New cams but already been tuned

Discussion in 'Engine, Fuel and Exhaust' started by david26, Nov 2, 2010.

  1. david26

    david26 Active Member

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    Got a great deal on some SE 255 cams. $350 for the cams and bearings gaskets and the tech selling them to me is goin to help me install them at his place along with checkin the crank runout before they go in. Doin all this on thursday in time for the Lone star rally this weekend. My question is I just got my power comander III dyno around a month ago and its runnin great and cant afford another $250 to do it agian right now. The guy helpin me with the cams is the one that tunned it and said they arnt that agressive and we should just be able to throw a little more fuel at it and it should be fine but i was thinkin the cams would throw off the timing. Will it be easy enough to get it runnin well just by makin some adjustments without the dyno?


    Thank
    Dave
     
  2. Jack Klarich

    Jack Klarich Expert Member

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    Seat of the pants a couple of hard runs should be close IMO
     
  3. BUBBIE

    BUBBIE Well-Known Member

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    I had exhaust and intake(stage one) on my 09 FLHR then Installed TFI unit... When I installed the SE255 cams, I needed to turn the first pot (Green) DOWN just a little for the Runabiltiy to be good..(less fuel)

    It was running a little rich and turning down JUST a little was the way I went..

    I doubt IF it will need More fuel, as the cams and the intake will suck MORE air and fuel mix Into the cyl-head area. It will probably run good enough to NOT need any-or much adjustment and could be tuned OFF the dyno by a knowledgeable person on your unit..

    Dyno's are nice way but a good mechanic can do it with out the dyno especially IF only a little tweeking is needed......

    TFI is so simple to adjust, BUT I know nothing on how your fueler works..

    NOT suggesting a TFI for you BUT others who read this might consider it for the ease of working and changing the fuel mix.

    signed....BUBBIE

    NO Fancy-Pants needed here to adjust mine!!!!
     
  4. worse case i'd say you may need to take a little fuel away on decel to keep from having decel pop. but the cams being mild i;d put a new set of plugs in and compare them to the old set after about 10 miles. i'll bet you don't need any adjustment. its not what you'd call the "correct" procedure to tune a bike to standards today but thats how i did it when i didn't have a dyno. i still do it at the track now.
     
  5. Hoople

    Hoople Account Removed

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    Timing? What timing are you referring to?

    Since it is fuel injected and the Air/Fuel ratio is created after the throttle body,, making it breath better just adds air and not any more fuel to the mixture. So my guess is you will need more injector pulse width.:34:
     
  6. gamspaugh

    gamspaugh Member

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    I am getting ready to install the same cams into my 96 I also have done a stage one with slipons and k&n I used a fule pak and the bike runs great I then got on the fuelpak web site and added the cams and they sent me entire diffrent set up for the pak so I think it will need cahnge a few things like a Doebeck tfi or product like that to make her run like the wind
     
  7. david26

    david26 Active Member

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    I put rv cam in my 95 chevy and had to retard my timing a bit so the bottum end could catch up with the top end sort of speak same EFI setup as the bike real with a throttle body.figured they would effect timing on this to. I yet to do any engine work on a harly or any bike my 91 softtail ran great till the day i sold it had the throtle cable break once and that was the one and only issue it ever had and this bike has alway been under warranty. These cams where gonna be the first major project i did myself but he said if i wanted them he help put them in so heck if i did it myself by the time i bought the cams the locking tool and cam bearing removal tool I would already be losing $$$.
     
  8. Hoople

    Hoople Account Removed

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    Awesome 1st project to jump into. I wish I was there to watch.:)

    I really don't think you are going to see too many people degree-ing in there cams when it comes to these bikes. A pair of chains just don't lend to that type of precise work. Maybe those few trying to break records running gear drives but the vast majority will just plug and play cam sets.

    But I see & understand what you mean now about the timing..
    The price sure sounds right! I also have been thinking about a set of mild cams...
    Let us know how she turns out.

    I have never did cams on a bike, but it makes sense to me that you would have to juice up the A/F ratio a bit when under WOT.
     
  9. david26

    david26 Active Member

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    The only other thing that worries me abit is the crank run out could have non and could have a lot .012 or more and then slam it back together and make them fix it under waranty but what to do if its .004-.010 do i put the cams in cause Harley anit goin to do anything about it or do i decide to pull the motor and tear it down to true the crank? One of those thing i just might not want to know about.
     
  10. Hoople

    Hoople Account Removed

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    That is a really hard call to make. Of course the "purist" will say it should be less than .003 and that is true... it really should be. But I think most "real world" engines that come off the HD line have .004 to .006. If I measured .007 or less I would put the cams in and enjoy it. If it had .010, I would still put the cams in, but make plans for a winter tear down for a "true & tig" job.

    I bet you will see something in the area of .004 to .007. With a number like that, I would not let myself get too crazy over it.

    (this is not a gear drive cam set correct?)