For a 340 with Eddy RPM heads which would be a better intake? Eddy Preformer RPM or a Weiand 8007? Have not picked a cam.
Many thanks.
Many thanks.
Intake choice.
- Thread starter moparmarks
- Start date
-
MidnightSwinger
Well-Known Member
Performer RPM hands down imo
If the Edelbrock was an Air Gap, it would have a clear advantage, but the regular RPM against the Weiand and I think it's a crap shot.
Somehow, I knew you'd say that. And I agree! lol
33IMP
Well-Known Member
Bewy covered it.
Running a Holley? Eddie
Running a thermoquad, quadrajet, other large secondary carb? Weiand.
Running a Holley? Eddie
Running a thermoquad, quadrajet, other large secondary carb? Weiand.
I have run both the Weiands and the Edelbrocks.
I’d run the RPM. I’ve run Weiand’s intakes before, they’re very good. I believe the runners on the RPM are better and thus make more power.
Depending on the power level & target of the build, these two intakes are a toss up on a driver with added pep. If your going to twist some screws up and look for a real bruiser, there’s a little more power in the RPM.
MoParMarks - What’s the engine build consist of?
Gear ratio and tire size would be of help.
I’d run the RPM. I’ve run Weiand’s intakes before, they’re very good. I believe the runners on the RPM are better and thus make more power.
Depending on the power level & target of the build, these two intakes are a toss up on a driver with added pep. If your going to twist some screws up and look for a real bruiser, there’s a little more power in the RPM.
MoParMarks - What’s the engine build consist of?
Gear ratio and tire size would be of help.
junkyardhero
Well-Known Member
- Joined
- Jan 23, 2005
- Messages
- 2,963
- Reaction score
- 4,640
to note: the weiand doesn't have a coil mount, if that's important to you
i like the eddy because it and the heads are designed to compliment each other.
i like the weiand because it's designed for a spread bore.
weiand lists their ports at 1.00 x 1.96 and the RPM lists as 1.01 x 2.17 (i could not find the port data on the eddy heads)
in a knock down drag out brawl, i think the RPM would have a hair more on top power wise and not fall off as quickly. i think the weiand with a spread bore offers more potential in overall driveability, throttle response and mileage without sacrificing much performance wise.
i like the eddy because it and the heads are designed to compliment each other.
i like the weiand because it's designed for a spread bore.
weiand lists their ports at 1.00 x 1.96 and the RPM lists as 1.01 x 2.17 (i could not find the port data on the eddy heads)
in a knock down drag out brawl, i think the RPM would have a hair more on top power wise and not fall off as quickly. i think the weiand with a spread bore offers more potential in overall driveability, throttle response and mileage without sacrificing much performance wise.
RPM ootb you can bolt right on, you could gasket match but IMO it’s not really needed as is. Weiand you will need to do some more involved gasket matching and tapering up into the runners, especially the roofs to match up with your heads. I’ve run both (AG) at the track the AG wins hands down. The Weiands a good intake though. Cheaper for sure.
Wow, a lot of real good info and points. Many thanks. I'm a Holley guy so I think the RPM is the one for me plus as stated it is made for these heads.
Just starting a plan and trying to use what I have which is a fresh 340 boat motor, the set of RPM heads and the two manifolds. Don't even know which car it is going in.
Thanks again guys.
Just starting a plan and trying to use what I have which is a fresh 340 boat motor, the set of RPM heads and the two manifolds. Don't even know which car it is going in.
Thanks again guys.
I recently read an article where Dave Hughes tested a bunch of SBM intakes. Some of the group of intakes had as much as 43.6 cfm spread between runners.
The Performer RPM only had 16.3 cfm difference and the Weiand had 31.4 cfm difference.
Edelbrock did a fabulous job with Performer RPM intakes for SBM & BBM engines. However they were computer designed and that allowed for much better product.
In Hughes testing there were intakes that showed more cfm port flow than the RPM, but on the actual engine dyno the RPM intake made more HP and produced
more TQ than ones that had more volume. Mopar Small-Block Intake Manifold Flow Test
Tom
The Performer RPM only had 16.3 cfm difference and the Weiand had 31.4 cfm difference.
Edelbrock did a fabulous job with Performer RPM intakes for SBM & BBM engines. However they were computer designed and that allowed for much better product.
