Anyone run an Edelbrock RPM Intake

Engine, Transmission & Driveline

  1. 65CopCar

    65CopCar New Member

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    Anyone run an Edelbrock RPM intake on a big block? If so, can you please post your experience? What is the combo and are you happy? I am most concerned about how it does in low rpm with a stockish converter and tall gears. I now run a Holley Street Dominator and it really struggles down low - may not be the intakes fault though, not sure if it is contributing.
     
  2. 413

    413 Well-Known Member

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    That combo you have won’t work very will, that Holley SD is a single plane intake. The eddy RPM is better down low than what you have, but sounds like you want to go fast and freeway gears are hurting that Goal by a bunch.

    what cam do you have?
     
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  3. stubs300

    stubs300 Senior Member

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    Isn't the dominator a single plane intake? I have the RPM on a 383, 750cfm, w/3.23 gears, stock converter, very mild cam and it's a great highway cruzer. You sound like you have more of a race car.
    The board needs to know tons more info on what you have and what you're lookin for. Good Luck
     
  4. 57fury440

    57fury440 Member

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    I have the Edelbrock Performer RPM on my 440. It's a 4 speed with 3:91 gears and a long duration cam. It is a nice manifold for the street and has good low end response even with the cam I have. I think it would work well for you. Make sure you have enough clearance for the hood to close without hitting.
     
  5. 1978 NYB

    1978 NYB Warfighter FCBO Gold Member

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    11 to 1 Venolia's, aluminum heads, aggressive cam, runs great.

    20180817_141218.jpg
     
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  6. 1978 NYB

    1978 NYB Warfighter FCBO Gold Member

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  7. 65CopCar

    65CopCar New Member

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    The car is not a race car, although my daughter does race it occasionally. Its a little north of 4000 lbs with driver and currently runs around 15.0's. This is supposed to be a very mild street car that my daughter occasionally goes down the track with just for fun. I know how to make heavy cars go fast - my almost done 69 GTX Street /Strip car will go low 10's at around 3900 lbs and my 67 Coronet that I have had since 1981 will go high 8's (hopefully 8.70's) around 152+ mph with the new 1060 hp motor at over 3500 lbs. Just about ready to make some runs with the new motor. None of my motors have any power adders and are all naturally aspirated.

    But I am more lost on the milder side. There is a mismatch. it is a 0.030 over 383. Tires are 27 tall with 3.55 gears. Converter flashes to 2500 rpm. Has a 750 Holley Double Pumper with the Holley Street Dominator intake.

    Yes the SD is a single plane but does not really act like it. I love that intake but I think it may not be right for this combo. I was thinking that the Edelbrock RPM dual plane may be worth going to.

    I ran into issues putting the motor together and ended up with only 8.9:1 compression. A little less than my target. Other than the cam, intake and carb, the motor is stock.

    The cam is wrong and will be changed. It does not idle well and is too lumpy for my liking for this car.

    The cam is a Comp Cams 21-670-4. Specs:

    Grind Number: PP280H
    Engine Family: Chrysler 383-440 c.i. 8 Cylinder (1959-1980)
    RPM Operating Range: 2,000-6,000
    Cam Type: Hydraulic Flat Tappet
    Lifter Style: Hydraulic Flat Tappet
    Camshaft Series: Nostalgia Plus
    Camshaft Gear Attachment: 1-Bolt
    Usage: Street/Performance
    Valve Springs Required: Yes
    Camshaft Material: Cast Iron
    California Proposition 65: WARNING: Cancer and Reproductive Harm P65Warnings.ca.gov
    Advertised Intake Duration: 280
    Advertised Exhaust Duration: 287
    Intake Duration at .050 Inch Lift: 233
    Exhaust Duration at .050 Inch Lift: 240
    Intake Valve Lift: 0.474
    Exhaust Valve Lift: 0.474
    Lobe Separation: 110

    My hope is to make it just a tad bit more gentle to drive at low rpms, idle better, wake it up just a tad coming out of the hole and not make it any slower. Its doable. I am going to change the cam, good chance go with the RPM intake, Brawler 650 DP carb and maybe a converter change. It all needs to be matched better.

