Speedmaster vs Edelbrock air gap intakes

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318willrun

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I hear (and believe) the edelbrock offers better flow.
  1. Has anyone tested these either at a drag way or bench flow ??
  2. Are the gains only noticable on bigger hp builds (400+) ???

Thanks
318WR
 
The Edelbrock is a better cast unit with bigger runners and ports. The more powerful the build the more you’ll feel the difference. How well they compare on low power builds is a good question. If the build is a real low power deal, the smaller ports may prove to be advantageous.

I have zero complaints about mine on top of a ‘00 - 5.9 with a Edelbrock. carb, Hooker 1-3/4 - 2-1/2 exhaust, 727/3.55’s on 245/60/15’s, chrome boxes ignition/JY distributor. The ride pulls nicely from idle to about 5K.
 
The Edelbrock is a better cast unit with bigger runners and ports. The more powerful the build the more you’ll feel the difference. How well they compare on low power builds is a good question. If the build is a real low power deal, the smaller ports may prove to be advantageous.

I have zero complaints about mine on top of a ‘00 - 5.9 with a Edelbrock. carb, Hooker 1-3/4 - 2-1/2 exhaust, 727/3.55’s on 245/60/15’s, chrome boxes ignition/JY distributor. The ride pulls nicely from idle to about 5K.
I agree, the better the heads and bigger the cam, the more the edelbrock would be favored. I am curious though in mild street builds, per say .500 lift, what the difference would be. Interesting point about the smaller runners actually helping, lets say a stock engine.
 
Yes I think the speedmaster knockoff would be a good manifold but would not achieve the power levels of the Edelbrock I believe Pittsburgh went through one and found it to be somewhat restrictive in comparison to the air gap.maybe it was in Pittsburgh but someone on this form.
 
I agree, the better the heads and bigger the cam, the more the edelbrock would be favored. I am curious though in mild street builds, per say .500 lift, what the difference would be. Interesting point about the smaller runners actually helping, lets say a stock engine.
Well the smaller runners would have a higher velocity. How far that works in your favor I can’t say. I myself never recommend the chink knock off’s.

The mention of how well it would do with a .500 lift cam is not exactly a fair one since I have seen cams like the MP 292/.508 that has the duration @050 at 248* and I have a Crane Hyd with 236*s @050 and .497 lift. I can find cams with greater and lesser duration and still have around that .500 lift.

The intakes have slightly different characteristics even though the look the same, the small differences of “How well they feed the engine” is another story. Remember the cylinder head can be hurt in how well it flows via the intakes ability, or lack of it.

Since the cams duration dictates to some degree the engines rpm range & the cylinder head depending on how well that flows air and fuel can expand on the amount of power and its range (cams and engines power) to some extent, the big trick with low lift cams (generally considered under .500 lift) is in the valve job. (It really is more complicated than this)

In short, testing the two intakes is a great idea, something I used to do on the street quite often in decades past. A dyno would be awesome, (watch out Rich Holdner!) but a drag track would do well also.

The test, should ones wallet and Curiosity be willing, compare 2 or 3 different cams, if you could keep the lift as close as possible to each other. A spread like,
a cam @ 218@050, (another @236@050) and @ 255*’s.

The difference cam durations would test how well each intake performs in higher and higher rpm bands under the same/similar lift at the valve.

2 or 3 different cams (I guess 2 would really do) would be cheaper than a set of well ported heads….. and a lot of fun.

Working with a stock engine, actual driving parameters and style come into play. I know very docile everyday drivers and pretty quick bracket racing cars with a mere .500 lift.
Are we talking about the drag truck?
 
the Professional Product air gap made 477hp on a 318 in Engine Masters some years ago.

i ran that engine in a 71 duster i had. Intake looked good to me. I seriously doubt it loses much if any power to the eddie intake, with both cleaned up, matched to heads.
It pulled good to 6500, although i shifted it slightly lower
 
i ran that engine in a 71 duster i had. Intake looked good to me. I seriously doubt it loses much if any power to the eddie intake, with both cleaned up, matched to heads
OH! Modified intakes. Now we are twisting things.
I do wonder how far the chink intake can go.

Another thing on looks… MoPar did a write up on this on there own intakes. They would find big disparities between there M1 single plane intakes not on just the B to RB intakes but also between the LA vs W2 intakes.
 
Well the smaller runners would have a higher velocity. How far that works in your favor I can’t say. I myself never recommend the chink knock off’s.

The mention of how well it would do with a .500 lift cam is not exactly a fair one since I have seen cams like the MP 292/.508 that has the duration @050 at 248* and I have a Crane Hyd with 236*s @050 and .497 lift. I can find cams with greater and lesser duration and still have around that .500 lift.

The intakes have slightly different characteristics even though the look the same, the small differences of “How well they feed the engine” is another story. Remember the cylinder head can be hurt in how well it flows via the intakes ability, or lack of it.

Since the cams duration dictates to some degree the engines rpm range & the cylinder head depending on how well that flows air and fuel can expand on the amount of power and its range (cams and engines power) to some extent, the big trick with low lift cams (generally considered under .500 lift) is in the valve job. (It really is more complicated than this)

In short, testing the two intakes is a great idea, something I used to do on the street quite often in decades past. A dyno would be awesome, (watch out Rich Holdner!) but a drag track would do well also.

The test, should ones wallet and Curiosity be willing, compare 2 or 3 different cams, if you could keep the lift as close as possible to each other. A spread like,
a cam @ 218@050, (another @236@050) and @ 255*’s.

