FtrSpeedy

Any ideas, center cylinders both sides pretty lean, 4 corners slightly rich. Im stumped

FRMULA88

Fuel distribution; Remember it's a single carb with a common plenum manifold and the intake runners are different lengths.

Pretty typical, however the cylinders with the longest intake runners the plugs will usually read leaner, 1 2 7 8 that does not mean it's wrong.


what kind of carb and jetting? what engine speed? short drive or? with a lumpy cam fuel distribution will be less than ideal until engine speed picks up.. are you checking plugs after idling only?

FtrSpeedy

Edelbrock 1411 750cfm weighted secondary butterfly removed. 110 pri, 107 sec, 75/47 rod 8in spring. Cruise speed 2000-2500 20mile round trip with occasional playin, checked plugs after couple hundred miles. 224 duration 112lsa. Intake holley street dominator

FRMULA88

I know little about edelbrock carbs but if the jetting is like holley then

holy smokes you have way too much jetting for a small cu in. "street engine"/


Case in point on my 950 cfm QFT double pumper had 86 primaries and 94 secondaries with a primary power valve. Otherwise 94s all around with no power valve and this was with E85 fuel making 680 HP.

jetting with gas carb would be less. also you want smaller jets on the primary side... not other way around.




110s and 107s those are alchohol sized jets...

JaBoT

The jetting on edelbrocks have no relation to holley jetting. That is not big for edelbrocks.

FRMULA88

I have no experience with Edelbrock carbs, however if larger # means larger jet orifice then it seems odd to use larger primary jets and smaller secondaries, typically you do the opposite.. (smaller primaries)

if the metering rods act as the "power valve" does on a Holley you are
dumping more fuel on the primary side, before the secondaries open.

you also have the accelerating pump squirting fuel when you mash the gas. (dumping even more fuel on the primary side)

I would try leaning out the primary jets a bit and see if that improves the fuel distribution.

JaBoT

Once again edelbrock jets have no... I repeat no relation to holley jetting.
It comes with 113 in the primary and 101 in the secondary from the factory for a reason.
The primary jet always has a part of the multi step metering rod in it.

FtrSpeedy

Ya the rod goes into the pri jet, so. 110 hole with a .057 rod inside.

FtrSpeedy

Ok well i believe i got it figured out, just waiting to get car back then ill check my theory. Thanks for your help.