[moneypit]

Like the title says.
467 Butler rotating assembly
87 cc E-heads, 310 cfm also from Butler
Superior tunnel ram ( Nash copy) 750 cfm edelbrock carbs
Carbs are set up one step fatter than out of the box.
Pulled all the plugs today while changing header gaskets.
#7 and #8 were white/gray, the others looked fine.
Also grayish color inside respective header tubes.
Anyone else have this issue running a warrior style tunnel ram on the street?
Can fuel distribution be a problem at low rpm cruise speed?

Any thoughts would be appreciated!

Thanks, Colt

[Gach]

Yes it can, kind of rule of thumb make a pass shut off and pull over and read the plugs. It’s tough reading after just Cruising around. Unless of course it’s supper rich or super lean.

[25stevem]

The first thing I would do would be to go down one heat range on your plugs and see if the coloring evens out enough that you notice it after 30 to 50 miles of driving.

What matters first though and foremost is the heat range of the plugs.

The determination of this being ideal is the color change over point on the ground strap.
It should be half way up the vertical portion that is welded to the threaded portion.

This can only be easily seen on new plugs and after 3 to 4 full throttle runs of 5 to 8 seconds, but the motor can not have more then a few seconds of idle time on it after the full throttle run.

If the color change over point it close to the threads then the plug is too hot, if it’s too close to the 90 degree bend in the ground strap then it’s too cold.

Also due to the shape of your hood you might be getting much hotter air drawn into your rear carb, and this will lean things out some.

This leanness can also be due to the shape of the entry of those two runners ( 7 and 8 ) from the Plenum area into each runner.
Too much of a radius leading into each runner WILL move air in nicely, but fuel will just sheer away and not load into the runner along with the air.
To get the fuel to turn in there needs to be a pressure differential between the Plenum and the runner, and too much of a radius stops that needed differential from taking place.

[mgarblik]

25Stevem may be on to something concerning air flow into the carbs. Those Edelbrock AFB knockoffs are extremely sensitive to air flow and air flow quality through the secondary side of the carb due to the weighted air valve secondary flap. With a tunnel ram, cyl 7 and 8 are fed by the rear carb secondary. We had one heck of a time on the dyno with 2 AFB's on a bathtub intake. Those secondaries are so sensitive, we couldn't run an air hat on the carbs and make them run right. Trying a colder plug might be an idea that can produce a little data for you. Another thing to try would be to make a fairly dramatic jet increase change to the 2 secondary jets on the rear carb only to see what happens on a new pair of spark plugs. Like 6 jet sizes just to establish a pattern. Then tune from there. My MOPAR friends that have to run those AFB's, have them stagger jetted all over the place to make them run their best. This is in tunnel ram and cross-ram configuration. They came stagger jetted from the factory on the Mopar stuff. I had the air horns off my AFB's over 15 times before I was happy with them on the dyno. Then once in the car, I had them off another 5-6 times to make them work right under the hood going down the road. Finally runs excellent.

["QUICK-SILVER"]

Being cyl #7 and #8 are the only ones lean...

I'd be checking throttle linkage to make sure both primary throttle shafts are in sync.

Also make sure idle mixture screws are well balanced. That can get tricky if you don't use a Tee so the PCV draws off both carbs.

I could go along with flow problem if cyl #3 and #5 were also lean.

Nash 2X4 really needs a bigger balance tube if you're not running center squirter carbs that the intake was designed for. But it should still work fine if everything is in balance. That's throttle shafts and idle mix.

Clay

[moneypit]

Thanks for the replies and suggestions! I'm using NGK BKR6E plugs as per Butlers recommendation.
Yesterday I took about a 30 or 40 mile drive. I kept the rpm's above the 2k range, made a couple blasts to 5k through 2nd & 3rd before I got home.
The change in driving style made a pretty dramatic change in the plugs! I was using the same plugs and they all kind of evened out. I'm about to go get a new set of plugs to install. The car shifts to OD at 2500 rpm but doesn't kick out until around 1500 rpm or so. Now I'm manually shifting out of OD at 2k. I think maybe I've been lugging it around too much at 1600 to 1800 rpm! I will post the results. Thanks again for the replies.

Colt.