• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Performer RPM

old guys rule

FBBO Gold Member
FBBO Gold Member
Local time
10:21 AM
Joined
Sep 14, 2016
Messages
1,322
Reaction score
445
Location
Jacksonville, FL
Anyone know the height difference between a stock 440 intake or ch4b and the performer RPM?
 
Last time I looked years ago, they showed the difference on Eddies website!
 
I don't if it would be the same, but an RPM is 1 15/16" taller than a factory iron manifold on a B engine.
 
The more I am thinking about it, I went through this on my last 440 as well. Pretty certain the RB Performer RPM is also almost 2" taller than a stock cast intake. I ended up with a 1.25" drop base and a 2.125" or so element to fit under the hood, if that's what you are asking about.
 
Anyone know the height difference between a stock 440 intake or ch4b and the performer RPM?

The RPM is 1.5” taller than the factory 178 cast intake. It is 1.1” taller than the CH4B.
 
Not mentioned, but most important of all......
The Performer RPM power range is 1500-6500 rpm.
The Performer powr range is idle to 5500 rpm.
Using a RPM on a stock engine or engine that is dead by 5500 will show a performance loss, not a gain [ compared to the Perf ].
 
Not mentioned, but most important of all......
The Performer RPM power range is 1500-6500 rpm.
The Performer powr range is idle to 5500 rpm.
Using a RPM on a stock engine or engine that is dead by 5500 will show a performance loss, not a gain [ compared to the Perf ].
So, if I read your post right you are saying a preformer rpm on a stock 440 will at let's say 4,500 rpm make less hp than the preformer on the same engine at the same rpm.
Interesting , I have to ask were did you get this information ? I have a preformer on a pretty stock 440 and was considering a upgrade to the rpm.
 
This information comes from Edelbrock, who state the rpm ranges for their intakes.
When the intake fits a variety of engine sizes, I believe Edel quotes the #s for the middle of the range.
Eg, For BB Mopar 413-426-440, the 1500-6500 is for the 426. On a 413, it will be more, maybe 1600-6600; on a 440, it will be less, maybe 1400-6400.

The point is the int should match the rest of the combo. You do not put a high rpm intake on a low rpm engine, & vice versa.
 
Not mentioned, but most important of all......
The Performer RPM power range is 1500-6500 rpm.
The Performer powr range is idle to 5500 rpm.
Using a RPM on a stock engine or engine that is dead by 5500 will show a performance loss, not a gain [ compared to the Perf ].

So, if I read your post right you are saying a preformer rpm on a stock 440 will at let's say 4,500 rpm make less hp than the preformer on the same engine at the same rpm.
Interesting , I have to ask were did you get this information ? I have a preformer on a pretty stock 440 and was considering a upgrade to the rpm.

This information comes from Edelbrock, who state the rpm ranges for their intakes.
When the intake fits a variety of engine sizes, I believe Edel quotes the #s for the middle of the range.
Eg, For BB Mopar 413-426-440, the 1500-6500 is for the 426. On a 413, it will be more, maybe 1600-6600; on a 440, it will be less, maybe 1400-6400.

The point is the int should match the rest of the combo. You do not put a high rpm intake on a low rpm engine, & vice verI have used the RPM-AG on otherwise dead stock small blocks (minus the headers & dual exhaust) and I certainly could feel the power gain. There is a minor loss of low end torque. Easily ignored.

My most recent use of the RPM-AG is on a 5.9 Magnum engine. Topped with a 600 AFB, OEM trap door air cleaner, chrome box ignition on a junk yard distributor & 1-3/4 primary tube Hooker super competition headers into a H pipe dual exhaust at 2-1/2 inches using Dynomax turbo mufflers.
(No pressure wave cancellation box as of yet.)

The stock 5.9 Magnum engine is well known to roll over at 4500 rpm. There is no way I’d use a lesser intake manifold than the RPM. (That would be MoPars M1 dual plane.)

Edelbrock lists the rpm ranges of there intakes where there intended to work best in. This does not mean they fall on there face at high rpm. I also agree that the intakes should be matched to the intended performance characteristics and RPM ranges the car & engine are designed for. But I disagree with a RPM is a bad match for an otherwise stock engine. Even more so on a B/RB. I also disagree with the suggestion that the RPM is a high rpm intake manifold. While certainly capable, it is not something I would ignore and bypass. In all honesty, I would not use a Performer ever & always skip right over it in a street performance application or if hood clearance or something like an air grabber usage was an issue.

These cars do not cruise below 2K @ interstate Hwy speeds or even on most smaller road way arteries. The RPM-AG works fine with my small blocks. IMO, it was an excellent upgrade over the stock iron intake.

If my engine didn’t have an upgraded camshaft in it and the intake was a performer, I would not make the change and even more so if the gear ratio is under 3.23 w/stock tires. My route would be to do a minor deep port matching to the Performer & test spacers under the carb.

IF the car had headers, I would search for low end torque with header collector extensions into a pressure wave cancellation box. This method has been a proven worth while measure.

Geoff2’s second quote on how he feels the rpm changes with the size of the engine I feel is completely wrong as the rpm range of the engine will be dictated by several factors. Camshaft and ability to breath. The actual CID difference will not alter the window of performance of the intake. Especially on the high end! If the effect is seen on the low end, that’ll be a camshaft issue and a bet I’ll make.

