mazdatrucking.com
Dec 13, 06
Update
Holley 5200 Page changed to new layout!
 

Holley 5200 Carburetor Information

Mazda B2200 Forum
Bookmark and Share

This page is meant to provide some general information on modifying your Mazda B2200 or 2000 with a Holley 5200 carburetor. For those who don't know the Holley 5200 is a liscensed copy of the Weber 32/36 and was available on many production cars. Because of this there are many different versions of the 5200, some are designed more for power, some for fuel economy, some for emissions, etc... Because the 5200 is available on many different cars this also means that you will need a little fabrication know how in order to adapt one.

Holley 5200 Tech Video

Tech Video: Holley 5200 Introduction

To clarify some questions you may have at this point. Most people who install webers do get much better drivability out of the truck. Many of the stock carburetors in the Mazda B2200 and B2000 are so old and had so many complicated systems that they don't function very well. For those with stock to mild builds done to their engines you can probably expect an increase in fuel milage with better engines getting between 25-33 mpg on the highway and atleast 20 mpg in the city. If you are more interested in performance and want to know how much you will get out of it that will also depend on your build. For a good power gain you will need the Holley 5200 with atleast a custom exhaust. Mechanical Rocker Arms, and cam and ignition upgrades will also compliment better gains.

The biggest issue people are concerned about with performing a modification with the 5200 is emissions and if it will pass. Current emission laws require a visual inspection on all emission levels. This means that if you have a Weber or Holley or any other carb other than the stock one on your mazda pickup and they open the hood during inspection you will AUTOMATICALLY FAIL emissions. Now if you know someone who just does a safety inspection or will just do a 5 gas analyses and not worry about what is actually in the truck you can get it passed but know that it is still illegal. It is possable to bring gas emission down to half of requirements with a properly tuned engine and a 5200 with no cat on the exhaust. Even so if you are going to go with a 5200 and aftermarket exhaust I highly recommend that you put an aftermarket cat on it as well. Modern converter designs are available which won't hinder performance and everyone should be worried about pollution. There is no reason why you shouldn't have a catalytic converter on your vehicle.

Ok, now for actual information about the modification and the carb. In order to do the conversion you will need an adapter plate, a carburetor, air breahter, and a way to adapt the throttle cable. For the adapter plate the one made to adapt the weber to the Mazda B2200 or B2000 will work just fine. Different places sell a 1 3/4 inch breather and a 2 1/2 inch breather the two and a half inch breather is the one you want.

Below is some ordering information from the cheapest place I have found to get filter assemblies for either your Weber 32/36 or your Holley 5200, just click on either of the pics. Part # 99217.472 is the short 1 7/8" filter that comes with most kits Part # 99217.473 is the tall 2 5/8" filter that is recommended. At the time of writing this to order either one should cost about $28. Replacement filters, parts, and recharge kits can also be ordered from the same page.

Going off flow numbers for K&N filters the one inch high filter barely provides enough air for the engine. Since a larger filter has no negative effects on power and will probably help low end torque the 2 inch high breather will insure the engine is getting all the air the carb can flow and will also require less cleaning.

Holley 5200 Cars

The next common questions I get are where to get one and what car to get it off of. All I can recommend for finding one is either a junk yard or Ebay. Cars to look for are the late 70s Ford Pinto and Mustang II or any other car with an engine that is close to 2.2 or 2.3 liters.

Ford Pinto Holley Mustang II Holley

The carbs from the Pinto and Mustang II are tried and known to work and for the Mazda B2200 & B2000 should not require any rejetting for daily driving, however for high performance retuning would be required for best results. Carbs from smaller cars such as VolksWagen will probably be so badly out of tune that they won't even run without rejetting and even then will run rich because of improper air bleeds.

Cars with Holley 5210

The Holley 5210 became available in 1973 on the 2.3 Liter Chevrolet Vega and in 1977 it was also used on the Pontiac 2.5 Liter Iron Duke engines shown in the chart below. Audi also used it for the AMC Gremlin. In the 1970s during the last "gas crisis" Chevy was often praised for it's Vega platform getting between 27-30 mpg.

Installing the Holley 5210 isn't as smooth and simple as the Holley 5200 used on the pinto and mustang II which are very close to the weber design. The carb off the vega used a slightly different casting shape and had more emission devices. Below is a picture.

Vega Holley Carb

The things to be concerned about with this carb is a hump in the casting shown by the blue arrow. This hump will interfere with installing the standard Weber air breather so the bottom plate will need to be modified to fit. This carburetor also has a different throttle linkage setup allowing you to run the throttle cable to it without an extention or interchange with a longer one. Fabrication or adapting is probably still required though. The fuel filter inlet shown by the green arrow is on the opposite side from many other 5200s making it easy to route fuel lines from the stock fuel filter and the vega carb has a filter built in just inside the fuel inlet like some 5200s which will certainly help keep all the junk in your old gas tank from plugging up the jets in the float bowl.

