Small Block Chevy Performance Parts - Danger Mouse Part 3

New Headers, Cam, Rockers...And A Twist

Mike Petralia Nov 1, 2002 0 Comment(s)

CLICK BELOW TO SEE ALL OF THE STORIES COVERING THE BUILD OF PROJECT DANGER MOUSE

DANGER MOUSE PART 1

DANGER MOUSE PART 3

DANGER MOUSE PART 4

DANGER MOUSE PART 5

DANGER MOUSE PART 7

DANGER MOUSE PART 8

DANGER MOUSE PART 9

DANGER MOUSE PART 10

DANGER MOUSE PART 13

DANGER MOUSE PART 14

DANGER MOUSE PART 15

DANGER MOUSE PART 18

DANGER MOUSE PART 20

DANGER MOUSE PART 22

DANGER MOUSE PART 23

DANGER MOUSE PART 24

DANGER MOUSE PART 25

Sucp_0211_03_z Chevy_small_block_performance_parts Dyno 1/11

The New Bumpstick Certainly Adds Some Grunt!
Our second dyno test session for Danger Mouse (DM) could really just be considered an extension of the baseline testing we did last month. We found some great low-end power increases, especially after swapping in a slightly larger COMP Cams XE256H cam. We really didn't pump up peak power figures that much, but our new combination would definitely have responded well on the street with all the extra low-end grunt we made.

Sucp_0211_04_z Chevy_small_block_performance_parts Waterpump 2/11

Last month we had to borrow a water pump from Westech for testing. This time DM gets its own Meziere electric beauty that itcan keep.

Power Recap
Last month during DM's first time on the dyno, we were rewarded with a maximum 349 hp and 405 lb-ft of torque, and the average power and torque figures were 278 and 390, respectively (see: Test 4). That was outstanding for a mild 355-cid motor running stock iron heads and a tiny cam. So this month we thought we'd install a new cam and some bigger headers, along with a few extra parts to see what they'd do. The reward this month was a maximum 357 hp and 413 lb-ft of torque (+8 and +8) and 293/396 (+5 and +6) averages.

Test 5: 1 3/4-Inch Headers
The first new test item was a set of larger, 1 3/4-inch headers. Why, you ask? 'Cause that's what people do. They think if 1 5/8 headers are good, then 1 3/4 may be better. And in fact, they were, barely. Compare tests 4 and 5 and you'll see that average torque was down 2 lb-ft, but average horsepower increased by 9. That's a fair trade to us, so we left them on.

Sucp_0211_05_z Chevy_small_block_performance_parts Torque_chart 3/11

Test 6: Full-Roller Rockers
After the header test, we wanted to see if replacing the roller-tip rocker arms we used last month with a set of full-roller, 1.5:1-ratio aluminum rocker arms would help. We've tried this same type of test many times before with mixed results. If an engine responded favorably to the full-roller rockers, it probably had stiffer valvesprings than DM, and that created more friction and heat. DM's springs aren't that stiff, so it didn't really benefit from the new rockers. Average and max power really didn't change at all (compare tests 5 and 6). However, we did get 5 more lb-ft of torque at 3,200 rpm, so like the headers, we left them in place.

Test 7: Xe256h Cam
Now things really started to get fun. The first cam we used in DM worked exceptionally well. We never would have guessed that a cam so small could make such big power. However, this time we swapped in a slightly bigger cam, installing it 2 degrees advanced to maximize low-end power, and were rewarded with lots of grunt. DM was now making over 400 lb-ft of torque at 3,000 rpm! That's cool. Both max and average power also increased, so the new cam was deemed a success (compare Tests 6 and 7). Low-end grunt improved so much (+17 lb-ft at 2,800 rpm) compared to the first cam in Test 4 that this new cam would really be a tire-fryer in a hot street car. And since the cam was only about 6 degrees longer at 0.050 with around 0.020-inch more lift, it still idled well and would be very docile on the street.

