Small-Block Chevy Build - Dyno Test Results

We tried the next-larger COMP Cams Xtreme Energy camshaft and got the power we expected. Torque fell off slightly at the bottom end, but top-end power picked up. That's typical when you start installing larger camshafts.
We tried the next-larger COMP Cams Xtreme Energy camshaft and got the power we expected. T
Not only does the COMP Cams beltdrive DM uses make cam swaps easier, it's also great for setting endplay. By turning the adjustable retaining plate (black ring with all the holes in it), clearance can be changed in minute amounts without any shims or sealant.
Not only does the COMP Cams beltdrive DM uses make cam swaps easier, it's also great for s
The same Speed Demon 750 carb has been kept in service since the first time we installed it. This time around we tried a few jet changes to see if it would net some power, but the original fuel curve we established some time ago still proved best.
The same Speed Demon 750 carb has been kept in service since the first time we installed i

Last Month's Power Recap
DM's fifth bash on the dyno last month ended with a maximum 416 hp and 440 lb-ft of torque. Those are fantastic numbers coming from a 9.25:1 small-block running a very small hydraulic camshaft (the XE262H). The Vortec heads have made 30 more peak horsepower than the other set of "factory" heads we tested-the camel humps (see Test 12, December '02). Also, last month's average power ended up at 333 hp and 417 lb-ft (see Test 15).

This month we tried a new Wilson carb spacer and gained some extra power at 3,000 rpm (Test 16). We wrestled rocker arm ratios around like they were going out of style and saw some torque improvement with no horsepower losses (Test 17). And we finally swapped in a bigger cam with the results we were expecting (Test 18), more horsepower upstairs and less torque downstairs. As usual, if you feel you've got an idea for us to try, send it in and we'll tackle it in the upcoming months.

6th Series Of Dyno Tests
We'll number every series of tests 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 which to compare the new tests. So this month, our first new test is number 16. Unless listed, no other changes were made for any test.

Test 15: Last test from last month. Vortec iron heads: Scoggin-Dickey PN SD8060A (64cc chambers, 170cc intake runners, 1.94/1.50 valves), Edelbrock RPM Air-Gap Vortec manifold, Speed Demon 750 carb, 1 1/4-inch open Wilson spacer, COMP XE262H cam (262/270 adv, 218/224 at .050, .462/.469 lift, 110 lobe separation) straight up. COMP 1.6:1 Magnum roller-tip rockers.

Test 16: Install Wilson four-into-one tapered carb spacer.

Test 17: 1.5:1-ratio exhaust rockers, 1.6:1-ratio intake rockers (best results of all rocker ratios tested).

Test 18: Install COMP Cams XE268H camshaft (268/280 adv, 224/230 at .050, .477/.480 lift, 110 LS) straight up. Changed all rocker arms back to 1.6:1 ratio.

Click here for the Danger Mouse dyno chart

Send your test suggestions to:
Super Chevy Magazine
Attn: Danger Mouse
720 Hundley Way
Placentia, CA 92870

Or Email:
mike.petralia@primedia.com

SOURCES
Scoggin-Dickey (SDPC) 5901 Spur 327 Lubbock TX 79424	76 RACING FUELS & LUBRICANTS (800) 345-0076 www.76.com
Demon Carburetion Dahlonega Ge 7-06/-864-8544 barrygrant.com	COMP Cams
Edelbrock Dept. 5.0 2700 California St. Torrance CA 90503 310-781-2222 www.edelbrock.com	Mechanix Wear 24950 Anza Dr. Valencia CA 91355 6-61/-257-0474 www.mechanix.com
Wilson Manifolds 4700 NE 11th Ave. Ft. Lauderdale FL 33334 954-771-6216 www.wilsonmanifolds.com	Westech Performance Group 11098 Venture Dr., Unit C Mira Loma CA 91752 9-09/-685-4767 www.westechperformance.com