I just installed a 850 dp carb on my 388 SBC and have some questions. The motor runs fine with the stock 80/80 jetting. I pulled the plugs and they were black as night. And reeked of raw fuel. Then soon after it started misfiring and backfiring and all that, put new plugs in and down jetted the primaries. Can anyone tell me there procedures for selecting the right jetting. How do you go about selecting the secondary jets. I've heard you're supposed to drive the car around for a while and kill the motor and pull a plug a check it for like a light brown, but what about the secondaries? Do you drive it hard enough to get the secondaries to open and check the plugs?
carb tuning
- Thread starter T56elcamino
- Start date
Yup open it up then shut it down. I always run 2 jets higher in the rear. Another thing you could try is a smaller set of squirters, is this a annular or downleg booster type carb? Whats the timing at? Stock ign?
A couple questions come to mind,
1) Is this a used carb?
2)Have you checked the float level adjustments, and or fuel pressure?
3)Is the power valve blocked off? (Usually when the jetting is squared off the PV is blocked off.)
4) If there is a Power Valve what is the rating on it? 3.5? 4.5? 6.5?
1) Is this a used carb?
2)Have you checked the float level adjustments, and or fuel pressure?
3)Is the power valve blocked off? (Usually when the jetting is squared off the PV is blocked off.)
4) If there is a Power Valve what is the rating on it? 3.5? 4.5? 6.5?
Not saying its right at all,,,But,,,I always run my carb squared....(same jets all the way around)
With a power valve (only in the front)...
With a power valve (only in the front)...
