65Fastback
Active member
Hello,
after dropping in the recurved DSII from Bill, I started a AFR measurement series with some variations on the carb setup.
At the end I am fine with cruise, light acceleration and WOT AFR values. Everything between 12.5 (WOT) and 15 (Cruise) on the Innovate gauge. Engine performs very well.
What makes me wonder is that I read significant rich AFR values at idle.
About 11.5 is the best I can achieve without going too far in with the idle mixture screws (actually 1 1/4 turns out).
Going leaner with ims leads me up to 13 AFR but has negative effects on cold run and off-cruise acceleration.
So, is this only a false reading at idle from the 260 /260 cam with 110 lobe center?
Or do I oversee something?
Idle in general is slightly rough with shaking vacuum gauge needle 13.5 in.hg. +/- 1 (shaking only at idle).
Pls. see engine spec below.
Cheers
Joerg
65 Mustang Fastback, 68 Inline 200, OZ 250 Head, Holley 2V 7448 350 cfm, Comp 260 cam, Hooker Headers, 2” dual exhaust, DSII, MSD 6A. 4 speed toploader, 3.2 rear end.
after dropping in the recurved DSII from Bill, I started a AFR measurement series with some variations on the carb setup.
At the end I am fine with cruise, light acceleration and WOT AFR values. Everything between 12.5 (WOT) and 15 (Cruise) on the Innovate gauge. Engine performs very well.
What makes me wonder is that I read significant rich AFR values at idle.
About 11.5 is the best I can achieve without going too far in with the idle mixture screws (actually 1 1/4 turns out).
Going leaner with ims leads me up to 13 AFR but has negative effects on cold run and off-cruise acceleration.
So, is this only a false reading at idle from the 260 /260 cam with 110 lobe center?
Or do I oversee something?
Idle in general is slightly rough with shaking vacuum gauge needle 13.5 in.hg. +/- 1 (shaking only at idle).
Pls. see engine spec below.
Cheers
Joerg
65 Mustang Fastback, 68 Inline 200, OZ 250 Head, Holley 2V 7448 350 cfm, Comp 260 cam, Hooker Headers, 2” dual exhaust, DSII, MSD 6A. 4 speed toploader, 3.2 rear end.