The following covers the restoration of a 1981 Toyota Sunchaser by JAM Engineering
In the past couple of years the quality of our fuel has changed drastically in different regions of the United States. It changes from summer to winter and seems to be different in Los Angeles or Maine compared to Texas or Alaska. To keep up with the Government mandated leaner, oxygenated fuel, Redline has had to increase the size of the idle jets in our kits 3 times due to the leaner fuel.
A properly jetted carburetor, that worked well a couple of years ago, may have lost some of its performance due to today’s leaner fuels. Some symptom’s of a lean fuel condition are: needing to adjust the idle too high, rough idle, hesitation or a stumble on acceleration, a flat spot at around 2500 RPM and/or surging at a constant RPM in higher gears.
Along with leaner fuels, any modifications to an engine to improve performance can compound the lean effect and require more mixed fuel volume. Modifications could be as simple as: an opened or larger air filter, an open exhaust system, or ignition modifications. Some modifications could be as extensive as a larger camshaft, head modifications, headers, or increased engine displacement. Also, altitude & extreme temperature or humidity affects the air to fuel ratio. Any and all of these modifications are exaggerated when combined with the lean fuel.
REDLINE recognizes your need to have a variety of jets for all circuits available when tuning your engine. Our jet kits come with simple tuning instructions and a variety of jets to cover the stock and modified engine. We have designed these jet kits from years of experience jetting carburetors on engines all over the country with all types of modifications. If you are experiencing any of these symptoms from your Weber carburetor or simply want to improve the quality and performance from your engine, one of these kits is for you
All adjustment procedures are the same for Progressive and Synchronous carbs, however it is important to understand the differences between the two carb styles. Progressive carbs idle through one barrel and one mixture screw, then transition to the secondary barrel which has an additional idle (low speed) jet. Synchronous carbs have individual idle jets and mixture screws for each barrel. They also have an additional air bleed screw and lock nut. The air bleed screw is not used for idle adjustment or quality. The settings for this screw should be closed. The adjustments settings for synchronous carbs tend to be half of what is recommended for progressive carbs. Example, if a progressive carb is set at 2 turns, the synchronous carb would be set at 1 turn.
All adjustment procedures are the same as the progressive carbs. It is important to understand the dynamic differences of the two carb styles Progressive and Synchronous carbs Or better described as individual runner carbs.
The progressive idles through barrel and one mixture screw hole, then transitions to a secondary barrel with an additional Idle / low speed jet. The Individual Runner carbs IDF and DCOE have individual Idle jets and mixture screws for each barrel. They also have an additional air bleed screw and lock nut. This is not used for Idle adjustment or Idle quality. The settings for this screw should be closed.
The Main adjustments Speed and Mixture Screw for the individual runner carbs have different values than the Progressive. They tend to be ½ of those used on the progressive
Standard IDF & DCOE Settings
Speed screw ¼ to ½ turn in after contact with lever.
Mixture Screw 1 turn out from seated
Follow the same basic procedures as used with the progressive carbs with the exception that there is no choke system and no need to clear the choke cam.
It is important to be very sure there is no throttle shaft bind or over tightened levers. This is the number one reason for most adjustment and tuning problems.
The rules of thumb still hold true the base line settings are only the starting point. The example would be
If your mixture screw is out more than one turn like 11/2 turns then your idle jet is too lean go up one half size on the Idle jet not main jet.
If you mixture screw is not out one full turn something like only 1/2 turn out from seat then your Idle jet is too rich. This is all based on the important fact that your speed screws are not open more than ½ turn if they are then that is also an indication that you have a lean Idle circuit. You are cheating by opening the throttle plates and exposing additional progression holes in the transition.
These carbs are also commonly used in pairs, this makes the synchronization important please be sure when ever balancing twin carbs to bring the high carb down to the low carburetor.
Todays project: Fixing a “No Heat” situation.
