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7 Posts
Looking for some input from the engine builders on here.
I rebuit a 360 Magnum motor in a Durango RT Clone, it’s a SLP+.
Botton end is stock.
I used the following components
New EQ 318 Heads:
2.02 stainless intake
1.625 stainless exhaust
.042 mopar head gasket
New stock head bolts
New stock lifters
M1 2bb intake
Fast Man 52 mm throttle body
8mm wires
Pioneer Spring 810102 installed at 1.66 height.
KN air filter
Comp Cams XR264HR with 212/218 and .480/.480 installed straight up / which is ground with 4 degrees advance.
Comp Cams 1.6 Roller Rockers with Comp guide plates.
Edelbrock hardened 6.93
1.5 inch shorty header thru. Custom 2 inch into 3 inch flow master in and out. High flow new cats
SCT tuner /tuned by Hemifever
Edge 2600 stall billet cover
MSaine valve body.
Computer Engine Dyno shows this combo making 351bhp at 5000rpm and 402 ft lbs at 4000 at the crank when I use ultra conservative inputs. Thats 100 hp over stock and what i was shooting for with heads, cam, intake and headers.
Here is my dilemma: I am missing 60 BHP and TQ at the wheels. Even if computer dyno is over estimating I should make 275 rwhp 320 rwtq with this combo.
The comp roller kit came with 6.8 pushrods, which looked good in the valve train set up as far as geometry goes. But I'm not a valve train expert.
The motor ran well but pulled a disappointing 222 rwhp and 273 rwtq. Valve train was loud.
When resetting the lash to 3/4 turn past zero lash I noticed several were below zero lash? I re-measured and the stock pushrods looked better on the roller tip. (Again I'm no expert). 6.8 seemed small. I ordered stock size but hardened for the guide plate compatibility. So 6.93 are in there.
This woke the motor up some and eliminated some of the sewing machine ticking noise. Still there at idle, could be there at higher rpm just can't hear it if it is.
My second pull was 243rwhp and 293 rwtq.
Here is my issue my peaks are way to low. At 5000 this thing is done. Dyno guy shuts it down, graph drops and line goes erratic. I can post graph is anyone can read these things. Peak HP is around 4500 rpm. Torque is highest at 3000 when the converter catches, and nose dives at 4000 rpm.
Cylinder pressure was good before the build but I will check again.
There are no misses or stumbles anywhere. Plugs good but I will check and re gap anyway. Fuel pressure is good and the motor gets fat when it dies off a little so there is fuel there. No valve damage from short push rods. Bind is at 5.44, not close to that.
valve float? But I have 125 and 310 for pressures. Comp says it is good for the cam. They recommend at least 115 / 300. Pull a spring and have tested? Did I get wrong items shipped?
Pushrods still undersized? The XR is a small base circle cam did I measure wrong twice? Use 7.05 or more and check for clearance rotating by hand, set lash and do a pull.
The motor works really well. Pulls nice and smooth and will toast the 275/60 17.
I just cant figure out why its running out of steam early?
Any thoughts would be greatly appreciated. Thanks all.
I rebuit a 360 Magnum motor in a Durango RT Clone, it’s a SLP+.
Botton end is stock.
I used the following components
New EQ 318 Heads:
2.02 stainless intake
1.625 stainless exhaust
.042 mopar head gasket
New stock head bolts
New stock lifters
M1 2bb intake
Fast Man 52 mm throttle body
8mm wires
Pioneer Spring 810102 installed at 1.66 height.
KN air filter
Comp Cams XR264HR with 212/218 and .480/.480 installed straight up / which is ground with 4 degrees advance.
Comp Cams 1.6 Roller Rockers with Comp guide plates.
Edelbrock hardened 6.93
1.5 inch shorty header thru. Custom 2 inch into 3 inch flow master in and out. High flow new cats
SCT tuner /tuned by Hemifever
Edge 2600 stall billet cover
MSaine valve body.
Computer Engine Dyno shows this combo making 351bhp at 5000rpm and 402 ft lbs at 4000 at the crank when I use ultra conservative inputs. Thats 100 hp over stock and what i was shooting for with heads, cam, intake and headers.
Here is my dilemma: I am missing 60 BHP and TQ at the wheels. Even if computer dyno is over estimating I should make 275 rwhp 320 rwtq with this combo.
The comp roller kit came with 6.8 pushrods, which looked good in the valve train set up as far as geometry goes. But I'm not a valve train expert.
The motor ran well but pulled a disappointing 222 rwhp and 273 rwtq. Valve train was loud.
When resetting the lash to 3/4 turn past zero lash I noticed several were below zero lash? I re-measured and the stock pushrods looked better on the roller tip. (Again I'm no expert). 6.8 seemed small. I ordered stock size but hardened for the guide plate compatibility. So 6.93 are in there.
This woke the motor up some and eliminated some of the sewing machine ticking noise. Still there at idle, could be there at higher rpm just can't hear it if it is.
My second pull was 243rwhp and 293 rwtq.
Here is my issue my peaks are way to low. At 5000 this thing is done. Dyno guy shuts it down, graph drops and line goes erratic. I can post graph is anyone can read these things. Peak HP is around 4500 rpm. Torque is highest at 3000 when the converter catches, and nose dives at 4000 rpm.
Cylinder pressure was good before the build but I will check again.
There are no misses or stumbles anywhere. Plugs good but I will check and re gap anyway. Fuel pressure is good and the motor gets fat when it dies off a little so there is fuel there. No valve damage from short push rods. Bind is at 5.44, not close to that.
valve float? But I have 125 and 310 for pressures. Comp says it is good for the cam. They recommend at least 115 / 300. Pull a spring and have tested? Did I get wrong items shipped?
Pushrods still undersized? The XR is a small base circle cam did I measure wrong twice? Use 7.05 or more and check for clearance rotating by hand, set lash and do a pull.
The motor works really well. Pulls nice and smooth and will toast the 275/60 17.
I just cant figure out why its running out of steam early?
Any thoughts would be greatly appreciated. Thanks all.