Holley 600 on na 6 port 13b tuning help
11-26-13, 12:54 PM
#26
Then change the idle air bleeds to fine tune. You can make a rich idle that's leaner on the highway or a lean idle the richer on the highway. Ur primary jetting has a very small effect on what your rotary is doing under 3000rpm. Everything is done with your idle circuit.
This is the sole reason people struggle with holleys on rotarys.
This is the sole reason people struggle with holleys on rotarys.
11-26-13, 01:00 PM
#27
FYI that tear in your vacuum diaphragm is a vacuum leak. Plug the whole and use a screw until you get a new diaphragm. Also the screw helps the engine build power and vacuum so keep using it. You'll find the right position for it. I recommend buying aed high flow shafts and making it true mechanical secondaries.
11-26-13, 02:21 PM
#28
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Then change the idle air bleeds to fine tune. You can make a rich idle that's leaner on the highway or a lean idle the richer on the highway. Ur primary jetting has a very small effect on what your rotary is doing under 3000rpm. Everything is done with your idle circuit.
This is the sole reason people struggle with holleys on rotarys.
This is the sole reason people struggle with holleys on rotarys.
11-26-13, 02:30 PM
#29
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so i have to pull the carb off the base to lengthen the idle slots...damn then i will need new gaskets. im already having issues getting to idle much lower than 1100 rpm, or will opening the idle slots more not change my idle?
the engine has about 82k miles on it. it came out of an 88 vert that read 74xxx on the clock. since then i've probably added about 7k miles onto it.
okay so i need to fix that diaphragm, as said previously, i will have that tonight
if i had a vacuum leak there, if i fix that will that improve my intake vacuum say to 19"? or am i misunderstanding? (credit 19" is just a number i threw out there for sake of argument).
since i tuned the idle mixtures and got my peak vacuum numbers, i havent changed anything else. heres my question, did that LEAN out my idle circuit? i asked this question, for one the engine idles smooth, no more brap brap at idle. problem though is she has began breaking up more starting around 3200 rpm like a lean condition and then as i drive more it gets worse say down to 3k then 2800 and down as low as 2600 rpms. i was beginning to doubt my regulator, then i gave it a wide open throttle pull from a stop and she barely broke up around 3500 and then pulled to 7k. then when i came back to cruising it was right back how it started to breaking up earlier and earlier. should i richen the idle mixture back up?
i would prefer to keep the carburetor as a vacuum secondary when once working properly. i hear they get better fuel mileage and i know the vacuum secondary will only open as much as needed and not more than needed.
the engine has about 82k miles on it. it came out of an 88 vert that read 74xxx on the clock. since then i've probably added about 7k miles onto it.
okay so i need to fix that diaphragm, as said previously, i will have that tonight
if i had a vacuum leak there, if i fix that will that improve my intake vacuum say to 19"? or am i misunderstanding? (credit 19" is just a number i threw out there for sake of argument).since i tuned the idle mixtures and got my peak vacuum numbers, i havent changed anything else. heres my question, did that LEAN out my idle circuit? i asked this question, for one the engine idles smooth, no more brap brap at idle. problem though is she has began breaking up more starting around 3200 rpm like a lean condition and then as i drive more it gets worse say down to 3k then 2800 and down as low as 2600 rpms. i was beginning to doubt my regulator, then i gave it a wide open throttle pull from a stop and she barely broke up around 3500 and then pulled to 7k. then when i came back to cruising it was right back how it started to breaking up earlier and earlier. should i richen the idle mixture back up?
i would prefer to keep the carburetor as a vacuum secondary when once working properly. i hear they get better fuel mileage and i know the vacuum secondary will only open as much as needed and not more than needed.
11-27-13, 06:32 AM
#30
carb whisperer
so i have to pull the carb off the base to lengthen the idle slots...damn then i will need new gaskets. im already having issues getting to idle much lower than 1100 rpm, or will opening the idle slots more not change my idle?
the engine has about 82k miles on it. it came out of an 88 vert that read 74xxx on the clock. since then i've probably added about 7k miles onto it.
okay so i need to fix that diaphragm, as said previously, i will have that tonight if i had a vacuum leak there, if i fix that will that improve my intake vacuum say to 19"? or am i misunderstanding? (credit 19" is just a number i threw out there for sake of argument).
since i tuned the idle mixtures and got my peak vacuum numbers, i havent changed anything else. heres my question, did that LEAN out my idle circuit? i asked this question, for one the engine idles smooth, no more brap brap at idle. problem though is she has began breaking up more starting around 3200 rpm like a lean condition and then as i drive more it gets worse say down to 3k then 2800 and down as low as 2600 rpms. i was beginning to doubt my regulator, then i gave it a wide open throttle pull from a stop and she barely broke up around 3500 and then pulled to 7k. then when i came back to cruising it was right back how it started to breaking up earlier and earlier. should i richen the idle mixture back up?
i would prefer to keep the carburetor as a vacuum secondary when once working properly. i hear they get better fuel mileage and i know the vacuum secondary will only open as much as needed and not more than needed.
the engine has about 82k miles on it. it came out of an 88 vert that read 74xxx on the clock. since then i've probably added about 7k miles onto it.
