Retrofit/Rebuild Requirements for 1993 and Earlier Model Year Urban Buses; Public Review of a Notification of Intent to Certify Equipment

ENVIRONMENTAL PROTECTION AGENCY

[FRL-5918-4]

Retrofit/Rebuild Requirements for 1993 and Earlier Model Year

Urban Buses; Public Review of a Notification of Intent to Certify

Equipment

AGENCY: Environmental Protection Agency.

ACTION: Notice of Agency receipt of a notification of intent to certify

equipment and initiation of 45-day public review and comment period.

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SUMMARY: Detroit Diesel Corporation (DDC) has submitted to the Agency a

notification of intent to certify urban bus retrofit/rebuild equipment

to a 0.1 gram per brake-horsepower-hr(g/bhp-hr) particulate matter (PM)

standard pursuant to 40 CFR Part 85, Subpart O. The equipment, referred

to by DDC consists of the base engine components used on the 25%

reduction retrofit/rebuild kit certified by DDC (October 2, 1995),

components from the 25% retrofit catalyst kit previously certified

under the program by Engine Control Systems, Ltd. (January 6, 1997),

and a TurboPac supercharger system supplied by Turbodyne Systems, Inc.

which supplies additional charge air during engine acceleration. The

candidate kit is applicable to all 6V-92TA MUI engine models made by

DDC for model years 1979 to 1989 and equipped with mechanical unit

injectors (MUI).

DDC intends this equipment to be certified to the particulate

matter level of 0.10 g/bhp-hr. If the Agency certifies that this

equipment complies with the 0.10 g/bhp-hr level, then operators with

affected engines will have the choice of using this equipment or other

equipment that is already required for use and certified to the 0.10 g/

bhp-hr standard within the cost limitation.

Pursuant to Sec. 85.1407(a)(7), today's Federal Register notice

summarizes the notification, announces that the notification is

available for public review and comment, and initiates a 45-day period

during which comments can be submitted. The Agency will review this

notification of intent to certify, as well as any comments it receives,

to determine whether the equipment described in the notification of

intent to certify should be certified. If certified, the equipment can

be used by urban bus operators to reduce the particulate matter of

urban bus engines.

The notification of intent to certify, as well as other materials

specifically relevant to it, are contained in Category XX-A of Public

Docket A-93-42, entitled ``Certification of Urban Bus Retrofit/Rebuild

Equipment''. This docket is located at the address listed below.

Today's notice initiates a 45-day period during which the Agency

will accept written comments relevant to whether or not the equipment

included in this notification of intent to certify should be certified.

Comments should be provided in writing to the addresses below.

DATES: Comments must be submitted on or before December 22, 1997.

ADDRESSES: Submit separate copies of comments to each of the two

following addresses:

1. U.S. Environmental Protection Agency, Public Air Docket A-93-42

(Category XX-A), Room M-1500, 401 M Street S.W., Washington, DC 20460.

2. Anthony Erb, Engine Compliance Programs Group, Engine Programs

and Compliance Division (6403J), U.S. Environmental Protection Agency,

401 ``M'' Street S.W., Washington, DC 20460.

The DDC notification of intent to certify, as well as other

materials specifically relevant to it, are contained in the public

docket indicated above. Docket items may be inspected from 8:00 a.m.

until 5:30 p.m., Monday through Friday. As provided in 40 CFR Part 2, a

reasonable fee may be charged by the Agency for copying docket

materials.

FOR FURTHER INFORMATION CONTACT: Anthony Erb, Engine Programs and

Compliance Division (6403J), U.S. Environmental Protection Agency, 401

M St. SW, Washington, D.C. 20460. Telephone: (202) 233-9259.

[[Page 60078]]

SUPPLEMENTARY INFORMATION:

I. Background

On April 21, 1993, the Agency published final Retrofit/Rebuild

Requirements for 1993 and Earlier Model Year Urban Buses (58 FR 21359).

The retrofit/rebuild program is intended to reduce the ambient levels

of particulate matter (PM) in urban areas and is limited to 1993 and

earlier model year (MY) urban buses operating in metropolitan areas

with 1980 populations of 750,000 or more, whose engines are rebuilt or

replaced after January 1, 1995. Operators of the affected buses are

required to choose between two compliance options: Option 1 establishes

particulate matter emissions requirements for each urban bus engine in

an operator's fleet which is rebuilt or replaced; Option 2 is a fleet

averaging program that establishes a specific annual target level for

average PM emissions from urban buses in an operator's fleet.

A key aspect of the program is certification of retrofit/rebuild

equipment, which begins when an equipment manufacturer submits an

application for certification (referred to in the rule as a

notification of intent to certify). To meet either of the two

compliance options, operators of the affected buses must use equipment

that has been certified by EPA. Emissions requirements under either of

the two options depend on the availability of retrofit/rebuild

equipment certified for each engine model. To be used for Option 1,

equipment must be certified as meeting a 0.10 g/bhp-hr PM standard or

as achieving a 25 percent reduction in PM. Equipment used for Option 2

must be certified as providing some level of PM reduction that would in

turn be claimed by urban bus operators when calculating their average

fleet PM levels attained under the program.

