning. If the engine isn't pumping the air in and out smoothly and predictably, then the carburetor hasn't much chance to match that air with gas. If the electrical system isn't firing all of the cylinders properly, tuning the carburetor will be no help. I find that, most of the time, my first evaluation of whether a problem is carburetor or ignition is exactly wrong! The point is to first get the simple stuff right.
We are now ready to start in on tuning the carburetor. Take the top off the carburetor and locate all of the jets, the nice brass parts. They are brass so they can be easily produced with the required precision, but you can easily mess them up with the wrong size tools. (The correct tools for this job were covered in the previous article, which also has cutaway drawings to help you locate and identify the parts.) Write down their values and put them back in exactly the same place from which they came. Few will fit into the wrong location, but be very careful and thorough here. The top is held on with six screws and a clip on the choke linkage. Use the proper sizes of screwdrivers and take your time. You may be able to buy all the little pieces for a Weber but you'll not like their cost!
The idle jets are in holders on both sides at the top of the body. The air jets are in the center on the top, the e-tubes are directly beneath them in the body, and the main jets and power valve are in the bottom of the float chamber. The accelerator-pump jet is the little aluminum wing-shaped part overhanging both halves of the carburetor. The float valve and float are in the top cover. Generally, you won't change the power valve unless it is damaged. It's located on the very bottom of the float-chamber floor. You should now have a list of jets something like: primary idle 60, primary main 140, primary air 170, primary e-tube F50, secondary idle 60, secondary main 135, secondary air 170, secondary E-tube F 52, and pump jet 40. Measure the float height from the top by holding the cover vertically with the pivot at the top and the float dangling and just closing the valve. If you just measure it upside down, the distance will be too small. It should be 41mm with a brass float or 35mm with a plastic float.
Reassemble everything and test the performance of the car. Make note of any popping or surging and where they occur as the throttle position and load changes. Write things down and take your time. Try to imagine where you are in the range of flow I rambled on about a little while ago. The trick is to go right to the area of concern instead of the one next to it. It isn't easy but it can be fun. It is typical for this carburetor to have richness in the primary progression. This offers good power characteristics but is overdone for our application (The DAF is just the opposite). You will feel it as a hesitation at light load, and you may have a black tailpipe after a freeway cruise. This may not be as much a problem on a two-liter as a 1600. Also, it is typical for the secondary to have a lean progression which will feel like a hesitation as you open the secondary and maybe even cause a pop back through the carburetor. You should be able to feel the resistance of the secondary as you open it with the throttle at about 2/3 travel. Finally, look for a hesitation when you suddenly add throttle at several points along the flow range. The accelerator pump is usually a bit small, and this is a good indication. Lean will feel like a sudden loss, whereas rich feels like a gradual one, and right on feels very good.
[/quote][quote]
Now you get to make your first guess for improvements. Do everything one-step at a time and test your results. The basic process is to go lean until you know you're too far then back up one jet. You will feel the lean condition much more easily than a rich one. Remember to change only one thing at a time even though I am giving you about ten here. This means you will have lots of fun, and it is also why shops don't sell this procedure, no one wants to pay for the time. The primary circuit is where you spend most of the time when you drive the car so it is a good place to start. If your carburetor is rich as I suspect, you will need a smaller main fuel jet or larger air jet. Replace the 170 air jet with a 160. Small motors will likely want a smaller main, a 135 or 130. The #40 pump jet is always too small, go ahead and install a 45 for small motors, a 50 for large motors and violate the one thing at a time rule.
Reassemble and test the car, remembering that lean will surge and rich will lag. You want crisp and happy. Try jet changes one at a time if you want perfection. You may become sensitive to the area around 1/4 throttle feeling soft, we can change the e-tube to a F11 to correct that. Next, we'll tune the secondary. Remember to test it by getting into it, I mean really into it! You should feel a full-power surging which will be more apparent as you fine tune the primary, partly from improvements in your carburetor and partly from improvements in your technique. I find an L18 to like a secondary air of 115 and a secondary main as low as 85 (bigger motors may like a main of 90 to 100). These values assume you are using the F9 emulsion tube in the secondary main circuit.
