E-Tec's The Way

Edelbrock's 200 Series Heads Offer The Most Average TQ And HP To Date

Mike Petralia Sep 13, 2005 0 Comment(s)

Testing engines is cool. Sometimes, ok almost all of the time, when testing a new combination, we walk away with a feeling of accomplishment, even if we didn't make any more power that day. And the feeling's even better when we do make more power, or, as in the case of Major Mouse Pt. 05, more AVERAGE power and torque is what we walked away with thanks to a pair of Edelbrock's E-TEC 200 cylinder heads.

HEAD COMPARISONS
We usually try to remain passive and unbiased in our reporting of the day's dyno events. But every time we've tested and engine using Edelbrock's E-Tec line of cylinder heads, we've been astounded at how much power they can bring to the table. And we like to give credit where credit is due to the folks in the engineering departments of Edelbrock for coming up with a cylinder head design that can work equally well on a little 350 or a big 427-inch small-block. When you look at this month's tests, you may not see a huge increase in power compared to other months. But, at this level, any gains, especially those in average power, which is power throughout the entire rpm band, are worth the praise. And when tested with Edelbrock's matching Vortec-style intake manifolds, both the Performer RPM Air Gap and Super Victor, Major Mouse has broken almost all of its own personal records. In past tests, only the Brodix RR180 heads made more peak torque, eclipsing the E-Tec 200's by 7 lb-ft at 4,200 rpm (572lb-ft to 565 lb-ft). However, if you look at the start of the run, you'll see that MM made more low-end torque with the E-Tec's than it has in a long time which means that MM has set the new standard for power this month.

PEAK HP
In Test 05 we installed Edelbrock's single-plane Super Victor Vortec intake manifold and got the highest peak horsepower to date, 526. Of course, as with all good things in the world of horsepower, there was a trade off when compared to the torque made using Edelbrock's dual-plane Performer RPM Air Gap Vortec manifold where we saw some great, if not record setting peak torque figures of 565 lb-ft. As is almost always the case when swapping from a single-plane intake manifold to a dual-plane, low-end torque was traded for top-end horsepower and the power curves in the accompanying graphs show the details.

But, it's all good, because this is yet another example of two, tailor-made combinations that can fit a variety of applications. The E-Tec 200's along with the Perf Air Gap manifold would be great to power a heavier car or truck, while the Super Vic manifold would be best suited to a lighter car that can hook and launch. And keep in mind that these power figures were generated with a mild camshaft in this big small-block that'd idle like a kitten and roar like a lion.

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We've found Edelbrock's line of E-Tec cylinder heads to be most fulfilling when it comes to making great power across the board. These are the biggest of the bunch with 200cc intake runners. Which, as it turned out, made the highest peak horsepower Major Mouse has seen yet and still managed to pull off some terrific low-end torque figures as well.

This close up of Edelbrock's E-Tec chamber design shows their distinct shape, which Edelbrock spent countless hours on the dyno and flow bench constructing.

The E-Tec 200's are CNC port-matched for added flow. They're also designed for only the GM "Vortec" style intake manifold bolt pattern that uses only 8 bolts. You can see the Fel-Pro intake gasket we ran is cut out for either type of intake.

The last tests of the day were run with Edelbrock's Performer RPM Air Gap Vortec intake manifold, which netted the highest average TQ and HP in MM's career. To keep everything equal to previous tests, Speed-O-Motive used the same Pertronix distributor and "Second Strike" ignition box with all tests.

Speed-O-Motive also used the same set of 1 3/4-inch dyno headers that we've been using for many months now.

The E-Tec 200 heads accept standard stud mounted rocker arms so we reused the COMP Cams Magnum 1.6:1 rockers we'd used in the past.

Our first tests of the day saw MM equipped with Edelbrock's bigger, Super Victor Vortec intake manifold. Its single-plane design gave MM the best top end horsepower to date, but it sacrificed some low-end power getting there.

MAJOR MOUSE PART 05 - TEST 05:
As is our usual format, the crew at Speed-O-Motive once again left everything else the same and only swapped heads and intake manifolds this month. All other items in this test including: timing, jetting, cam installed position, etc., were duplicated from last month. They also reused the same COMP Cams 1.6:1 rockers, and the same Demon 750 carb, then bolted Major Mouse back onto their DTS dyno to see how much power it could crank.