According to the Holley 5200 Handbook this carburetor also has a port for the float bowl vent to connect to a charcoal canister shown by the red arrow. Newer vents where solenoid assisted and will have some wires coming from them. The older carbs have a vacuum powered vent like that showed in the picture above. The solenoid assist valve is higher and may also interfere with the regular Weber air breather.

Holley 5210 Chart
Make Model Engine Year
Chevy Vega 2.3L L4 1973-
Chevy Monza 2.5L L4 1978
Oldsmobile Starfire 2.3L L4 1977-1978
Pontiac Astre 2.5L L4 1977
Pontiac Phoenix 2.5L L4 1977-1978
Pontiac Sunbird/2000 2.5L L4 1977-1978
Pontiac Ventura 2.5L L4 1977

Cars with Holley 5220

The Dodge Omni and Plymouth Horizon use a 5220 which has most of the external devices of the mazda carb. Before you cringe this carb still flows much better then the stock carb and most of the devices don't affect performance and can actually be used to tune the performance or increase driveability. These carbs feature a throttle position sensor which can be used for electronic ignition. For those of you with AC or power steering this carb also has devices to increase idle speed when the AC is on or when making a sharp turn in a parking lot which may cause a stall. The sensor and solenoids can also be used to turn off the AC at wide open throttle for increased performance. Lastly it features a feedback solenoid which if used with an O2 sensor and a Pulse Width Modulator (PWM) can be configured to adjust fuel mixture according to driver input or predetmined by a computer. Some of these devices may be adaptable to a standard Holley 5200 for added functionality with accessories.

Below is a table of cars and known specs for each carb:

5200 Carburetor Chart
Years Model Engine Flow Pri Venturi Sec Venturi Pri Throttle Sec Throttle
72-74
Capris
V-6 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
71-74
Capris
2.0 SOHC 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
79-82
Fox Capris
2.3 L 235 cfm @ 3" Hg
23 mm
UNK
32 mm 36 mm
77-79
Pinto
2.3 L 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
78-81
Fairmont
2.3 L 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
78-81
ZEPHYR
2.3 L 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
79-81
Mustang
2.3 L 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
81
Granada
2.3 L 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
81
Cougar
2.3 L 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
77-78
Mustang II
2.3 L 270 cfm @ 3" Hg
26 mm
27 mm
32 mm 36 mm
UNK
Cortina
UNK UNK
UNK
UNK
32 mm 36 mm

Holley 5200 Economaster

There is also the standard model of 5200 and the Economaster version of the 5200 made available in modles starting in 1975. The economasters where slightly modified for better emissions. The biggest difference is probably the double booster in the primary which provides better vacuum signal for better fuel economy. This booster is said to sacrifice about 20 CFM of flow, but better fuel distribution optimises combustion.

Holley 5200 Boosters

This could potentially kill about 1-3 hp on a very well built engine but most engines probably won't notice much of a difference since the loss of flow is small and the better fuel distribution will make up for some of the resulting power loss. The other modifications shouldn't hinder air flow and I don't think will alter fuel delivery enough to cause performance loss. I will add details on those as I start revising the page.

Holley 5200 Jets

Contrary to popular belief standard Holley jets do NOT fit the Holley 5200 because it is based off of the weber 32/36. The first couple of years the Holley 5200 was made jets for these carburetors where made in the U.S. and stamped with a diameter for the size of the jet. These jets where numbered with the 22R-103-xxx numbers shown in the table below where the xxx would be the diameter of the jet opening in millimeters. Only the last 3 numbers are stamped on the jet so a 157 size jet would have a 1.57 mm hole. These older jets are supposidly brass colored and newer jets where suppose to have a green coating.

In 1975 jets started to be labeled according to the flow of the jet. This means that the exact size no longer was of concern. Each jet is individually flowed at a constant vacuum of 50 centimeters (probably using water). This would mean that two jets of the same size are now gauranteed to flow the same where as before one could flow more than the other. These jets are suppose to be colored green an the number dictates its flow so a 423 jet would flow 423 cc of fluid at a constant pressure drop of 50 centimeters.

Carburetor jets should not be drilled or modified in any way as shape affects flow as well as the opening size. Therefor you cannot know how much fuel and how effective a jet delivers fuel after it has been modified unless you test it on a flow stand.

Below is a chart of the new and old Holley 5200 jets according to flow thus a 124-311 green jet would have close to the same flow as a 22R-103-147 jet. Note that not all available jets may be listed as they might not flow an equivlant volume between old and new jets.

