Excellent than rules out some of that in my above post except for CR on a side note if you ever wanted to put a Turbo on it you are set then.
All Small Six Weber 32/36 won't idle
- Thread starter krbostic89
- Start date
This relates to all small sixes
krbostic89
Active member
So rough 48 hours for me, ton of disappointment and frustration on my part.
All of the gaskets associated with the carb and intake are making good impressions and sealing. I purchased custom gasket material to make one for between the log and adapter plate. again, all of it seems to be marrying up and sealing fine. I haven't been able to spray fluid on the connections to see if I have a leak, I need an extra set of hands to hold the accelerator or throttle so I can search. My dad (who helped me install the engine) left Thursday night before I could really start digging.
Went back through my notes on the head work that I had done. We only took a true CC measurement before machining. The combustion chambers were all fairly close to 62cc. Per the Falcon performance hand book we took off .050 for the combustion chamber reduction plus .025 for the compressed thickness difference in the shim gasket and the fel-pro one I used (original .024, felpro .050 from the manual). I thought we had taken a measurement after milling but we did not. I did use stock dished pistons and didn't deck the block. My math gave me a ratio of 8.8 but didn't account for the .040 over bore.
Took the suggestion yesterday of setting the timing to 18*. With some throttle pushed in I could get it to run at about 1000 rpm, but with the idle speed screw all the way in and a varying the mixture screw, still no success in maintaining an idle without some extra input.
Anyone know anyone in the Hampton Road Virginia beach area that would be able to help. I'm officially completely over my head (and probably have been from the beginning).
I'm thinking probably have too much cam and not enough compression. I need to get some better experience than myself to work this.
All of the gaskets associated with the carb and intake are making good impressions and sealing. I purchased custom gasket material to make one for between the log and adapter plate. again, all of it seems to be marrying up and sealing fine. I haven't been able to spray fluid on the connections to see if I have a leak, I need an extra set of hands to hold the accelerator or throttle so I can search. My dad (who helped me install the engine) left Thursday night before I could really start digging.
Went back through my notes on the head work that I had done. We only took a true CC measurement before machining. The combustion chambers were all fairly close to 62cc. Per the Falcon performance hand book we took off .050 for the combustion chamber reduction plus .025 for the compressed thickness difference in the shim gasket and the fel-pro one I used (original .024, felpro .050 from the manual). I thought we had taken a measurement after milling but we did not. I did use stock dished pistons and didn't deck the block. My math gave me a ratio of 8.8 but didn't account for the .040 over bore.
Took the suggestion yesterday of setting the timing to 18*. With some throttle pushed in I could get it to run at about 1000 rpm, but with the idle speed screw all the way in and a varying the mixture screw, still no success in maintaining an idle without some extra input.
Anyone know anyone in the Hampton Road Virginia beach area that would be able to help. I'm officially completely over my head (and probably have been from the beginning).
I'm thinking probably have too much cam and not enough compression. I need to get some better experience than myself to work this.
Your getting it narrowed down and yes sometimes it takes quite a bit of time and it's frustrating when trying to get everything dialed in. On If you your compression ratio is on the low side yes that's a shame the heads CC's wasn't rechecked but all is not lost and you don't have to guess. Do you have or you can barrow (from one of the local auto parts stores that have a tool loaning program) a compression tester then you can get a good ball park idea of the Compression Ratio. Example the stock 1965 to 68 200 six in top condistion had a 8.7 to 1 CR and this will show up as 175 PSI on a cranking compression test. You might also be a bit rich if you have to have the mixture screw turned in all most all the way for it to even try at a high idle. You might first try dropping the fuel pressure down to 2.5 PSI or even a little lower down to 2 and see if there is any improvement. Have you checked the float level setting? Best of luck.
Yes, Check compression..Hold throttle open, crank it over 3 or 4 times .
krbostic89
Active member
I will see if I can go borrow one, the NAPA, Autozone, and O'reillys have faily good loaner programs near me.
I have not checked the float levels. I haven't had the idle mixture screw all the way in, just turned it in a half turn to a turn from weber's initial recommendation of 2 turns out.
I have not checked the float levels. I haven't had the idle mixture screw all the way in, just turned it in a half turn to a turn from weber's initial recommendation of 2 turns out.
Ok then that's good you might try turning mixture screw in a little more maybe another 1/4 to 1/2 turn. I usally set the mixture screw by a tach to the highest RPM then turn it in another 1/4 turn this is the lean best idel, however if you at about 1000 RPM you are maybe already out or close to being out of the idle circuit.
If it was a Holley or Autolite i could help you, One thing you could try is remove the idle mixture screw completely & blow compressed air at low pressure, 15-20 # & there maybe a piece of debris blocking the idle fuel flow.
I believe you stated that above 1K rpms the engine performs fine?? If thats the case then your problem is in the idle circuit or transition area.
I believe you stated that above 1K rpms the engine performs fine?? If thats the case then your problem is in the idle circuit or transition area.
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Its possible that if you have the idle speed screw in as far as it will go is the throttle blade is above the idle transfer slot & the mixture screw will not change the idle mixture.
