FLUIDYNE Engine Cooling System

Water Cooling of a Ford 427 FE Side Oiler

Specific Characteristics of the 427 Side Oiler

The 427 FE Side Oiler is an engine designed for endurance and high RPM, but with well-known constraints:

• Large displacement (7.0 L) → high heat generation

• Massive cast-iron block → significant thermal inertia

• FE architecture → coolant circulation sometimes less uniform than on modern blocks

• Performance use (spirited road driving, track days, drag runs) → rapid thermal spikes

👉 Even though the Side Oiler is extremely robust on the lubrication side, cooling remains a key point, especially at low speeds or in hot conditions.

Principle of the Water Cooling Circuit (Simplified)

1. High-flow water pump (FlowKooler in your case ✔️)

2. Circulation through:

   • cylinder jackets

   • cylinder heads (critical areas around the combustion chambers)

3. Hot coolant outlet → radiator

4. Air/water heat exchange

5. Return to the engine

Critical Points

• actual flow rate (not just pressure)

• heat exchange surface

• radiator thermal capacity

• temperature stability (avoid “yo-yo” effects)

Realistic Target for a 427 FE

• Stabilized temperature: 82–90°C

• No overheating at idle

• No uncontrolled temperature rise after engine shutdown

• Ability to handle sustained loads

Technical Analysis of the Fluidyne RSH.COB Radiator

This is a very high-end choice, without any doubt.

Dimensions & Design

• 23.7” x 18” x 3.5”

• 5-row core

• Crossflow design (excellent choice)

• All-aluminum construction

• NOCOLOK brazing (very important)

👉 The crossflow layout is clearly superior to a traditional downflow design in terms of:

• thermal uniformity

• reduction of hot spots

• better efficiency at high flow rates

🧠 What truly defines radiator quality (and where Fluidyne stands above the rest)

1. NOCOLOK Brazing (Major Strength)

Unlike many radiators that use:

• ❌ epoxy bonding

• ❌ partial brazing

Fluidyne employs:

• full aluminum brazing in a controlled atmosphere

• excellent thermal conductivity

• extreme durability (no delamination over time)

👉 This is competition / aerospace-level engineering, not tuning-grade hardware.

2. Fin Density and Fin Design

• high-efficiency fin structure

• optimized for:
  
  

  • real-world airflow (not just wind tunnel conditions)

  • compatibility with electric fans

  • low-speed operation (traffic, pit lane)

• 
  

👉 Many “thick” radiators perform poorly at low speed — this is not the case here.

3. Real Thermal Capacity

With:

• 5 rows

• 3.5” thickness

• high-conductivity aluminum

👉 This radiator can absorb violent thermal spikes (long accelerations, heat soak after stops).

This is exactly what a 427 FE requires.

Comparison with Other Solutions

🔻 “Generic” Aluminum Radiators (eBay / Mid-Range Brands)

• Often 2 or 3 rows

• Approximate brazing or epoxy bonding

• Good on paper, unstable over time

• Poor efficiency at low RPM / low airflow

❌ Insufficient for a built 427

⸻

🔻 Griffin / Champion–Type Radiators

• Good manufacturing quality

• Decent performance

• But:

• lower fin density

• slightly reduced efficiency at equal flow rates

✔️ Good choice

❌ Fluidyne remains superior

⸻

🔺 Fluidyne (THE Solution)

• Reference brand in NASCAR, endurance racing, and drag racing

• Very high thermal capacity

• Excellent temperature stability

• Exceptional longevity

👉 Clearly overkill for a small block

👉 Perfectly suited for a 427 FE

Synergy with the Current Setup (Important)

The system already includes:

• ✔️ High-flow FlowKooler water pump

• ✔️ 82°C thermostat

• ✔️ Water Wetter additive

• ✔️ Thermostatic oil cooler

👉 Result:

• clear separation between water and oil cooling

• overall thermal stability

• no cross thermal overload

This is exactly the right architecture for a large FE V8.

Clear Verdict

Straightforward assessment:

The Fluidyne RSH.COB is one of the best radiators available for a 427 Side Oiler.

This is not about looks — it’s serious engineering.

• no capacity issues

• very large thermal margin

• suited for aggressive use

• fully consistent with the rest of the build