07/02/03 1

ARB ARB – Exhaust Emissions –– Exhaust Emissions – Tier 3Tier 3

Small Off-Road Engine Workshop – July 2, 2003

EMA / OPEIEngine Manufacturers Association / Outdoor Power Equipment Institute

Clean Air Act Committee

07/02/03 2

ARB ARB – Exhaust Emissions –– Exhaust Emissions – Tier 3Tier 3

Current production systems -- what do they achieve?

Southwest Research test program -- what does it demonstrate?

ARB’s current proposal -- what will it require for the air-cooled engine?

07/02/03 3

Small Off-Road Engine -Production Catalyst SystemsSmall Off-Road Engine -Production Catalyst Systems

International Catalyst System – B&S

– 20-30% HC+NOx Efficiency at 0 hrs

– 7-10% HC+NOx Efficiency at 125 hrs

– Marginal CO Conversion

07/02/03 4

Average Emissions - Quantum International Catalyst System -125 hr data ( 1.3 in Catalyst )

13.84

1.75

15.59

12.78

1.74

14.53

302294

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

HC (g/hp-hr) NOx (g/hp-hr) HC+NOx (g/hp-hr) CO (g/hp-hr)

HC

- N

Ox

- HC

+NO

x

0

25

50

75

100

125

150

175

200

225

250

275

300

325

350

SWC

O (g

/hp-

hr)

Engine Out Catalyst Out

3 %7 %

07/02/03 5

Small Off-Road Engine -Production Catalyst SystemsSmall Off-Road Engine -Production Catalyst Systems

Tecumseh TVM220

• 21.8 in3 Vertical L-Head• 15% HC+NOx Efficiency at 0 Hours

Tecumseh H35

• 9.5 in3 Horizontal L-Head• 29% HC+NOx Efficiency at 0 Hours

07/02/03 6

Southwest Research Test ProgramSouthwest Research Test Program

– Six engines equipped with high-load three-way converters

– Three engines equipped with non-integral systems

– Exhaust emissions and temperatures measured at 0 hours and after test stand operation

– No noise abatement or measurement

07/02/03 7

Muffler Skin Temperatures - SwRI B&S #1 ( 0 hrs )

675

622

539

471438

770

721

671

629 614

200

300

400

500

600

700

800

900

1000

100% Load - 9% 75% Load - 21% 50% Load - 31% 25% Load - 32% 10% Load - 7%

Te

mp

era

ture

(°F

)

B&S #1-STK B&S #1 Cat C

Cat C = 59% CO Efficiency = 133 g/hp-hr Ave Weighted Temp Increase => +133°F ( 25% ) from 540°F to 673°F

07/02/03 8

SwRI’s Catalyst System SwRI’s Catalyst System

07/02/03 9

Muffler Skin Temperatures Muffler Skin Temperatures

07/02/03 10

Temperature Measurements at SwRITemperature Measurements at SwRI

–Temperature measurements at SwRI are incomplete

–Temperature measurements at Briggs & Stratton indicate temperatures at 1150 F, not 770 F

–Southwest Research should conduct additional temperature measurements

07/02/03 11

SwRI – Honda GCV160SwRI – Honda GCV160

07/02/03 12

Muffler Skin Temperatures - SwRI SwRI Honda GVC160 ( 0 hrs )

571

508

441393

350

698

631

556505

449

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

100% Load - 9% 75% Load - 21% 50% Load - 31% 25% Load - 32% 10% Load - 7%

Te

mp

era

ture

(°F

)

Honda-STK Honda Cat J (remote)

Cat J = 63% CO Efficiency = 185 g/hp-hrAverage Weighted Temperature Increase => +116°F ( 26% ) from 445°F to 561°F

Note: Catalyst Remote Mounted

07/02/03 13

SwRI – Honda GCV160SwRI – Honda GCV160

07/02/03 14

SwRI –Honda GCV160SwRI –Honda GCV160

Heat is Dissipated from extension pipe and Muffler.

Heat is Dissipated from extension pipe and Muffler.

Catalyst has been moved away from engine.

Catalyst has been moved away from engine.

07/02/03 15

Conclusions -- SwRI Test ProgramConclusions -- SwRI Test Program

– High-load catalysts will require additional thermal management

• More hardware • More horsepower

– Other requirements related to after-treatment:• Noise: new, larger mufflers• Lean fueling: accelerator pumps, auto-choke

and warm-up feature – New base engine for walk-behind market in

California – New packaging/envelope challenges for

equipment manufacturers

07/02/03 16

Preliminary and Partial Cost EstimatesPreliminary and Partial Cost Estimates

–Approximately $60 for exhaust only (does not include evap)

–Cost estimates do not include:

• Warranty, testing or R&D

• OEM assembly and other costs

07/02/03 17

SummarySummary

–Can small engines achieve high conversion efficiency in the laboratory?

–Yes, but…

07/02/03 18

Summary Summary

Production for California will require complex changes at higher costs:

• Three-way high-load converters• Noise and thermal management• Major fuel system changes• New, larger base engine• New packaging solutions