Evil holley !!!!
05-10-10, 07:48 PM
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Evil holley !!!!
Ok I have done everything I could. I'll start from the beginning.
I bought a used intake and holley. Put it on and it was bogging like a horse.
Open it up dirty inside and change the power valve. It has 49 jets.
Put it back on got much better but it has a slight bogging when I first put into gear but once it catches it's fine. It's idleing right now about 1k. While I'm driving when I come to a light it wants to stalk on me. I have to hit the gas so it won't stall(drives me nukin futs)timing is right on point,so I think. I have it at stock plus a few degrees.
It also don't think that it has the power that it should.
This is what I have:
84gsl
RB RR header straight to a RBRR muffler
RB intake
465 holley
holley blue fuel pump
holley regulator
blaster 2 coils
removed rats nest
also when I turn a corner she bogs. I have the floats to just a slight trickle.
Any help would b greatly apreciated.
It's no fun driving my 7 like that
I bought a used intake and holley. Put it on and it was bogging like a horse.
Open it up dirty inside and change the power valve. It has 49 jets.
Put it back on got much better but it has a slight bogging when I first put into gear but once it catches it's fine. It's idleing right now about 1k. While I'm driving when I come to a light it wants to stalk on me. I have to hit the gas so it won't stall(drives me nukin futs)timing is right on point,so I think. I have it at stock plus a few degrees.
It also don't think that it has the power that it should.
This is what I have:
84gsl
RB RR header straight to a RBRR muffler
RB intake
465 holley
holley blue fuel pump
holley regulator
blaster 2 coils
removed rats nest
also when I turn a corner she bogs. I have the floats to just a slight trickle.
Any help would b greatly apreciated.
It's no fun driving my 7 like that
05-10-10, 08:16 PM
#2
You've listed most of the reasons why I think the Holley's are the worst carb choice for a rotary. The cornering bogging can be fixed by changing from side hung to center hung floats, if they make them to fit the 465.
Get the idle down to to 750-800, disconnect and plug the vacuum lines to the dizzy and reset the timing. What do you have your fuel pressure set at?
Get the idle down to to 750-800, disconnect and plug the vacuum lines to the dizzy and reset the timing. What do you have your fuel pressure set at?
05-10-10, 08:26 PM
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Yeah tell me about it. My buddy warned me but nooooo did I listen of course not.
Fuel pressure is set at 6psi.
Thinking about getting a NEW 600 holley.
Anything else I can put instead that will give me some HP.
Want to keep the RB intake though.
Fuel pressure is set at 6psi.
Thinking about getting a NEW 600 holley.
Anything else I can put instead that will give me some HP.
Want to keep the RB intake though.
05-10-10, 08:49 PM
#4
I think a 600cfm Holley might be a bit too much for the lil 12a. I had a 600 on my BP a few years ago. I also had a Edelbrock carb which was awesome! 
I currently use Nikki's and IDA's. Have you check your fuel filter? Sounds like a stupid suggestion but you'd be surprised how much a clogged filter could affect driveability. Goodluck
I currently use Nikki's and IDA's. Have you check your fuel filter? Sounds like a stupid suggestion but you'd be surprised how much a clogged filter could affect driveability. Goodluck
05-10-10, 08:50 PM
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The easy fix. Sell Holley, buy Sterling. www.sterlingmetalworks.com. At the very least theres tons of info there that might help you with your existing problem.
The 600 is way too big. The stock engine won't exceed 400CFM naturally aspirated, so you won't get any more out of a larger carb. If anything your bogging and low end power will be much worse.
The 600 is way too big. The stock engine won't exceed 400CFM naturally aspirated, so you won't get any more out of a larger carb. If anything your bogging and low end power will be much worse.
05-10-10, 09:06 PM
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I only wish I could get my hands on a sterling Nikki.
That's what I wanted from the beginning but I would nerd to wait 3 months
at this point I have to do something since it's my daily driver.
Plus the fact that to find a good "reputable and HONEST"rotary mechanic in my area is nearly impossible. I'll check the fuel filter which us really not such a bad idea, thanx.
Wish I can take it to someone who really knows ROTARIES!!
Belive me don't mind spending money as long as I'm getting great,honest and knowledgeable.
That's what I wanted from the beginning but I would nerd to wait 3 months
at this point I have to do something since it's my daily driver.