After replacing a faulty water pump, as well as the thermostat, on our ’69 MGB GT we still were not getting heat in the cabin. After flushing the system we were certain that the heater core was not clogged but noticed that once all of the hoses were hooked up there was no coolant running through the core (both inlet and outlet hoses were cold). We pulled the heater control valve from the block and what do you know??!! The valve was completely blocked.
Once we scraped the block and cleaned out the valve we had heat. It appears that with the valve being at the lowest point within the heating system, and the valve spending most of it’s life closed (assuming you’re like most of us that drive mostly in nice weather) most of the junk in the system just sits in the valve and heats up into a solid mass.
Started to install a new alternator in our ’69 MGB GT today.
We don’t intended to do a play by play on the install but a few things worth noting:
- To remove the old pulley and fan have an impact wrench handy. It makes removing the nut much easier
- Once the nut is removed it’s helpful to have a puller available to remove the pulley from the shaft
- Keep an eye on the woodruff key. We dropped it into the alternator but fortunately it came out after a few shakes
Base line Settings
Speed Screw 1 to 11/2 turns
Mixture Screw 2 turns
Your settings with engine running
It is important to follow all linkage and lever installation instructions. The number one and two reasons for tuning errors are improper linkage installations and over tightened linkage nut, causing a binding in linkage assembly.
CALIBRATIONS MAY VARY DUE TO REGIONAL FUELS AND STATE OF ENGINE TUNE AND PERFORMANCE. POOR RUNNING QUALITY DOES NOT MEAN A DEFECT IN THE CARBURETOR. AN ADVANTAGE OF THE WEBER CARBURETOR IS ITS EASE OF ADJUSTMENT AND TUNING.
SET UP ADJUSTMENTS
Start set up by confirming carb base line settings. Do not depend on the factory delivered settings. Check them before the carb is installed.
All settings are done with choke disengaged or warmed up so that the choke is fully opened and disengaged. This is done on automatic choke carburetors by first opening the choke butterfly by hand and inserting a wood block or wedge of some kind to hold open while the linkage is cycled (linkage operated through its full movement ) to clear the choke cam. (You will hear a metallic click as the cam is released. You can check the fast Idle screw under the choke assembly to confirm that it is not in contact with the choke fast idle cam.)
Set the Idle stop screw (speed screw see fig 1) by backing out the Idle speed screw until it is not in contact with the throttle stop lever. Cycle the linkage again to be sure that the linkage comes to close without any assistance. (Checking for linkage bind) Now bring screw back into contact with the lever and continue to open or screwing in 1 turn no more than 11/2 turns.
Set the mixture screw (see Fig 1) by first screwing in until the screw stops, bottoms out. DO NOT FORCE OR BIND AS THIS WILL CAUSE DAMAGE TO THE SCREW AND IT’S SEAT IN THE BODY OF CARBURETOR. Back out the screw 2 full turns
- BE SURE TO FOLLOW THE NEXT INSTRUCTIONS IN THE PROPER SEQUENCE, DEVIATION WILL CAUSE THE CARBURETOR TO NOT FUNCTION TO ITS IDEAL SPECIFICATIONS AND MAY NOT PROVIDE THE PERFORMANCE AND FUEL ECONOMY AS DESIGNED.
- Start the engine, the engine will run very slowly more like a tractor. As long as the engine stays running idle speed is not important at this point.
- The first thing to do is not set up the idle speed, but to set the Idle mixture screw to lean best idle setting. First, turn in the mixture screw until the engine dies or runs worse, then back out the screw (recommend turning ¼ to ½ turn at a time). The engine should pick up speed and begin to smooth out. Back out ½ turn more, or until the screw does nothing or runs worse then turn back to the point where it ran its best.
- Use your ear, not a scope or tuning instruments at this point. You want to tune the engine by sound. Adjust to best, fastest and smoothest running point.
- Now that the mixture screw is at its best running location, you can adjust the Idle speed the screw. The screw will be sensitive and should only take ¼ to ½ turns to achieve the idle speed you like.
