Stirlingkit Independence Day Sales 2026

Independence Day · Limited Time

The American
V‑Twin Heritage Sale

Six brass-and-steel motorcycle engine replicas, born from Harley-Davidson's Panhead, Shovelhead and Evolution lineage. Already marked down — now stacking an extra 20% off automatically at checkout.

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Sale ends July 6, 2026, 11:59 PM PT — edit the date in the code once your team confirms the close date.
How The Discount Works

Two Discounts, One Price

Every price shown is already reduced from regular. This collection adds one more discount automatically at checkout — no code needed.

Example: CISON FG‑VT9 V‑Twin Panhead
Regular price: $599.99
+ Extra 20% off, applied automatically
$456.00
Your Price At Checkout
You save $143.99
Choose Your Engine

Six Engines, Three Eras

All are 4–9cc air-cooled V‑twins built from brass and stainless steel. Here's how they compare at a glance.

Swipe left for prices →
Model Era / Style Displacement Regular Final Price*
CISON FG‑VT9 Panhead 9cc $599.99 $456.00
RETROL R30 · Ready to Run Panhead 4.2cc $799.99 $616.00
RETROL R31 Shovelhead Shovelhead 4.2cc $799.99 $536.00
RETROL R32 Shovelhead 4.2cc $799.99 $536.00
RETROL R33 Evolution Evolution 4.2cc $799.99 $616.00
RETROL R34 Evolution 4.2cc $799.99 $616.00

*Final price reflects the collection's already-reduced price with the automatic 20% checkout discount applied. R34 pricing carried over from the collection listing — confirm before publishing.

Save $143.99
CISON · Panhead 1940s–60s

FG‑VT9 V‑Twin Panhead Engine

Named for the pan-shaped rocker covers that defined post-war Harley engines. CNC-machined aluminum, chrome rocker covers, electric-drill start.

$456.00 $599.99
View Engine
Save $183.99
RETROL R30 · Panhead 1970s

OHV V‑Twin, Ready to Run

Brass and stainless steel construction on a wooden display base. Includes starter rod, hand puller, and full ignition kit — runs right out of the box.

$616.00 $799.99
View Engine
Save $263.99
RETROL R31 · Shovelhead 1960s

Miniature Shovelhead Engine

Modeled on the 1960s shovel-shaped rocker cover era. New carburetor design and toggle throttle lever for a more authentic feel. Deepest discount in the collection.

$536.00 $799.99
View Engine
Save $263.99
RETROL R32 · Shovelhead, Upgraded

V‑Twin OHV, Improved Valves

The R31 platform with upgraded intake and exhaust valves for a noticeable power bump. Same collectible brass-and-steel build.

$536.00 $799.99
View Engine
Save $183.99
RETROL R33 · Evolution 1970s

Evolution Big Twin Engine

Based on the Evolution-era motor that carried Harley through the late 20th century. Upgraded valves, new carburetor, flick-style throttle lever.

$616.00 $799.99
View Engine
Save $183.99
RETROL R34 · Evolution 1980s

V‑Twin Engine Model, OHV

The final chapter of the Evolution lineage, with large-and-small valve upgrades for a meaningful power increase over earlier Evo replicas.

$616.00 $799.99
View Engine
Why V‑Twin

A Shape That Became A Sound

The V-twin, or "panhead" engine, gets its name from rocker covers shaped like cooking pans on early overhead-valve Harley-Davidson motors. Two cylinders set 45 degrees apart on a shared crankcase — originally so the engine would fit a bicycle-style frame built for a single cylinder.

That compromise became a signature. The 45-degree angle gives the V-twin its unmistakable uneven firing rhythm — the shudder and pulse enthusiasts call the engine's "soul." Every model in this collection reproduces that geometry, from the Panhead's rounded covers to the Shovelhead's angular top end to the Evolution's refined internals.

Each engine ships assembled, air-cooled, and ready to run — a static display piece or a working power plant for your next RC build.

From The Shop Floor

What Builders Are Saying

★★★★★

A striking replica that draws attention wherever it's displayed — owners describe it as a centerpiece for any collection or workshop.

William W. · CISON FG‑VT9
★★★★★

Builders who've documented their runs on video describe the Panhead replica as beautifully finished and a genuine joy to operate.

Verified Buyer · RETROL R30
★★★★★

First-time owners report the engine met expectations right out of the box, firing up on the first attempt with minimal setup.

Ronald T. · RETROL R33 Evolution
Before You Order

Questions, Answered

Each product page already shows a reduced "collection price." When you add it to your cart, an automatic 20% discount is applied on top — no coupon code needed. The price you see at checkout is your final price.

Both. Every engine ships assembled and ready to run on gasoline (25:1 mix), with electric-drill or manual start. Many owners run them occasionally and display them the rest of the time.

Yes. All U.S. orders are tax-free, with free shipping and secure payment on every order in this collection.

They represent three distinct eras of the real Harley-Davidson V-twin: Panhead (1940s–60s, rounded rocker covers), Shovelhead (1960s–80s, angular shovel-shaped covers), and Evolution (1980s onward, refined internals and improved reliability). All six models here share the same 45-degree V-twin architecture.

Every engine ships with a manual, and our user guide library covers carburetor tuning, timing, and common troubleshooting steps for V-twin models.

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