People running BIG cams........inside
#1
People running BIG cams........inside
Please post specs on your BIG cam (240+ duration) you are running. Also post any issues you may have had with idle.....specifically surging.
I would also like to know what your manifold pressure is at at idle (RPM)
Thanks for the input. Trying to diagnose a problem.
tom Ulrich
I would also like to know what your manifold pressure is at at idle (RPM)
Thanks for the input. Trying to diagnose a problem.
tom Ulrich
#2
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Comp Cams 292H-10
Intake/Exhaust: 292 degrees @ 0.006"
Intake/Exhaust: 244 degrees @ 0.050"
(all specs @ 0.050")
IVO: 16 BTDC
IVC: 48 ABDC
EVO: 56 BBDC
EVC: 8 ATDC
Overlap: 24 degrees
Intake Centerline: 106 degrees
LSA: 110 degrees
Manifold pressure @ 800 RPM (200 ft. elevation): 6 in./hg.
Cons:
No assist for brakes. Very choppy idle. Low RPM power is weak (*until about 2000 RPM).
Keep in mind this is not an LS1 engine, but certain characteristics will apply.
Hopefully it will spark an idea to help you out.
Intake/Exhaust: 292 degrees @ 0.006"
Intake/Exhaust: 244 degrees @ 0.050"
(all specs @ 0.050")
IVO: 16 BTDC
IVC: 48 ABDC
EVO: 56 BBDC
EVC: 8 ATDC
Overlap: 24 degrees
Intake Centerline: 106 degrees
LSA: 110 degrees
Manifold pressure @ 800 RPM (200 ft. elevation): 6 in./hg.
Cons:
No assist for brakes. Very choppy idle. Low RPM power is weak (*until about 2000 RPM).
Keep in mind this is not an LS1 engine, but certain characteristics will apply.
Hopefully it will spark an idea to help you out.
#3
Thanks adrenaline........everyone please post same specs........
My cam is a 250/256 113 lobe seperation.
My vacuum is 8in./hg
I am being told that this may be the cause of my surge.....I have a 427ci motor.....
Tried everything...and 2 tuners tried as well.......still real bad surge
My cam is a 250/256 113 lobe seperation.
My vacuum is 8in./hg
I am being told that this may be the cause of my surge.....I have a 427ci motor.....
Tried everything...and 2 tuners tried as well.......still real bad surge
#6
TECH Veteran
iTrader: (1)
Any time you have a cam with 240+ degrees duration you're going to get some surging and bucking, and I don't think there is any way you can tune it out. Smaller LSA's make it worse also. Mine runs rough and surges/bucks at any rpm less than 2000. At first I hated it and tried to tune it out, but I'm pretty much used to it now.
Last edited by Cal; 04-19-2005 at 11:21 AM.