okay so i need to fix that diaphragm, as said previously, i will have that tonight
if i had a vacuum leak there, if i fix that will that improve my intake vacuum say to 19"? or am i misunderstanding? (credit 19" is just a number i threw out there for sake of argument).since i tuned the idle mixtures and got my peak vacuum numbers, i havent changed anything else. heres my question, did that LEAN out my idle circuit? i asked this question, for one the engine idles smooth, no more brap brap at idle. problem though is she has began breaking up more starting around 3200 rpm like a lean condition and then as i drive more it gets worse say down to 3k then 2800 and down as low as 2600 rpms. i was beginning to doubt my regulator, then i gave it a wide open throttle pull from a stop and she barely broke up around 3500 and then pulled to 7k. then when i came back to cruising it was right back how it started to breaking up earlier and earlier. should i richen the idle mixture back up?
i would prefer to keep the carburetor as a vacuum secondary when once working properly. i hear they get better fuel mileage and i know the vacuum secondary will only open as much as needed and not more than needed.
The vac reading you show at 1100 rpm will be tough to beat at your desired idle speed (800-900 rpm). youll probably find it gets a little lower at lower RPM's...
11-27-13, 10:19 AM
#31
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11-27-13, 11:34 AM
#32
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In. As i turned the screws in the idle cleared up and vacuum readings went up as well but drivability seems to have gone down and i have to pump the throttle once for her to start where before i could just reach in through the window and hit the key and would fire right up.
I seen pictures of the transfer slot and idle hole and how the slot should look once opened up a mm or 2 pastvthe throttle plate.
I really think my main issue is with my regulator. I think the regulator is going out. Yesterday things got so bad that while cruising in 5th and 2400 rpms without changing throttle position it began breaking up and i had to reduce speed/rpm down to 2200. Then after a long stop light things got better again. Then repeated later.
I did change out the secondary diaphragm last night. I think this one is too bad to be used to open rhe secondaries but no more vacuum leak.
I seen pictures of the transfer slot and idle hole and how the slot should look once opened up a mm or 2 pastvthe throttle plate.
I really think my main issue is with my regulator. I think the regulator is going out. Yesterday things got so bad that while cruising in 5th and 2400 rpms without changing throttle position it began breaking up and i had to reduce speed/rpm down to 2200. Then after a long stop light things got better again. Then repeated later.
I did change out the secondary diaphragm last night. I think this one is too bad to be used to open rhe secondaries but no more vacuum leak.
11-27-13, 11:57 AM
#33
Your carb is getting leaner between idle and 3000rpm. At 1100 rpm idle the idle transfer slot is covered. As the blade passes the slot you will get a lean condition. You need to set the idle with part of the slot exposed.
If you set your idle @1600rpm this might go away no mod to trans slot.
If you cut the trans slot u can idle around 900.
If you cut the slot too far your idle will be high because to much air will pass the blade.
I keep my idle @1350 to help with cold starts. But it idles fine at lower speeds.
Also you will need to buy jet extensions and nitrophy floats. The floats have to be cut to fit the extenstions but after u do this you can take trns like a champ. I can slide my car with no fuss.
If you set your idle @1600rpm this might go away no mod to trans slot.
If you cut the trans slot u can idle around 900.
If you cut the slot too far your idle will be high because to much air will pass the blade.
I keep my idle @1350 to help with cold starts. But it idles fine at lower speeds.
Also you will need to buy jet extensions and nitrophy floats. The floats have to be cut to fit the extenstions but after u do this you can take trns like a champ. I can slide my car with no fuss.
11-29-13, 10:12 AM
#34
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I richened the idle mixture back up and she is driveable up to 3400 again before she begins breaking up (back where i started) i i go heavier on the throttl it helps but then im wasting fuel.
I will bing the idle up 1600, may take it to 1800 just to be sure the transfer slot is open some before i begin my drivin for the day. If it helps (like i expect it to) then i will plan to pull the carb off so i can open the transfer slots some. I wish i had a picture showing how much they should be opened up. This my daily driver and what scares me is, if opened too far then there will be a problem and its one of thosr things that you cannot just tale away unless i jb welded and i dont want to do that.
I will bing the idle up 1600, may take it to 1800 just to be sure the transfer slot is open some before i begin my drivin for the day. If it helps (like i expect it to) then i will plan to pull the carb off so i can open the transfer slots some. I wish i had a picture showing how much they should be opened up. This my daily driver and what scares me is, if opened too far then there will be a problem and its one of thosr things that you cannot just tale away unless i jb welded and i dont want to do that.
11-29-13, 06:48 PM
#35
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Alright so i brought the idle up to 1800. Made the car much easier to drive by far! But still some break up. I truly believe my fuel pressure regulator is bad, i dont think its getting to 6lbs. The guage i sm using was given to me and it reads 0 half the the time, i can feel pressure in the line do i know it isnt actually at 0 but doesnt help any.
I need a new regulator, pressure gauge, and 50cc accelerator pump and to open the transfer slots a little bit. Still wish i knew how far to open it from where it is stock.