    The RPM intake is 0.550" taller than the SD intake - I can handle that I believe with no issues.

    stubs300 - can you please share your cam specs?

    Thanks for all the responses thus far!
     
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  8. Turboomni

    Turboomni Old Man with a Hat

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    I have not run an RPM Eddy but wanted to. Your finger pointing at the Holley Dominator as the possible culprit is logical but the cam you are running may not be happy with the rear ratio or stall of the torque converter etc. I just went through this over at FCBO as the designer of my engine is over there. My problem was after careful measurements it seemed the RPM intake with my stock dual snorkel air cleaner would not fit under the hood. The RPM eddy is 1.75 inches higher than the stock intake manifold. Some have problems and some don't. Some find out the hard way after installing it and try to close the hood for a test drive. 1978 NYB doesn't have a problem and runs a rather low profile air cleaner. My goal was/is to have my engine look stock. With this problem in mind I went to FCBO with the topic title "Holley Street Dominator on a RB stroker."
    Since mine is not a stock sized 440 it is a different can of worms possibly. In the end most experts and Dwayne Porter of PRHeads [engine designer]on FBBO said in my case it would be no problem and barely noticable as the engine will be making more torque than I need down low on street tires. Many guys rave about the Holley Dominator there and with the low profile but very good flow. I have 3.23 rear also but had a 11 inch [hard to find and out of production I hear] converter built for my application. They wanted the weight ,tire diameter ,rear ratio, cam card, displacement and style of most driving. We don't know what cam you have and what you want from the car. You could possibly put a new Performer RPM for 300 bucks only and it may help a little or you could still have the same problem. What you want from the car first would be helpful.
    I patterned my build from Furygt and MEV. Mev runs a 3.23 rear in a 66? 4 door New Yorker with a 440 stroker ,cast iron exhaust manifolds [not HP's} weighing in at a whopping 4700 pounds ,drives 50 miles to the track and is in the mid to low 12's. An old saying says "the torque converter is where the magic happens." Lot's of ways to skin a cat as they say.
     
    Last edited: Apr 3, 2021
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  9. 65CopCar

    65CopCar New Member

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    Thanks! I have already talked to Dwayne and I have his opinion and I know Bill (FuryGT) and am somewhat familiar with his cars - or at least what he had. Not sure what he has left. Haven't talked to him in a bit.
     
  10. Turboomni

    Turboomni Old Man with a Hat

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    Good ! Dwayne said in a perfect world he would prefer for me the Eddy RPM but the Dominator would work very well too. Good luck to you and keep us posted. You are in good hands with Mr Porter.
     
  11. CBODY67

    CBODY67 Old Man with a Hat

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    In looking at the cam specs, it seems that the .050" duration might be about 10 degrees too long. The 110 degree lobe separation is probalby helping the upper rpm more than down low and with the idle quality (as most stock cams are at 114 degrees). Then, the single plane (ANY single plane) might not help lower rpm power, typically, as the end result is shorter runners to the cyl head (compared to a dual plane). It CAN be possible to make more power with the single plane if the flow in each runner is the same (with shape and size variations to achieve that result, which the original Edelbrock Tarantula intakes were supposed to do). The old Direct Connection race manual had a section on epoxying "popsicle sticks" of a particular dimension into the port floors of particual cylinders in particular aftermarket intakes (which might "dated" at this point in time) for flow equalization purposes.

    I suspect the engine has good off-idle throttle response and the converter is probably about right, as it is, BUT the issues mentioned above might be the side issues to your current dynamics of the situation.

