I think the Edelbrock LD4B and the Weiand Stealth are the same thing...

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LXguy

LXguy

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Hey All:
A lot of times on here I see people asking for a good intake for a 318. Seems like everyone recommends the LD4B, and either don't recommend or have actively bad things to say about the Weiand Stealth.

Of course, the LD4B isn't made any longer and if you can find one, it'll be as much as the Stealth, and you'll have the old intake potential can of worms to deal with.

Well, I just happen to have both of these intakes. They are not identical but are very very very very very very similar.

The carb pad is raised about 1/4-1/2" on the Stealth, which anyone who's messed with an LD4B knows can only be a good thing for reducing clearance issues with thottle linkages, return springs and the like. The Stealth does not have the provisions for the heated choke, which either sucks or is awesome depending on what you're doing. The Stealth also has an additional provision for a water port on the front. The port sizes are identical (approx 1-1/8 x 2-1/16th). EDIT: It also appears that the Stealth is not thermoquad compatible.

Behold!

IMG_2026.jpg



LD4B on bottom, Stealth on top (Stealth appears taller because of carb studs).

IMG_2027.jpg


Based on personal experience, I'd say the LD4B (and thus the Stealth) perform better than the Eddie Performer, so 318 guys enjoy, now you can get a new in box high rise performance intake for your 'teen without worrying about port mismatch!

Steve
 
Almost identical, cool.

I wasn't aware the stealth had 318 ports, I always thought only the action plus had the small windows.

Weather it been done or not, I'm gonna post a picture comparison between the LD340 & RPM
 
The stealth has 340/360 ports..ld4b has 318 ports thats the difference..
 
The LD4B appears to have slightly larger runners. Could be the angle of the picture?
 
yeah, its the angle of the photo. I have the stealth a little too low in the shot, so they aren't exactly parallel. Also, the raised carb pad on the stealth plays all kinds of tricks on your eyes.

I think the Edelbrock LD4B script makes that runner look larger than it is. I measured that one in particular, and they're so close its pretty unbelievable. Interestingly to me, the driver's side front runners on the Stealth look bigger than the LD4B in these photos, but they're not.

It doesn't help that I don't have all the fittings stripped off of there either.

Steve
 
I had an inquiry about 2 Stealths I have for sale and was concerned about the person using them with 318 heads. But I was surprised at the port openings when I measured them: 1" x 1 15/16"

I believe the LD340 has the port layout reversed...if you know what I mean.

Never had them side-by-side, but I was always under the impression that the Weiand Stealth and Action Plus were the same casting but with different carb pads.

The Edelbrock RPM and RPM Air-Gap are the same, except for the "air-gap".

Another bit of info that would be interesting is the actual internal cc volume of the respective intakes. However, just like ports in a cylinder head, more volume may not be as beneficial as port shape.


I ran the Stealth on my car for a season or two. But in the end, the Holley Strip Dominator was faster for my combo. The Stealth did actually flash the converter at least 100 rpm higher on launch. (I have an Autometer playback tach & swapped intakes during a weekend race.) But I didn't need the extra bottom end since I use 4.86 gears, 30" tall tires, 2.71 low gear 904, converter flashes to 5100+ and I shift at 6,500+
 
Locomotion said:
I had an inquiry about 2 Stealths I have for sale and was concerned about the person using them with 318 heads. But I was surprised at the port openings when I measured them: 1" x 1 15/16"

I believe the LD340 has the port layout reversed...if you know what I mean.

Never had them side-by-side, but I was always under the impression that the Weiand Stealth and Action Plus were the same casting but with different carb pads.

The Edelbrock RPM and RPM Air-Gap are the same, except for the "air-gap".

Another bit of info that would be interesting is the actual internal cc volume of the respective intakes. However, just like ports in a cylinder head, more volume may not be as beneficial as port shape.


I ran the Stealth on my car for a season or two. But in the end, the Holley Strip Dominator was faster for my combo. The Stealth did actually flash the converter at least 100 rpm higher on launch. (I have an Autometer playback tach & swapped intakes during a weekend race.) But I didn't need the extra bottom end since I use 4.86 gears, 30" tall tires, 2.71 low gear 904, converter flashes to 5100+ and I shift at 6,500+
Click to expand...

