Cam Choice Help

Discussion in 'Touring Models' started by Wilamantic, Apr 12, 2015.

  1. Wilamantic

    Wilamantic Member

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    I have a question about cam choice for my '07 FLHRS. I will really appreciate any reactions to my question/dilema.

    I have a 2007 FLHRS that I purchased new in February 2007. Before taking delivery in May 2007, I had quite a bit of performance and non-performance (e.g. replaced stock handle bars with Carlini sweep bars; custom gauges, etc.) work done to the bike. On the performance side, I added a Screamin' Eagle Big Bore Stage II kit for EFI Models (this increased displacement from 96 CI to 103 CI, included SE-255 cams, big bore cylinders, big bore flat top pistons, etc.). I also added Rinehart True Dual performance exhaust and a ThunderMax Autotuner. The bike runs well; on the dyno I get 85 HP and 102 TQ.

    I am planning on putting new heads on my motor; specifically HR Part No. 16500013A - Screamin Eagle Pro CNC Factory Heads with Valve Upgrade.

    My goal is to get better low to mid range torque than I am getting. My dyno curve suggests I am not getting enough air and I expect the new heads will address that.

    Depending on who I talk to, I am being told that when I switch to the Screamin' Eagle heads I should also change cams - from my SE 255 cams to SE 585 cams, Red Shift 575 cams, S&S 570 cams, or maybe T-Man 555 cams.

    I understand that, as a general proposition an early intake closing (less than 30 degrees after bottom dead center) will result in good low end torque, and a medium intake closing (30 - 50 degrees ABDC) will result in good midrange torque. The thing is, the SE 255s have an intake closing of 25 degrees ABDC, which is an earlier intake closing than any of the other cams that are being suggested. I know there are things than intake closing to consider, but until I have a better understanding of those other factors, I find myself questioning whether I should stick with the SE 255s or switch to one of the other cams that are being suggested. As mentioned above, my goal is strong low end to mid range torque. Horsepower increase, if achieved as a by product is fine of course, but I am after the improved low to mid range torque.

    Any and all reactions/comments/suggestions will be GREATLY appreciated!
     
  2. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    Head work should open that thing up and do wonders for it. I would buy a pair of take offs and send them to one of the below linked shops and have them work them for you. Having said that call each one of these guy's and discuss your goal(s) with them and decide whom to use after your discussion with each. Scott Palmer, Don Dorfman, and Kirby Apathy are all pro's who do this everyday for a living and have been doing it for years. They know what they are doing. I personally used Scott at Hillside. I found him easy to talk to, answered every question, and more than willing to help.
    Not sure where you are located but one these guy's may be close by and can do the wrenching for you, since you didn't mention if you were or not.

    Hillside Cycle

    HD Street Performance Head Porting and engine packages for Harley Davidson motorcycles

    VEE-TWIN Performance Center - High Performance Machining and Services for Harley Davidsons
     
  3. dolt

    dolt Senior Member Contributor

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    Good advice from Bodeen.

    I would have to see the dyno chart to comment on the curve but the numbers are typical for your configuration although a bit light on TQ. The SE255 cam is a torque monster in a 103 motor and you should have plenty of low end TQ. I would expect about 85HP/110TQ in a 103; 100TQ by 2000rpms, peaking at about 110-112 between 3000-3500, tapering off to 100TQ by 4000 and all done by 4500.

    A set of ported heads will definitely help add some TQ but the bigger increase will be in HP. Additionally, a set of ported heads will save some $$. No need to buy a set of take off heads as the shops that Bodeen listed will work with customers on an exchange basis. You will pay a core charge that will be refunded when the shop receives your heads in good condition. You can return your cores in the same shipping container your new heads came in. So no down time.

    The CNC heads you listed also come with heavy valve springs, IMHO, too heavy and add the potential for more valve train noise. JMHO.:)

    A cam change will help; all of the cams you listed are good choices but you should listen to the head porter and let him assist you with cam choice based on your goals. You are correct about the impact of intake valve closing with regard to producing TQ but the intake valve closing, in and of itself, is the event the creates dynamic/corrected compression; the TQ comes from the compression. Go to the BigBoys website and play around with their compression calculator. A reasonable target for corrected compression and cold cranking compression for a street build is 9.3-9.4 and 185-190psi respectively.:coffee

    As I said, I would have to see the dyno chart to comment on the curve but not many cams are going to do better on the low end.:coffee

    Don't forget to upgrade the inner cam bearings while you are in the cam chest. I would also 86 the OEM cam plate; have never cottoned to the concept of running performance cams in the parent plate material.:coffee
     
    Last edited by a moderator: Apr 12, 2015
  4. chief08

    chief08 Member

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    I would leave se-255 in good cam for low end tq.
     
  5. Wilamantic

    Wilamantic Member

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    Bodeen, Dolt and Chief08: Thanks for your comments. I had a good conversation today with Bruce at Big Boyz (Big Boyz Head Porting - Powered by vBulletin) in Augusta, Maine (I live in Portland) and I will be sending my heads to him for porting. Will figure out the cams along the way . . . the SE 255s may remain the ticket for me as they do have terrific low end torque . . . will think about and investigate T-Man 555 Torqsters and the Andrews 57s to see if I can extend the torque hill into the mid range a bit more.
     
  6. Mongo1958

    Mongo1958 Junior Member

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    So, what Cam Plate would you recommend? S.E.?
     
  7. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    S.E. is a good choice if you want outer bearings for the cams.
     
  8. Fisherking

    Fisherking Active Member

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    I'm going with the andrews 37 cam in my build . The 37 has the same profile as the 57 but only a .510 lift were I think the 57 has .575 lift .
    I went with these because it will be better with mid range .
     
  9. dolt

    dolt Senior Member Contributor

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    Here's my recommendation, for what it's worth.

    Talk to Bean/Bruce at BigBoyz. If you are going for the "street" port, be advised that Bean retains OEM valves and springs. Bean used to install a larger valves at customer request; 1.9 int/1.6 exh.; OEM springs are OK. IMHO, if you go that route, replacing the SE255 cams with "longer" cams is a waste of money and you will see a nice improvement on HP but not so much on TQ.

    If you want to see real increases in TQ and HP, you need more cam; the SE255is a great TQ cam but still a cam designed to meet EPA regs and it will not take full advantage of any head porting. More cam will require an increase in the "lung" capacity of the motor, i.e., the heads which means larger valves.

    All of the cams you have referenced in previous posts are good choices but the heads need to be set up for the cam you choose. IAW, if you set the heads up for a cam like the SE255 with an intake close of 25*, those heads won't work well with a cam like the S&S 585 with an intake close of 45*. Comprende?

    Your call of course, but I think you would be very happy with any of the cams you have referenced but that means you need to select a cam and tell Bean you want larger valves, you will be using a .030" head gasket and your chamber volume needs to be set for that specific cam and you are targeting 10.2 static CR. All of the cams you have referenced will work at 10.2 static; but I would eliminate the S&S 585 as it would like 10.4.

    IMHO, the cost/benefit of the money you are about to spend is diminished considerably if you retain the SE255 cams and don't have larger valves installed as part of the head work. Compression releases would also be a good idea.:coffee
     
  10. dolt

    dolt Senior Member Contributor

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    The billet plate and pump, PN 25282-11. About $360, plus shipping if ordered from an online discount dealer.
     

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