What a 95" Twin Cam big bore makes
Simulated rear‑wheel horsepower and torque — measured after the primary drive, clutch and transmission, the same way a chassis dyno reads a bike. These are not flywheel numbers, and they are not directly comparable to a manufacturer’s crank rating. Rev ceiling for this combination: 5700 rpm, limited by cam.
The classic way out of a tired 88: a big-bore kit, a cam, a carburettor that can feed it and a pipe that lets it out. This is the build that kept early Twin Cams relevant.
Displacement is the easiest horsepower on any engine, but notice it is not doing this alone — the cam is what lets the extra cubic inches breathe. A big bore with the stock grind still signs off at the same rpm.
Compression is worth watching on a build like this. The head gasket and piston combination in the parts list keeps it where pump fuel is comfortable rather than chasing the last half point.
The build
| Engine | TC95 SE (1999–2006 big bore) 3.875 × 4.00 |
|---|---|
| Crank / balancer | A motor — non-balanced (Dyna / Touring / CVO) |
| Pistons | Forged flat-top (11cc combustion gain) |
| Head gasket | Cometic .030" — neutral baseline |
| Cylinder heads | STOCK 1999–2004 (-99 casting) · 1.85/1.565 |
| Porting | As-cast / factory (no additional work) |
| Camshaft | S&S 510 · 238/252 dur · 0.510" lift |
| Valve springs | Stock springs (as fitted to the heads) |
| Rocker arms | Stock rocker arms — 1.625:1 |
| Pushrods | Stock pushrods |
| Lifters | Stock hydraulic lifters |
| Induction | S&S Super G (2-1/16") |
| Exhaust | 2-into-1 stepped (D&D FatCat / E-Series) |
| Air cleaner | Screamin' Eagle / Stage I high-flow |
| Tune | Dyno-tuned (matched to build) |
| Power adder | None (naturally aspirated) |