IHC-TYPE 'M'

Thumb screw type speed changer

Fig. 15: Thumb screw type speed changer

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This is the second and final part of an article written by Wayne Grenning of 318 Summit Street, Boonville, New York, 13309. The article was begun on page 4 of the September/October 1982 issue of GEM. Part One of the article covered the development of the 1 HP IHC 'M' engine; this part goes on to explore the development of the 3, 6 and 10 HP models.

3 Horsepower: 1918

Production of the 3 horsepower type 'M' engines began in 1918 and continued through the Great Depression until 1937 (see figure 17). The very first few 3 horsepower 'M's used only one pushrod. Both exhaust valve and ignitor were operated by this single pushrod, which was quickly discontinued. The two push rod version was then adopted. From 1918 to approximately 1922, the 3 horsepower unit was built with the type 'L' low tension rotary gear driven magneto (see figures 4 and 5 in S/O 82 GEM). It was the same in every way as the magneto used on the 1 horsepower 'M' except for the number of teeth on the gear. Location of the drive gear was also within the crankcase. The engine was only offered in the kerosene version unlike the 1 horsepower. Carburation consisted of the two needle valve unit, one for fuel on the right and water on the left. It operated almost in the same way as the 1 horsepower engine.

1923

As with the 1 horsepower 'M' the 3 horsepower underwent similar changes. International offered the high tension American Bosch magneto, but only 1000 of these were built with this option between the years 1923 and 1932. White metal was used instead of cast iron for the fuel pump and the needle valve heads.

A new carburetor was added. It featured three needle valves, a take apart body, and individual chamber drains for kerosene, gasoline and water (see figures 8 and 9 in S/O 82 GEM). The crank-case hatch was changed from the butterfly fastener to four machine bolts.

The Wico type 'EK' magneto was offered with the engine in addition to the American Bosch type 'S' (see figures 12, 13 and 14 in S/O 82 GEM). At the same time the International Harvester type 'L' rotary low tension magneto and ignitor were retired. The spark plug was positioned on the governor side of the head and to the left of the intake valve. From the years 1918 to 1922 a total of 75,310 3 horsepower engines were built with the type 'L' magneto. Later, 27,885 engines were built with either the Wico EK or the American Bosch 'S'. In 1937 the list price was $95.00 and only 48 units were built. A total of 103,195 3 horsepower engines were manufactured in 19 years of production.

6 Horsepower: 1918

International Harvester offered the 6 horsepower 'M' to the public in 1918. The developments and design of this engine paralleled the 3 horsepower unit except for the following items: 1) The magneto was a low tension International Harvester type 'R' rotary gear driven unit, (see figures 18 and 19 The ignitor was the same as the 3 and 1 horsepower units. They were in fact interchangeable) 2) The Flywheels had dogs to which a flat pulley or clutch was bolted. 3) The head was always water cooled.

1923

The wing nut type rear access hatch fastener was changed to the plate and four machine bolts, (see figures 6 and 7 in S/O 82 GEM). White metal was used for the fuel pump casting as in the needle valve heads. Two part construction and three needle valves were used on their 'improved' carburetor. The rotary type 'R' drive gear was also cast in white metal. (Drive gears similar to this appeared intermittently on the smaller horsepower units.)

1924

High tension ignition supplied by the Wico EK or the American Bosch 'S' replaced the type 'R' low tension magneto and ignitor. Only 491 6 horsepower engines were sold with the American Bosch rotary magneto. The remainder were equipped with the Wico type 'EK'. (see figures 12, 13 and 14 in S/O 82 GEM) When production of the 6 horsepower ceased in 1937 the list price was $165.50. A total of 56,788 engines were manufactured in the 19 years of production between 1918 and 1937.

10 Horsepower: 1920

Production of the 10 horsepower type 'M' started in the middle of 1920 and continued into the 1930s. Low tension ignition was supplied. Type 'U', 'O', and 'OL' International rotary impulse magnetos were commonly used, (see figures 20, 22 and 23). The tripping mechanism for the ignitor and the magneto itself were both exposed on the outside of the engine. A long push rod directly connected the ignitor to the impulse trip arm located on the end of the armature shaft of the magneto. This push rod was used so the ignitor would be struck the instant the magneto was tripped, (see figure 21)

In this early production the 10 horsepower version was also manufactured with two needle valves, a one piece carburetor, a cast iron fuel pump and wing nut type crankcase access hatch. As with the 6 horsepower unit the 10 horsepower offered machined dogs on the flywheel for the mounting of a pulley or clutch.