Under Option 1, additional information regarding cost must be

submitted in the notification, in order for certification of that

equipment to initiate (or trigger) program requirements for a

particular engine model. In order for the equipment to serve as a

trigger, the certifier must guarantee that the equipment will be

offered to affected operators for $7,940 or less at the 0.10 g/bhp-hr

PM level, or for $2,000 or less for the 25 percent or greater reduction

in PM. Both of the above amounts are based on 1992 dollars and include

life cycle costs incremental to the cost of a standard rebuild.

II. Notification of Intent To Certify

In a notification of intent to certify equipment signed July 16,

1997, DDC has applied for certification of equipment under the

Environmental Protection Agency's (the Agency) Urban Bus Retrofit/

Rebuild Program. The candidate kit is applicable to all 6V-92TA, urban

bus engine models made by DDC from model year 1979 to 1989 and equipped

with mechanical unit injectors (MUI). The equipment, consists of the

base engine components used on the 25% reduction retrofit/rebuild kit

certitied by DDC , components from the 25% retrofit catalyst kit

certified by Engine Control Systems, Ltd.(ECS) and a TurboPac

supercharger system supplied by Turbodyne Systems, Inc. that supplies

additional charge air during engine acceleration. The kit would be

available in three horsepower levels (253, 277, and 294) for 6V-92TA

engines.

The equipment to be certified includes three distinct hardware

sets. The three sets included are as follows:

Base engine components include the equipment certified by DDC to

provide a 25% reduction in PM (60 FR 51472; October 2, 1995. These

components are provided in two separate sets of parts. The first set of

components is comprised of newly manufactured parts, including a gasket

kit, air inlet hose, cylinder kits (piston assemblies and cylinder

liners) a by-pass valve and a truck type throttle delay. The second set

of components includes ReliabiltTM remanufactured parts,

including the fuel injectors, camshafts, blower assembly, turbocharger,

and head assemblies. Kit usage is based on engine rotation (righthand

(RH) or lefthand (LH)), engine orientation, right bank cam gear

mounting (bolt or nut), and engine power output based on injector size.

The only differences from the previously certified equipment according

to DDC is the inclusion of a truck style throttle delay, adjustment to

the throttle delay and injector timing settings to improve

driveability. The cylinder kit components were modified to improve

durability.

The converter/muffler supplied by ECS was certified by EPA (see 62

FR 746; January 6, 1997) to provide a 25% reductionn in PM emsssions.

The kit consists of an oxidation converter/muffler (CM) which was

developed specifically for diesel applications, and is packaged as a

direct replacement for the vehicle's muffler. Several kits will be

provided to accommodate the installation requirements of the various

engine and vehicle configurations.

The third component set consists of an electrically powered

supercharger system which is supplied by Turbodyne Systems, Inc. This

component set, referred to as the TurboPacTM supplies

additional intake air during engine acceleration from low engine

speeds. DDC states that in addition to decreasing PM emissions and

visible smoke during engine acceleration, the supercharger also

improves engine response and vehicle driveability by reducing the fuel

modulation during acceleration. The basic kit consists of a blower, a

diverter valve, a boost pressure sensor, an electrical control box and

power cables, and a throttle switch for detecting the start of the

engine acceleration mode. The equipment will be supplied in two kits,

one includes those components common to all installations and a second

kit to accommodate the installation requirements of the various engine

and vehicle configurations.

To complete an engine rebuild two (2) base engine component kits,

one (1) converter muffler kit, and two (2) supercharger kits would be

required. The specific kits used will depend on the engine/vehicle

combination.

DDC states there are no differences in the service intervals or

maintenance practices for the base engine associated with the

installlation of the upgrade kit. The converter/muffler requires no

regularly scheduled maintenance, only an occasional cleaning if the

maximum backpressure of the exhaust system is exceeded according to

DDC. The supercharger does not require scheduled maintenance: however,

a visual inspection for air leaks is recommended whenever the engine is

serviced.

Standard procedures as described in the service manual for 92

Series engines are to be used when rebuilding the base engines using

the candidate equipment. No unique rebuild procedures are required.

Use of the candidate kit is restricted to 6V-92TA Detroit Diesel

engines manufactured from January 1979 through December 1989, equipped

with mechanical unit fuel injectors (MUI), and originally certified to

meet Federal emission standards. The required fuel is low sulfur (0.05%

max by weight) diesel fuel, either number 1 or number 2.

The notification states that the candidate equipment achieves a

particulate matter (PM) level of 0.10 g/bhp-hr. DDC has not supplied

life cycle cost information and is not requesting certification based

on cost to operators. The use of the equipment by transit operators to

meet program requirements is discussed below.

[[Page 60079]]

DDC presents exhaust emissions data from testing a Detroit Diesel

Corporation (DDC) engine in accordance with procedures set forth at 40

CFR Part 86, Subparts N and I. A 1984 model year DDC 6V92TA MUI model

engine (277 HP) was rebuilt to the 1989 urban bus configuration as per

the previously certified DDC kit and was retrofit with the specified

components of the 0.1 g/bhp-hr kit prior to testing. In the rebuild

process, all parts not included in the rebuild kit were inspected.

