Engine dies round bends and under hard braking
Burning Brakes
Joined: Jun 2008
Posts: 1,086
Likes: 1
From: Michigan
I also agree with Paranoid. A hard stop in one of my cars would stall it out and cause hydrolock and wouldn't restart until it cooled down. It was the float.
Melting Slicks
Joined: Jan 2004
Posts: 3,247
Likes: 210
From: Detroit MI
Instructor
Joined: Aug 2008
Posts: 159
Likes: 0
From: Northern California
I have this issue as well, and I have a Holley 650. Mine stumbles when I break really hard. I haven't noticed it around corners, but when I have to stop fast the engine almost dies... sounds like it isn't getting any gas all of a sudden.
Melting Slicks
Joined: Mar 2008
Posts: 2,666
Likes: 289
From: Spring Park MN
A Holley is pretty easy to set up to handle the G forces from accelerating, braking, or turning. Run jet extensions on the main and secondary jets that extend to about the center of the bowl area. Set the float level so fuel just barely dribbles out the fuel level holes. Put a piece of fuel line between the front and rear bowl vent that arcs up over the throats of the carb. Cut a rectangular shape hole in the line for the air cleaner stud to fit through large enough to leave room for the vents to breath properly.
Pro
Joined: Oct 2006
Posts: 545
Likes: 2
From: Peoplez Republik (communist portland) Orygun
You have an Edelbrock performer. That's why. I have one too. That is the way they are. The first time I had my Vette on the track, older C3 racers would ask me if the engine sounded like it died at hard corners, I was like "as a matter of fact, yes it does." They would chuckle. BUT... IT has stopped doing that ever since I installed the TREMEC 5 speed tranny.
Do you have an automatic transmission?
I wouldn't be surprised if you did.
My car probably still does it to some extent but with the 5 speed I am usually more controlling of the RPM's under higher speed.
Good luck. Get used to it or get a different carb
Do you have an automatic transmission?
I wouldn't be surprised if you did.
My car probably still does it to some extent but with the 5 speed I am usually more controlling of the RPM's under higher speed.
Good luck. Get used to it or get a different carb
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 845
Likes: 54
From: Bangor, Northern Ireland
i don't know:o
every time iv'e gone out to do it i find 5 other jobs that are more pressing, i'll read the Edelbrock instructions tomorrow and do it, any pointers?
Just taken my car out for the first time tonight since i changed out the mincie for a tko600rr, i can see where you are coming from, awesome
out of interest, i took the carb off yesterday as i thought the gasket was leaking and i turned it upside down to clean the bottom and lots of fuel came out of one side and not half as much out of the other, could this be my badly adjusted float issues?
every time iv'e gone out to do it i find 5 other jobs that are more pressing, i'll read the Edelbrock instructions tomorrow and do it, any pointers?
Just taken my car out for the first time tonight since i changed out the mincie for a tko600rr, i can see where you are coming from, awesome
out of interest, i took the carb off yesterday as i thought the gasket was leaking and i turned it upside down to clean the bottom and lots of fuel came out of one side and not half as much out of the other, could this be my badly adjusted float issues?
Last edited by aaroncorvette; May 27, 2009 at 05:22 PM.
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Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
Check your float levels and I bet they are too high (especially secondaries).
When you stop, it sloshes over into the discharge tubes and floods the engine causing it to stall out.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
The purpose of these extensions is so that when the car accellerates and the fuel sloshes toward the rear, the extensions let the secondaries access this fuel at the back of the bowl rather than having their orfices uncovered.
But on the primary with the jet extension you put this pick-up at the front of the carb, and you would uncover the jet as the fuel rushes to the back of the carb, which is where the primary jet is placed without the extension.
Melting Slicks
Joined: Mar 2008
Posts: 2,666
Likes: 289
From: Spring Park MN
Why would you run jet extensions on the primaries?
The purpose of these extensions is so that when the car accellerates and the fuel sloshes toward the rear, the extensions let the secondaries access this fuel at the back of the bowl rather than having their orfices uncovered.
But on the primary with the jet extension you put this pick-up at the front of the carb, and you would uncover the jet as the fuel rushes to the back of the carb, which is where the primary jet is placed without the extension.
The purpose of these extensions is so that when the car accellerates and the fuel sloshes toward the rear, the extensions let the secondaries access this fuel at the back of the bowl rather than having their orfices uncovered.
But on the primary with the jet extension you put this pick-up at the front of the carb, and you would uncover the jet as the fuel rushes to the back of the carb, which is where the primary jet is placed without the extension.
The extensions do not extend to the front or rear of the bowls. If you read my original post you will see I said to extend to the center of the bowl.
Last edited by v2racing; May 27, 2009 at 09:09 PM.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
You put jet extensions on the front so the fuel won't move away from the primary jets when you brake hard. Unless you are hiking the front wheels pretty high when you leave the line, you won't uncover the primary jet extensions accelerating. The OP wasn't talking about a drag setup anyway. A couple other people mentioned Holleys having problems unless setup for the track, the ones with curves. This will fix them.
