aftermarket intakes with airgrabber

[dangina]

Question for you guys who have used aftermarket intakes with their airgrabber 4 bbl setup. Which intakes work? Car has a 383, I have the 383 airgrabber setup (car was non AG) but it'll be awhile till i get the engine in. The intakes I have that I wanna use is the edlebrock performer rpm intake or the 383 torker intake.

[471Magnum]

I'm just going from memory here based on what I've read in the past. Haven't actually experimented myself.

Most dual plane after market intakes for the B-motor are about 3/4 inch taller than stock. The RPM is much taller, as is the Torker, although I don't recall the specific dimension. Won't work with an AG without MAJOR modifications to the air cleaner base.

Best starting point would be to use a 340 or 440 air cleaner base. Both are the same height IIRC, and shorter than the 383 base. They might work with some dual plan intakes unmodified.

To use a RPM or Torker, you will still probably have to graft in a dropped air cleaner base. I've seen it done before. Not pretty, but it works. I am in no way endorsing hacking up an original base to do this.

The other problem you will run into will be the throttle and kick down linkage. Assuming you've got an automatic, you'll probably have to use a Lokar cable set-up and one of the adjustable aftermarket brackets.

[dangina]

man its not what i wanted to hear lol I have a 4 speed so I shouldn't have to worry about that, blast. I found this pic and it seems I would gain a inch if I goto a 440 base over my 383:

[dangina]

does anyone know the height of a stock intake for the 383? My engine came with the torker intake so i don't have a stock one kicking around...

[NOrrTH]

I went through hell getting my air grabber to fit under the hood with an aftermarket intake (440 4bbl). Turned out I had a 383 AG air cleaner base on my 440. After trimming the base it was still too tall.

Measured at the carb pad where A is the front of the pad and B is the rear:
Stock A 3.4 B 4.2
Weiand Actions Plus A 3.25 B 3.69
CH4B A 3.8 B 4.8
Performer A 3.8 B 4.8
Street Dominator A 4.13 B 5.25
Performer RPM A 4.9 B 5.8

If you choose higher than stock you will have to make up the extra height either through cutting the air grabber base flute or a shorter air filter. There is just not enough play with the rubber gasket on the air grabber box sitting on the air cleaner lid base. You might get it to fit under the hood without the air cleaner lid rubbing on the bottom of the air grabber box but the engine torquing will push the hood up on the drivers side.

The bottom line is that if you go with a taller than stock manifold you are going to have to trim the air grabber base. The 440 base is shorter than the 383 base due to the 440 being a taller motor. I think its 0.5", cant quite recall.

[dangina]

thanks for the reply - according to this website:

http://www.nicksgarage.com/aircleaner.htm#compare

and your measurements, even if I went with a 440 base , I'd still have to cut 1" outta the aircleaner to make the rpm airgap fit right - oh why couldn't I just afford the 6 pack setup?!

curious - have any of you guys ran the aluminum 383 6pack intake? did you have any clearance issues?

[NOrrTH]

Personally I wouldn't go for a six pack set up. They dont offer a signifcant gain over a good four barrel set up even if you can get the dammed things tuned properly.

I just had my motor rebuilt, they are in the process of put it back in the car as I type this, and I went for a CH4B, stealth heads, 800 cfm Eddy carb. Will only have to trim the flute a little bit. The bases are rare'ish and they are repoping them now... finally.

I had a Challenger with a HP 440 in it. We took off the alumium intake and carb and put on a six pack set up. Even if I did add another 15hp, our seat of the pants testing couldnt feel a difference.

[471Magnum]

B motor Street Dominator and a 440 base should give you the performance and fit you're looking for.

Once you find an SD (out of production, so you need to hunt down a used on), you'll want to gasket match it. They're notorious for core shift, as are all vintage aftermarket intakes.

[dangina]

when they say trim the flute - do they mean on the air cleaner or on the base? i can weld, so I have no problem trimming something and rewelding it, its just a PITA..

[NOrrTH]

It is a royal PITA. The flute is the velocity stack on the air cleaner base plate. You can trim a fair amount off but if you go too high it widens up and then you run into the hole being too big problem.

[dangina]

It is a royal PITA. The flute is the velocity stack on the air cleaner base plate. You can trim a fair amount off but if you go too high it widens up and then you run into the hole being too big problem.

sounds fun already.

[road chicken]

I just went through this on the runner. I have a 383 under hood and a 440 steel base plate as a starting point.

I bolted on a Performer RPM intake (1.5" taller than stock) and Edelbrock carb and put the 440 base plate on, ( the 440 velocity stack is about 1/2 " shorter than the 383 baseplate). it was still too tall. The hood would almost close....almost. But it would start to lift the back of the hood indicating it was pivoting on the baseplate. enter the fiberglass repo baseplate from Year One. It is decent, but not a show winning part- Which is ok since I'm looking for it to function properly and I can throw the original part on if I really need to. Anyway..