    Personally, you might like Comp Cams, but it seems that Lunati has some better cams with longer street durations and assymetrical lobes for better cylinder filling (one of Comps' early claims to fame on their "High Energy" street cams of the later 1970s). Seems like the Summit 60601 is a repackaged Lunati that others in here have used on their stock 383s with good results? A re-imagined 440/375 cam, as I recall.

    Just some thoughts,
    CBODY67
     
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  12. furious70

    furious70 Senior Member

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    My own experience with the SD in a mild 383 was terrible, it killed low end torque. The great intake comparison showed it was way down on torque but made the best power. Rpm perf was only down a touch on power but way better on torque.
    My efi turbocharged 383 runs the rpm perf and it's great
     
  13. Turboomni

    Turboomni Old Man with a Hat

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    Interestingly I just watched engine masters episode 66. It was about turbocharging a low compression 440. The point I found interesting is they did a baseline NA before the turbo was installed. They had a Performer RPM which they tested NA and went to a Holley Street Dominator NA because they wanted to use that with the turbo. The results were very interesting. In my crude fashion I just took pictures on my screen to post here. That is not my finger LoL.
    The Black line is the Dominator
    20210403_235343.jpg After the merge at 3700 rpm the Dominator starts pulling away but the RPM had a bit more torque till 3600 or so. 20210403_235028.jpg
    Their final results. Not arguing here but they are similar and each manifolds strengths are the other's weakness if you can call it that. Maybe the Dominator doesn't work well with the smaller 383. I had read the 383 was not as well regarded as the 440 intake. I believe they discontinued the one for a 383 but could be wrong. Final HP for the Dominator below is 364.8 as above. Since you described your car and have a 383 i would think the eddy would be better. Just thought it was interesting.
    20210403_235200.jpg
     
    Last edited: Apr 4, 2021
  14. furious70

    furious70 Senior Member

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    I'm pretty sure the old hot rod intake comparo in a 383 had the SD down almost 30lbs ft. But it did make a little more up top. And it fits better height wise. And fits oem ac brackets.
    That was still with stock cam I think. It's a solid intake on a performance engine when hood clearance is an issue.
     
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  15. FinFury

    FinFury Member

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    I have SD on my 383 in a Challenger with 3.23 gears and about 2800 stall converter. It was a dog with edelbrock avs thunder down low but run great on high rpm. I switched to Holley by friend's recommendation and got shit load of low end grunt more and the same high end power. Now it rips the 275 tires with ease for the first two gears. Never figured out why it ran lazy with the Edelbrock down low as the AFR was spot on. Maybe some distribution problems with the single plane, who knows. It ran flawlessly with less cam and performer 383 dual plane intake with the rest ot the combo being same.

    I have roughly 9.8 static compression with KB domed pistons, ported stealth heads and Lunati Voodoo cam with bit over 230 degrees at 0.050"
     
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  16. Turboomni

    Turboomni Old Man with a Hat

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    DISCLAIMER! My above post maybe no good because after reviewing the video again they state the Eddy intake was in their words "The base performer 440 intake" so it may not be the RPM. My apologies.
     
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  17. stubs300

    stubs300 Senior Member

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    I'm running the Hughes 2330 cam that's no longer made. Dur. @ .50 is 223/230, Adv. dur. 272/276, Lift is .405/.415 @ 1.5 ratio on a 107 centerline.
     
    Last edited: Apr 4, 2021
  18. 413

    413 Well-Known Member

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    I’d call Hughes engines for a cam recommendation to your specs. I do think you will be helped by going to the RPM intake.
    I wouldn’t call your 3.55 and 27” tires freeway gears.
     
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  19. MEV

    MEV Active Member

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    3.23 gears, 2800 converter 505 cubic inches performer RPM and quick fuel SS830 carb.

     
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  20. 70bigblockdodge

    70bigblockdodge Old Man with a Hat

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    What size AVS thunder was it?
    It was just a AVS not a AVS2 ?
    Just asking for info gathering.
    Thanks