It would be interesting to dyno a 273 with the HP manifold vs the LD4B. (and start the readings out at 1000 rpm instead of 3000 like most dyno operators do)
Edelbrock LD4B
- Thread starter MOPARJ
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Locomotion
Well-Known Member
Thanks. I forgot when the changeover occured.
PM sent.
Just to clarify to other members, The D4B's are for 64 and 65 cylinder heads only. LD4B's are for 66 and newer 273/318 heads. They will bolt to 340/360 heads but because of their smaller ports there is a mismatch.
2010 thread then revived now 
interesting read, though
interesting read, though
LXguy
Well-Known Member
As you're going for consistency this is nearly impossibly to do. As soon as you WOT it, it is going where the converter flashes anyway. Doing it twice for a back to back comparison consistently would be unlikely. How long are you at WOT under 3500 RPM anyway?
I've got a Mustang dyno and I can do part throttle dyno pulls as well as WOT, which would be useful for really comparing the intakes. I've even got a 318 powered plymouth, but it currently has a Holley Street Dominator on it.
I am very curious to know if the LD4B is really better than the Performer, and I want to know if the LD4B is the same thing as the Weiand Action Plus, but I'm not spending $750 on intakes to find out. haha.
no problem. I do that often when I post on my phone. Those 4 little icons are pretty close together.
welcome, David! If you look at the dates on the post, it will help you. before you posted in this thread, the last post was back in 2010
I started a thread on "Action Plus vs...." to see if there was an intake for my particular combo that would offer a gain. The thread left the intake subject pretty fast, but I like stuff like this. The Action plus has performed very well.
A consistent strip car (stock converter) using both manifolds would be a good test. I could do a low rpm test on the Desktop Dyno if I had flow rates for both.
Where's my manners. Welcome David. What a beauty of a 65 Valiant (American Dart) you have. I re-read your first post and you have a 66 273 with a stock cast 4 barrel intake. The LD4B should make a little difference but I can't say how noticeable it will be. A little more low end power and torque I am sure.
David Chan
Active Member
Thanks for the info. As I'm not a mechanic the conversation is a little over my head. I've had my engine on a dyno and it confirmed what I already knew. Torque was all in the low end and hp dropped off quickly after 4000 rpm.
LXguy
Well-Known Member
What car was this? 2900 lbs? Why did they turn the inertia off? Do you have a dyno graph? What's the combination being tested
here?
137 hp and 242 lb/ft torque. There should be more power hidden there with some tuning. It just takes time and money.
I wish I had dyno'd my 273. I was in a hurry to get it in and running. The speed shop in town didn't have their dyno going yet. Chassis dyno I presume?
I wish I had dyno'd my 273. I was in a hurry to get it in and running. The speed shop in town didn't have their dyno going yet. Chassis dyno I presume?
I like doing things like switching intakes. See what my "seat of the pants" dyno tells me, then take it to the strip and see what the E.T. says about it. That's the real verdict...
I removed a '73 cast intake for the Holley Street Dominator this summer just to see... kind of fun
I removed a '73 cast intake for the Holley Street Dominator this summer just to see... kind of fun
LXguy
Well-Known Member
This crap has gotten ridiculous....Edelbrock LD4B intake manifold for mopar dodge chrysler small block 273,318 | eBay
There's another one listed for $550.
As soon as I can get my hands on an LD4B, I'm going to dyno it back to back on my car vs. the Weiand Action Plus (that's available NEW for $200).
I get it if you're running stock eliminator you've got all the dollars so it doesn't matter, but for anyone else looking for better results than you get with a performer, its flat ridiculous.
There's another one listed for $550.
As soon as I can get my hands on an LD4B, I'm going to dyno it back to back on my car vs. the Weiand Action Plus (that's available NEW for $200).
I get it if you're running stock eliminator you've got all the dollars so it doesn't matter, but for anyone else looking for better results than you get with a performer, its flat ridiculous.
I would love to see it vs the Action Plus. My experience has always been, if you pull one decent dual plane intake and install another, not much of a difference. Like the LD340. I pulled a TQ cast intake for one of these "ruby-sit on the throne" intakes. E.T. changed .1. Yes, 1 tenth of a second in the 1/4 mile on a mild 340/3.55 Duster. Did the same experiment on a 360 Dart/3.91's, gained that same tenth. Junkyard cast intake vs the polished diamond.....
I also this past summer pulled a TQ cast intake for the Holley Street Dominator, and so far the cast intake has run .08 quicker, 1 mph faster. Ironically, the SD cut a better 60 ft time. Very mild 318/2.76/auto stock converter.
In addition to the information above, here's a thread with part numbers and pictures of the necessary brackets and such for the LD4B especially if you are switching from a 2 barrel to a 4 barrel.
2-Barrel to 4-Barrel Conversion
2-Barrel to 4-Barrel Conversion
LXguy
Well-Known Member
MPH is a much better show of horsepower, but:
If its a mild combo, .1 isn't that bad. Obviously the better part is only going to be able to improve power if the original part is a restriction. Alternatively, if there's a restriction somewhere else (carb or heads for example) putting on a better intake won't help much. If you're running an edelbrock carb, there's your restriction. Out of curiosity which cast intake are you running?
On the 318, I'm seeing similar results with the same Street Dominator intake. I believe the issue is that the 318 doesn't make power high enough to take advantage of the single plane. Every single vs dual intake test in history shows that the dual is better down low and the single is better up top. Problem is, the 318 never goes up top! So you and I are taking the torque and power hit down low, but not revving the engine high enough to see any potential gains up top. My 318 is stock other than the intake, headers, and the Summit 6901 cam, and only makes power to 4950 RPM. It can't even get to where the HP and TQ curves cross at 5252! With the low compression and crappy 318 heads, it probably won't no matter what I do.
I'm absolutely certain my car would pick up with a dual plane over the single plane. I'm spraying the car so I am reluctant to put nitrous through a dual plane, however as soon as the weather improves I am going to try it. If I can borrow or buy a reasonably priced LD4b in that time, I'll do a back-to-back with the Action Plus. If not, its straight to Action Plus.
My intake is the '73 340 cast intake. I had a 600 eddy, but wasn't happy so I went to a 670 Street Avenger. My cam is the K50052 summit. I home ported the heads. Short block is still factory assembled with about 126,*** miles, '76 motor. Ironically, the single plane SD offers more low end than the cast intake. Not surprising, though, as the SD was just that, designed to work on the street.
I do not have headers, converter is factory, and it has 2.76 gears. I shift around 5300 rpm's.
soulds like you have a ign.problem or weak valve springs.
I agree the prices have gotten a tad out of hand, but std. Performer vs the LD4B, if You're running any kind of cam at all in a teener (215-220deg@ .050) the LD4B is gonna
spank that Perf's *** and send it wimpering back to Mommy...............there have been a number advertised here on FABO, most have sold AFAIK. No $550 ridiculousness.
Who's talking flashing converters? Mine was a 4spd w/3.23's, driving & torque were great with a bone stock 318 w/a Crane Blazer cam & a 600VS Holley to top it off.
LXguy
Well-Known Member
What makes you say that? I suppose everyone else's stock longblock 100,000 mile 318 makes peak power at 6500 RPM?
Never mentioned running the Performer intake.
You'd have to run an adapter to run the holley on the 73 intake, right?
Is the last question for me (you quoted teringer). Anyways, I ran an adapter to run a Holley on the cast, yes.
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