Plus the fact that to find a good "reputable and HONEST"rotary mechanic in my area is nearly impossible. I'll check the fuel filter which us really not such a bad idea, thanx.
Wish I can take it to someone who really knows ROTARIES!!
Belive me don't mind spending money as long as I'm getting great,honest and knowledgeable.
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05-10-10, 10:06 PM
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How u been stock?
Really I can't take this carb any longer.
How's that elderbrock run?
Would I notice the difference between that and the holley?
They have a couple of 500 thunder series. U happen to know which one for me?
U the mang...thanks.
Really I can't take this carb any longer.
How's that elderbrock run?
Would I notice the difference between that and the holley?
They have a couple of 500 thunder series. U happen to know which one for me?
U the mang...thanks.
05-11-10, 02:08 AM
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Edelbrocks are neat carbs, I like 'em. However, on a rotary, they suffer from bogging when cornering just like Holleys with side-hung floats do. I've never had the opportunity to try a Holley with center-hung floats, but I've heard they help.
True.
False.
True.
False.
05-11-10, 05:11 AM
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Why don't you do more than just state that I'm wrong. Prove me wrong, right after some math proves I'm right
Here's one with the 12A numbers
(85%) ( 70 ci ) x ( 8400 RPM )
And here's one with PERFECT numbers which no street rotary will likely acheive.
(100%) ( 70 ci ) x ( 10,000 RPM )
So your right, if the engine was perfect, and a never saw the street, it might suck more than 400CFM at a high enough RPM to require a scatter shield.
(VE) ( engine displacement ) x ( maximum RPM )
1728 = Maximum CFM
Here's one with the 12A numbers
(85%) ( 70 ci ) x ( 8400 RPM )
1728 = 289 CFM
And here's one with PERFECT numbers which no street rotary will likely acheive.
(100%) ( 70 ci ) x ( 10,000 RPM )
1728 = 405 CFM
So your right, if the engine was perfect, and a never saw the street, it might suck more than 400CFM at a high enough RPM to require a scatter shield.
05-11-10, 11:51 AM
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*Sigh*
That math is not wrong. An NA rotary will never pull more than about 400 CFM and probably a whole lot less. I think I remember hearing that a streetported 12A with a Yaw carb maxed out at something like 290 CFM on a dyno. However, what you're not taking into account is what the flow rate of a carb actually means.
Airflow occurs when there is an area of higher pressure and an area of lower pressure. For carbs, there is a pressure differential between the atmosphere and the intake manifold because of the suction the engine creates when it pulls in air. The important part to know is that the rate at which the air flows is in direct proportion to how much of a pressure differential there is.
4-barrel carbs are typically rated at a pressure drop of 1.5" Hg. With a smaller pressure drop they will flow less, and with a larger pressure drop they will flow more. A stock Nikki (313 CFM at 1.5" Hg) could flow 750 CFM given a large enough pressure drop. Does that mean you could drop it on a V8 in place of a 750 CFM Holley and expect to make the same power? Of course not, that would be ridiculous.
Likewise, notice that your "realistic" 12A numbers give a maximum flow rate of 289 CFM - less than the stock Nikki flows at 1.5" Hg! So that means the stock Nikki has all the airflow you'll ever need, right? You won't make any more power with a bigger carb such as a Sterling... oh, wait... that doesn't make sense, now, does it? For that matter, why would a Weber 48 DCOE yield more power on a rotary than a 45 DCOE, when the 45 is already around 440 CFM at 1.5" Hg with 40mm venturis? Yet over and over, that's shown to be the case. Why did Hyper4mance2K gain power on the dyno when he switched to larger venturis in his 48 IDA when he was already near 600 CFM with the smaller ones?
For another example, take all those Chevy 350 guys who plugged their numbers into that equation and figured they'd want a 600 CFM carb. Time and time again, it's been shown that they've gained power when switching to a 750 CFM carb, with little impact on drivability. How can that be?
As it turns out, 1.5" Hg is a pretty big pressure drop. Seems that most V8 guys who know what they're doing assume a pressure drop in the 0.5-1.0" Hg range when choosing a carb, depending on the vehicle's intended use. Sometimes less for full race engines. Sure, a smaller carb will work, but you'll be increasing pumping losses and reducing VE, which means less power.
