88 TCA TO 110 CI

  • newschool
    newschool
    5 years ago
    Long winded post irrelevant to many showing my experience of increasing displacement of 2003 TC 88A to 110 CI using the SE PRO 4” Big Bore bolt on Cylinder/Piston kit (92500039) but hey, I have tried to keep it like good porn, minimal talking but lots of images! First is that this conversion is not bolt on as, you need to split the cases to fit the 4 3/8" SE PRO Stroker Flywheel and Rod Assembly (23728-07A?). Images from SE catalog below, show the kit fitted to 1999-2005 TC A cases (Bolt on oil filter adaptor). The cylinder/piston kit specifies 96-103CI so there is a potential issue? Searching internet forums and cross referencing HD catalog/installation instructions did not yield any reliable information about crankcase/cylinder spigot dimensions/compression ratio so, having only images, I was hoping that no crankcase machining was required for 2005 earlier TC A cases. As it turns out, No! This post is mainly to inform of the bottom end build but, I have included some minor detail of final engine/primary assembly for information.


    Determined to make this combination to work, I bought the following genuine HD parts:
    1. SE PRO 4” Big Bore bolt on Cylinder/Piston kit (92500039)
    2. SE PRO Stoker Flywheel and Rod Assembly (23728-07A?)
    3. Bearing Assembly 24003-03B (lefty) and 24605-07 (has lefty outer race).

    Having all the bottom end parts, it was time to trial assembly, first inspection showed that flywheel Assembly (23728-07A?), has the required clearance for tapered small end clearance for the 110CI pistons, shown below. The flywheel I bought must be bravo as the bronze pin bushing has been omitted. Pistons are flat top P/N 21900051 (MAHLE). These pistons combined with SE CNC factory ported heads should give approximately 10.2:1 compression ratio which, is the same combination used in SE stage V tyre shredder kit. Cannot confirm as I have not conducted any cylinder pressure tests.  


    Next was a trial fit of flywheel, cylinder/piston into LH crankcase to determine piston crankcase clearance? The barrels fit the case however, as seen below, the 4" piston skirt interferes with crankcase before BDC.  

    To provide clearance for piston skirt, crankcases (as mated pair) the cylinder spigots were machined, as shown on LH case below. I used Ø4.125" x 0.625" deep below original spigot. (Indicative only, make sure you determine your clearance requirements)

    Trial fitment of barrels and piston shows required piston skirt/crankcase clearance. 

    Now satisfied piston/crankcase clearance is sufficient, assembling the bottom end was next. After installing lefty inner bearing race on flywheel assembly (23728-07A), outer main bearings and SE inner cam bearings (24017-10) into crankcases, I was ready to assemble the bottom end. (note cam side main bearing uses lefty outer race combined with STD inner main race) 

    Cases assembled, piston and cylinder trial fitted to confirm piston skirt clears the modified 88CI case at BDC.


    Piston skirt clearance confirmed, assembled short motor was installed into frame.

    Piston/cylinder assembly performed using custom ring compressor.

    Front rear piston/cylinder and head gaskets installed. 
    This concludes bottom end build and cylinder installation. Following is an abbreviated description of the rest of the build. Listed at the end is some of the major parts used for this build. 
    SE CNC factory ported heads installed. Compression ratio is estimated at 10.2:1, so to allow easier starting, I installed manually operated HD ACR valves.

    Next was fitting the SE intake manifold and 45mm Mikuni flat slide to determine cylinder fin clearance. As seen below, the 110CI barrel cooling fins provide sufficient clearance. 

    Assembly of rockers/covers/motor mount/exhaust/AC done.

    Belt drive primary installed.

    Final bike assembly is a given so for information major engine build components are as follows:
    1. 110CI Bolt on kit (92500039).
    2. SE PRO Stoker Flywheel and Rod Assembly (23728-07A/B)
    3. SE CNC factory ported heads (Manual ACR)
    4. S&S 570G Gear drive cams/SE Hyd Lifters
    5. SE perfect fit pushrods +0.30"
    6. HD SE Billet cam plate and HV oil pump
    7 SE "High Tensile" cylinder stud kit (16505-01)
    8. 45mm Mikuni flat slide carburetor, SE intake manifold, Zipper high flow AC
    9. Daytona Twin Tec Ignition module/Coil
    10. Engine oil cooler 
    What I like about this 110CI and SE CNC head combination is that it is incognito, unless you really know what your looking at it could pass as 88CI with carburetor upgrade! However, performance is good. This is the fourth engine configuration for this bike and IMO the best, previous builds are:
    1. Original build (2010) STD 2003 TC88CI/Primary/5 Speed/CV carb
    2. (2012) SE 95CI, 10.25:1/Morris magneto/3" BDL primary/5 Speed/45mm Mikuni
    3. (2014) SE 120CI, 12:1, MVA heads, Andrews 64G cams, S&S G carburetor/3" BDL primary/5 Speed (Pig to ride)
    4. Current configuration