Another option is with your overcamed engine is drill a .060" hole in the primary throttle blade.
That will get the throttle blades back into the idle circuit area??? Don't do this mod till you get more help from a Weber carb expert. X need you help.
Another option is with your overcamed engine is drill a .060" hole in the primary throttle blade.
That will get the throttle blades back into the idle circuit area??? Don't do this mod till you get more help from a Weber carb expert. X need you help.
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If you had a 4bbl Holley & to keep the primary throttle blade in the lower 1/3rd of the transfer slot is adjust the secondary throttle blades open a little to let more air into the engine with a set screw adjustment.
Can the Weber be adjusted with this option?????
There is a set screw on the bottom facing up to set the stop position for the secondary
You may have to lift the carb to get to it.
You can try putting some masking tape on top of the set screw under the stop just to test if opening the secondary helps with the adjustments at the primary.
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If opening the secondary allows the primary plate to close into the idle circuit and it idles OK after adjustment are made then this is an indication that the primary is too small and the 32/36 is the wrong carburetor for the job.
The correct carburetor would be the 38/38 where both throttle plates open together and both have idle circuits.
There would be no problem adjusting the idle.
The correct carburetor would be the 38/38 where both throttle plates open together and both have idle circuits.
There would be no problem adjusting the idle.
krbostic89
Active member
So this morning went out and tried to start the car. timing was at 18* and the car was completely cold. Car turnover, started and idled (i'll be it expectedly rough with the cam and at about 650 rpm) almost immediately. however, as the choke opened and the car warmed up, the idle got more rough and started to starve up. I goosed the throttle a little to see what would happen, car immediately died. I tried starting the engine again but couldn't with out a significant throttle input, but could get it started and would hold with throttle input at about 1000 rpm.
So my initial analysis is that with the choke closed, the mixture was enrichened enough to start and run, but as the choke open, the mixture got too lean and slowly starved out.
Doing some reading, increased throttle can overcome a vacuum leak making the mixture too lean at low speeds but less of a factor at high speeds. I've got some deeper digging to do on leaks. I have 2 manifold vacuum holes, the one on the log and the one on the adapter plate, plugged up as well as the ported vacuum advance line and the 2nd vacuum line on the carb. The spacer and carb both look like the are sealing correct and have been tight. My most likely point of leak is between the log and the adapter. I have a self cut gasket between the log and the adapter, but it is thinner than the carb ones. Once I can get an extra set of hands I'll start to checking those fittings.
So my initial analysis is that with the choke closed, the mixture was enrichened enough to start and run, but as the choke open, the mixture got too lean and slowly starved out.
Doing some reading, increased throttle can overcome a vacuum leak making the mixture too lean at low speeds but less of a factor at high speeds. I've got some deeper digging to do on leaks. I have 2 manifold vacuum holes, the one on the log and the one on the adapter plate, plugged up as well as the ported vacuum advance line and the 2nd vacuum line on the carb. The spacer and carb both look like the are sealing correct and have been tight. My most likely point of leak is between the log and the adapter. I have a self cut gasket between the log and the adapter, but it is thinner than the carb ones. Once I can get an extra set of hands I'll start to checking those fittings.
Can we rule out carburetor icing?
krbostic89
Active member
It's been in the 70s and 80s over the last couple days. Humidity has been high, but I have not seen any signs of ice in the carb throat.
... been following this thread since I have a H/W 32/36 on my built 170 with great results for @ 15 years. I did have initial tuning issues but not the idle problem. H/W Idle is consistent unlike Holley 1Bbl's.
I would recommend considering other issues related to idle before committing to the carb being central problem.
.
here's some old notes I have from 'stang200' @ 2005 from this or FCA forum that may help:
The Holley/Weber 32/36 carburetor is a great carburetor but can be a little tricky to set up correctly with a 6 cylinder engine. For those of you who don't know, the 32/36 was originally designed for a 4 cylinder engine. This is not to say that is will hinder any potential performance or fuel economy when used in conjuction with your inline 6 cylinder engines. Only a few changes or rather adjustments will more than likely need to be made for your particular application.
Jets. With a few minor changes to the stock jets, this carburetor will give you the performance, as well as fuel economy, that most others cannot deliver. Notice I said stock jet sizes. More often then not, rebuilt Webers don't necessarily have stock jets installed in them during the rebuild. So, before you purchase any replacement jets, it's best to see what you have to determine what needs to be replaced. Each jet is stamped with the number on top or on the side of the jet themselves. They are a little difficult to see but a magnifying glass can rectify this problem.
Here is a list of jets and their associated technical names that should help you in determining the right set-up for your engine.
4 cylinder
Primary Main Jet 140
Secondary Main Jet 140
Primary Air Corrector Jet 170
Secondary Air Corrector Jet 160
Primary Idle Jet 060
Secondary Idle Jet 050
Pump Jet 050
6 cylinder
Primary Main Jet 160
Secondary Main Jet 160
Primary Air Corrector Jet 190
Secondary Air Corrector Jet 180
Primary Idle Jet 075
Secondary Idle Jet 065
Pump Jet 060
The first list is comprised of the stock jet sizes as originally intended by the manufacturer. Remember, these numbers are based typically on a stock 4 cylinder engine displacing no more than 151 cubic inches.
