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wanting to discuss a few differences in builds

July 5 2012 at 9:23 AM

Tony Marbury  (Login tmarbury)
from IP address

This is the kind closest build to mine I could find.
The First Build is my build the second is Torino Johns Build that I got out of the build section, not picking on any body just wanting to discuss the differences here, so I can apply to my next build, and I am totally happy with my motor, pulls like a bear, and revs like a CR or KX 250 2stroke dirt bike, only thing that kinda puzzles me is the fact that mine quit producing at 6100 RPM, and I dont think it should have, and his build has a 130 more Horse power than mine. I know I can gain some in a intake change and some maybe in a carb change, but what are the real differences here? What do yall think? I am wanting to build another motor for another project thats why I ask.

Cam Specs, Hydro. Roller
Gross Valve Lift In. 640 Ex 646
Tappet Lift In 286 Ex 289
Valve timing Open Close
@ .050 Int. 9 BTDC 41
Exh 52 BBDC 4
These specs are for cam Installed
@ 106.0 Intake centerline
Intake Exhaust
Duration @ .050 230 236
Lobe Lift .3770 .3800
Lobe Separation 110.0

Horsepower as Dynoed 421hp at 6100 RPM
Max Torque 417 at 3700 RPM
10 to 1 compression
.30 over 2 bolt block
Manley stainless valves
Comp springs/push rods/and retainers
Blue Thunder Intake, 850 Double Pumper Holley
D0AE heads, shaved ports cleaned up, Exhaust opened up a little
Ross pistons and stock rods.

BLOCK: production 4-bolt - .030" over, water jackets filled half way, oil restrictors to cam and left lifter bank, external oil line added
CRANK: SCAT forged light weight 3.500" stroke, SBC rod journal, internal balanced
RODS: Probe light weight 6" SBC (like a billet I-beam)
PISTONS: JE flat top
HEADS: factory 4V CC - I: 2.190", E: 1.710", home ported- I- 315cfm at .550", E- 200cfm at .650", Ferrea valves
CAM: Comp Cams custom solid flat tappet; Dur: 254 / 265 at .050", Lift: .622" / .650", LCA: 108, 3/8 pushrods, Comp Cams Aluminum roller rockers
INTAKE: Edelbrock Torker home ported
CARB: Holly 4150HP 1000cfm with annular boosters (I talked to several engine builders/carburetor specialists, and they all reccomended approx. this carb, it's supposed to flow about 880cfm), 1.500" Wilson spacer
CR: approx. 10.6:1

5000 376 395
5200 435 440
5500 449 429
6000 484 424
6500 524 424
7000 557 418

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