Cam

[rich weyand]

Again, a high-rise manifold is intended for high rpm horsepower, and will reduce low-end torque. Just go with the 2701 like MadOgre says.

firebane: 12-300-4 is what I have, as you know. Maximum torque at lowest rpm and stock lift for long-term reliability of the drivetrain. I love it. I did move the TH350 shift points down about 500 rpm to get back into that torque curve before it wound over the top and down the other side.

 

[Driver4r]

It's an older grind. But I have a l79 cam in my truck and it runs good. But it's a 355@10:1.

 

[MikeB]

For what it's worth, Doug Flynn at Holley says high rise manifolds like the Weiand 8150 and Edelbrock Performer RPM give up little if any power at low RPMs on 350-383-400 small blocks, while increasing the rev potential.

That said, I like this manifold for use with that Comp cam recommended above. It's a newer design than the Performer EPS, which essentially uses the runners from the original spread bore Performer.
https://www.holley.com/products/intakes/dual_plane_manifolds/parts/8120

 

[MadOgre]

For what it's worth, Doug Flynn at Holley says high rise manifolds like the Weiand 8150 and Edelbrock Performer RPM give up little if any power at low RPMs on 350-383-400 small blocks, while increasing the rev potential.

That said, I like this manifold for use with that Comp cam recommended above. It's a newer design than the Performer EPS, which essentially uses the runners from the original spread bore Performer.
https://www.holley.com/products/intakes/dual_plane_manifolds/parts/8120

Well there is a big difference between an RPM intake and a high rise single plane manifold. The difference is one is a single plane while the RPM is still a dual plane intake.

I would agree that a you probably wouldn't notice too much of a difference from a performer dual plane to an RPM dual plane intake.

How ever you will notice a big drop off on low end torque and throttle response if trying to use a single plane high rise manifold! This manifold is not appropriate for an RV cammed engine with smaller valves.

The performer intakes were designed for throttle response right off of idle which is great when paired with an RV cam that starts @ 600 RPM

If using a cam like a roller RV cam that starts @ 1500 RPM then the RPM is really the way to go for sure!

And that Holley intake is exactly the same as the Edelbrock just minus a few coolant sensor port locations. Which might be a shortfall if planning on running a stock style setup. Although for that you would probably have an EGR manifold anyways.

 

[MikeB]

Well there is a big difference between an RPM intake and a high rise single plane manifold. The difference is one is a single plane while the RPM is still a dual plane intake.

And that Holley intake is exactly the same as the Edelbrock just minus a few coolant sensor port locations. Which might be a shortfall if planning on running a stock style setup. Although for that you would probably have an EGR manifold anyways.

He didn't say single plane, just "high rise" which typically describes dual plane manifolds like the Performer RPM and Weiand Stealth (now Race Warrior), which are taller and have larger volume runners than the Performer EPS and Weiand Street Warrior.

Also, the Holley (Weiand 8120) is certainly NOT the same as the Edelbrock EPS. It was computer designed 10 or so years ago and has a more uniform flow from port to port vs. the Edelbrock. That's not to say it won't work just fine, but it's not the same. And the large vacuum port on the #8 runner is farther away from the carb base, so it will clear Holley secondary fuel bowls.

 

[MadOgre]

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I dunno dude? They look exactly the same?

 

[MadOgre]

It actually just looks like the bolt pads for the alternator bracket and the throttle cable bracket are in the wrong place on the Holley. I do like that the rear vacuum port is further back but don't like where those bolt pads are!

 

[350runner]

if your talking to someone who works for a company whom sells products. of course no product will be bad. fact is they made those high rise intakes to perform at higher rpm. I've personally experienced the difference and it's night and day for a DD. loss in torque down low is there and if the engine build doesn't match for high rpm that engine will just looks pretty for shows. like thumper cams just sound good lol.

Sent from the dust in front of you!

 

[MikeB]

Saying the intakes must be the same because they look similar on the outside is kinda like saying early GM double-hump heads look similar to modern Dart Iron Eagles on the outside, so they must perform the same. After all, they each have 4 intake ports and 4 exhaust ports, and the valves are the same size.

