EGR

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Revision as of 04:35, 9 November 2011

Exhaust Gas Recirculation (EGR) was first used starting with 1974 B-210 (North American B210) models. Australia 1200 utes got EGR in 1982. Japan 1200 trucks got it in 1989. It recirculates a small portion of the exhaust back into the combustion chamber. Although this dilutes the the air/fuel mixture (reducing performance), it reduces burning temperatures resulting in drastic reductions of Oxides of Nitrogen (NOx).

Overview

EGR is a key emission control technology. Even the new 2012 models use EGR, although now it can be effected by variable camshaft overlap and engine computer control. Datsuns use an early version of EGR which is heavy-handed regarding performance, but really does clean up the air.

For a detailed explanation of EGR, see the AutoZine Technical School article.

Datsun EGR consists of:

• Exhaust manifold with an EGR port tube
• Intake manifold with EGR passage
• EGR valve and body, which bolts to the intake manifold
• One or two switches

EGR parts in red:

Exhaust Manifold

The only modification to the Exhaust Manifold to enable EGR is the casting is changed to add a threaded port to which a tube is fastened. The tube goes up to the EGR Valve.

First EGR (1974) -- tube goes behind manifold

Late A14 style

Early A14 FU style

Vanette Style

Variations consist of:

• Size of the EGR port (diameter of hole and thread size)
• Location. Early engine had it come straight out of the manifold outlet, while newer ones have it pointing almost up

There are also Tube variations: Some tubes are threaded on both ends, others threaded only on the manifold end

Intake Manifold

Intake Manifold has a specially machined flat area where the EGR Body bolts. Nissan calls this adapter body the "EGR passage". In turn, the EGR Control Valve bolts to the body.

H95 EGR (valve not installed)

EGI

A14E and A15E EGI fuel injection engine manifolds use an EGR system.