[/quote][quote][/quote][quote]Once you are happy with your primary jetting, you may choose to work on the idle jetting. This is a different technique and doesn't require removing the top of the carburetor, but it doesn't work well until the primary is pretty close. The technique is to drop the idle to a minimum value with the two adjusters (the mixture screw will be about two turns and the throttle screw at the minimum setting) as close to completely shut as possible while still keeping the motor running. You want maybe 750 rpm here. Now, slowly screw in the throttle adjust to speed up the motor to about 1500 rpm and listen to the progression. You want a smooth progression with no surging. A lean mixture may cause stalling. Now return to the low rpm and open the mixture screw 1/2 turn and do the test again. If it improves, then raise the idle jet to a 70 or the next size. If it deteriorates, drop one jet. Retest. The carburetor will run on the idle circuit, but since this is the smallest jet, it is the most likely to become plugged. If you lose your idle, check this jet first as it's the most likely to be plugged and the easiest to get to. If you just can't get the engine to idle without propping open the throttle with the idle speed screw, the secondary idle needs adjustment (if your carburetor has in idle hole below the secondary throttle plate). The secondary idle circuit has no metering screw so you will need to clean or replace the jet if adjustment is needed.
To repeat, you will find in your experimentation that lean is very easily sensed. You can do a very good job of tuning if you use the technique of going leaner in steps until too lean, then back one step. Smaller mains are leaner, larger airs are leaner. The progression from low throttle up, as you feel it, is idle to e-tube, to main jet, to air jet, and, of course, primary to secondary. The pump and choke circuits are not involved. Now, if you have the equipment to read the tailpipe you can do a little better in the lean vs. rich sensing. You will be looking for CO readings of 3% to 6% (3% are the best smog value for cruise conditions, and 6% is the best power number for WOT.) Hydrocarbons (HC) under 200 ppm (parts per million) is reasonable with a carburetor tuned for a full power A/F ratio of 11:1 to 12.5:1 for load and 15:1 for cruise, which should work with the above values. Idle screw adjustments are done to minimum C0 and HC readings. 2-5% C0 and 200 ppm HC seem reasonable goals. If the HC level reads above 200 ppm check for a spark miss. For a drag strip type dyno run, one step too lean will cost 0.3 seconds between 3000 and 6000 rpms, while one step too rich will cost 0.1 second. A final note: Altitude corrections are mostly done with the primary main: one size smaller for every 3000 feet. That means one or two steps for Shasta.
To summarize and deliver the promise, I have given you a chart of spiffy jets to build your collection, the infamous small box. You will learn to disagree with and expand upon this list. Earlier, I said you would likely feel no power increase with a super tuning of your carburetor, and that is true, but you will get a bunch more power in the area between idle and full power which will feel like a lot more power and allow you to go faster and use less gas. Or is that OR use less gas!
Good luck.
[/quote]
[quote]
So what can you do on your own? Well, you could buy a box of spiffy jets and other hardware, then spend about 100 years trying all the combinations to find the ultimate results. This is done commonly and is generally called racing. Or you could listen to what others have done with similar applications and buy a much smaller box of spiffy jets and things and probably achieve the same results. Or you could go to someone who has already done this enough times to know how and is willing to do it for you. In the end, you will have a simple little carburetor that performs great and that you understand a bit better.
The good news is that the Webers, as you buy them, are set up very close to what you need. (Caution: if you are the junkyard dog insisting that the $10 DFV off the old Renault you found is right for you, you have your work cut out for you, I promise. I intend to try to save you some of the joy of that tuning exercise here.) This data is for rather mild, more or less stock-type motors. If you really want some unique, high-power motor, you probably aren't going to use the DGV anyway. You may elect to challenge my advice and, if you add to it, I'll be pleased. What I just promised is to lay out a tuning procedure using the small box of spiffy jets. To begin, you must have a solid engine and fully functional electrical system. It sounds silly, but most of the time a carburetor is replaced because another part is malfunctioning. If the engine isn't pumping the air in and out smoothly and predictably, then the carburetor hasn't much chance to match that air with gas. If the electrical system isn't firing all of the cylinders properly, tuning the carburetor will be no help. I find that, most of the time, my first evaluation of whether a problem is carburetor or ignition is exactly wrong! The point is to first get the simple stuff right.