  • Baloffski
    Baloffski
    5 years ago
    Ohhhh Fuckkkk. That is Bike Porn, as my Mrs keeps telling me. I gota a problem. But I love the stats.
  • Krash Kinkade
    Krash Kinkade
    5 years ago
    enjoy it m8!
    have you taken any of your combinations to a drag strip?
    what pipes?
    also just saw your 3" belt primary, I ran one set up same as you have there , only you have a electric starter, mine was kick start only on a shovel, did lot of miles never broke a belt. its still going but with electric start like yours ( mate I sold too did not kick to well , or like it ) miss the clutch rattle

  • paulybronco
    paulybronco
    5 years ago
    Nice perv, thanks for posting
  • markwoumla
    markwoumla
    5 years ago
    Very interesting …     Thanks for posting ….. Look forward to see , and hear , (if possible), the final product ….  Good Luck ...
  • newschool
    newschool
    5 years ago
    Hilly, I really like the 570G as they seem to work well with this combination however, I need to do a bit of carb tuning  as seems to be lean? minor hesitation during 3/4 throttle acceleration as carb still jetted for 95CI.
  • newschool
    newschool
    5 years ago
    Quoting Krash Kinkade on 19 Aug 2018 06:23 AMedited: 19 Aug 2018 06:27 AM

    enjoy it m8!

    have you taken any of your combinations to a drag strip?
    what pipes?
    also just saw your 3" belt primary, I ran one set up same as you have there , only you have a electric starter, mine was kick start only on a shovel, did lot of miles never broke a belt. its still going but with electric start like yours ( mate I sold too did not kick to well , or like it ) miss the clutch rattle

    Krash, have never run any on the drag strip as this bike is more of a bar hopper that I use to try adapting genuine HD and aftermarket part combinations. For exhaust, the bike is a highly modified 1970 4 speed frame and rubber mounted 2003 Dyna engine/Trans so, I used genuine TC Softail front pipe/TC Dyna rear pipe with Dyna transmission support and S&S slip on mufflers. At this time there is no balance tube cause the pipe combination did not match (Another future mod). Starter is the 2 Kw unit used on the 120CI build. Shown below is old image of the wrapped exhaust used on 95CI which is still current on this 110CI. As for clutch rattle, I like it to.


  • Krash Kinkade
    Krash Kinkade
    5 years ago
    Quoting Krash Kinkade on 19 Aug 2018 06:23 AMedited: 19 Aug 2018 06:27 AM

    enjoy it m8!

    have you taken any of your combinations to a drag strip?
    what pipes?
    also just saw your 3" belt primary, I ran one set up same as you have there , only you have a electric starter, mine was kick start only on a shovel, did lot of miles never broke a belt. its still going but with electric start like yours ( mate I sold too did not kick to well , or like it ) miss the clutch rattle

    Quoting newschool on 21 Aug 2018 07:47 AM

    Krash, have never run any on the drag strip as this bike is more of a bar hopper that I use to try adapting genuine HD and aftermarket part combinations. For exhaust, the bike is a highly modified 1970 4 speed frame and rubber mounted 2003 Dyna engine/Trans so, I used genuine TC Softail front pipe/TC Dyna rear pipe with Dyna transmission support and S&S slip on mufflers. At this time there is no balance tube cause the pipe combination did not match (Another future mod). Starter is the 2 Kw unit used on the 120CI build. Shown below is old image of the wrapped exhaust used on 95CI which is still current on this 110CI. As for clutch rattle, I like it to.



    very impressive! well done!
    I'm an old man that still likes to test every Harley I own at the drag strip. I know not everyone understands why.
    those pipes would be my choice, a lot like 2 into 1 ( that's cool ) just I tried a few then made some duels from tampered end mufflers & bends from Sonic in Victoria . I knocked off 5 tenths of a second & gained 12mph 1/4 mile trap speed ( no balance tube one piece  duels, ceramic coated no baffles ) was not overly loud. also was runing a CV51mm carb was a beauty! best time was 11.2 with best trap speed ( in 4th gear 121mph ) road to track road home to anywhere.
    but what you have done, impress's me!! I like the sporty gas tank too!! I owned a 4 speed big twin. it flew as well, an old Shovel & also ran standing quarter in 11's. but with a 4 speed, so every time at the track with that motor I had, the 4 speed gear box had to be pulled down thats about 5 pass's 1/4 mile, also I would bend the rear axle. finished up making an outrigger bearing support so axle had the bearing up against inside of swingarm, never bent another axle.
    if heathcoat not too far from you, should take it there see what trap speed it hits, don't worry about ET just look at trap speed as that will tell you how much HP you have.
    cheers