Main Jet Conversions
Green Jets Brass Jets Green Jets Brass Jets
124-227
22R-103-130
124-325
22R-103-150
124-239
22R-103-132
124-346
22R-103-155
124-243
22R-103-133
124-357
22R-103-157
124-255
22R-103-135
124-374
22R-103-160
124-263
22R-103-137
124-404
22R-103-165
124-275
22R-103-140
124-423
22R-103-170
124-283
22R-103-142
124-455
22R-103-175
124-299
22R-103-145
124-477
22R-103-180
124-311
22R-103-147
124-524
22R-103-185

Choke Mechanisms

Holley 5200 Water Choke Electric Choke Manual Choke

The holley 5200 was produced with several tyes of chokes. There is the water operated choke which requires an input and output coolant line to be connected to it. This type of choke has two large ports to it for the lines to connect to and sort of looks like an artificial hart. There is also an electric assist water choke, this type of choke also uses engine coolant to open and close the choke but has a heater on the intake side of the choke to help heat the coolant before it hits the bi-metallic spring. This electric assist choke can be found on some Ford Pintos and Mustangs. The electric assist choke will have the water housing with a single wire comming out the back of it.

Another choke is a full electric. This choke requires no bulky coolant lines and simply needs a 12 volt power supply that is only on when the ignition is on. Most carbureted Mazdas should have a spot in the back of the alternator to connect this type of choke.

The last type is manual. I don't think this came stock on any production 5200s. This type will have a cable which runs to the inside of the cab were the driver can activate it on start up. Activation requires you to pull the knob then pump the gas once and then start. After the vehicle is warmed up you push the knob back in and lightly tap the throttle to kick the idle back down. This choke can be installed using several different universal kits that are available but will require some fabrication to install since there are no provisions to mount the cable in the engine compartment or cab.

The 5200 also features some automatic choke kick down mechanisms. Once the knob is pushed in the choke should deactivate the next time any throttle is given and then let off. Also since it is not good to engauge the secondary barrel with the choke engauged there is a lever which will progressively open the choke as throttle is given and the choke will automatically open if at any time Wide Open Throttle (WOT).

Accelerator Pump

Holley 5200 Accelerator Pump Holley 5200 Pump Diaphram

The accelerator pump circuit is designed to be hightly tunable. The accelerator pump is linked to the throttle linkage and squirts a small amount of fuel into the engine when the throttle is being pressed and there are 3 things to tune it on the 5200. The easiest and most common is the accelerator pump linkage. This runs from the accelerator pump down to a cam which is attached to the throttle shaft on the carb. The pivot point for this linkage can be set to 3 different locations default location is the middle one. The top location should decrease the amount of fuel the pump injects and the bottom hole increases the amount of fuel that is injected.

Holley 5200 Accelerator Pump Positions

The second thing that is tuned is the pump nozzle. This is located between the two barrels and held in place with a single screw. Only the side that goes into the primary barrel is drilled, since the primary throttle plate opens before the secondary plate on the 5200 the nozzle on the secondary side is not needed and if drilled will cause drivability problems. The size of the hole in the nozzle controls how much pressure the fuel has when it comes out and how long it is injected. A smaller jet size is going to have more of a spray to the fuel stream and therefor will provide better throttle response, and fuel economy. (Note the picture shown below has had the leg on the secondary cut off because it was not needed.) The last thing that can be adjusted is the cam that moves the accelerator pump lever. This is rarely modified and requires removal of the throttle shaft to change it. The cam controls maximum movement of the lever and shapes the delivery curve of the pump.

Holley 5200 Pump Nozzle Holley 5200 Accelerator Cam

Float Bowl

The float bowl is very important for several reasons, many think this is just a resevoir to store fuel but there is much more to it especially on a race only or circle track application. Inside the float bowl there is the main jets, the power valve seat, and ports for the accelerator pump. Also in the float bowl but mounted to the air horn are the floats, the power valve and the fuel inlet needle and seat. Probably one of the most critical things is keeping this area clean. The main jets have precision drill holes that may only be .020" or .040" in size, if your fuel tank has rust in it and just one piece makes it past the fuel filter and into the float bowl it could get stuck in one of these jets. If it gets stuck in the primary the vehicle may not start or may not run more than a few seconds after starting, it may also run but may quit if you give it any throttle at all. Even though the hose going to the carb may be pretty big the passageways going into the float bowl itself are very small it is just as easy for a small piece of dirt to get stuck in there which my restrict flow or stop it all together. If your really unlucky a piece of dirt can get stuck between the inlet needle and seat not allowing the needle to seal completly when the floats push it up and the float bowl may overflow and cause a fire.

Thanks to Keir, InOhmaha, Brandon007, Tyrinator, 89B2000, and RussD for their input.

Please support mazdatrucking.com by searching for your needs here:

Google