It's a compromise. Going with a larger and larger carb will give you more and more peak power, but it's not a linear increase. After a while it tapers off to the point where you're not gaining much power by going larger, but drivability keeps getting worse and worse. The trick is to find that "sweet spot", the point where you get the most power while maintaining acceptable drivability. There's no one "ideal" carb size, because everyone has a different definition of what "acceptable" drivability is, and at a given flow rate one carb might have better drivability than another.
I don't pretend to know what the perfect carb is for any given engine. I'm certainly not saying the Sterling Nikki isn't awesome (I've never had the pleasure of trying one, but from all accounts it's a great carb). All I'm saying is that it's not as simple as just plugging numbers into an equation. It's actually even more complex than I'm making it out to be, as the type of intake manifold also changes things. (E.g. a separate runner manifold will want a bigger carb than one with an open plenum. Ever wonder why serious ACVW guys use dual 48 IDAs when we can get by just fine with one?)
That math is not wrong. An NA rotary will never pull more than about 400 CFM and probably a whole lot less. I think I remember hearing that a streetported 12A with a Yaw carb maxed out at something like 290 CFM on a dyno. However, what you're not taking into account is what the flow rate of a carb actually means.
Airflow occurs when there is an area of higher pressure and an area of lower pressure. For carbs, there is a pressure differential between the atmosphere and the intake manifold because of the suction the engine creates when it pulls in air. The important part to know is that the rate at which the air flows is in direct proportion to how much of a pressure differential there is.
4-barrel carbs are typically rated at a pressure drop of 1.5" Hg. With a smaller pressure drop they will flow less, and with a larger pressure drop they will flow more. A stock Nikki (313 CFM at 1.5" Hg) could flow 750 CFM given a large enough pressure drop. Does that mean you could drop it on a V8 in place of a 750 CFM Holley and expect to make the same power? Of course not, that would be ridiculous.
Likewise, notice that your "realistic" 12A numbers give a maximum flow rate of 289 CFM - less than the stock Nikki flows at 1.5" Hg! So that means the stock Nikki has all the airflow you'll ever need, right? You won't make any more power with a bigger carb such as a Sterling... oh, wait... that doesn't make sense, now, does it? For that matter, why would a Weber 48 DCOE yield more power on a rotary than a 45 DCOE, when the 45 is already around 440 CFM at 1.5" Hg with 40mm venturis? Yet over and over, that's shown to be the case. Why did Hyper4mance2K gain power on the dyno when he switched to larger venturis in his 48 IDA when he was already near 600 CFM with the smaller ones?
For another example, take all those Chevy 350 guys who plugged their numbers into that equation and figured they'd want a 600 CFM carb. Time and time again, it's been shown that they've gained power when switching to a 750 CFM carb, with little impact on drivability. How can that be?
As it turns out, 1.5" Hg is a pretty big pressure drop. Seems that most V8 guys who know what they're doing assume a pressure drop in the 0.5-1.0" Hg range when choosing a carb, depending on the vehicle's intended use. Sometimes less for full race engines. Sure, a smaller carb will work, but you'll be increasing pumping losses and reducing VE, which means less power.
It's a compromise. Going with a larger and larger carb will give you more and more peak power, but it's not a linear increase. After a while it tapers off to the point where you're not gaining much power by going larger, but drivability keeps getting worse and worse. The trick is to find that "sweet spot", the point where you get the most power while maintaining acceptable drivability. There's no one "ideal" carb size, because everyone has a different definition of what "acceptable" drivability is, and at a given flow rate one carb might have better drivability than another.
I don't pretend to know what the perfect carb is for any given engine. I'm certainly not saying the Sterling Nikki isn't awesome (I've never had the pleasure of trying one, but from all accounts it's a great carb). All I'm saying is that it's not as simple as just plugging numbers into an equation. It's actually even more complex than I'm making it out to be, as the type of intake manifold also changes things. (E.g. a separate runner manifold will want a bigger carb than one with an open plenum. Ever wonder why serious ACVW guys use dual 48 IDAs when we can get by just fine with one?)
05-11-10, 03:40 PM
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*sigh*
that math is not wrong. An na rotary will never pull more than about 400 cfm and probably a whole lot less. I think i remember hearing that a streetported 12a with a yaw carb maxed out at something like 290 cfm on a dyno. However, what you're not taking into account is what the flow rate of a carb actually means.