The difference cam durations would test how well each intake performs in higher and higher rpm bands under the same/similar lift at the valve.

2 or 3 different cams (I guess 2 would really do) would be cheaper than a set of well ported heads….. and a lot of fun.

Working with a stock engine, actual driving parameters and style come into play. I know very docile everyday drivers and pretty quick bracket racing cars with a mere .500 lift.
Are we talking about the drag truck?
In the end, yes, I'm looking at Drag Truck. I have the SM intake on it now, and I've had a New Eddy air gap in the box for a few years now. Simple enough to swap and let the ET slip tell the story, however, we have a long winter ahead without knowing (tracks are closed till April). Thus the reason for the thread, to see if anyone else chased down this rabbit hole. My cam is 218/224 @050 with basically a .520/.530 lift. Heads are stock magnum heads but remans that I got cheap, and I guess we'll say they've been mildly home-ported by me with hughes spring kit. All else is stock 200k miles short block.
 
In the end, yes, I'm looking at Drag Truck. I have the SM intake on it now, and I've had a New Eddy air gap in the box for a few years now. Simple enough to swap and let the ET slip tell the story, however, we have a long winter ahead without knowing (tracks are closed till April). Thus the reason for the thread, to see if anyone else chased down this rabbit hole. My cam is 218/224 @050 with basically a .520/.530 lift. Heads are stock magnum heads but remans that I got cheap, and I guess we'll say they've been mildly home-ported by me with hughes spring kit. All else is stock 200k miles short block.
in this situation ^^ just curious if anyone did this swap in a like situation
 
Will there be a cam change in the future?
 
Edelbrock will make more power everywhere.
I think so as well. But I do wonder at a part throttle cruise. Would it be better with a small cam and Hwy gears?

Doesn’t matter much for this exercise with the “Drag Truck.”
 
I think so as well. But I do wonder at a part throttle cruise. Would it be better with a small cam and Hwy gears?

Doesn’t matter much for this exercise with the “Drag Truck.”
Correct. I don't care what part throttle or idling around town offers from either in this case. I will say, it idles great, putts around town great, and has plenty of part throttle snap. However, it would be nice to know those things also for somebody that had a different project (more of a town driver). But just thought somebody may have compared on a bench flow or on their car and state the gains/losses.
 
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If nobody post actual results over the upcoming weeks, then a good chance in the spring I'll do the swap and say what the seat of my pants says about the swap, and post before/after ET slips.
 
It'll probably be up to you...
Somebody may chime in... seen quite a bit of bashing of SM over the past year (s) so thought somebody might have put the intake to the test. I know Pittsburgh Racer did a test and was miserably disappointed with the flow of the intake OOTB. BUT, not all of us are building 9 second cars... lol But as stated, if not, then I'll most likely do it and see for myself. Only cost me a gasket.
 
Ive had both on the dryer and eyeballing them told me the flanges were the same, both dropped onto a 360 with no gaps so the angles were correct. The Edelbrock port shape was not good. None were the same and the port divider wall was like a noodle. one bowed into the other port a nd one was not straight. The clone had perfect ports (they are not sand cast but permanent mold cast so they are way more consistent). IF you were to port match both, this is not a factor. The Edelbrocks plenum was larger and the intake was slightly taller so the plenum volume would be greater in the Edelbrock. The clones runners may have been smaller but I could not tell, it would have been that close. I had a polished version of the clone, a big CHINA on the flat bottom. I paid $20 for it on craigslist from a Chevy guy who bought it used but didnt realize it was for a Mopar. For a street car with under .500 lift, I think it would actually work better than the Air-gap due to the smaller plenum.
 
Ive had both on the dryer and eyeballing them told me the flanges were the same, both dropped onto a 360 with no gaps so the angles were correct. The Edelbrock port shape was not good. None were the same and the port divider wall was like a noodle. one bowed into the other port a nd one was not straight. The clone had perfect ports (they are not sand cast but permanent mold cast so they are way more consistent). IF you were to port match both, this is not a factor. The Edelbrocks plenum was larger and the intake was slightly taller so the plenum volume would be greater in the Edelbrock. The clones runners may have been smaller but I could not tell, it would have been that close. I had a polished version of the clone, a big CHINA on the flat bottom. I paid $20 for it on craigslist from a Chevy guy who bought it used but didnt realize it was for a Mopar. For a street car with under .500 lift, I think it would actually work better than the Air-gap due to the smaller plenum.
Good Stuff !! Thanks!
 
I've got a new Speedmaster intake on the new stroker for my Power Wagon...
If it doesn't leak and delivers air and fuel I'll be happy...
 
Good Stuff !! Thanks!
Indeed good to read and I agree, the smaller plenum would be better for the mild upgrade drivers experience. But your testing and testimonial I eagerly await.

I do plan for an upgraded cam on my set up.
What cam are you running in yours?
 
Indeed good to read and I agree, the smaller plenum would be better for the mild upgrade drivers experience. But your testing and testimonial I eagerly await.

I do plan for an upgraded cam on my set up.
What cam are you running in yours?
Oregon re-grind. It's on a LA roller so I have the long snout. I listed the size in above post
 
The professional products intake made 30 less horsepower on our aluminum headed 408 than the edelbrock. So 470 to 440. Can't speak for the speedmaster but I wouldn't expect edelbrock numbers.
 
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