We are now ready to start in on tuning the carburetor. Take the top off the carburetor and locate all of the jets, the nice brass parts. They are brass so they can be easily produced with the required precision, but you can easily mess them up with the wrong size tools. (The correct tools for this job were covered in the previous article, which also has cutaway drawings to help you locate and identify the parts.) Write down their values and put them back in exactly the same place from which they came. Few will fit into the wrong location, but be very careful and thorough here. The top is held on with six screws and a clip on the choke linkage. Use the proper sizes of screwdrivers and take your time. You may be able to buy all the little pieces for a Weber but you'll not like their cost!
The idle jets are in holders on both sides at the top of the body. The air jets are in the center on the top, the e-tubes are directly beneath them in the body, and the main jets and power valve are in the bottom of the float chamber. The accelerator-pump jet is the little aluminum wing-shaped part overhanging both halves of the carburetor. The float valve and float are in the top cover. Generally, you won't change the power valve unless it is damaged. It's located on the very bottom of the float-chamber floor. You should now have a list of jets something like: primary idle 60, primary main 140, primary air 170, primary e-tube F50, secondary idle 60, secondary main 135, secondary air 170, secondary E-tube F 52, and pump jet 40. Measure the float height from the top by holding the cover vertically with the pivot at the top and the float dangling and just closing the valve. If you just measure it upside down, the distance will be too small. It should be 41mm with a brass float or 35mm with a plastic float.
Reassemble everything and test the performance of the car. Make note of any popping or surging and where they occur as the throttle position and load changes. Write things down and take your time. Try to imagine where you are in the range of flow I rambled on about a little while ago. The trick is to go right to the area of concern instead of the one next to it. It isn't easy but it can be fun. It is typical for this carburetor to have richness in the primary progression. This offers good power characteristics but is overdone for our application (The DAF is just the opposite). You will feel it as a hesitation at light load, and you may have a black tailpipe after a freeway cruise. This may not be as much a problem on a two-liter as a 1600. Also, it is typical for the secondary to have a lean progression which will feel like a hesitation as you open the secondary and maybe even cause a pop back through the carburetor. You should be able to feel the resistance of the secondary as you open it with the throttle at about 2/3 travel. Finally, look for a hesitation when you suddenly add throttle at several points along the flow range. The accelerator pump is usually a bit small, and this is a good indication. Lean will feel like a sudden loss, whereas rich feels like a gradual one, and right on feels very good.
[/quote][quote]
Now you get to make your first guess for improvements. Do everything one-step at a time and test your results. The basic process is to go lean until you know you're too far then back up one jet. You will feel the lean condition much more easily than a rich one. Remember to change only one thing at a time even though I am giving you about ten here. This means you will have lots of fun, and it is also why shops don't sell this procedure, no one wants to pay for the time. The primary circuit is where you spend most of the time when you drive the car so it is a good place to start. If your carburetor is rich as I suspect, you will need a smaller main fuel jet or larger air jet. Replace the 170 air jet with a 160. Small motors will likely want a smaller main, a 135 or 130. The #40 pump jet is always too small, go ahead and install a 45 for small motors, a 50 for large motors and violate the one thing at a time rule.
Reassemble and test the car, remembering that lean will surge and rich will lag. You want crisp and happy. Try jet changes one at a time if you want perfection. You may become sensitive to the area around 1/4 throttle feeling soft, we can change the e-tube to a F11 to correct that. Next, we'll tune the secondary. Remember to test it by getting into it, I mean really into it! You should feel a full-power surging which will be more apparent as you fine tune the primary, partly from improvements in your carburetor and partly from improvements in your technique. I find an L18 to like a secondary air of 115 and a secondary main as low as 85 (bigger motors may like a main of 90 to 100). These values assume you are using the F9 emulsion tube in the secondary main circuit.
