Audi CEUC, CTFA, CWUB, CWUC Specs: 84.5 x 89 mm (3.3268 x 3.5039 in), 420 hp

See other engines in this family

Audi CEUC, CTFA, CWUB, CWUC specs: 4.0L (244.1 ci) 8-cylinder, 84.5 x 89 mm (3.3268 x 3.5039 in) bore and stroke, 10.1:1 compression. Rated 420 hp. DOHC.

The Audi CEUC, CTFA, CWUB, CWUC is undersquare — the 3.5039" stroke exceeds the 3.3268" bore by 5.1% — a layout that trades peak RPM for leverage and torque low in the range. The 3.5039" stroke puts mean piston speed at 4,000 ft/min around 6,850 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 30.5 ci (500 cc).

10.1:1 on aluminum heads is in the range that usually runs on pump premium; aluminum sheds heat faster than iron, which makes the same number a little more forgiving.

It is one of 9 engines in the EA824 family, the smallest at 244.1 ci. Factory fitments include the Audi S6 (C7), Audi S7 (C7), Audi S8 (D4).

Dimensions

Displacement244.1 ci / 4 L
Bore3.3268"
Stroke3.5039"
Cylinders8
Compression ratio10.1:1
Bore/stroke ratio0.949

Construction

Block materialaluminum
Head materialaluminum
ValvetrainDOHC
Fuel typegas
Advertised HP420 hp

What these numbers mean

Bore/stroke character0.949 — undersquare — stroke exceeds bore, which favours low-end torque
Mean piston speed at 6,000 RPM3,504 ft/min — in the range typical of performance street engines
Displacement per cylinder30.5 ci
Static compression10.1:1 — in the range that usually runs on pump premium

Run the numbers for this engine

Each link opens the calculator with this engine's specs already filled in.

Vehicles (3)

Similar engines

← All EA824 engines