There are 3 flats on top of the base plate velocity stack section. I used this as my "0" point because the bottom of the stack is wavy and not really finished off flat and true by the Year One vendor. From the 3 flats I measured down 1 1/8 inch and marked the stack all around so I had a line true to where the air cleaner seats and cut off the excess. The height was very close to where it needed to be. However, as pointed out earlier- the hole that fits over the carb was now much bigger and has about 3/8" of play. That is right on the edge of what the carb can seal. To fix that I took a length of 1/8 " vacuum hose and cut it to the circumference of the carb hole in the base plate. I then split the hose along it's length and slid it over the bottom edge of the carb hole on the base plate. That worked pretty well. There is still some play but not enough to worry about. It also acts as a seal between the base plate and carb. If I wanted to try a tighter fit, I would take the same 1/8" vacuum hose and make it into an 'O' ring around the top of the carb, ( cut it and super glue the ends just like when you make a custom "o" ring) and glue to the inside of the carb hole in the baseplate. This may not work as well because the seal ( tubing) isn't mechanically around the baseplate and may be prone to shearing off or coming undone. Where the way I have it now it is mechanically held there. There may be problems but I won't know that until I get some run time on the set-up and see what fails. I also went with a 2 1/2" high air filter- but it's a K/N unit so the lower height should be a wash with the better airflow of the filter.

Anyway, Just what I found to tentatively accomplish this on a B block car. I don't think it will work on the RB blocks because the extra depth that needs to be cut from the velocity stack will make the hole big enough drop over the carb. Although that doesn't stop someone from fiber glassing the velocity stack to fit.

[road chicken]

Pictures of the Process:

Stock 440 base plate carb neck fitment. Nice and tight.


Stock 440 base plate height of carb in velocity stack.


Height the fiberglass base plate velocity stack was cut to- 1 1/8" from the flat. this could go a little shorter but the ID on the velocity stack would drop over the carb, so some fiber glass work would be needed to close up the hole.


The fiberglass baseplate, cut to 1 1/8" height- how it fits on the carb neck. It has about a 1/4-3/8 play and just on the edge of dropping off.


Height of the carb to velocity stack- fiberglass baseplate cut at 1 1/8"



Fiberglass base plate to carb fitment with the vacuum hose gasket in place. Not perfect, but it works. Seals well and takes the force of cranking down the air cleaner lid.



Bottom side view of the vacuum hose in place. I used 1/8 " hose here but I think 1/4" might be doable as well or better as long as the wall thickness of the hose stays thin 3/32- 1/8". That's so it doesn't raise the baseplate any more than necessary. The heights are very very close in the scoop ornament.



I will need to go get better pictures of the fit inside the scoop and add them. It isn't much leeway and the tightest spot is the top of the air cleaner and furthest right, ( passenger side). there might be 1/8" clearance there. I'm going to find my clay and see just exactly it is this weekend and add the pictures then. Since the motor pivots to that side- and really shouldn't be torquing over that much if held properly, it should work. Plus there is room to cut the base plate another 1/4 inch and then close the carb hole up with fiberglass. The fiberglass base plate does flex a little bit ,( which is good because it is has a bit of a bow to it), and the hood to base plate seal is squished a bit more than stock as well. So far though I'm seeing no witness marks on the hood or air cleaner and I have been playing with it for about 150 miles of various driving. fingers crossed I did see the effect the airgrabber has at speed though. At 70 mph cruise and pulling 15 in of vacuum, it drops to 13.5" of vacuum when the scoop is opened. So it's gets fresh air and a ram effect.

[dangina]

great pics! I gotta go and pick one up now!

[road chicken]

Ok, Heres the final assembly:


The baseplate with the air cleaner just sitting. A little taller than the cowl.




Hood Closed and a look in the scoop:



Time for some clay and see what we have:



The clay was at least 3/8" thick and just touched the air box in a couple places:
You can see the arc of the lithium grease and a couple dots further forward.



I'm running it.

So far I haven't seen the hood lift, or seen any sign of excessive stress on the base plate, tapping of the air cleaner lid to the air box. The Year One baseplate being fiberglass, has some flex and and should give a bit. It may not be the worst thing to trim a little more from the velocity stack, if possible, to give the airbox gasket a little relief, it is pinched almost solid in a couple places. Since the year one base has a bow to it. ( Up in front) I'm hoping that is will stress relieve a little bit with the heat and pressure- that is where the gasket is " smushed" the worst.
And one last thing I noticed... the first time you clamp the assembly down to run it- use the paper carb neck gasket and center the velocity stack with the 1/8" hose gasket as exactly centered as you can. Once the car has gotten hot a couple times the two stick together. That will help centerr the base plate on the carb automatically. Otherwise you'll have to be aware of centering it when you install it.