[/quote][quote][/quote][quote]Once you are happy with your primary jetting, you may choose to work on the idle jetting. This is a different technique and doesn't require removing the top of the carburetor, but it doesn't work well until the primary is pretty close. The technique is to drop the idle to a minimum value with the two adjusters (the mixture screw will be about two turns and the throttle screw at the minimum setting) as close to completely shut as possible while still keeping the motor running. You want maybe 750 rpm here. Now, slowly screw in the throttle adjust to speed up the motor to about 1500 rpm and listen to the progression. You want a smooth progression with no surging. A lean mixture may cause stalling. Now return to the low rpm and open the mixture screw 1/2 turn and do the test again. If it improves, then raise the idle jet to a 70 or the next size. If it deteriorates, drop one jet. Retest. The carburetor will run on the idle circuit, but since this is the smallest jet, it is the most likely to become plugged. If you lose your idle, check this jet first as it's the most likely to be plugged and the easiest to get to. If you just can't get the engine to idle without propping open the throttle with the idle speed screw, the secondary idle needs adjustment (if your carburetor has in idle hole below the secondary throttle plate). The secondary idle circuit has no metering screw so you will need to clean or replace the jet if adjustment is needed.
To repeat, you will find in your experimentation that lean is very easily sensed. You can do a very good job of tuning if you use the technique of going leaner in steps until too lean, then back one step. Smaller mains are leaner, larger airs are leaner. The progression from low throttle up, as you feel it, is idle to e-tube, to main jet, to air jet, and, of course, primary to secondary. The pump and choke circuits are not involved. Now, if you have the equipment to read the tailpipe you can do a little better in the lean vs. rich sensing. You will be looking for CO readings of 3% to 6% (3% are the best smog value for cruise conditions, and 6% is the best power number for WOT.) Hydrocarbons (HC) under 200 ppm (parts per million) is reasonable with a carburetor tuned for a full power A/F ratio of 11:1 to 12.5:1 for load and 15:1 for cruise, which should work with the above values. Idle screw adjustments are done to minimum C0 and HC readings. 2-5% C0 and 200 ppm HC seem reasonable goals. If the HC level reads above 200 ppm check for a spark miss. For a drag strip type dyno run, one step too lean will cost 0.3 seconds between 3000 and 6000 rpms, while one step too rich will cost 0.1 second. A final note: Altitude corrections are mostly done with the primary main: one size smaller for every 3000 feet. That means one or two steps for Shasta.
To summarize and deliver the promise, I have given you a chart of spiffy jets to build your collection, the infamous small box. You will learn to disagree with and expand upon this list. Earlier, I said you would likely feel no power increase with a super tuning of your carburetor, and that is true, but you will get a bunch more power in the area between idle and full power which will feel like a lot more power and allow you to go faster and use less gas. Or is that OR use less gas!
Good luck.
[/quote]
Which adapter, as there are 3 different ones and how much?
The 2 piece unit is prone to leaks and should be avoided unless brand new...
the tall one piece is good for the L16 and 18's and helps with lowend torque...
the short adapter is needed for the L20's to clear the hood with the short air cleaner....:shock:
The 2 piece unit is prone to leaks and should be avoided unless brand new...
the tall one piece is good for the L16 and 18's and helps with lowend torque...
the short adapter is needed for the L20's to clear the hood with the short air cleaner....:shock:
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Pac. coast Datsun
- Posts: 286
- Joined: Wed Dec 31, 1969 5:00 pm
do you have a picture?
or maybe you can identify this is the one you have:
http://cgi.ebay.com/ebaymotors/Datsun-N ... enameZWD1V
or maybe you can identify this is the one you have:
http://cgi.ebay.com/ebaymotors/Datsun-N ... enameZWD1V
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jetjocks2003
- Posts: 62
- Joined: Wed Dec 31, 1969 5:00 pm
My experiance is some of the weber parts are getting harder to get. I had been messing wit jetting for quit awile, trying to correct for bad points. Ikept going richer, canging E-tubes and such, that why I went to the pertronix kit. Well now to make a long story short I running rich. I will try the next bigger air corrector, The tubes and idle jet selection seemed small, any well stocked suppliers you kinw?