- Check and set idle to your driving preference. Put the car in gear and apply slight load, (AC on) and set the Idle as you like it. Don’t set it too high, as this will cause causes excessive clutch and brake wear. The Idle only needs to be 7 to 900 RPM with light load or AC on.
- Recheck timing and vacuum hook ups. Recheck mixture screw to lean best idle again. If all is still best and smoothest idle then confirm and note the final settings.
- To confirm settings with the engine running. Start by screwing in the mixture screw and count the number of turns it takes to bottom out and note if the engine dies. If Idle Mixture screws are with in ½ turn of base line setting then all is well and have fun. Also check the speed screw and note how many total turns from initial contact. You may have opened (turned in) the speed screw. Your final setting should be under 2 full turns. Reset the screws (back in) to the best final settings (Per your notes) and go on a test drive and have fun. If the settings are other than described then you may want to recalibrate the Idle circuit (low speed circuit) to your engines needs. This is done by following the rule of thumb BELOW.
Simple Rules for low speed calibration
If the mixture screw is more than 2 1/2 turns out turns then the Idle jet is too lean (too Small). When the mixture screw is less than 11/2 then the Idle jet is too rich (too large). These assumptions are based on the fact that the speed screw setting is not opened more than 11/2 turns. If the speed screw has to be opened 2 or more turns then this is also an indication of a lean condition usually requiring greater change. At times it may appear to be showing signs of richness or flooding it is really a lean condition. See pictures and notes in the tech 2 article supplied in the kit instructions, view and please understand the need to keep throttle plate as near to closed as possible so as not to prematurely expose the transition holes. This is what causes the visible rich condition, and confirms the need to increase the jet size. JET KITS are available if needed.
EXAMPLE With the speed screw set at no more than (1 1/2) turns in after contact with the stop lever; and the best idle occurring with the mixture screw set at 3 turns from bottom, indicates the need for a larger Idle jet. Achieving the best idle at under 2 turns indicates the need for a smaller idle jet.
The secret to understanding the critical nature of the carburetor set up and the advantages of a WEBER over other carburetors is the Idle circuit. Referred to as the low speed circuit by Weber, this circuit is responsible for 80% of the driving operation. This is the reason that the Weber should give a fuel economy improvement over most factory carbs along with significant performance gains. In the worst case you should not see a significant fuel economy loss over stock, while improving HP & Drivability.
The Weber Carburetor is a sequentially timed device to the motor like the distributor. Time taken in the setup will provide more fun later.
If you should need to call REDLINE for technical assistance we will need to know your final settings to help. Technical assistance is free for the first 60 days of purchase. Units in service over 60 days may be assessed a service fee. All charges will be noted up front after a brief consultation to determine any possible defect. If the carb is out of the warranty period and no defect is determined we will estimate the possible cost of tech support or recommend literature available that may help.
ALL WARRANTIES ARE HANDLED DIRECTLY THROUGH REDLINE NOT THE RETAILER. DO NOT SEND PARTS TO MANUFACTURER WITHOUT CALLING FOR TUNING CONSULTATION AND WARRANTY CONFIRMATION OR INSPECTION RETURN AUTHORIZATION. PARTS RETURNED WITHOUT AUTHORIZATION NUMBERS WILL BE REFUSED AND RETURNED FREIGHT COLLECT.
PARTS RETURNED FOR INSPECTION AND WARRANTY CONSIDERATION AND NOT FOUND TO BE DEFECTIVE WILL BE CHARGED A MINIMUM INSPECTION AND ADJUSTMENT CHARGE OF $35.00 AND RETURNED FREIGHT COLLECT.