Airflow occurs when there is an area of higher pressure and an area of lower pressure. For carbs, there is a pressure differential between the atmosphere and the intake manifold because of the suction the engine creates when it pulls in air. The important part to know is that the rate at which the air flows is in direct proportion to how much of a pressure differential there is.
4-barrel carbs are typically rated at a pressure drop of 1.5" hg. With a smaller pressure drop they will flow less, and with a larger pressure drop they will flow more. A stock nikki (313 cfm at 1.5" hg) could flow 750 cfm given a large enough pressure drop. Does that mean you could drop it on a v8 in place of a 750 cfm holley and expect to make the same power? Of course not, that would be ridiculous.
Likewise, notice that your "realistic" 12a numbers give a maximum flow rate of 289 cfm - less than the stock nikki flows at 1.5" hg! So that means the stock nikki has all the airflow you'll ever need, right? You won't make any more power with a bigger carb such as a sterling... Oh, wait... That doesn't make sense, now, does it? For that matter, why would a weber 48 dcoe yield more power on a rotary than a 45 dcoe, when the 45 is already around 440 cfm at 1.5" hg with 40mm venturis? Yet over and over, that's shown to be the case. Why did hyper4mance2k gain power on the dyno when he switched to larger venturis in his 48 ida when he was already near 600 cfm with the smaller ones?
For another example, take all those chevy 350 guys who plugged their numbers into that equation and figured they'd want a 600 cfm carb. Time and time again, it's been shown that they've gained power when switching to a 750 cfm carb, with little impact on drivability. How can that be?
As it turns out, 1.5" hg is a pretty big pressure drop. Seems that most v8 guys who know what they're doing assume a pressure drop in the 0.5-1.0" hg range when choosing a carb, depending on the vehicle's intended use. Sometimes less for full race engines. Sure, a smaller carb will work, but you'll be increasing pumping losses and reducing ve, which means less power.
It's a compromise. Going with a larger and larger carb will give you more and more peak power, but it's not a linear increase. After a while it tapers off to the point where you're not gaining much power by going larger, but drivability keeps getting worse and worse. The trick is to find that "sweet spot", the point where you get the most power while maintaining acceptable drivability. There's no one "ideal" carb size, because everyone has a different definition of what "acceptable" drivability is, and at a given flow rate one carb might have better drivability than another.
I don't pretend to know what the perfect carb is for any given engine. I'm certainly not saying the sterling nikki isn't awesome (i've never had the pleasure of trying one, but from all accounts it's a great carb). All i'm saying is that it's not as simple as just plugging numbers into an equation. It's actually even more complex than i'm making it out to be, as the type of intake manifold also changes things. (e.g. A separate runner manifold will want a bigger carb than one with an open plenum. Ever wonder why serious acvw guys use dual 48 idas when we can get by just fine with one?)
that math is not wrong. An na rotary will never pull more than about 400 cfm and probably a whole lot less. I think i remember hearing that a streetported 12a with a yaw carb maxed out at something like 290 cfm on a dyno. However, what you're not taking into account is what the flow rate of a carb actually means.
Airflow occurs when there is an area of higher pressure and an area of lower pressure. For carbs, there is a pressure differential between the atmosphere and the intake manifold because of the suction the engine creates when it pulls in air. The important part to know is that the rate at which the air flows is in direct proportion to how much of a pressure differential there is.
4-barrel carbs are typically rated at a pressure drop of 1.5" hg. With a smaller pressure drop they will flow less, and with a larger pressure drop they will flow more. A stock nikki (313 cfm at 1.5" hg) could flow 750 cfm given a large enough pressure drop. Does that mean you could drop it on a v8 in place of a 750 cfm holley and expect to make the same power? Of course not, that would be ridiculous.
Likewise, notice that your "realistic" 12a numbers give a maximum flow rate of 289 cfm - less than the stock nikki flows at 1.5" hg! So that means the stock nikki has all the airflow you'll ever need, right? You won't make any more power with a bigger carb such as a sterling... Oh, wait... That doesn't make sense, now, does it? For that matter, why would a weber 48 dcoe yield more power on a rotary than a 45 dcoe, when the 45 is already around 440 cfm at 1.5" hg with 40mm venturis? Yet over and over, that's shown to be the case. Why did hyper4mance2k gain power on the dyno when he switched to larger venturis in his 48 ida when he was already near 600 cfm with the smaller ones?
