carb stumble???
#1
Senior Member
MASTER BUILDER
Thread Starter
Join Date: Apr 2009
Posts: 175
carb stumble???
I recently changed the carb and intake on my sbc (350 .60 over .510 lift cam 292 duration,edelbrock rpm heads 10.5-1 comp. victor jr intake 750 dp) now when I feather the accelerator to take off (4 spd) it has a slight dead spot and it has a low speed miss?? But as soon as I get past that spot in the accelerator pedal it clears right up. I was planing on going to the track sat. for test and tune, and was wondering what I should be looking for to cure this problem, I already played with the accelerator pump adjustment and checked the floats, and low speed mixers. thanks in advance.
#7
Originally Posted by whitey70ss
the fronts are 66 the rear is 72H does this sound right??
4779 came with 75/76 and 8.5 PV
4779-1 came with 70/80 and 8.5 PV
4779-2 came with 70/80 and 6.5 PV
4779-3 came with 70/73 and 6.5 PV
4779-4 came with 70/80 and 6.5 PV
4779-5 came with 70/80 and 6.5 PV (same as the dash 4)
4779-6 came with 71/80 and 6.5 PV
84779 came with 70/73 and 6.5 PV
There are also some other OEM and marine part numbers.
Dave
#8
Senior Member
MASTER BUILDER
Thread Starter
Join Date: Apr 2009
Posts: 175
I drove to the (local)speed shop today and talked to a guy that teaches a hi-po class at the local college. he told me I needed a 45 power valve I had a 65 and told me to jet it 72 in the fronts and 80 in the rears. I put it together and now its raining :cry: it does seem to have better throttle response now :roll: I guess I'll see sat.
#9
Senior Member
RACING JUNKIE
Join Date: Sep 2007
Location: Belleville, IL
Posts: 658
That's a pretty big jet spread. Rear cylinders are going to get more fuel than the front.
Last I heard (haven't run carbs in a long time), 4 jets were the biggest spread you want to do from front to rear.
Maybe someone with better carb knowledge can comment on that.
Last I heard (haven't run carbs in a long time), 4 jets were the biggest spread you want to do from front to rear.
Maybe someone with better carb knowledge can comment on that.