SPECS for MM05-T05:
427 cid, 11.0:1 cr, 4.125"-bore Mowtown iron 4-bolt block, 4.00"-stroke Lunati crank, 5.850"-inch Lunati rods, Lunati pistons (14cc dish) installed @ "0" deck, Lunati Moly rings, Edelbrock E-Tec 200 heads (64cc chambers, 200cc runners, 2.02" intake valves, 1.60" exhaust valves), Edelbrock Super Victor Vortec intake manifold, Edelbrock Performer RPM hydraulic roller camshaft installed at 108-degree intake CL (234/238 @ .050, 296/300 adv, .574/.584 lift w/ COMP 1.6:1 rockers, 112 LS), Demon 750 carb, 32 degrees total advance, "0" degree Crank Angle Offset (C.A.O.)*, 91-octane Shell gasoline. Tested on Speed-O-Motive's DTS dyno.

SPECS for MM05-T06:
Same as T05, but with Edelbrock Performer RPM Air Gap Vortec intake manifold

*C.A.O. refers to the setting on the Pertronix "Second Strike" ignition box. It re-fires the spark plug after its initial firing, such as 32 degrees BTDC on the first firing, and then once again at 30 degrees BTDC if the box is set for a 2-degree C.A.O. In this case, as was the same last month, Major Mouse responded best to a C.A.O. of "0" degrees, meaning there was actually no second strike of the spark plug. In the past on some other engines we've found extra power by re-firing the plug around 2-3 degrees later, but not this time

MAJOR MOUSE COMPONENTS
FOR PT05: TEST 05 & TEST 06
   
CAM EDELBROCK HYDRAULIC ROLLER (PN 2201)
CARB SPEED DEMON 750
FASTENERS ARP
GASKETS CORTECO
HEADS EDELBROCK E-TEC 200 (PN 60989)
IGNITION PERTRONIX DISTRIBUTOR, "SECOND STRIKE" IGNITION BOX*
LIFTERS COMP HYDRAULIC ROLLER (PN885-16)
MANIFOLD EDELBROCK SUPER VICTOR VORTEC (PN 2913)
MANIFOLD EDELBROCK PERF RPM AIR GAP VORTEC (PN 7116)
OIL SYSTEM MOROSO
PISTONS LUNATI DISHED FORGINGS
ROCKERS COMP CAMS 1.6:1 PRO MAGNUM (PN 1302-16)
SPARK PLUGS ACCEL (PN 8191)

MM05-T05   MM05-T06  
Super Vic   Perf RPM  
RPM TQ HP TQ HP
2600 495 245 508* 251
2800 516 275 529 282
3000 527 301 538 307
3200 522 318 536 327
3400 518 335 535 346
3600 527 361 544 373
3800 542 392 558 404
4000 550 419 564 430
4200 559 447 565 452
4400 563 472 562 471
4600 561 491 556 487
4800 552 504 546 499
5000 539 513 536 510
5200 526 521 522 517
5400 511 525 505 519
5600 493 526* 484 516
5800 474 523 468 517
6000 454 519 443 506
         
Max 563 526* 565 519
Avg 524 427 528* 429*
* indicates Major Mouse's personal record-breaking performance

EDELBROCK E-TEC
200 CYLINDER HEADS
(200cc intake port)
FLOW NUMBERS
When shopping for cylinder heads there's lots of choices to consider and not every one of them will work best in every situation. So it's important to collect as much data as possible and then make your decision based on what you've learned. When comparing cylinder heads, it's important to look at other figures besides just airflow. Port volumes, chamber shape and size, valve sizes, angle and locations, how much spring/lift they can take and will it match your camshaft? These are just a few of the items that you should make your decision on, not just the power they produced in some magazine story. I also personally feel that a good indicator of how well a cylinder head will work is it's ratio of intake to exhaust flow, listed as "IvE flow" in this chart. Although this is not the "Holly Grail" of horsepower, it does indicate a head's potential to move air into and out of the cylinders effectively. A head with a ratio of less than 60% is not a very effective air mover, particularly since it indicates that it can move air into, but not out of, the cylinders. A head with a ratio of over 90%, although rare, is capable of extremely good power numbers so keep an eye out for it. Check out the very high 90% IvE flow at the low .200-lift area of the Edelbrock E-Tec 200 heads. This is an area of critical performance for any head, but particularly a street head that won't be run with much lift. Since the valve will see this area twice during every cycle, once on the way up and then again on the way down-as opposed to seeing max lift only once in every cycle- low lift flow figures are often overlooked, but very critical to making the best power.

Intake port: 200cc, 2.02" intake valve, 1.60 exhaust valve
Figures shown at 28-inches water depression
Valve Int Ex IvE flow
Lift CFM* CFM* ratio
.100 67 57 85%
.200 122 110 90%
.300 175 153 87%
.400 223 182 82%
.500 252 196 78%
.600 259 204 79%
  Average 83%  

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