For another example, take all those chevy 350 guys who plugged their numbers into that equation and figured they'd want a 600 cfm carb. Time and time again, it's been shown that they've gained power when switching to a 750 cfm carb, with little impact on drivability. How can that be?
As it turns out, 1.5" hg is a pretty big pressure drop. Seems that most v8 guys who know what they're doing assume a pressure drop in the 0.5-1.0" hg range when choosing a carb, depending on the vehicle's intended use. Sometimes less for full race engines. Sure, a smaller carb will work, but you'll be increasing pumping losses and reducing ve, which means less power.
It's a compromise. Going with a larger and larger carb will give you more and more peak power, but it's not a linear increase. After a while it tapers off to the point where you're not gaining much power by going larger, but drivability keeps getting worse and worse. The trick is to find that "sweet spot", the point where you get the most power while maintaining acceptable drivability. There's no one "ideal" carb size, because everyone has a different definition of what "acceptable" drivability is, and at a given flow rate one carb might have better drivability than another.
I don't pretend to know what the perfect carb is for any given engine. I'm certainly not saying the sterling nikki isn't awesome (i've never had the pleasure of trying one, but from all accounts it's a great carb). All i'm saying is that it's not as simple as just plugging numbers into an equation. It's actually even more complex than i'm making it out to be, as the type of intake manifold also changes things. (e.g. A separate runner manifold will want a bigger carb than one with an open plenum. Ever wonder why serious acvw guys use dual 48 idas when we can get by just fine with one?)
05-11-10, 05:26 PM
#15
Efficiency curve effect, perhaps? Max airflow condition for a given carb doesn't necessarily equate to max fuel flow condition, or even most-effective mass mix - which is kind of the whole point of a carb.
It's not like they're linear devices.
Maybe those "oversize" carb applications are just overcoming the non-linear response of the carb above a certain flow rate.
It's not like they're linear devices.
Maybe those "oversize" carb applications are just overcoming the non-linear response of the carb above a certain flow rate.
05-11-10, 08:45 PM
#16
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Ok guys like I always say"the sun has to shine on a dogs *** once in a while"I got some news...I just got a whole T2 rx for free!!!!
My cousin crashed it but it's not to bad(maybe front bumper is messed up)
he had to move to Miami so he left it in my house and said keep it
gonna take it apart rebuild it and put it in my fb.
Here are my questions:
1-how hard to do a swap
2-I want to get a haltech is it much better?
3-basically what do I need to get it running perfect
4- what kind of HP should I expect.
Thanks for all your imput guys will record and take pics off the build and put them up.
Can't wait to get started!!!
My cousin crashed it but it's not to bad(maybe front bumper is messed up)
he had to move to Miami so he left it in my house and said keep it
gonna take it apart rebuild it and put it in my fb.
Here are my questions:
1-how hard to do a swap
2-I want to get a haltech is it much better?
3-basically what do I need to get it running perfect
4- what kind of HP should I expect.
Thanks for all your imput guys will record and take pics off the build and put them up.
Can't wait to get started!!!
05-12-10, 04:11 AM
#17
I also suffer from a bit of corner bogging....... This EXACT setup in my other 7 didnt do it but in my 2nd 7 it bogs....... the ONLY thing that was touched was the float bowl level so if you still need your DD for now mess with the float bowl adjustment in the top of the primary bowl. Probably lower it a tad.
05-12-10, 07:58 AM
#18
I also suffer from a bit of corner bogging....... This EXACT setup in my other 7 didnt do it but in my 2nd 7 it bogs....... the ONLY thing that was touched was the float bowl level so if you still need your DD for now mess with the float bowl adjustment in the top of the primary bowl. Probably lower it a tad.
05-12-10, 05:34 PM
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05-15-10, 10:31 AM
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well i have to say that with all the help i got here specially a big shout out to rotospeed my baby is running good.i adjusted the acc pump,mess with the air/fuel mix and i think she good.had to change the plugs though with all that carb work they were black as night.
also did some spring cleaning,well i tried to clean up
cleaned up all the emmision wires and DAMN that was a pain in the behind.thanks to one of the threads here though is how we got it done.she still needs a lot of work...
also did some spring cleaning,well i tried to clean up
cleaned up all the emmision wires and DAMN that was a pain in the behind.thanks to one of the threads here though is how we got it done.she still needs a lot of work...
