Welcome to Our Community

Wanting to join the rest of our members? Feel free to sign up today.

Sign Up

Cone air filters

Discussion in 'Motor' started by nobbyjohn, Dec 25, 2017.

  1. francoblay1

    francoblay1 The Spaniard

    Joined:
    Aug 14, 2011
    Messages:
    14,736
    Likes Received:
    11,911
    Trophy Points:
    113
    Location:
    L´Escala, 17130 Spain
    My Bike(s):
    K9 (2006)
    First Name:
    Franco
    What size Mikuni would be ideal for the 117 ci ???
     
  2. liferider

    liferider Guru

    Joined:
    Jan 4, 2011
    Messages:
    8,513
    Likes Received:
    8,003
    Trophy Points:
    113
    Location:
    Louisiana
    My Bike(s):
    2003 BDM Chopper, 1996 HD Ultra Classic Custom
    First Name:
    Jonathan
    The Mikuni 48
    [​IMG] [​IMG]

    [​IMG] [​IMG]

    Mikuni: HSR42/45/48 High Performance Carburetors for Harley-Davidson motors

    Go To: Data Sheet & Exploded View(downloads PDF file, .9mb)

    Details & Application Notes:

    Mikuni's new HSR48 is a special version of the proven HSR42 carburetor. Its purpose is to provide maximum airflow for the most demanding high performance engines.

    The amount of power any engine can deliver is directly related to the volume of air it can use in a given time together with its efficiency in using that air. Everything else being equal, more air equals more power.

    Leaving port and combustion chamber design aside, airflow through an engine can be enhanced or limited by anything it must pass through. A restrictive air cleaner assembly, a too small carburetor, restrictive intake manifold and a restrictive or poorly designed exhaust system can (each or all) limit power output. The HSR48 was developed to deliver additional airflow to highly developed engines.

    Modified Harley or Harley-based engines tend to fall into one of three categories:

    1) Modified stock --- This engine typically has stock cylinder heads, a high flow air cleaner, high flow mufflers, perhaps a bolt-in cam and (Hopefully!) a Mikuni HSR42 carburetor.
    2) Highly modified --- A hotter cam, professional cylinder head port work, a more specialized exhaust system, high compression pistons and (Please!) a Mikuni HSR45 carburetor.
    3) All-out ground pounder --- Highly modified heads, a displacement increase, either by way of fitting larger pistons, a stroker kit or both. This engine is more likely to be a special engine, built from the ground up to be stronger and to process more air than even a highly modified Harley motor. This is the sort of motor that should have the HSR48.



    There is little to be gained from installing the HSR48 on an engine with stock cylinder heads or one that is going to be fitted with an exhaust system more suited to looking good than passing gas. The number of bolt-on performance options becomes very narrow when one attempts to get their engine above 100 (or so) Horsepower. We advise that you carefully consider the suitability of other performance components when you consider installing the new HSR48.

    Our HSR48 is slightly larger than either the HSR42 or the HSR45. It is taller and the spigot (engine side) is larger in diameter. This may result, with some installations, in interference problems with chassis parts. We do not make special manifolds for engines with non-standard cylinder head spacing or larger diameter intake ports. However, our HSR48 kit includes our rubber flange adapter that fits the S&S "G" series manifolds.

    The large variation in "Ground Pounder" engine configurations together with the relatively small number of such engines limits Mikuni's ability to produce special manifolds. You may need to cut some metal.
    Airflow:

    The stock Harley CV40 carburetor flows about 185 CFM (cubic feet per minute) when flow is measured at a pressure difference of 12 inches of water. All the Mikuni HSR series flow considerably more:

    Stock Harley: 185 CFM
    Mikuni HSR42: 213 CFM
    Mikuni HSR45: 237 CFM
    Mikuni HSR48: 270 CFM

    If carburetor airflow were the only factor, the HSR48 could deliver almost 50% more power than the stock carburetor. It isn't, of course, but a 50% gain could not be realized without a high flow carburetor.

    In fact, one of our test "48's" was fitted to "Fireman" John Kownacki's 113" Evo-based motor with which he then recorded 156 Horsepower on a Dynojet 150 Dyno. This is a streetable engine and Mr. Kownacki prides himself on the fact that he rides it nearly every day.

    If you think your motor is a candidate for an HSR48, contact your favorite dealer. The "48" is available from all the usual sources.
     
    francoblay1 likes this.
  3. Nཛ͢ཀཇཧ༏ཧי

    Nཛ͢ཀཇཧ༏ཧי ... .... .- .. -.
    Supporting Member

    Joined:
    Nov 3, 2015
    Messages:
    690
    Likes Received:
    1,217
    Trophy Points:
    93
    Location:
    Springfield, Missouri
    My Bike(s):
    2007 K-9
    First Name:
    Shain
    So, which would be the better performing carb, the Mikuni, or the XXX?
     
  4. dentdude36

    dentdude36 Guru

    Joined:
    Nov 9, 2015
    Messages:
    8,628
    Likes Received:
    19,695
    Trophy Points:
    113
    Location:
    Suburbs of Buffalo NY
    My Bike(s):
    2007 K9
    First Name:
    Kevin
    XXX it's modified for more fuel/air flow and is extremely easy to dial in
     
  5. Th3InfamousI

    Supporting Member

    Joined:
    Sep 26, 2009
    Messages:
    10,677
    Likes Received:
    15,906
    Trophy Points:
    113
    Location:
    Texas
    My Bike(s):
    04 Ridgeback & 07 K9
    First Name:
    Eric
    I run my spike up on the 04 Ridgeback installed it and running a 31 INT and 78 Main and run a short FSD exhaust. I get about 40-42mpg/160 miles on a tank

    Never had any issues runs without issues at all speeds and I never even removed the AUX Vent on the carb because the D&M mount came with the standard S&S vent hole required.

    Stock G Carb

    Thanks to Jonathan for the pic.[​IMG]

    Sent from my 2PS64 using Tapatalk
     

Share This Page