Marine Par Curve Development{1000} Caterpillar

Introduction

This Special Instruction is designed to aid in the development of Marine Par Curves for those Caterpillar Marine Engines for which no existing data is available. It will also help the user to determine how and where to obtain the information needed to develop the required Marine Par Curves.

A sample page with existing Marine Engine Performance Curves and Data from the Marine Power Systems Technical Manual, Form LEBM8308 is shown at the back of this instruction.

Reference: Engine Technical Data System (ETDS), Technical Information File (TIF), Marine Power Systems Technical Manual, Form LEBM8308, and Caterpillar Sea Trial Rules of Thumb! Marine Gear Performance Specifications, Form LEXM7151, CAMPAR.

Sources of Information

To develop the Marine Par Curves, the following specific information is required:

* Engine Model

* Engine Serial Number

* Engine Arrangement Number

* Rated hp

* Rated rpm

* OT Number

There are several possible sources for the information that will be needed. The first source to try is the Engine Technical Data System (ETDS). Refer to the topic Using the Engine Technical Data System in this instruction. The information in this system is for current production engines and is available through the dealer terminal system.

The second source for the needed information is the Sea Trial Microfiche (beginning with Fiche No. 9400) in the Technical Information File (TIF). Information in the TIF is for current production engines and it dates back to approximately mid-1987.

If the information needed can not be found in either the Engine Technical Data System (ETDS) or the Sea Trial Microfiche (TIF), it will then be necessary to make reference to the Computer Aided Marine Performance Analysis Review (CAMPAR). This program does contain some of the older and/or non-current engines.

If the needed information can not be found in any of the media given, it will be necessary to develop the data and the marine par curves. This will require a good working knowledge of CAMPAR software. Refer to the topic entitled Using the Caterpillar Computer Aided Marine Par in this instruction.

If it is necessary to develop the marine par curves, certain specific data will be needed for input into the CAMPAR program. This data can be obtained by using the Engine History Option from the Engine Technical Data System (ETDS). Refer to the topic entitled Using the Engine Technical Data System in this instruction.

Two additional items that will be needed are the BP and the BP1 correction factors. These correction factors are needed to develop the correct slope on the curves. This is due to the part load situation and its effect on the BSFC of the engine, compared to a true cubic demand curve of a typical fixed pitch propeller. It is important, therefore, that these numbers be correct.

A BP/BP1 Correction Factor Table is given in this instruction, however, it is not all inclusive. If the information needed is not given in the BP/BP1 Correction Factor Table or in any of the previous sources given, the correction factor needed can be calculated using a formula given in the topic entitled BP/BP1 Correction Factor Table.

Once all the needed data is available, enter it into the CAMPAR program. It will be necessary to sort the data before the program will be able to find the new data for the engine. Use the DOS "SORT" procedure to sort the data.

NOTE: Refer to the topic entitled Campar Specification File - Sort Procedure in this instruction.

Any temperature specifications that may be needed can be obtained from the Service Manual, the Marine Engine Sea Trial Guide, Form LEBM6302, or, from the pocket card Rules of Thumb, Form LEXM7151.

Pressure specifications that are needed can be obtained from the Service Manual.

Using the Engine Technical Data System

Marine Auxiliary/Propulsion Sea Trial Data

1. Use the dealer terminal system to bring the ENGINE TECHNICAL DATA SYSTEM program onto the screen.

2. Proceed to the MENU screen as shown.

3. In this instance, an "s" has been put in front of PGM. NUM. (PROGRAM NUMBER) "15" for MARINE AUX/PROP SEA (MARINE AUXILIARY/PROPULSION SEA TRIAL DATA).

Press the ENTER key.

4. Fill in the requested information for inquiry options (A) or (B) according to the directions given. [Both options (A and B) are shown.]

Press the ENTER key.

5. The necessary sea trial data now begins to appear with the screen that follows. Use this data as needed.

6. Press ENTER to continue to the next screen.

7. Press ENTER to continue to the next screen.

8. Press ENTER to continue to the next screen.

9. Press ENTER to continue to the next screen.

Engine History Information

1. Use the dealer terminal system to bring the ENGINE TECHNICAL DATA SYSTEM program onto the screen.

2. Proceed to the MENU screen as shown.

3. In this instance, put an "s" in front of PGM. NUM. (PROGRAM NUMBER) "18" for ENGINE HISTORY INFO as shown.

Press the ENTER key.

4. Fill in the requested information for the inquiry options as shown according to the directions given.

Press the ENTER key.

5. The requested data now begins to appear on the screen as shown. Use this data as needed.

Conversion Factors

In the event that conversion factors are needed when working with the CAMPAR program. Put an "s" in front of PGM. NUM. (PROGRAM NUMBER) "01" MKTG CONVER FACTORS.

Press the ENTER key.

Follow the procedure described to view the conversion factor table(s) that are needed.

Using the Caterpillar Computer Aided Marine Par (CAMPAR) Program

1. Load your personal computer (PC) with the CAMPAR program.

2. Proceed to the MENU screen as shown.

3. Enter the desired option number between the brackets. [In this example, a "1" is inserted between the brackets for Marine PAR Performance Specification Verification.]

Press the ENTER key.

4. On this screen enter the desired option number between the brackets. [In this option the number "2" has been chosen.]

5. As shown in the illustration, the information requested was for a new engine that is not as yet in the file. For assistance, call Caterpillar Inc. at the number given.

