Hi guys,
Please give me some fresh ideas what might be the trouble maker.
After a long winter period was taking today the 69 Charger R/T out of the garage for the maiden pass at 1/4mile with the new setup of 440 and could not get the motor to rev past 5500 rpm.
Today's best time at our local airfield 1/4 mile strip was 12.467s @ 112mph, with best 60ft time 1.944.
The track was very slippery, but traction was getting better after each run.
By the butt dyno the engine has capabilities for better times, but the engine won't rev past 5500rpm...
The new engine combo is as follows
ENGINE:
440 .055 over, SRP flat top pistons with valve reliefs
Compression Ratio: 10.5:1
Cylinder Heads from 440Source, fresh professional valve job and a mild bowl blend
Roller rockers with 1.6 ratio
Cam, Lunati hydraulic roller 60312
Intake Duration @.050: 231
Exhaust Duration @.050: 239
Intake Duration: 282
Exhaust Duration: 290
Lobe angle: 110 deg
Cam centerline: 106 deg, straight up
Intake Valve Lift: 0.571 with 1.6 rockers
Exhaust Valve Lift: 0.587 with 1.6 rockers
Valve springs: Lunati 73124: 150lbs seat pressure, 350 lbs open, as recommended by Tim @ Lunati.
All valve springs shimmed for exact seat pressures
Roller Lifters: Lunati by Morel, preload 3/4 turns, .0375"
Intake Manifold: Holley SD
Carb: 850 cfm Demon, mech. secondaries. Secondaries opening full.
Air filter K&N 14" with XStream Air Flow Top
A/F ratio on the track, constant 12.2...12.5, by an AF meter
Exhaust: Hedman Headers 1 3/4" primaries, 3" collectors. 2½" full length exhaust with X pipe,
BUT tried today also with open exhaust, NO help with open exhaust still would not rev past 5500 rpm
IGNITION
Distibutor: Mopar Performance, .008 reluctor cap.
Even two different dist. used today
#1 With recurved mechanical advance, 18 deg.initial and 34 total, vacuum advance NOT connected
#2 With stock mechanical advance, 15deg initial and 39 total, vacuum advance NOT connected. Pulled better with this dist. and no pinging.
Dist bushings are tight on both dists.
ECU, tried today with two different ECU's,
#1 Vintage Mopar Orange box from the 80's with MSD Blaster 2 coil and matching ballast
#2 FBO ECU with FBO coil and ballast
No rev limiter
Spark plugs: Denso with .042 gap
Dist, coil and ECU wiring double checked.
Fuel pump: Old work horse, mechanical high volume Carter M6903, 120 GPH flow rate. Has brand new push rod with brass tip for the steel cam.
Fuel line: stock of a 69 Charger R/T 440
Weight of the Car: 4100
Transmission: Automatic with B&M converter, 3000 stall
Gear Ratio: 3.73
Tires ET Street radials, 28 x 11.50R15
Car runs great down low and pulls hard, just seems to run out of steam at about 5000 rpm and is hitting a wall at 5500 with little banging or sputtering.
Do you have any new ideas on what might be the reason???
