CARB TECH

[WAYNE0]

Any carb gurus on here ? I have a 397 ci 360 w/ 8.7 comp. I have a paxton super charger. Im running a quick fuel 750 cfm blow thru carb. 7 psi fuel pressure at the regulator. It runs awesome at higher rpms. It runs rich at idle. Really rich. It has the plugs black, smokes at idle & you can smell fuel. I dont want to go changing any thing because i was told i need extra fuel due to the super charger. The engine was already built when i bought it. The only thing i dont know about it is the cam size. You can tell its not even close to stock. The fuel level at the site holes on the carb it about half way. Any ideas ? Thank you

 

[toolmanmike]

Cut your pressure back to 5# or less and see how it runs. It's probably bleeding over.

 

[WAYNE0]

Cut your pressure back to 5# or less and see how it runs. It's probably bleeding over.

ill give it a try thank you

 

[crackedback]

Take carb hat off, look down carb throat to see if fuel is dripping in. If dripping, lower the float level.

Turn the pressure down as well and sneak up on the level it overpowers the needle and seat. As suggested do the above at 5psi.

 

[jbc426]

Any carb gurus on here ? I have a 397 ci 360 w/ 8.7 comp. I have a paxton super charger. Im running a quick fuel 750 cfm blow thru carb. 7 psi fuel pressure at the regulator. It runs awesome at higher rpms. It runs rich at idle. Really rich. It has the plugs black, smokes at idle & you can smell fuel. I dont want to go changing any thing because i was told i need extra fuel due to the super charger. The engine was already built when i bought it. The only thing i dont know about it is the cam size. You can tell its not even close to stock. The fuel level at the site holes on the carb it about half way. Any ideas ? Thank you

Is your fuel pressure regulator boost referenced? Can you post some pictures of your set-up. I'm wrapping up a build with a Novi 1500 on my '68.

 

[WAYNE0]

Is your fuel pressure regulator boost referenced? Can you post some pictures of your set-up. I'm wrapping up a build with a Novi 1500 on my '68.

View attachment 1716420950

Nice ill post them later this evening Yes the regulator is boost referenced & along with the MSD box. Here is what i was told to do. The fuel reg. vacuum line goes to the carb hat. The MSD box & blow off valve vacuum lines goes to an intake vacuum port. They said its best if they go to a vacuum port on the carb but my carb doesnt have any. I also learned that the more the valve cover breathers you have the better you are. I only had 2 at the time & i kept blowing out the pan gasket. I have 2 K&N breathers & i have 2 that are gonna go to a catch can

 

[WAYNE0]

Take carb hat off, look down carb throat to see if fuel is dripping in. If dripping, lower the float level.

Turn the pressure down as well and sneak up on the level it overpowers the needle and seat. As suggested do the above at 5psi.

Ok i tried to lower the fuel pressure & i can get it to move. New gauge, new regulator, new pump. The front carb bowl was about half at the glass site holes. I lowered it alittle. No difference still smokes & idles rich. It clears up when i run the rpms up. I had someone fallow me & they said they didnt see any smoke until i sat at a red light for a few minutes Ill remove the carb hat later & check it out

 

[jbc426]

Ok i tried to lower the fuel pressure & i can get it to move. New gauge, new regulator, new pump. The front carb bowl was about half at the glass site holes. I lowered it alittle. No difference still smokes & idles rich. It clears up when i run the rpms up. I had someone fallow me & they said they didnt see any smoke until i sat at a red light for a few minutes Ill remove the carb hat later & check it out

Are you running a wideband?

 

[Snake]

How much vacuum you have at idle,what number power valve you have do you know.power valve could be opening up too soon hence rich mixture. Just my 2 cents worth bin there once.

 

[WAYNE0]

How much vacuum you have at idle,what number power valve you have do you know.power valve could be opening up too soon hence rich mixture. Just my 2 cents worth bin there o

How much vacuum you have at idle,what number power valve you have do you know.power valve could be opening up too soon hence rich mixture. Just my 2 cents worth bin there once.

45 power valve just got it running to put some miles on it to work the bugs out i need to get a boost gauge for it yet

 

[WAYNE0]

Are you running a wideband?

No this kit doesnt call for one

 

[jbc426]

No this kit doesnt call for one

Regardless, it's one of the most valuable tuning tools I've ever used on my carbureted N/A motors.

I'd be scared not to have one on the boosted engines I'm upgrading to, and they are Holley EFI controlled.

 

[WAYNE0]

Here are some pics. Everything under the hood might be for sale at some point. I thinking of going big block.