I need a new regulator, pressure gauge, and 50cc accelerator pump and to open the transfer slots a little bit. Still wish i knew how far to open it from where it is stock.
11-30-13, 06:26 AM
#36
carb whisperer
In. As i turned the screws in the idle cleared up and vacuum readings went up as well but drivability seems to have gone down and i have to pump the throttle once for her to start where before i could just reach in through the window and hit the key and would fire right up.
You dont have a choke.
11-30-13, 06:28 AM
#37
carb whisperer
No you dont "need" any of that. But since you (and everyone else) ignore my advice on these, screw it.
11-30-13, 11:47 AM
#38
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This carb does not have a choke.
Wankel, im sorry i guess i don't understand. Im not sure which part your refering to that i am not listening? I took the time to read back through all of your posts and i think your refering to the 50cc pump, and that part i opoligize for. I know i read it previously, but i guess i forgot. I can say that at idle if i give it a rev it comes back down to idle smoothly with no stumbles.
I need to richen the idle circuit more but i do not know if there is another way to do this besides bringing out the idle mixture screws? I did bring them out since i tuned it on the vacuum gauge. It helped a bit but still breaks up around 32-3400. If i bring them out any more though i begin to have a bit of off idle bog again. Maybe i will try another 1/4 turn out and see if that works. Now that i think about it i believe i had tried 1/2 turn more and had a bog.
The regulator i have is relatively old, it was a doner and ao was the gauge. The regulator is a turn **** style that ranges from 1lb up to 6lb. Most of the turn **** styles i see are from .5lb to 5.5lb, im not sure what brand this one is. The name has worn off. I tried searching oreviously and someone told me it was a profuel, like what racingbeat used to carry (not sure if they still do), that lerson said that profuel was the only company they knew of that had a turn **** style regulator that went up to 6lbs. All i know, its old lol. I do know that holley specifies to use 6lbs of fuel to the carb and i dont know if thats what im getting. If i turn the psi down a few clicks and the idle gets rougher and as i bring the pressure back up one click at a time the idle smooths out and sounds healthier.
So if i need to richen my idle circuit more, what is the easiest way to do that?
Also though, my break doesnt happen until 3200-3400 rpms. Isnt that when the carb should be pulling fuel through the boosters? Maybe my breakup is caused from too big/small primary jets? If the 10.5 PV is richening the fuel mixture almost soon after i tip the accelerator than perhaps the issue isnt caused from the idle circuit at all.
Im going to pull the filter off an with the assistance of a buddy slowly bring the revs up to 3400 and see when it begins pulling fuel throught the boosters.i think this is a good place to look. I am currently running .66 jets in the primary (needed them to be driveable before i got the correct PV) but i have a pair of .64 jets sitting in the glove box that i could swap in.
Wankel, im sorry i guess i don't understand. Im not sure which part your refering to that i am not listening? I took the time to read back through all of your posts and i think your refering to the 50cc pump, and that part i opoligize for. I know i read it previously, but i guess i forgot. I can say that at idle if i give it a rev it comes back down to idle smoothly with no stumbles.
I need to richen the idle circuit more but i do not know if there is another way to do this besides bringing out the idle mixture screws? I did bring them out since i tuned it on the vacuum gauge. It helped a bit but still breaks up around 32-3400. If i bring them out any more though i begin to have a bit of off idle bog again. Maybe i will try another 1/4 turn out and see if that works. Now that i think about it i believe i had tried 1/2 turn more and had a bog.
The regulator i have is relatively old, it was a doner and ao was the gauge. The regulator is a turn **** style that ranges from 1lb up to 6lb. Most of the turn **** styles i see are from .5lb to 5.5lb, im not sure what brand this one is. The name has worn off. I tried searching oreviously and someone told me it was a profuel, like what racingbeat used to carry (not sure if they still do), that lerson said that profuel was the only company they knew of that had a turn **** style regulator that went up to 6lbs. All i know, its old lol. I do know that holley specifies to use 6lbs of fuel to the carb and i dont know if thats what im getting. If i turn the psi down a few clicks and the idle gets rougher and as i bring the pressure back up one click at a time the idle smooths out and sounds healthier.
So if i need to richen my idle circuit more, what is the easiest way to do that?
Also though, my break doesnt happen until 3200-3400 rpms. Isnt that when the carb should be pulling fuel through the boosters? Maybe my breakup is caused from too big/small primary jets? If the 10.5 PV is richening the fuel mixture almost soon after i tip the accelerator than perhaps the issue isnt caused from the idle circuit at all.
Im going to pull the filter off an with the assistance of a buddy slowly bring the revs up to 3400 and see when it begins pulling fuel throught the boosters.i think this is a good place to look. I am currently running .66 jets in the primary (needed them to be driveable before i got the correct PV) but i have a pair of .64 jets sitting in the glove box that i could swap in.
11-30-13, 04:22 PM
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352 304 4482
Can text it anytime.
Pics of transfer slots would be great so i can have an idea of what im doing.
When i brought the idle up to 1800 it made driving easier, less break up.
Can text it anytime.
Pics of transfer slots would be great so i can have an idea of what im doing.
When i brought the idle up to 1800 it made driving easier, less break up.
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