The second list was developed from a group of off road enthusiates, namely individuals from the Jeep crowd. Typically their engines are 6 cylinders with displacements of 232 cubic inches or more.
I have found the latter jet sizes to work very well(save one size small on the air jets 185 & 175 vs. 190 & 180) with my inline 200.
**********************
The following write-up is from Weber.
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.
TUNING
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.
*************
I would recommend considering other issues related to idle before committing to the carb being central problem.
.here's some old notes I have from 'stang200' @ 2005 from this or FCA forum that may help:
The Holley/Weber 32/36 carburetor is a great carburetor but can be a little tricky to set up correctly with a 6 cylinder engine. For those of you who don't know, the 32/36 was originally designed for a 4 cylinder engine. This is not to say that is will hinder any potential performance or fuel economy when used in conjuction with your inline 6 cylinder engines. Only a few changes or rather adjustments will more than likely need to be made for your particular application.
Jets. With a few minor changes to the stock jets, this carburetor will give you the performance, as well as fuel economy, that most others cannot deliver. Notice I said stock jet sizes. More often then not, rebuilt Webers don't necessarily have stock jets installed in them during the rebuild. So, before you purchase any replacement jets, it's best to see what you have to determine what needs to be replaced. Each jet is stamped with the number on top or on the side of the jet themselves. They are a little difficult to see but a magnifying glass can rectify this problem.
Here is a list of jets and their associated technical names that should help you in determining the right set-up for your engine.
4 cylinder
Primary Main Jet 140
Secondary Main Jet 140
Primary Air Corrector Jet 170
Secondary Air Corrector Jet 160
Primary Idle Jet 060
Secondary Idle Jet 050
Pump Jet 050
6 cylinder
Primary Main Jet 160
Secondary Main Jet 160
Primary Air Corrector Jet 190
Secondary Air Corrector Jet 180
Primary Idle Jet 075
Secondary Idle Jet 065
Pump Jet 060
The first list is comprised of the stock jet sizes as originally intended by the manufacturer. Remember, these numbers are based typically on a stock 4 cylinder engine displacing no more than 151 cubic inches.
The second list was developed from a group of off road enthusiates, namely individuals from the Jeep crowd. Typically their engines are 6 cylinders with displacements of 232 cubic inches or more.
I have found the latter jet sizes to work very well(save one size small on the air jets 185 & 175 vs. 190 & 180) with my inline 200.
**********************
The following write-up is from Weber.
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.
TUNING
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.
*************
Some encouragement - after @ 15 years with the H/W 5200 (Capri 2.8 V6) the 170 still runs great... Smooth consistent idle, economical (primary Bbl) light cruise performance and decent interstate ramp 2Bbl max-CFM performance.
some tech diagrams about the 32/36 or H/W5200 clone may help if carb is opened.
.
170 has stock bottom end/cam but big valve head work running @ 10:1 CR with decent mileage (on 93 octane) .. > Direct mount mod is a great performance option, but for MPG/daily driver, probably a simple 2X1 adapter is viable option .
. 
have fu...
some tech diagrams about the 32/36 or H/W5200 clone may help if carb is opened.
.170 has stock bottom end/cam but big valve head work running @ 10:1 CR with decent mileage (on 93 octane) .. > Direct mount mod is a great performance option, but for MPG/daily driver, probably a simple 2X1 adapter is viable option .
. have fu...
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krbostic89
Active member
So it's been about a month of screwing with the thing, sealing up the mounting base and fiddling with the idle speed screw and mixture screw. I finally have the thing running at what could be called a good idle. Figured I owed an update.
Current settings, timing set at 16*, idle speed screw at 1 3/4 turn, mixture at 1 turn. Idle at about 800, pulling about 15 inHg vacuum.
Next plans are to get with Bill to get the distributor recurved and to get a weber jet kit and re jet the carb for a leaner jet, per the guidance from Redline/weber and from power band (mixture jet less than 1 1/2 turns and carbon build up on the plugs signaling a rich mixture)
Spark plugs have a pretty good amount of carbon build up right now. I honestly don't know if I should replace them now since I have the car running well or if I should drive the car and let the carbon burn off to analyze the mixture setting.
Thank you to everyone who provided input and help!
Plus side, the machine runs!
Current settings, timing set at 16*, idle speed screw at 1 3/4 turn, mixture at 1 turn. Idle at about 800, pulling about 15 inHg vacuum.
Next plans are to get with Bill to get the distributor recurved and to get a weber jet kit and re jet the carb for a leaner jet, per the guidance from Redline/weber and from power band (mixture jet less than 1 1/2 turns and carbon build up on the plugs signaling a rich mixture)
Spark plugs have a pretty good amount of carbon build up right now. I honestly don't know if I should replace them now since I have the car running well or if I should drive the car and let the carbon burn off to analyze the mixture setting.
Thank you to everyone who provided input and help!
Plus side, the machine runs!
