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Thread: Went to a solid roller from a flat tappet..

  1. #1
    Not much more power but more torque.For some reason this motor fell on its face at 6100 rpm when even the flat tappet made power all the way up to 6500? Wtf?
    Im getting the 5% overdrive dyno pull faxed to me, but just for now the apples to apples comparison has the flat tappet beating the roller by 15 peak hp.
    Heres the pulls

  2. #2
    Cam specs..
    LOBE seperation 110
    LIFT in .645 ex .665
    dur in 262,ex 272
    lob sep 112
    lift in .740 ex .725
    dur in 267 ex 278
    installed c-line int 107.9 ex 115.9
    This is a car motor,but please just treat me like a boat dude
    I read this blower forum ALL THE TIME, you guys share great info, so lets fix this BBFORD.
    More details
    New crower springs, install details for springs are available if anyones interested. I ran c12 33 total timing,heads flow 355 in and 235 ex

  3. #3
    Might be floating the valves eek! . What is your open spring pressure (in spec for the cam)? Maybe the lifter is not following the cam 100%.

  4. #4
    I don't know much about fords and have little experience but:
    #1. You have increased exhaust lift by a whopping .095
    #2. The 112 cam is degreed at near 108?
    #3. Don't know your heads, but ford heads have never been that good at flowing. Maybe your heads don't flow that well for all that lift. Fords own 514 roller cam is quite a bit smaller and they wanted it installed retarded 4 degrees. Since it's on a dyno, maybe some valve lash playing could give you direction. Blower cavitaion enters my mind also with that little blower. Just some thoughts.

  5. #5
    "Blower cavitaion enters my mind also with that little blower. Just some thoughts"
    Can you explain more about cavitation? You think the 871 is too small?

  6. #6
    Please disregard that. My mistake. I just glanced at the picture and thought it was one of those small Wiend type blowers. I guess the long snout tricked my eyes. Sorry about that.

  7. #7
    In both dyno pulls it looks like the torque numbers fall off more quickly after 6100 rpm's than the horsepower numbers rise. I would say that you are running out of enough boost (compression to sustain high rpm's) or fuel capacity after 6100rpm's. Heads may not be able to deliver adequate flow (volume and or velocity) to fill cylinders after 6100 rpms. kojac...

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