1.03.041 GM 8.1 (496) Cylinder head torque procedure

This Policy is completed and is waiting on Field Service, Engineering, and Safety approval.

Purpose

The purpose of this procedure is to establish the minimum requirements for torquing the engine cylinder heads on General Motors 8.1 (496) Vortec style engines as laid out in this procedure.

Procedure

This procedure applies to all General Motors 8.1 (496) Vortec style engines on Flogistix skids equipped with the General Motors 8.1 Vortec engine drive units that are currently in service in the Field, Test Loop, at a Repair Shop, or in Storage Yards. Flogistix Service Technicians will perform the torque procedure as outlined in this procedure. This procedure will be performed after cylinder heads have been replaced, or removed from the engine and reinstalled or anytime the engine cylinder heads torque needs to be checked.

Before any work is performed a JSA needs to be done according to Flogistix procedure along with any Customer requirements before any work is started.

GM 8.1 (496) Cylinder Head Torque

When replacing cylinder heads or after replacing the cylinder head gasket on the GM 8.1 (496) Vortec style engine the proper torque and head bolt torque sequence must be done to assure the proper head gasket crush and head bolt stretch according to GM guidelines. Any time the head bolts have been removed from the engine a new set of head bolts must be used. The head bolts are designed to be a torque and turn method of bolt torquing. With this type design the bolts are not designed to be reused after they have been previously torqued.

Below is how the GM 8.1 head bolts are numbered when torquing, this is a number reference for the bolt only.

This is not the Head Bolt torque sequence

1. With the cylinder head on engine install new head bolts. Head bolts do not need to be lubricated. Head bolts should already have a sealant/lubricant on threads when they are taken out of the packaging

2. With a socket run all the head bolts into cylinder block until the head of the bolt touches cylinder head.

3. First Pass torque all bolts to 22 ft lbs

4. Second Pass rotate all bolts an additional 120 degrees.

5. Third Pass rotate Long bolts an additional 60 degrees. Long Bolts designated by numbers on example 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, 17

6. Third Pass continued rotate Medium bolts an additional 45 degrees designated by numbers on example 15, 18

   1. Third Pass continued rotate Short bolts an additional 30 degrees designated by numbers on example 4, 5, 12, 13

After the previous steps have been completed the engine cylinder head will be torqued to GM guidelines.

**When installing the intake manifold a special torquing procedure of the intake manifold bolts must be followed or damage to the intake manifold bolts may occur.

Responsibilities

Management - Management is responsible for implementing, supporting, and enforcing the requirements of this procedure to their respective locations/area.

EHSS - Responsible to assist in the implementation of this procedure and to review for effectiveness.

Employees, Contractors, Vendors, ETC. - Are responsible to follow the follow the requirements outlined in this procedure and ask for assistance

Scope

This procedure applies to all General Motors 8.1 Vortec style Natural Gas Engines and is applicable to all Flogistix employees, contractors, and temporary employees.

Hazards

Employees need to be aware of the possibility of extremely hot exhaust pipe surfaces, potential exposure and the inhalation of engine exhaust. Employees should be aware that units could contain flammable and toxic gasses. Potential for the possible hazards of gas ignition or fire, hot surfaces & fluids, rotating equipment. Risk of possible concentration of H2S. Hazardous gases could be in the units pressure vessels, cooler, or associated piping and risk of inhalation of hazardous gas fumes.

Safety

All Personal Protective Equipment (PPE) for normal Field Mechanical duties apply for this procedure.

Four Gas Monitor, which is outlined in the Flogistix EHSS Manual, PPE Section 8, Procedure 8.3

This procedure applies to all units in service in the field, at a service shop, or in any storage yard.

Insure Flogistix personnel have proper safety certification or site orientation if required by the Flogistix Customer.

Insure Flogistix personnel adhere to all Customers safety practices.

Proper use of required tools

Training

All employees shall be initially trained on the following topics:

• Employee Personal Protective Equipment (PPE)

• Lock Out Tag Out (LOTO) procedure according to Flogistix policy

• Emission set up knowlege for Natural Gas Engines

• Methods and Observations that may be used to detect the presence or release of a hazardous chemicals or gas in the work place

Tools & Equipment Required

All employees performing this procedure shall be required to have the listed tools to perform job tasks:

• All required PPE according to Flogistix Safety Policy

• Lock Out Tag Out LOTO items to properly perform LOTO procedure according to Flogistix policy

• Basic Hand Tools to include metric sockets

• Torque Wrench capable of torquing 22 ft lbs

Approvals

Field Service approved by:

Date:

Engineering approved by:

Date:

EHSS approved by:

Date: