Picked up a holley dual plane from a member here to put a small 4bbl on my 318. I cant help but notice a small port under the carb flange. I have seen the notch before for what I assume is a pressure equalizer....but what's with the round hole? I vaguely remember seeing a hole in an iron intake somewhat like this years ago. Anyways...what is it? Thoughts? Thanks!
odd crossover ports in early dual plane holley?
- Thread starter Caco2120
- Start date
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That thing has enough vac ports...thats for sure. Lol 4?
Does it appear to come out on the bottom?
Does it appear to come out on the bottom?
Its at least got 3. Lol I haven't decided if #4 is blind or not yet.
That little circle port appears to go down into a 5 inch square basin on the bottom of the valley. You can only see it on the bottom. Appears to go nowhere...? Connected to the heat crossover maybe? Cant tell.
That little circle port appears to go down into a 5 inch square basin on the bottom of the valley. You can only see it on the bottom. Appears to go nowhere...? Connected to the heat crossover maybe? Cant tell.
That's something someone has done. It did not come like that.
Marcohotrod
Well-Known Member
that is a single plane. more pics please. trace where it goes. I think it came from Holley like that
After a little research, that is the vacuum port to the EGR and it did come like that.
I think it came like this. It appears to be in the casting. No grinding is evident.
It goes nowhere upon investigation. Just filled it with water. it appears to share a wall with the heat crossover, but it is not through to it.
I have more pics on my phone, but this site works absolutly terrible on my phone. I will have to upload them tomorrow from a pc.
So...this is a single plane because the runners aren't staggered? I assumed It was dual because its split in 2?
Thanks guys
It goes nowhere upon investigation. Just filled it with water. it appears to share a wall with the heat crossover, but it is not through to it.
I have more pics on my phone, but this site works absolutly terrible on my phone. I will have to upload them tomorrow from a pc.
So...this is a single plane because the runners aren't staggered? I assumed It was dual because its split in 2?
Thanks guys
Wouldn't it actually go somewhere if that was the case? This is blind. im asking...because im not sure...
I downloaded Firefox...works equally bad, but let me attach more pics
It does go somewhere. To the EGR port.
Forgive my ignorance, but wouldn't it be more than a blind hole if that was the case? I stated above, I filled it with water and it didnt leak out anywhere. Just like I filled a blind bolt hole.
It looks like the EGR ports are blocked off. If they are, water would not leak out.
There you go.
65Val
Average Length Member
The 2 nearest the thermostat housing are not vacuum ports....they go into the water passages for senders.
Thank you very much. That makes sense.
Is this a dual plane, or no since its not fully divided?
Im well aware what a temp port is bud. Look closely, there are 2 ports on the runners, and two bolts sticking up on the rear that also appear to be blocking ports into runners, or Egr as RRR points out they may be for. The op even states it has 3 if not 4 plugs.
It is a single plane intake with a divider in the middle.
AKA, split single plane intake.
Read, lern, try not to loose your mind here; http://victorylibrary.com/mopar/intake-tech-c.htm
AKA, split single plane intake.
Read, lern, try not to loose your mind here; http://victorylibrary.com/mopar/intake-tech-c.htm
Johnny is completely correct. A port on each front runner, and 2 bolts in the back that are tapped into passages as well. man look at that wierd rear crossover runner between 7 and 8. just an odd intake. lol hope it does ok on my teener
Im learning! Thanks!
65Val
Average Length Member
Johnny Pace said:
OK..BUD!!!. the pic I have shows 4 ports...2 beside the thermo, one in #1 runner, and one in the plenum...= "4"!!
...just like this one, right???????????????....
Wanna show me the other ones??
OK there is one Vacuum port on #1 runner.
The two in front are water taps.
The front passenger side is a boss to mount a bracket.
The passenger rear pair are bosses to mount the coil.
The two expansion plugs are for an EGR valve.
The internal port is the outlet for the EGR
It is a split single plane manifold.
Did I miss any?
The two in front are water taps.
The front passenger side is a boss to mount a bracket.
The passenger rear pair are bosses to mount the coil.
The two expansion plugs are for an EGR valve.
The internal port is the outlet for the EGR
It is a split single plane manifold.
Did I miss any?
65Val
Average Length Member
............that is a great lil intake.......kim.............
Marcohotrod
Well-Known Member
sometimes the experts are wrong
pishta
I know I'm right....
That is a Duntov crossover design from the old Chevy days that Holley crossed over to their line. See the 2 blank holes on the rear in the crossover valley, that is EGR. One side is plumbed to blind ;intake' hole, the other is ported to exhaust crossover. The 2 smaller holes are the threaded mounting holes for the EGR plate. You can run it as is as there is no physical connection between the exhaust and intake plenum. I think that design is called a 180 as it only draws from 1/2 of the carb, as opposed to the open plenum Offy "360" design that pulls from all 4 barrels. Probably a torque theory thing.
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