For starters, you can plainly see the runners on the Weiand Street Warrior are a little taller than on the EPS. Wouldn't surprise me if they are also narrower internally, which would mean similar volume to the EPS, but higher velocity at lower engine speeds -- a trick used in the Vortec and LS1 heads.

Regarding a modern high-rise dual-plane manifold giving up little, if any, low RPM torque and throttle response to a low-rise dual-plane on a 350->400: It's hard for me to disagree with a Holley engineer who said that about his Weiand Stealth manifold as well as Edelbrock's Performer RPM. Of course the story would be different on a 265->327, as well as a single plane manifold on any small block.

Don't take my word for it. Write Doug Flynn to confirm my comments above. He's Doug_F on the ChevyTalk.com forum and is currently Holley's fuel injection engineer. If you ever speak with him, you'll immediately agree he's 100% engineer and 0% marketing.

 

[MadOgre]

I appreciate where your coming from but actually according to some tests the Weind 8120 scores below the 2701 on both HP and Torque and even the 8150 scores lower for peak torque while besting in peak HP by 6 hp.

http://www.hotrod.com/how-to/engine/1309-dual-plane-intake-manifold-comparisons/

 

[MadOgre]

Also the 8120 is 4.62 inches tall vs the 2701 at 4.80 inches so its highly doubtful that the Weind has taller runners then the Edelbrock 2701

I believe my comparison picture is of an 8150 though so that might cause some confusion lol my bad

 

[MadOgre]

In fact according to that article that I linked the 2701 wins over the Weind 8120 in all categories and is cheaper then the Holley 8120 intake.

 

[350runner]

Saying the intakes must be the same because they look similar on the outside is kinda like saying early GM double-hump heads look similar to modern Dart Iron Eagles on the outside, so they must perform the same. After all, they each have 4 intake ports and 4 exhaust ports, and the valves are the same size.



For starters, you can plainly see the runners on the Weiand Street Warrior are a little taller than on the EPS. Wouldn't surprise me if they are also narrower internally, which would mean similar volume to the EPS, but higher velocity at lower engine speeds -- a trick used in the Vortec and LS1 heads.



Regarding a modern high-rise dual-plane manifold giving up little, if any, low RPM torque and throttle response to a low-rise dual-plane on a 350->400: It's hard for me to disagree with a Holley engineer who said that about his Weiand Stealth manifold as well as Edelbrock's Performer RPM. Of course the story would be different on a 265->327, as well as a single plane manifold on any small block.



Don't take my word for it. Write Doug Flynn to confirm my comments above. He's Doug_F on the ChevyTalk.com forum and is currently Holley's fuel injection engineer. If you ever speak with him, you'll immediately agree he's 100% engineer and 0% marketing.

fact is fact man. You can believe whom ever you like. I'm only stating my personal experience with said intake. fact is he still works for the company.

Sent from the dust in front of you!

 

[Joe383]

https://youtu.be/NWU3ZqmDS08 Her is a video of my vortec 350 with a mild cam in it running the EPS intake and a 670 street avenger carb. I use to have 2.73 gears stock stall and 28" tall tires 275-60-15 and could light the tires up like nothing. Drives great and has great bottom end. I will probably be towing with this motor. I will be putting this motor in my 85 chevy 4X4 while I rebuild the 454 and then swap every thing back after the 454 is back together. You need higher compression though. If you can find a pair I would get some aluminum L98 heads and run something like the COMP Cams K12-238-2 the kit is around $310. You need some iron heads with a 64cc chamber or aluminum with 64cc or 58cc chambers. One thing when picking a cam if your looking for a cool idle stay away from cams with a 112-114 LSA and pick something with a 108-110 LSA. I built this motor with towing and a cool idle in mind cuz I don't plant on having it in my car for ever and built it for torque. The motor is idling at 750 RPM in the video and pulls 14.5" vacuum.

 

[MadOgre]

Nice sounding engine. Bet it goes like stink heh ? LOL