(Even more so since I’m not a betting man and only do so when I’m super 100% sure I’m taking your money. I work to dang hard for mine to loose!)
 
Last edited:
Rumble,
Sorry, what I said was correct. As cubic inches increase, the intake manifold runners need to pass a greater volume of air at a given rpm. At the upper end they will reach a choke point where they stall. So this changes the rpm range of the intake. The info I gave on the rpm ranges versus the engine size is correct in concept, & I gave approximate figures to show the difference...& the concept.

Do you think if a 440 Perf intake was put on a 800 cu in engine it would still pull hard to 5500 rpm? I don't think so.....
And no, never said or implied that the intakes, fall on their face at the Edels nominated number. They slow down & do not pull as hard.
For some engines such as the SB Chebby, there is a range of single plane race intakes to cover a wide range of rpm ranges. There is not a one size fits all because it would not provide optimum power.
The intake rpm ranges quoted by Edel are for optimum performance. Does not mean that the intakes will not work outside these ranges.
 
The installed camshaft in question is a factor that will determine the efficiency of the intake as well.
A single plane intake which is good for higher rpm's efficiency will be complimented by a big camshaft.
It's the overall combination that makes the engine.
 
Rumble,
Sorry, what I said was correct. As cubic inches increase, the intake manifold runners need to pass a greater volume of air at a given rpm. At the upper end they will reach a choke point where they stall. So this changes the rpm range of the intake. The info I gave on the rpm ranges versus the engine size is correct in concept, & I gave approximate figures to show the difference...& the concept.

Do you think if a 440 Perf intake was put on a 800 cu in engine it would still pull hard to 5500 rpm? I don't think so.....
And no, never said or implied that the intakes, fall on their face at the Edels nominated number. They slow down & do not pull as hard.
For some engines such as the SB Chebby, there is a range of single plane race intakes to cover a wide range of rpm ranges. There is not a one size fits all because it would not provide optimum power.
The intake rpm ranges quoted by Edel are for optimum performance. Does not mean that the intakes will not work outside these ranges.

The installed camshaft in question is a factor that will determine the efficiency of the intake as well.
A single plane intake which is good for higher rpm's efficiency will be complimented by a big camshaft.
It's the overall combination that makes the engine.
Geoff, I was about to more or less say what Wietse said.
I know you never said….. I’m just saying the same as well. I also don’t think, I know the intakes will perform below and beyond there rated rpm ranges. Your example of the engines is off IMO in this particular case.

Theoretical numbers of the engine or air pump are correct to a degree which do not span into this particular case and are limited per application. Been there, done that, tested that, track proven.

Your choke point mention doesn’t apply here and is also an extreme.

I’m not going to break out the slide rulers and start sliding beads across the strings to argue this point. Have your opinion. Think what you want. My usage of a RPM-AG as written above was a home run across the board as I stated it.

Do you think if a 440 Perf intake was put on a 800 cu in engine it would still pull hard to 5500 rpm? I don't think so.....
You don’t think so or you dyno tested this and know so?
This is a broad question since no specific parameters are mentioned outside the ridiculously huge displacement. Why would that size engine even enter the conversation here? But I can say in my small block testing, that specific combo of a RPM & AFB carbs has worked on everything I placed it on from a 340 to a well built 360. Just not a stock 360 and all engine had headers.

At 800 CU, that’s a bit bizarre to bring up for an example.
If your going to travel into extreme examples to prove a point, we’re done here.
 
Last edited:
Rumble,

Sometimes to demonstrate a concept, using an extreme example makes it easier to understand the concept.
Hence the 800 CI engine as an example.
What I have said is true.
 
Rumble,
I tried to find something in D. Vizard's writings to illustrate the point. I could only find this in How to Build HP vol 2, p. 117.
" For instance a particular intake manifold may only deliver deliver extra power on a 350 from 3000 rpm up....On a 300 cu in engine that same manifold may not show a gain until 4500 rpm".

Sorry you didn't like the 800 ci example, but it is totally valid for demonstrating the point.
 
The intake valve section will be the determining factor as a choke point before the intake manifold runner becomes an issue.
It's the length differences that throw things off, long runners or short runners, if there is a 50 or 55 CI chamber below does affect but not as much.
The air pulses from the cylinders filling vs the intake valve closing against that air flow is causing a bounce back to the intake, and if the length is right this is not going to affect the air flow in the plenum, and instead the "over pressure" in front of the closed valve will help in filling on the next intake cycle.
This length filling obviously takes time, time relates to rpm, so there is a rpm range this pulse will be optimal for the air flow, this is volumetric efficiency.
And since the camshaft determines opening and closing of the valve, it has great effect on this time.
Edelbrock sells Top end combo's of heads, intake and cam...guess how they determined that combination and set an rpm range against that.
 
Rumble,

Sometimes to demonstrate a concept, using an extreme example makes it easier to understand the concept.
Hence the 800 CI engine as an example.
What I have said is true.
Geoff, that was an idiot reply to bolster and idiotic example.
You have been historically proven wrong and to continue to travel forward with you on this is a waste of time. We’re done here. Enjoy the day.
 
No not an idiotic example or reply at all. Sorry if you don't get it, but it is all physics. You don't get gigantic runners on lawn mower engines, & at the other end of the scale, you do not get tiny runners feeding mountain motors. Runners are sized according to the engine they will be supplying with air.
 
Auto Transport Service
Back
Top