1927

In 1927 International discontinued the use of the low tension type 'U', 'O', and 'OL' magnetos, (see figures 20, 22 and 23) These were replaced with the Wico 'EK' and the American Bosch 'S'. (see figures 12 & 13 in S/O GEM) Only 317 10 horsepower engines were supplied with the American Bosch 'S' ignition. The 7/8 inch thread spark plug was mounted on the magneto side of the head and recessed at an angle. Water was used to cool the engine head. Like other 'M' engines the fuel pump and needle valve heads were changed to white metal. The carburetor was changed to the two piece design with three needle valves. In 1933, only 18 10 horsepower engines were built. However, they were sold as late as 1936 for a list price of $320.50. During the 13 years of production only 6249 of these units were built. From the beginning, the 10 horsepower 'M' was the only engine that offered a partial base.

TIMING OF THE IGNITION AND VALVES

To help collectors of International and McCormick Deering type 'M' engines, included is a procedure on ingition and valve timing.

Figure 24 shows a diagram and specific timing marks for valves and ignition. The following procedure is recommended to adjust these engines: 1) Turn the flywheels clockwise so that lines 'A' on the flywheel align with 'B' on the crankcase. 2) The ignitor should be at the immediate point of tripping as shown with push finger 'E' and ignitor 'F'. 3) At the same time align factory scribe mark 'J' on the magneto bearing with scribe 'I' on the end of the magneto armature shaft. They can align either way. 4) Without turning the flywheels, marks 'C' on the eccentric-plate should be in line with mark 'D' on the side of the magneto bracket and also with the center of the magneto shaft. Scribe marks 'I' and 'J' must align perfectly to allow for the peak electrical current to be in synchronization with the tripper of the ignitor. (If 'I' and 'J' do not line up when 'A' on the flywheel is in line with 'B' on the crankcase, the magneto gear should be shifted forward or back so that the scribes come in line.) 5)Rotate the flywheels slowly by hand until push finger 'E' is between 5/32' and 3/16' from the ignitor lever 'F'. (see figure 25) At this time the push finger should be in the farthest position from 'F'. 6) If an adjustment is necessary, the trip finger and rod 'E' may be turned one or more turns after loosening the nut and screw 'C'. If the above adjustment was necessary then 'A' and 'B' should be checked again to make sure the spark still occurs at the proper point. 8) The tripping of the ignitor is adjusted by either adding or removing shims at 'H'.

In reference to figure 24, the exhaust valve should close when 'B' on the crankcase is in line with 'N' on the flywheel. Adjustment for this is made by turning pushrod 'L' one or more times either way, after loosening lock nut 'M'. Lengthening the rod allows the exhaust valve to open earlier.

To further help International 'M' owners with the identification as to the date of manufacture of engine, a serial number list of all 'M' engines is supplied.

Research for this writing has been taken from original International Harvester manuals, catalogs, documents, books, sales literature, and engine collectors. The possibility for mistakes in my history of the 'M' engines exists, although I have done my best to write an accurate article. Correspondence concerning this article, corrections and the International model 'M' farm engines will be graciously received. All letters containing self-addressed, stamped envelopes will be answered.

SERIAL NUMBERS FOR IHC TYPE 'M' ENGINES

1? HP with type 'L' rotary magneto 650 RPM kerosene

3 HP with Wico high tension impulse magneto, kerosene

1917

A101 to A1969

1918

A1970 to A19491

1919

A19492 to A42764

1924

BW101 to BW585

1920

A42765 to A70744

1925

BW586 to BW8484

1921

A70745 to A82429

1926

BW8485 to BW16472

1922

A82430 to A85630

1927

BW16473 to BW23229

1923

A85631 to A99317

1928

BW23230 to BW28066

1? hp with American  Bosch type 'S ' rotary high tension magneto , 500 RPM gasoline

