Thread: Front cylinders running rich

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OK, for some reason, my 350 runs significantly richer on the front two cylinders than on the rest.
It has an Edelbrock Performer RPM manifold on double hump (1.940) heads and a Holley 650. The front jets are 68s and the rears 72s.

I just tore it down to install a set of Trickflow 195s an Edelbrock Airgap and a set of stainless roller rockers. Looking at the pistons and valves on the old heads confirmed that the front cylinders were running rich...any ideas??

Mike

Keep in mind that a cooler running cylinder will look like its richer than the warmer ones. The front ones sometimes run cooler because of the way the water flows. Thermostat good?

Good point Pope.
It has a 160 deg thermostat and runs 160 deg. no matter what so I assume the thermostate is good. The manifold gasket didn't have a provision for the heat port but since the manifold did it burnt through. The new Airgap has no heat port.

Another strange thing is clear oil tends to collect in the front valleys of the manifold. It appears like it's dripping from the Carburator but the carb is dry and clean everywhere including all vacume lines connected to it.

I first though that maybe I had a couple bad valve guides but after I make a long run and pull a plug, the front ones not only look rich but smell like gas...not oil.
Nomad Mike

Originally Posted by DennyW

Your running to cold. Minimum should be 180º.

Thanks for the replys guys.
Yeah, I'm putting in a 180 when I put it back together. I know it needs more heat especially with the new aluminum heads.

Don't know if that will fix the uneaven mixture problem though...what do you think?

Nomad Mike

With the oil getting on the manifold and the front plugs reading different, I'd look for a leak in the intake gasket. A little oil leaking into your front ports can look like a rich condition, and the oil on the manifold has to come from somewhere.

Originally Posted by DennyW

Your running to cold. Minimum should be 180º.

I would try and keep water temp. at or around 200 F.