Contact REDLINE at 1 800 733 2277 ex 7457 Monday thru Friday 8:00 to 5:00 Pacific Standard Time
Non warranty Tech support is on a fee for services basis with minimum charge of 35.00 per problem resolution . With tech support calibration and tuning parts will be available at discount pricing as well as access to technical support documents and mailings
In the past there have been questions and much miss information put out on the choice of a 32/36 DGEV carb or the 38 DGAS
1) The Kits utilizing the 32/36 Progressives Weber are designed to provide the market with an economical performance carburetor conversion that while increasing Hp also improves drivability and fuel economy over the stock carburetor. The kits using the 32/36 progressive carburetor is the optimum carburetor for use as a replacement carburetor for a worn out or hard to maintain factory carb.
2) When purchased in kit form, the REDLINE kit with the 38mm DGAS carb will perform on a stock unmodified engine without any problems. This is not going to be an over carburetion situation.
It will provide considerably more initial torque and acceleration but the top end performance will not be significantly improved over the 32/36 when used on a stock motor.
3) The 38mm DGAS carb should be the only consideration if the engine is in the future or currently going to have any level of additional engine modification. Such as headers, free flowing exhaust, a cam, or rebuilt engine. Usually these motors will be improved over stock with oversize pistons and towing cam. The 38 will enhance the improvements of any of these items. The 6 cylinder engine applications are particularly enhanced by this application. In-fact on ALL JEEP and LAND CRUSER applications with any upgrades this is a mandatory choice. Other wise the progressive will require extensive re-calibration to work properly.
4) When using a 32/36 in the above situations will require additional calibration and rejetting to attain the desired performance and standard fuel economy. There is a jet kit available for just this reason. The jetting is required due to the performance enhancements of the additional modifications. Although the 32/36 does out perform the original, to receive the full benefit of your investment the 32/36 will require helpful re-calibration. The 38 DGAS is the optimum choice and has a larger fuel delivery system and the calibration to handle the broader range of improved performance and improves substantially your other product investments.
5) While the 32/36 progressive carb will improve your fuel economy on a stock motor over the OEM carb. The 38 Synchronous carb will not get less fuel economy than the OEM carb
The 32/36 DGV progressive carburetor as used in any REDLINE kit is pre-calibrated and set to run on most normal standard and stock engines and provide a performance and fuel economy improvement. If that engine has been upgraded or improved with other performance items there will be a need to recalibrate or rejet the carburetor in some situations. There is a performance jet kit just for the Jeep applications Pt No. 701-DGV.
The 38 DGAS synchronous carburetor when supplied in kit form from REDLINE is also pre-calibrated for use on stock or slightly modified motors and will not be over carbureted. It also provides the best starting point for engines that are ultimately going to be upgraded with additional performance Items with performance over fuel economy being the ultimate goal.
|38 DGES Outlaw
|Progressive Series carburetor
22680 005 Manual choke
22680 051B Water choke
22680 033B Electric choke
|Synchronous Series carburetor
18930 032 Water choke
18930 020 Electric choke
|99006-105 for duel carb applications|
|99006-106 for triple carb applications|
INSTALLATION GUIDE/ LINKAGE ASSEMBLY DIAGRAM
These kits are universal in nature and come with all down rods and levers for carb connection. Aircraft rod ends for both linkage support and linkage rod hook up. Also included are cable anchor connections and hardware.
Recommended with use with Redline O Ring soft mount kit 99005 145
DCOE Float Height Adjustment
1. With the top of the carburetor in a verticle position, up and down, the float will hang downward from the float pin, closing the needle against the seat.
2. Measure 14mm from the gasket to the top of the float, as shown above.
3. The purpose of the approach is to avoid having the weight of the float depressing the spring loaded damping ball in the needle.
4. DO NOT INVERT THE CARBURETOR TOP, RESTING THE FULL WEIGHT OF THE FLOAT ON THE NEEDLE AND SEAT
DCOE Float Drop
1.With the top of the carburetor still in the verticle position the float drop is the needle fully open from its seat (shown above)
2. The optimal needle travel is 2mm, from the closed needle in its seat to the float fully opened off its seat. The needle travel should be no more than 2mm
3. In racing applications needle travel is limited to 1.5mm