Questions for Lars
Thread Starter
Racer
Joined: Jul 2001
Posts: 341
Likes: 0
From: macon, ga
Questions for Lars
waht are the recomended Main Jets Sizes and Metering Rods, secondary rods, and float level for a edelbrock #1910 carb on a 454, with true duels. i know this is a shot in the dark but i have a off idle stumble that does not improve when the pin is removed from the accel pump. thanks for any help.
Drifting
Joined: Aug 1999
Posts: 1,468
Likes: 1
From: Kirkland WA
Re: Questions for Lars (ykp53)
If you go to http://www.corvettefaq.com, Lars Q-jet tuning paper is there. He has all the specs listed for the carbs.
Since there is no factory 77 454, I just looked at some different configs
Application Jet Rod Sec.Rod Cruise Area WOT Jet Area
Chev 71 454 AT VETTE 77 49 BG 2.7709 4.1257
Chev 71 454 MT VETTE 77 49 BG 2.7709 4.1257
Chev 71 454 MT VETTE 77 49 BG 2.7709 4.1257
CHEV 72 454 AT VETTE 77 49 CM 2.7709 4.1257
CHEV 72 454 MT VETTE 77 45 CM 3.0662 4.1257
CHEV 73 454 all Auto 77 50 DA 2.6931 4.1257
CHEV 73 454 all M/T 77 48 DA 2.8471 4.1257
Chev 75 454 AT Chevelle 76 43 CJ 3.0843 4.0055
Looks like a 77main/49 rod BG Sec. rod is your best bet. What's in there now?
[Modified by Corellian Corvette, 5:26 PM 2/25/2002]
Since there is no factory 77 454, I just looked at some different configs
Application Jet Rod Sec.Rod Cruise Area WOT Jet Area
Chev 71 454 AT VETTE 77 49 BG 2.7709 4.1257
Chev 71 454 MT VETTE 77 49 BG 2.7709 4.1257
Chev 71 454 MT VETTE 77 49 BG 2.7709 4.1257
CHEV 72 454 AT VETTE 77 49 CM 2.7709 4.1257
CHEV 72 454 MT VETTE 77 45 CM 3.0662 4.1257
CHEV 73 454 all Auto 77 50 DA 2.6931 4.1257
CHEV 73 454 all M/T 77 48 DA 2.8471 4.1257
Chev 75 454 AT Chevelle 76 43 CJ 3.0843 4.0055
Looks like a 77main/49 rod BG Sec. rod is your best bet. What's in there now?
[Modified by Corellian Corvette, 5:26 PM 2/25/2002]
Thread Starter
Racer
Joined: Jul 2001
Posts: 341
Likes: 0
From: macon, ga
Re: Questions for Lars (Corellian Corvette)
Thanks For the info i couldnt get into the corvettefaq page recently. currently the carb has - main jets .74, meter rods 50m, and CE secondary rods.
Drifting
Joined: Aug 1999
Posts: 1,468
Likes: 1
From: Kirkland WA
Re: Questions for Lars (ykp53)
According to the charts, that's quite a difference. The variation to spec in my #1901 carb was much less, and Lars consulted that I was way out of whack!
Seems to me (and I'm far from an expert), that your setup is running quite a bit too lean on the idle/cruise side, then going really rich when you kick on the secondaries! (The CE rods have a long tip, which I believe means you go rich faster, and the tips are fatter on the CE rods than the BG rods, so less gas comes out until they open)
According to Lars' paper, both of those would give you a serious stumble.
I'm sure Lars can advise you better.
Seems to me (and I'm far from an expert), that your setup is running quite a bit too lean on the idle/cruise side, then going really rich when you kick on the secondaries! (The CE rods have a long tip, which I believe means you go rich faster, and the tips are fatter on the CE rods than the BG rods, so less gas comes out until they open)
According to Lars' paper, both of those would give you a serious stumble.
I'm sure Lars can advise you better.
