Next Update: Issue: Lean out the rpms above 55mph. Changes: .033 HSAB's (MAB's) to .036 Weather: Was 66 now 72 degrees.
The 036 swap leaned out the A/F ratio above 55mph. I added the new A/F ratio at the end (/). My 35 & 40mph A/F leaned out some but that might be from the temp change. But I am now aiming for 14.5-15.5 cruise and I am as close as I think that I can get.
64 degrees: 25mph ----------------14.0/ 14.0 30mph 1700rpms (16.2) 14.6 35mph ----------------14.6/ 15.4 40mph 2200rpms (16.0) 14.6/ 15.4 50mph 2500rpms (15.6/15.4) 14.6/ 14.6 55mph 2700rpms (15.0/15.2) 14.0/ 14.4 60mph 3100rpms (14.0/14.2) 13.6/ 14.4 65mph 3300rpms (13.8) 13.8 ---------- The following was a 2nd gear test to see what the A/F ratio was doing at higher rpms: 3000rpms @ 14.4 (same as above 60mph) 3500rpms @ 13.6 (not sure why richer) 4000rpms @ 14.6
The above was with the carb setup: 65/75 jets, .071 IAB's, .036" HSAB's, 8.5 high flow pv, .031 IFR's, red/037 primary cam and pink/.031 secondary cam, 40% secondary linkage delay.
I was able to get my cruising a/f raio into the 15's by leaning out the four metering screws but I was not comfortable with the 15-15.8 readings so I richened them back up. Plus I found that my in D/brake applied A/F ratio needs to be about 13.6-14.0 or my cruise A/F numbers start to change. I made one WOT run from 50mph and it shows the same as before with an A/F reading at 12.5 then it leans out slowly to 13.0 at the shift point. I am assuming that this 12.5 reading right at WOT is due to the pumps dumping the fuel (DP carb) and then the leaning out to 13.0 is the engine using the extra fuel. Is this a good number for the WOT stab? Note: I swapped my red secondary cam for the pink cam and found no difference in the A/F ratio.