Not to hyjack but the ld340 seems to have a lot more runner/plenum volume than the rpm, though the rpm runners are straighter and mostly stay the same shape unlike the ld340. the ld4340 runners change shape a lil where they bend/turn, for instance when they get shorter they widen to make up for it and vise versa.
The ld 340 is substantially lighter than the rpm too.
 
Myron, you are right. The LD340 has the port placement reversed from the 4b. The high side port on pass side goes to the #4 cylinder on a 340 v #2 on the 4b.

Couple of LD340's
LD340pair.jpg
 
LXguy said:
What cubic inch was this motor?
Click to expand...

360 +.40" or +.060", I forgot which I had at the time. 10.5-1, unported 1.88" OEM heads & tuned 750 double pump carb. Hydraulic cam is almost .474" lift but has a LOT of duration. The single plane intake worked better because the converter flashes to 5100+ at launch and the rpms never go under 47-4800, even on a "bad-air" day.

The best theory I can describe it with is that even though the advertised "power range" of the Stealth is idle - 6800, the engine operates only in the top 1/3 or so. The Holley starts at 35 or 4500 and goes to 75-8000. (I don't have a older catalog that still lists it.) So my engine's whole operating range is right in the middle of it. (Area under the curve.)

* Also keep in mind that the difference wasn't more than .10 and 1-1.5 mph! (All weather factors considered.) With a little more carb tuning on the Stealth (because of the different intake designs), the difference could have been a little less. But in class racing with all the restrictions, we look for small improvements. So I came to the conclusion that the Holley intake was a little better for "my" particular combo.

So for most people running any less gear, converter, cam duration, etc., my 2 cents is that a good dual plane, like the Stealth, LD340, LD4B, RPM, etc. would be as good or a little better than a single plane intake. But it can still take a lot of carb tuning to optimize the carb for the combo. I'm always tinkering with mine.

There are a lot of regular Stock class cars with OEM cast iron intakes and Thermoquads that are a lot faster than mine! But they tend to have more time and resources. The Demon that Physixx has is one example.
 
I had a LD4B and a Wieand Action+ I was able to compare on the bench. Obviously, the biggest difference was the spreadbore vs. squarebore carb mounting pad. In my case, I noted that the LD4B had larger ports than the Wieand by about a .100", but this comparison was done a bit over a year ago. The ports on the LD4B also looked like a bit of straighter shot to the ports compared to the Wieand as well, but this purely a subjective comparison. As was noted above, the Wieand also had the carb pad raised just a bit over the Eddy.

They are most certainly very close in design, but IMHO, I think the eddy was designed for a bit higher rpm then the Wieand. Just my 2 cents. I wish I would've taken pics at the time and posted measurements.
 
It appears I can't edit the original thread, but I wanted to put some of the pics back up.

Here ya go.

IMG_2026.jpg


IMG_2028.jpg


IMG_2029.jpg
 
Wow they are really close! Just enough changes by weiand,I think they are safe from a lawsuit,lol.

Great info and thanks for sharing!
 
the only thing I can see is that the eddy is a bit more rounded and smooth sort of like a worked version of the stealth.
 
On all the intakes listed, suprise yourselfs with port window measurements.

That's all I'm saying, just measure the port windows.

(Walks away whistling.......)
 
What's your point? My measurements on these two intakes were pretty much the same for port window size.
 
It is a non-issue because you can't get a new Weiand that actually fits right out of the box! The last one I got half the bolt holes were 1/4" off and the casting was so bad that it cut the **** out of my finger.
 
Measure all the intake port windows and then the (Various) heads. Just sayin.....

(Walks away whistling.................)

LXguy said:
What's your point? My measurements on these two intakes were pretty much the same for port window size.
Click to expand...

Comment not focused on you LX Guy. You would be exempt from measuring anything since you did the 2. Now, do you have any other intakes to measure up. Then check it out.
 
Buddy of mine has a flow bench and actually flow tested the LD4B. I'll ask him this evening what the numbers are.
 
The LD4B is made for the 318 sized ports. I have an unmodified LD4B in the shop as well as an unmodified 1972 340 intake. The ports on the LD4B are shorter and fatter than the 340. The LD4B will probably flow about the same as the 340 intake, but if you want the ports to match up, you need to run whichever intake matches your heads.
 
Here are some rough measurements from junk in my garage

Stealth 1.95 x 1.00
Performer 318/360 1.95 x .96
Victor 340 2.04 x 1.03
Performer RPM 2.17 x 1.00
RPM Air Gap 2.17 x .98
 
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