Stroker power issue
Posted: May 30th, 2021, 6:37 am
Hello guys,
I've got a 2004 4.0 TJ and I've built a Stroker with the following specs:
2004 Jeep Wrangler 4.0 Stage 3 Jeep Stroker Kit 4.6L 9.3:1C.R.
DSS 4032 Forged Dish Pistons -21cc #IC944 (Standard Piston
Set)
Hastings Moly Rings #2M4815 (standard)
Scat Enterprises 9000 Series Cast Steel Crankshaft 3.895" Stroke
#9-4.2L-3895
Clevite Rod and Main Bearings
Scat Forged Rods W/ARP Bolts (Bushed) -
Howards camshaft
Intake 273° valve lift 0.48 exhaust 279° valve lift 0.48
Lobe sep. 114° intake CL 110°
Degree of duration @ 0.05
Intake 219°gross lift at cam 0.3
Exhaust 225°gross lift at cam 0.3
Lifters - 12
Timing Set - Timing Chain, Cam Gear, Crank Gear
Pushrods - 12
Dual Spring Valve Springs - 12
Valve Retainers - Steel
Valve Keepers - 12 Valve Set
Complete Gasket Set (Felpro) Upper and Lower gaskets
Durabond Camshaft Bearings with oil control groove
Freeze Plug kit for engine Block
Melling Oil Pump
Jeep LS Oversize Valve Kit
FlowKooler Hi-Flow Mechanical Water Pump
Cylinder head Bolt Set
1996-2006 Jeep 4.0L Girdle Spacer Kit
Jeep 4.0L High Performance Fuel Injectors - 24lbs | 252cc
Borla headers
Borla cat back system
Cat replaced by a 3" pipe
Edge 62mm throttle body
Ported head
K&N Cold air intake with a new filter
Before I've pulled the engine at 80000 miles the following mods where already done and I've been driving it for 50000 miles:
Borla headers
Borla cat back system
Cat replaced by a 3" pipe
Edge 62mm throttle body
K&N Cold air intake
Now I've stroked it with all the above mentioned parts, broke the cam in with SAE 10W40 and ZDDP additive at 2800rpm but unfortunately it has a little bit more power but almost not noticeable.
I've checked the following:
Ignition timing => Adjusted with the toothpick method (outer ring from the balancer has not moved).
Compression => Measured Compression between 177 and 182 PSI on all cylinders
MAP Sensor => OK
Throttle position sensor => OK
Intake air temperature sensor => Ok
Valve Lifters => I've checked them again and they are in the middle of their operating range also no noise
The engine runs smooth and fine it just doesn't have the power I've expected (around 275 crank HP)!
I do not know what to do anymore…
Any advice would be highly appreciated.
Thanks
Frank
I've got a 2004 4.0 TJ and I've built a Stroker with the following specs:
2004 Jeep Wrangler 4.0 Stage 3 Jeep Stroker Kit 4.6L 9.3:1C.R.
DSS 4032 Forged Dish Pistons -21cc #IC944 (Standard Piston
Set)
Hastings Moly Rings #2M4815 (standard)
Scat Enterprises 9000 Series Cast Steel Crankshaft 3.895" Stroke
#9-4.2L-3895
Clevite Rod and Main Bearings
Scat Forged Rods W/ARP Bolts (Bushed) -
Howards camshaft
Intake 273° valve lift 0.48 exhaust 279° valve lift 0.48
Lobe sep. 114° intake CL 110°
Degree of duration @ 0.05
Intake 219°gross lift at cam 0.3
Exhaust 225°gross lift at cam 0.3
Lifters - 12
Timing Set - Timing Chain, Cam Gear, Crank Gear
Pushrods - 12
Dual Spring Valve Springs - 12
Valve Retainers - Steel
Valve Keepers - 12 Valve Set
Complete Gasket Set (Felpro) Upper and Lower gaskets
Durabond Camshaft Bearings with oil control groove
Freeze Plug kit for engine Block
Melling Oil Pump
Jeep LS Oversize Valve Kit
FlowKooler Hi-Flow Mechanical Water Pump
Cylinder head Bolt Set
1996-2006 Jeep 4.0L Girdle Spacer Kit
Jeep 4.0L High Performance Fuel Injectors - 24lbs | 252cc
Borla headers
Borla cat back system
Cat replaced by a 3" pipe
Edge 62mm throttle body
Ported head
K&N Cold air intake with a new filter
Before I've pulled the engine at 80000 miles the following mods where already done and I've been driving it for 50000 miles:
Borla headers
Borla cat back system
Cat replaced by a 3" pipe
Edge 62mm throttle body
K&N Cold air intake
Now I've stroked it with all the above mentioned parts, broke the cam in with SAE 10W40 and ZDDP additive at 2800rpm but unfortunately it has a little bit more power but almost not noticeable.
I've checked the following:
Ignition timing => Adjusted with the toothpick method (outer ring from the balancer has not moved).
Compression => Measured Compression between 177 and 182 PSI on all cylinders
MAP Sensor => OK
Throttle position sensor => OK
Intake air temperature sensor => Ok
Valve Lifters => I've checked them again and they are in the middle of their operating range also no noise
The engine runs smooth and fine it just doesn't have the power I've expected (around 275 crank HP)!
I do not know what to do anymore…
Any advice would be highly appreciated.
Thanks
Frank