carb help
Thread Starter
Racer
Joined: May 2005
Posts: 306
Likes: 0
From: Annandale Va
carb help
I just installed new Hooker headers and sidepipes on 350 cu with Edelbrock 1406 carb. Vette is running lean and has Performer Series Metering Rods, .075 x .047. What direction do I need to go with metering rod to help this situation.
Don't have a lot of knowledge with carb turning and trying to learn
to do it myself.
Any help on what direction to go with this would be very helpful or am I doing the the right thing by dealing with the metering rods.
Looking a Summit's list of rods has me confused
http://store.summitracing.com/defaul...0&autoview=sku
Don't have a lot of knowledge with carb turning and trying to learn
to do it myself.
Any help on what direction to go with this would be very helpful or am I doing the the right thing by dealing with the metering rods.
Looking a Summit's list of rods has me confused
http://store.summitracing.com/defaul...0&autoview=sku
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
You may need to provide a little more information to get a thorough response. On what did you base your decision that it is running lean? Do you think it's lean at cruise, WOT, or both?
If you have the manual for the carb, it suggests rods that will richen or lean out your mixture at cruise and/or WOT. I noticed that the 1405 (same carb with manual choke) is advertised to be 2% more rich than the 1406, and it has .100 primary jets with .070 x .047 rods. Your primary jets (if stock) are .098. So, if you want to go richer at cruise, you'd want something in the neighborhood of a .070 x .047 rod to go with your jets. That won't make you as rich as the 1405, and if it doesn't get you where you want, you may also want to change jets to the .100 primaries like the 1405. That should get you started, anyway.
Good luck!
If you have the manual for the carb, it suggests rods that will richen or lean out your mixture at cruise and/or WOT. I noticed that the 1405 (same carb with manual choke) is advertised to be 2% more rich than the 1406, and it has .100 primary jets with .070 x .047 rods. Your primary jets (if stock) are .098. So, if you want to go richer at cruise, you'd want something in the neighborhood of a .070 x .047 rod to go with your jets. That won't make you as rich as the 1405, and if it doesn't get you where you want, you may also want to change jets to the .100 primaries like the 1405. That should get you started, anyway.
Good luck!
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
I just found the link to the 1406 calibration chart:
http://www.edelbrock.com/automotive/eps_1406.html
Notice that if you are at Point 1 (stock) on the chart, and you want to go 4% richer at cruise, you change to configuration 24 (stock jet and 073 x 047 rod). If you want to go 4% richer in "Power Mode", go to configuration 2 (.095 jets and 070 x 037 rods).
If you're lean across the board, I think a better place to start would be with the stock 1405 setting.
http://www.edelbrock.com/automotive/eps_1406.html
Notice that if you are at Point 1 (stock) on the chart, and you want to go 4% richer at cruise, you change to configuration 24 (stock jet and 073 x 047 rod). If you want to go 4% richer in "Power Mode", go to configuration 2 (.095 jets and 070 x 037 rods).
If you're lean across the board, I think a better place to start would be with the stock 1405 setting.
Thread Starter
Racer
Joined: May 2005
Posts: 306
Likes: 0
From: Annandale Va
thanks for the help
After installing the headers it seem to be a little starved for gas and I notice the number eight exhaust pipe on the header was much hotter than the rest. It has a slight poping at idile and you get a large backfire when you turn it off.
Being a novice at this and asking around it was suggested that because of the new headers it was pushing more air through and running lean. I'm assuming they are right and it is a combination of that and timing.
Thanks for the suggestions, it's a learning curve for me but fun.
Being a novice at this and asking around it was suggested that because of the new headers it was pushing more air through and running lean. I'm assuming they are right and it is a combination of that and timing.
Thanks for the suggestions, it's a learning curve for me but fun.