In Hughes testing there were intakes that showed more cfm port flow than the RPM, but on the actual engine dyno the RPM intake made more HP and produced
more TQ than ones that had more volume. Mopar Small-Block Intake Manifold Flow Test
Weiand Action Plus (#8007) | |
| Scatter | 242.9 - 274.3 cfm |
| Spread | 31.4 cfm |
| Average | 258.6 cfm |
Edelbrock RPM | |
| Scatter | 248.6 - 264.9 cfm |
| Spread | 16.3 cfm |
| Average | 255.9 cfm |
Tom
Last edited:
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
- Jan 19, 2014
- Messages
- 24,933
- Reaction score
- 12,282
What elevation and ambient temperature will you be running? Cuz in "Western Colorado", that could be real important.
Are you thinking of stroking that 340?
Cuz that would hep to level the playing field.
Are you thinking of stroking that 340?
Cuz that would hep to level the playing field.
Last edited:
Well my county goes from 4300ft. to 10800ft. so that is a big variable. Not stroking it. Would be a street car.
Runners look different. I have an LD340 on my X-headed 360 in my 78 D100.
From the article I linked above.
Edelbrock LD-340 Shallow Port Match | |
| Scatter | 279.2 - 314.1 cfm |
| Spread | 35.0 cfm |
| Average | 299.7 cfm |
Test note:This was the best 4BBL intake for small-block Mopars for many years. This particular manifold (borrowed for testing) had a port match that was only -inch deep. The flow is impressive for an ancient dual-plane, but the flow bench does not always tell the entire story. |
Edelbrock RPM | |
| Scatter | 248.6 - 264.9 cfm |
| Spread | 16.3 cfm |
| Average | 255.9 cfm |
Test note:This intake has an excellent and well-deserved reputation and has taken the place of the LD-340. This is one of those cases where the flow bench does not tell the whole story. This manifold did not flow as much as the LD-340, but it will produce more power. Why? Look at the manifold intake runners. Notice how the port shape and runner arrangement has changed from the older LD-340 to the RPM. The runner lengths are shorter and the cross-sectional areas are more consistent from the plenum to the head. Lots of flow work and testing went into the newer intake design which paid off in horsepower. |
Tom
The runners in the Performer are thinner width wise. I wonder if they are taller though compared to the LD340. Improved velocity? Just spit ballin' here.
This mopar intake is a direct replacement for the factory cast iron intake. But if I were to choose from the two you listed for performance I would take the Wiend over the Edlebrach . I just installed one and can't believe how good it works over the factory intake. I mounted the coil to the rear carb stud.
Professor Fate
Push the button, Max...
Fresh boat motor? Better make sure it's not a reverse rotation engine, or it won't matter which manifold you pick. But you will have the fastest car in town- in reverse!Wow, a lot of real good info and points. Many thanks. I'm a Holley guy so I think the RPM is the one for me plus as stated it is made for these heads.
Just starting a plan and trying to use what I have which is a fresh 340 boat motor, the set of RPM heads and the two manifolds. Don't even know which car it is going in.
Thanks again guys.
QuickDart360
Well-Known Member
I used to run an air gap and then switched to a Victor 340. It made a difference. Much more throttle response. I do have 3.91's out back so that might be a factor too.
That can be a very particular thing, build dependent.
Yup I checked that first. It's standard rotation. It's a 1974 Super Bee III 340. Small cam and small heads.Fresh boat motor? Better make sure it's not a reverse rotation engine, or it won't matter which manifold you pick. But you will have the fastest car in town- in reverse!
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
- Joined
- Jan 19, 2014
- Messages
- 24,933
- Reaction score
- 12,282
This might be problem; depending on your expectations for the 340.
If performance is on the table, that elevation change is gonna be a big problem.
From 10,800 to 4300,is 6500ft.
With a very modest cam, that has an Ica of 58*, and at an Scr of say 10/1, that elevation change represents around 30/35psi cranking cylinder pressure. If 10/1 creates 150psi @ 4300, she will be down to 116 by 10,800
That 58*Ica, is a pretty small cam.
Typically, a guy will install something around 66*; Don't do it!
To get pressure of say 160psi @4300, with an Ica of 66*, would take a Static Compression ratio of ~11.2....... but at 10,800 she will be down to 126psi, and feeling pretty lazy.
Even if you stall it up, she'll still be lazy.
As a street car with an automatic, my guess is that you will be running 3.23s; which, this too will be a problem. With a cam that has a 66* Ica, the power will peak somewhere around 5200. Which is; 47mph in First, 80 in Second .On the 1-2 up-shift the rpm will drop from say 5500 to 3250. But the power doesn't start until ~3700, so, without decent cylinder pressure, even at 4300ft elevation, the poor 340 is wheezing....
never mind at 10,800ft.....
If it was me, I would be thinking about a bigger engine or a stroker.
Jus saying
-