6. Enter the word "SPEC" at the location indicated to return to the Performance Specification Menu as shown in the illustration that follows.

7. Use the examples that follow as a guide and fill in the needed information on the screens for the new engine rating. Use the directions on each screen to proceed to each succeeding screen.

BP/BP1 Correction Factors

Use the BP/BP1 Correction Factor given in either of these charts according to the engine with which you are working. If the correction factor required is not listed, refer to the topic entitled BP/BP1 Calculation Procedure for the formula to calculate and arrive at the correction factor needed.

In the event that the correction factor needed is not in either of the charts, the factor can be calculated. Refer to the topic entitled BP/BP1 Calculation Procedure in this instruction.

BP/BP1 Calculation Procedure

For an example, we will use a 3508 Engine that is 1000 hp and 1800 rpm. The figure for 75% of rated speed of this engine is 1350 rpm (75% x 1800 rpm = 1350 rpm).

NOTE: Refer to the Marine Engine Performance graphs in the Technical Information File (TIF) for values needed.

From the propeller demand curve "P curve" it can be seen that there is a 1400 rpm point and a 1200 rpm point.

* 1400 rpm = .363 BSFC

* 1200 rpm = .369 BSFC

The rpm needed is 1350 rpm. This is 50 rpm below the 1400 rpm given. There is also a 200 rpm difference between the two points on the "P curve".

... (50 ÷ 200) x [.385 (-) .363] = .0055 ... .363 + .0055 = .369 ... .369 ÷ .350 = BP ... BP = 1.054

The same procedure would be used to determine BP1 except, use the point at 50% of Rated rpm.

Additional Formulas Used to Develop Marine Par Curves

For Torque Check GPH proceed as follows:

Torque Check GPH = TQ COR. Fuel Rate (G/MIN) ÷ 454 x 60 = LBS/HR

LBS/HR ÷ 7.076 = GPH

For BSFC proceed as follows:

BSFC = Adjusted CSFC (G/Kw HR) ÷ 454 = LBS/Kw HR

LBS/Kw HR ÷ 1.34 = BSFC (LBS/HP HR)

Campar Specification File - Sort Procedure

If Steps 1 thru 7 as given in the topic "Using the Caterpillar Computer Aided Marine Par (CAMPAR) Program" have already been completed, proceed to Step 11 that follows. If these Steps have not been completed as stated, begin this "Sort Procedure" with Step 1 that follows.

NOTE: Before installing the "Campar Specification File - Sort Procedure," make backup copies of the master disks, then store the originals in a safe place. Use the copies to run the installation program.

After receiving the 12 data items that are needed to add a new engine rating to the "Campar Specification Data Base", load the Campar program into an IBM® (only) computer. It is preferable that the computer also have a hard drive system.

NOTE: If an IBM® computer is not available, contact Caterpillar Inc. at (309) 578-4167. Do not attempt to do this procedure on a compatible computer because language differences will prohibit completion of the procedure.

1. Turn on the computer and permit it to go to its DOS format. The monitor screen must have a C >, commonly known as "C PROMPT".

2. Insert the desired "Campar Program Diskette" into the "A" disk drive of the computer.

3. Type in A:CAMPAR after the "C > PROMPT" on the screen.

NOTE: Be sure the letters are all capital letters, then press the ENTER key. The "Campar" program should automatically execute.

4. When the main MENU of Campar appears on the screen, select OPTION 1. Selection of OPTION 1 will provide the "Marine Par Performance Specification Verification File".

5. Select OPTION 2 to obtain those new engine ratings that are not listed on file.

6. A screen will appear that asks you to enter a secret code to proceed.

7. Your code is "** SPEC **". Type this in and press the ENTER key.

8. A screen should appear and prompt you for the 12 data items that follow:

* MODEL

* ASPIRATION

* RATED HP

* RATED RPM

* RATED BSFC

* TORQUE CHECK NM

* TORQUE CHECK RPM

* TORQUE CHECK GPH

* EFFECTIVE SERIAL NUMBER

* 0T SPECIFICATION NUMBER

* BP CORRECTION FACTOR

* BP1 CORRECTION FACTOR

9. Input the items exactly the way they are provided to you.

10. Recheck the data. Make corrections as instructed on pages 14-15 in the Campar Operation Guide, Form LEXM7081.

11. Once the entry of these data items has been completed, it will be necessary to sort the new rating(s) into your Campar program disk specification data base. To do this, first return to the "CAMPAR MAIN MENU."

12. Select OPTION 5. This will direct you to the computer DOS system.

The C > should now appear on the monitor screen.

13. After the C >, type in the following:

COPY A:CAMSPEC1.DAT A:CAMBACK1.DAT

Press the ENTER key. This will create a backup file for sorting.

14. Now another C > will appear. After the C >, type in the following:

SORT/R < A:CAMSPEC1.DAT > A:CAMSORT1.DAT

15. The C > will now appear again. After the C > type in the following:

COPY A:CAMSORT1.DAT A:CAMSPEC1.DAT and then press the ENTER key.

16. A C > will appear again. After this C > type in the following:

DEL A:CAMSORT1.DAT and then press the ENTER key.

17. Another C > will appear. After this C > type in the following:

A:CAMPAR and then press the ENTER key. This will return you to CAMPAR to check the entry. The entry should now be sorted into the data base in model, hp and rpm order.

Sample Page From Marine Power Systems Technical Manual