The extensions do not extend to the front or rear of the bowls. If you read my original post you will see I said to extend to the center of the bowl.
The extensions do not extend to the front or rear of the bowls. If you read my original post you will see I said to extend to the center of the bowl.
If a quarter mile of accelleration can uncover the rear jets and the extensions keep this from happening, putting the front jets half way out into the float bowl could cause them to be uncovered at the big end of the quarter.
Seems to me that braking is a non-issue as I am usually off the gas at that point. (I think they are just trying to sell twice as many jet extensions.)
Melting Slicks
Joined: Mar 2008
Posts: 2,666
Likes: 289
From: Spring Park MN
If you brake hard enough the primary jets will uncover and the engine will die or try to.
The big end is not where the high G forces are at, they are highest accelerating from low speeds or from a dead stop. Braking at the big end however could make for high negative G's and that is where the fuel will pull away from the stock jet location.
If you were closer I would give you a ride in my Vette and you could try and lift your head off the back of the seat while I am accelerating in first gear. I have my carb set up just like this and is does not miss a beat in any condition I put it through.
As far as having to buy floats and extensions, nobody ever said racing was cheap. At least it has never been for me.
The big end is not where the high G forces are at, they are highest accelerating from low speeds or from a dead stop. Braking at the big end however could make for high negative G's and that is where the fuel will pull away from the stock jet location.
If you were closer I would give you a ride in my Vette and you could try and lift your head off the back of the seat while I am accelerating in first gear. I have my carb set up just like this and is does not miss a beat in any condition I put it through.
As far as having to buy floats and extensions, nobody ever said racing was cheap. At least it has never been for me.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
If you brake hard enough the primary jets will uncover and the engine will die or try to.
The big end is not where the high G forces are at, they are highest accelerating from low speeds or from a dead stop. Braking at the big end however could make for high negative G's and that is where the fuel will pull away from the stock jet location.
If you were closer I would give you a ride in my Vette and you could try and lift your head off the back of the seat while I am accelerating in first gear. I have my carb set up just like this and is does not miss a beat in any condition I put it through.
As far as having to buy floats and extensions, nobody ever said racing was cheap. At least it has never been for me.
The big end is not where the high G forces are at, they are highest accelerating from low speeds or from a dead stop. Braking at the big end however could make for high negative G's and that is where the fuel will pull away from the stock jet location.
If you were closer I would give you a ride in my Vette and you could try and lift your head off the back of the seat while I am accelerating in first gear. I have my carb set up just like this and is does not miss a beat in any condition I put it through.
As far as having to buy floats and extensions, nobody ever said racing was cheap. At least it has never been for me.
Sure there are more Gs at the beginning of the run, but it takes time to suck the fuel out of the bowls when the pump can't keep up so the jets are uncovered at the big end not when the bowls are full at the start.
Melting Slicks
Joined: Mar 2008
Posts: 2,666
Likes: 289
From: Spring Park MN
If I am braking, the engine is at idle (or spooling down) and running off the idle circuit, not the main jets.
Sure there are more Gs at the beginning of the run, but it takes time to suck the fuel out of the bowls when the pump can't keep up so the jets are uncovered at the big end not when the bowls are full at the start.
Sure there are more Gs at the beginning of the run, but it takes time to suck the fuel out of the bowls when the pump can't keep up so the jets are uncovered at the big end not when the bowls are full at the start.
Why would you ever consider running a fuel pump that can't keep the fuel bowl full at any speed or distance????
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
Not that the pump can't keep up, the regular seats don't allow enough to pass to keep up with demand. Otherwise, why would the level even ever go down? But it does.
Senior Member since 1492
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Instructor
Joined: Aug 2008
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From: Northern California
Cruising
Joined: Oct 2009
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Hi, my '71 small block Vette dies under hard braking and cornering, it has an Edelbrock performer RPM top end package, a new-ish holley mechanical fuel pump and the fuel lines are good with good fuel pressure, the car is a pro tourer and i like to throw her around
it seems most noticable round right hand turns and is really annoying!
my friend reckons all 4bbl carbs do this, do they? if that were true then no one could circuit race a 4bbl car, i don't believe this, but i don't want to spend out on a new carb if it won't solve it
Could it be the bowls? fuel tank?
if so any recommendations on an upgrade for my Edelbrock carb, and is it worth it?
Thanks guys.
Aaron
it seems most noticable round right hand turns and is really annoying!
my friend reckons all 4bbl carbs do this, do they? if that were true then no one could circuit race a 4bbl car, i don't believe this, but i don't want to spend out on a new carb if it won't solve it
Could it be the bowls? fuel tank?
if so any recommendations on an upgrade for my Edelbrock carb, and is it worth it?
Thanks guys.
Aaron