Prior to testing the engine was tuned with the injector timing set at

1.460 in. The throttle delay was set for optimum vehicle driveability

according to DDC. The data is summarized in Table A below.

Table A.--Exhaust Emissions Summary

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g/bhp-hr

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1989 HDDE 6V92TA MUI

standards with kit

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Gaseous and particulate test:

HC........................................ 1.3 0.1

CO........................................ 15.5 0.4

NOX....................................... 10.7 9.8

PM........................................ 0.60 0.091

BSFC\1\................................... -- 0.464

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Standards

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Smoke test:

ACCEL..................................... 20% 3.3%

LUG....................................... 15% 2.5%

PEAK...................................... 50% 4.2%

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\1\ Brake Specific Fuel Consumption (BSFC) is measured in units of lb/

bhp-hr.

The data of Table A indicate that, when rebuilt with the kit, PM

emissions of the test engine are less than 0.10 g/bhp-hr, and emissions

of hydrocarbon (HC), carbon monoxide (CO), and smoke opacity are within

applicable Federal standards. The Agency requests comments on whether

the emissions test data presented by DDC demonstrate that all engines

for which certification is requested will meet applicable Federal

standards with the candidate kit installed.

Applicability of the candidate is restricted to 6V92TA, urban bus

engine models made by Detroit Diesel Corporation (DDC) from model years

1979 to 1989 and equipped with mechanical unit injectors (MUI). The

Agency requests comments on whether the emissions data presented by DDC

demonstrate that all engines for which certification is intended will

meet the 0.10 g/bhp-hr PM standard. The part numbers of the specified

rebuild components are provided in DDC's notification.

DDC's notification does not provide life cycle cost information for

the candidate kit. Therefore, this kit will not be certified to comply

with the life-cycle cost requirements of the program. The 0.10 g/bhp-hr

PM level has already been triggered for all the engines covered by this

notification. If certified as proposed in the notification, this

equipment may be used by operators who are required to use equipment

that meets the 0.10 g/bhp-hr PM level based on earlier trigger

certification.

DDC indicates that the engine is to be rebuilt according to the

engine manufacturer's standard written rebuild procedures and

specifications except where amended by DDC written instructions. The

incremental maintenance cost and fuel economy impact are not provided

in DDC's notification and are not necessary for certification as the

cost limitation is not being certified to by DDC.

The DDC notification provides a product warranty that references

the emissions performance and emissions defect warranties required in

accordance with section 85.1409 of the program regulations.

Even if ultimately certified by the Agency, the equipment described

in DDC's notification may require additional review by the California

Air Resources Board (CARB) before use in California. The Agency

recognizes that special situations may exist in California that are

reflected in the unique emissions standards, engine calibrations, and

fuel specifications of the State. While requirements of the Federal

urban bus program apply to several metropolitan areas in California,

the Agency understands the view of CARB that equipment certified under

the urban bus program, to be used in California, must be provided with

an executive order exempting it from the anti-tampering prohibitions of

that State. Those interested in additional information should contact

the Aftermarket Part Section of CARB, at (818) 575-6848.

If the Agency certifies the candidate equipment, then urban bus

operators who choose to comply with compliance Option 1 of this

regulation will have the option to use this equipment or other

equipment which has previously been certified to the 0.10 g/bhp-hr

standard when applicable engines are rebuilt or replaced. If certified,

then operators using Option 2 will use the 0.10 g/bhp-hr certification

level in calculations for fleet level attained (FLA).

The date of this notice initiates a 45-day period during which the

Agency will accept written comments relevant to whether the equipment

described in the DDC notification of intent to certify should be

certified pursuant to the urban bus retrofit/rebuild regulations.

Interested parties are encouraged to review this notification, and

provide written comments during the 45-day review period. Separate

comments should be provided in writing to each of the addresses listed

under the ADDRESSES section of this notice.

At a minimum, the Agency expects to evaluate this notification of

intent to certify, and other materials submitted as applicable, to

determine whether there is adequate demonstration of compliance with:

(1) the certification requirements of Sec. 85.1406, including whether

the testing accurately substantiates the claimed emission reduction or

emission levels; and, (2) the requirements of Sec. 85.1407 for a

notification of intent to certify.

The Agency requests that those commenting also consider these

regulatory requirements, plus provide comments on any experience or

knowledge concerning: (a) problems with installing, maintaining, and/or

using the equipment on applicable engines; and, (b) whether the

equipment is compatible with affected vehicles.

The Agency will review this notification of intent to certify,

along with comments received from the interested parties, and attempt

to resolve or clarify issues as necessary. During the review process,

the Agency may add additional documents to the docket as a result of

the review process. These documents will also be available for public

review and comment within the 45-day period.

Dated: October 29, 1997.

Richard D. Wilson,

Acting Assistant Administrator for Air and Radiation.

[FR Doc. 97-29394 Filed 11-5-97; 8:45 am]

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