Description

Offenhauser 8021 — Ford 300 Water Plate

Eliminate off-idle bog. Improve cold-weather drivability. Give your Ford 300 the hot spot it was meant to have.

The Offenhauser 8021 Water Plate restores a critical function that went missing when you upgraded to a performance intake manifold — heat in the floor of the
plenum. By circulating engine coolant through a sand-cast aluminum plate bolted directly beneath your carburetor, the 8021 eliminates the cold stumble, fuel
puddling, and rough idle that plague inline six conversions, especially in colder months.

Every Offenhauser Ford 300 intake is a performance piece. But performance isn’t just about airflow — it’s about drivability. Cold intake floors cause fuel to drop
out of the air stream and puddle, creating hesitation when you need throttle response the most. The 8021 solves this by channeling warm coolant through the
manifold floor, vaporizing unburned fuel and maintaining consistent mixture quality from startup to highway speed.

This is not a generic heater plate. The 8021 was purpose-designed for the Offenhauser Ford 300 manifold family, cast at Chippewa Foundry, and machined in-house at
Offenhauser’s Los Angeles facility. Three precision mounting points, two 3/8″-18 NPT tapped ports for your heater hose connections, and a gasket included in the
box — everything you need to install it the same afternoon.

⚠️ Compatibility — Read Before Ordering

8021 Installation Instructions (< Click link to the left)

The 8021 is not a universal fit. It requires a manifold with a heat provision — a solid plenum floor with the stock heat-riser mounting footprint. It is a direct
fit only on:

✅ Offenhauser 6227C — has heat provision
✅ Offenhauser 6019DP — has heat provision

It will NOT fit manifolds without a heat provision:

❌ Offenhauser 6227HD (“Heat Delete”) — no heat provision
❌ Offenhauser 6284 — no heat provision

Not sure which manifold you have? Check the part number cast into your intake before ordering.

All users should read the included installation instructions carefully before installing. If your manifold carries the “NOT FOR USE WITH WATER PLATE” casting mark,
pay special attention — those earlier castings require a leak test before the plate is bolted on.

What’s Included

• 1x 8021 Water Plate — sand-cast aluminum, machined and ready to install
• 1x Gasket
• Complete hardware kit: set screws, hex bolts, washers, and brass 5/8″ hose barb fittings
• Installation instructions

Key Features

• Restores intake manifold heat — eliminates fuel puddling, off-idle bog, and cold-start hesitation
• Three mounting points + two 3/8″-18 NPT ports — for heater hose connection
• Sand-cast aluminum — matches the finish and quality of your Offenhauser intake
• Made in USA — pattern by Enlightened Moto, cast by Chippewa Foundry, machined at Offenhauser Los Angeles
• Direct fit — for Offenhauser 6227C and 6019DP manifolds with heat provision only (not compatible with 6227HD or 6284)
• Complete kit — everything needed for installation in one box

Why You Need It

If you’ve ever experienced a stumble when tipping into the throttle on a cold morning, or felt your engine bog coming off idle, you already know why this part
exists. The factory intake manifold had a heat riser passage cast into it for a reason — it’s basic carburetion physics. The 8021 gives that function back without
sacrificing the performance you gained from your Offenhauser intake.

Install it. Heat it. Drive it.