I’m contemplating running an old Weaind aluminum cross tunnel ram intake manifold, P3690982, on my 63 Sport Fury (see specs below). I have been trying to find some info on pros and cons about this intake. I have the option of running the 6 pack top or the single 4 barrel top. I was also thinking about having a dual quad top made. I have read the info in the Mopar engine book and it lists the mods for the 6 pack but I would like to hear form some people that have run it before. I know this intake will probably not work as well as some of the new ones, probably not as good as my TM7 that I just took off, but I think it looks cool. I have always liked to be different and I don’t think I have ever seen one of these intakes on a car before. I was going to go the traditional Max Wedge look but it is costly and it seams like lately every other 62 to 65 car I see has a cross ram. Don’t get me wrong I love the look, I just can’t afford it now and like I said before I like to be a little different.
I found this site that has more mods for the 6 pac also.
http://victorylibrary.com/mopar/weiand-c.htmThe site says the major problem with this intake is that the very low mixture velocity in the plenum will cause fuel to “drop out” of suspension, form large droplets, and collect on the plenum floor. This leads to poor idle quality, plug fouling and irregular mixture distribution between cylinders. Although this cannot be completely cured, the factory suggested some modifications (in the Engine book)
Looking at the manifold I can see why the fuel would puddle on the plenum floor, as it is perfectly flat. On the 6 pack setup the center carb (primary) is directly over the flat spot in the plenum and I can see this being an even bigger problem with the single 4 as the carb is in the center directly over the flat plane of the plenum.
This lead me to think about other tunnel ram designs with a single 4 and dual 4’s. I have used both and I always had better street manors from the dual quads. In theory I would say that a dual quad top made for this intake would work better and be less apt to having the problems noted above. What I was actually thinking was to have a 2x4 top made and place a large divider in the center of the plenum so that one 4 barrel would run the front cylinders and one would run the rear. This would reduce plenum volume, and increase velocity. I would leave an opening in the divider as a balance tube.
Any thoughts?
Thanks
John
Engine
440 = 0.040, forged flat tops (0.060 below deck) ported and polished 906 heads shaved to 80cc’s, final comp ratio is 9.5:1, MP mechanical .528 cam, roller rockers, Balanced rotating assembly, forged crank, LY rods w/new apr bolts, ½ inch oil pickup with high volume pump and 7 qt pan, just a good basic 440 build for street strip use.
Car
63 Plymouth, 518 OD transmission w/ transgo shift kit, 2600 stall, 3.91 gears, SS springs.