1929

BW28067toBW33204

1930

BW33205 to BW37466

1931

BW37467 to BW38250

1932

BW38251 to BW38433

1923

AA101 to AA5140

1933

BW38434 to BW38440

1924

AA5141 to AA11100

1934

BW38441 to BW39200

1? hp with Wico  EK high tension impulse magneto 500 RPM gasoline

1935

BW39201 to BW39294

1936

BW39295 to BW39326

1937

BW39327 to BW39375

1924

AW101 to AW3227

6 HP with low  tension type 'R' rotary magneto kerosene

1925

AW3228 to AW23292

1918

C101 to C751

1926

AW23293 to AW43871

1919

C752 to C6872

1927

AW43872 to AW61359

1920

C6873 to C16142

1928

AW61360 to AW73819

1921

C16143 to C20457

1929

AW73820 to AW90719

1930

AW90720 to AW100259

1931

AW100260 to AW106866

1922

C20458 to C25767

1932

AW106867 to AW111502

1923

C25768 to C31468

1? HP with American Bosch 'S' rotary 1 high tension magneto, 500 RPM, kerosene

1924

C31469 to C34574

6 HP with high tension American Bosch  'S' rotary magneto, kerosene

1924

C34575 to C34729

1925

C34730 to C34823

1923

AB101 to AB152

1926

C34824 to C34970

1924

AB153 to AB1060

1927

C34971 to C34993

1925

AB1061 to AB1785

1928

C34994 to C35025

1926

AB1786 to AB1879

1929

C35026 to C35034

1927

AB1880 to AB1922

1930

C35035 to C35057

1928

AB1923 to AB2005

1931

C35058 to C35067

1929

AB2006 to AB2030

1932

C35068 to C35071

1930

AB2031 to AB2038

1931

AB2039 to AB2045

1934

C35072 to C35074

1932

AB2046 to AB2047

6 HP with Wico  EK high tension impulse magneto, kerosene

1? HP with Wico EK high tension magneto, 500 RPM kerosene

1924

AX101 to AX529

1925

CW101 to CW2296

1925

AX530 to AX3406

1926

CW2297 to CW7101

1926

AX3407 to AX5343

1927

CW7102 to CW11201

1927

AX5344 to AX7451

1928

CW11202 to CW14400

1928

 AX7452 to AX10273

1929

CW14401 to CW17971

1929

 AX10274 to AX13177

1930

CW17972 to CW19988

1930

AX13178 to AX16091

1931

CW19989 to CW20632

1931

 AX16092 to AX16332

1932

CW20633 to CW21202

1932

 AX16333 to AX16473

1933

CW21203 to CW21207

1933

 AX16474 to AX16539

1934

CW21208 to CW21470

3 HP with low tension type 'L' rotary magneto, kerosene

1935

CW21471 to CW21782

1918

B101 to B3037

1936

CW21783 to CW21854

1919

B3038 to B15812

1937

CW21855 to CW21960

1920

B15813 to B37585

10 HP with type  OL and U low tension oscillating magnetos, kerosene

1921

B37586 to B42782

1922

B43783 to B45950

3 HP with high tension American Bosch magneto, kerosene

1920

D101 to D1389

1922

B45951 to B49812

1921

D1390 to D2748

1923

B49813 to B59659

1922

D2749 to D3075

1924

B59660 to B64818

1923

D3076 to D3929

1925

B64819 to B65031

1924

D3930 to D3954

1926

B65032 to B65393

1925

D3955 to D4227

1927

B65394 to B65321

1926

D4228 to D4679

1928

B65322 to B65361

1927

D4680 to D4782

1929

B65362 to B65380

10 HP with high tension American Bosch rotary magneto , kerosene

1930

B65381 to B65385

1928

D4783 to D4861

1931

B65386 to B65391

1929

D4862 to D4980

1932

B65392

1930

D4981 to D5051

1931

D5052 to D5068

1932

D5069 to D5081

1933

D5082 to D5100

10 HP with high  tension Wico EK impulse magneto, kerosene

1927

DW157 to DW671

1928

DW672 to DW847

1929

DW848 to DW1183

1930

DW1184 to DW1330

1931

DW1331 to DW1401

1932

DW1402 to DW1425