[Piwoslaw]

I first read about cooled EGR in Daox's EGR thread:
Increasing EGR flow for better mileage, post #163.
Since then I've found out that later versions of my turbodiesel engine have cooled EGR, but mine doesn't. Recently, I found a used EGR cooler for my engine and plan to have it installed. I started this thread to gather information (and experience) on C-EGR.

Here is what a quick Google search turned up:
Effects of Highly Cooled EGR on Modern Diesel Engine Performance at Low-Temperature Combustion Condition - sae.org

The present paper is focused on the application of the Low Temperature Combustion (LTC) systems to modern diesel engines.

Aim of the work was to assess the possibility to optimize LTC systems performances in terms of both engine efficiency and pollutant emissions.

In particular, the results of a study of the effects of highly cooled Exhaust Gas Recirculation (EGR) on a diesel engine running at LTC condition, will be presented and discussed.

The engine employed for the experimental activity was a FIAT JTD 4-cylinder CR diesel engine, EURO 4 version. The EGR layout was modified with respect to the production one, in order to obtain lower temperatures of the recirculated exhaust gases.

The performed tests evidence the advantages offered by the strong EGR cooling (and so the lower intake air temperature) in reducing NOx emissions, leaving very low soot emissions, typical of premixed low temperature combustion.

The results suggest the possibility to improve the EGR cooling system of the production engines or to arrange a "long route" EGR system in order to improve the engine emission performance.

Living with Cooled-EGR Engines

EGR cooler design differs
among engine manufacturers,
but all use engine coolant to reduce
exhaust temperature from around 1,100F
to 300F. Corrosion-resistant alloys help protect coolers
from acidic exhaust gases and poorly maintained coolant.
Cooled exhaust gases are channeled to a mixer, which
ensures that intake air and exhaust gases are thoroughly
blended before reaching the engine’s cylinders.