Sucp_0211_06_z Chevy_small_block_performance_parts Dyno_chart 4/11

Test 8: Stud Girdle
This was our very first weird test of the series. Most people would never think of installing a stud girdle on such a mild engine, but we're not most people. In last month's tests we witnessed the 3/8-inch screw-in studs in the heads flexing as we lashed the valves. The flexing was visible to the naked eye, so we hypothesized that it might kill some lift and duration. In an attempt to prove our hypothesis correct, we installed a COMP Cams stud girdle, which ties all the rocker arm studs together adding tremendous rigidity. It didn't help. Power and torque actually fell off at most rpm. We can't explain why, but the results speak for themselves. The stud girdle will come off next month.

Speaking of next month, we feel it's time to try a new set of heads to see what they're worth. We won't tell which heads we'll bolt on first, but let's say that DM won't be going on a diet any time soon.

Sucp_0211_07_z Chevy_small_block_performance_parts Oil_change 5/11

Although it's only a couple of months old, DM gets a fresh oil change because dyno abuse is tough. We poured in 5 quarts of 76 Racing 10W-30 motor oil-that should take care of DM for a while.

2nd Series Of Dyno Tests
For each series of tests, we'll number them consecutively, starting with the last number of the previous month's tests. We'll also list the last test from the previous month so you'll have something to compare the new tests to. This month our first new test is number 5. Unless listed, no other changes were made for any test.

Test 4: Last test from last month. Weiand 8004 intake, COMP Cams 1.5 roller-tip rockers, Carb Shop Q-jet, COMP Cams 246PE cam (246/263 adv duration, 203/212 duration @ .050, .429/.438 valve lift, 110 lobe separation) retarded 2 degrees.


Sucp_0211_12_z Chevy_small_block_performance_parts Stud_girdle 6/11

For a last stab at some extra power we installed a COMP Cams stud girdle for Test 8. It actually hurt power a little so we'll take it off next month and save it for when we have much stiffer springs and run at much high rpm.

Test 5: Install 1 3/4-inch Hooker Super Comp headers and Flowmaster 3 1/2-inch mufflers.

Test 6: Install COMP Cams 1.5:1 full-roller aluminum rocker arms.

Test 7: Install COMP Cams XE256H cam (256/268 adv duration, 212/218 duration @ .050, .447/.454 valve lift, 110 lobe separation.

Test 8: Install COMP Cams stud girdle.


Sucp_0211_11_z Chevy_small_block_performance_parts Balancer 10/11

Did you know that you can basically degree-in your camshaft using a degreed balancer like this one from Fluidampr? Since most dampers are marked off up to 60 degrees BTDC, it's easy to check intake valve opening right on the damper, as long as your timing pointer is dead on.

3200 395 241 396 241 401 244 411 250 408 249
3400 398 257 400 260 403 261 413 267 410 265
3600 401 275 403 276 405 277 413 283 411 281
3800 405 293 407 294 406 294 413 298 413 299
4000 403 307 405 308 407 310 412 314 410 312
4200 398 319 401 321 402 322 406 325 407 325
4400 395 331 395 331 367 332 402 337 402 337
4600 388 340 387 339 388 340 394 345 394 345
4800 380 347 380 347 380 347 385 352 385 352
5000 366 349 368 350 368 350 375 357 373 355
5200 N/A N/A 354 350 353 349 348 354 358 355
5400 N/A N/A N/A N/A 339 349 348 357 345 355
5600 N/A N/A N/A N/A N/A N/A 334 356 331 353
Max 405 349 407 351 407 351 413 357 413 356
Avg 390 278 388 287 389 288 396 293 395 292


Sources

Westech Performance Group
Mira Loma, CA
951-685-4767
WestechPerformance.com
Comp Cams
Memphis, TN 38118
800-999-0853
http://www.compcams.com
Summit Racing
Akron, OH
800-230-3030
SummitRacing.com
Fluidampr
Springville, NY 14141
716-592-1000
www.fluidampr.com
Meziere Cooling Systems
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