Would you use an Andrews 54 cam for this 103 build?

Discussion in 'Engine, Fuel and Exhaust' started by z1dave, Nov 4, 2013.

  1. z1dave

    z1dave New Member

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    I have a 1999 Road King with a 103" engine. I am using the Harley cylinders and flat top pistons. Along with this I am using the Screamin' Eagle Harley Kompressor heads, Andrews TW50 cam, Vance & Hines 2 into 1 Pro Pipe and a Mikuni carb. I was looking at the Andrews 54 cam. Harley says with these heads the compression is 10:5-1. Any thoughts?
     
  2. BUBBIE

    BUBBIE Well-Known Member

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    Looks like the TW50 intake close at 48 degrees and the TW54 close at 42 degrees...

    I would Want the added compression of the earlier cam intake close
    (tw 54)...

    The TW54 cam would work in the combo of the motor but I know nothing about the pipes...

    4 questions:
    What size mikuni ?
    How did the motor get 103? Still 4" stroke and a larger bore?
    Do the heads have compression releases?
    What elevation do you live and run the bike?


    10.5 X 1 compression shows the following ccc at sea level...
    50 cams show 192.5 .......(corrected compression 9.28 X 1) Valve lift is .510
    54 cams show 200.1 .......(corrected compression 9.56 X 1) Valve lift is .555

    Personally I'd like the 54 cam over the 50 cam... Compression Boost Plus more lift

    More low end torque by having earlier intake close. The Added compression is NOT overly changed... Higher valve lift should not be a problem but I'd check where you bought the heads and at least Ask.....

    Just My Way

    signed....BUBBIE
     
  3. z1dave

    z1dave New Member

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    4 questions:

    What size mikuni ? HSR 45

    How did the motor get 103?

    Screamin' Eagle 4 3/8 Stroker. Still 4" stroke and a larger bore?
    Harley 3 7/8 cylinders.

    Do the heads have compression releases? Yes

    What elevation do you live and run the bike? Pennsylvania approx. 1000 ft.
     
  4. dolt

    dolt Senior Member Contributor

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    The Kompressor heads are stock heads that have been decked .060" with heavier valve spring; about 200# on the seat. A set of OEM heads that have been "worked" will flow much better and OEM springs would be more suitable for most of the conventional cam profiles, like the 54. If you checked your compression, you should see more than 10.5; probably closer to 10.8 depending on head gasket thickness and deck height.

    JMHO but you are asking for trouble with the 54; too much compression, even with stock head gasket, for my taste anyway. If you have an adjustable ignition you can probably work around any detonation issues but that will likely reduce performance.

    If it were me, I would probably work with a head porter to work the Kompressor heads to improve the flow and open the chambers up a bit so I could use a .030" head gasket with the 54 cams at a little less compression; say corrected set between 9.3 and 9.6 and CCP in the low 190s. That would require opening up the chambers by about 4cc, dropping valves a bit and opening up the piston valve reliefs.

    Or 86 the Kompressor heads and pick up a set of OEM heads and have them worked for the 54 cams.

    Or try a different cam, like the S&S 585, Fueling 574, Redshif 577 or Andrews 55. As always, JMHO.
     
  5. z1dave

    z1dave New Member

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    Thank You guys! Now I'm really confused but I guess I should look at lowering the compression. I used the Harley multi layered head gaskets and need to see how thick they are. Maybe I can Get thicker ones from Cometic?
     
  6. BUBBIE

    BUBBIE Well-Known Member

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    I think you'd be fine here...

    WHY give away the compression? Compression is the POWER.

    Yes I know that Heat is also a problem with any air cooled motor but you have a good build within reach using like described..

    You asked this basic question on another forum I am on also and MOST BUILDERS said to use this setup.:s

    YOU have to make up YOUR mind not us so much to make up ours....

    You have beed given good information here and YOU can go with it the way you want.

    I bought a special set of THICK gaskets once and ended up not using them. I NEVER brought the compression down that way and would NEVER suggest to do so to another self builder...

    You have the SQUISH to consider. Opening up the distance of the heads Where They Were Not Designed to work is a Chicken-out foolish thing to do.

    Largest I would use would be the .040 or .045 Stock gaskets....

    MY Opinion is still use what you started out with.Take your elevation and use it instead of sea level...

    I'm at 4400 feet and IF I went by MANY here who think I run too much compression I'd Have a Big Heavy WHIMP for a ride.

    Just My Way

    signed....BUBBIE
     
  7. dolt

    dolt Senior Member Contributor

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    Hey z1dave, I didn't say not to use the 54s; just said I think you are exposing yourself to issues that can easily be avoided by selecting another cam that will provide similar performance. I agree with Bubbie's comment that compression = power but one can have too much of any good thing. I am just saying that you might want to consider a more conservative cam set.

    I am not going by what others have said on another forum; just going by the numbers and the numbers I see are different from Bubbies. I am seeing 10.9 static, 9.8 corrected and CCP at 203psi with your heads, .040" head gasket, 54 cams at your elevation. The Kompressor head chamber volume should run about 76cc. Crank the numbers into a compression calculator and see what you come up with.

    Corrected CR of 9.8 with a carbed bike? I think you are looking at detonation and related tuning issues. I am not a professional engine builder; don't build for a living, but the motors I have built for friends and family are typically configured to keep CCP below 190psi and corrected CR between 9.3 and 9.6 to avoid tuning and detonation issues. If your bike was EFI, I would be less concerned but still see the 54s with your current configuration on the cusp with regard to detonation and being a challenge to tune.

    As always, JMHO, your ride, you get to decide. Good luck with whatever you decide.:newsmile025:
     
  8. Jack Klarich

    Jack Klarich Expert Member

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    Keep in mind to check intake fit and alignment when using different thickness of gaskets, although it may be minor plus or minus changes it still needs to be checked JMO