Hercules Engine News

Hercules X Model Engines

Hercules Model XK

A 6HP Hercules Model XK, serial number 15795, built in 1929.

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Early in 1928, the Hercules Products Division of Servel, Inc. began producing the X model line of engines. The 1 -3/4 HP, 2- HP and 3- HP sizes were new designs. The 6 HP and 8 HP sizes were the same as their older models, with the exception of three-hole, disc type flywheels rather than the traditional spoke type.

A 1- HP and a 6 HP are shown here, and as you can see one of their most outstanding features was the three-hole flywheel. Almost all of the engines built were the XK Model (kerosene), with only a few of the XI (gasoline only) Model engines being produced.

Total production of the X model line came to 17,500 engines. I currently have 214 X model engines on my list that I have seen or that have been reported to me. The lowest known serial number at this writing is 1,317, and the highest is 18,357. The three smaller sizes were produced and sold for only two years. The Sears catalogs show them beginning in the fall of 1928 and ending in the spring of 1930.

Many of X model engines have casting dates on one or more of their parts, and the table below (Table One) shows engines where the casting dates were recorded.

Seventy-five percent of X model engine production were the Economy brand, the remaining 25 percent being the Hercules brand. It is interesting to note that after serial number 17,000 most of the production was in the 6 HP and 8 HP sizes. That is because production of these two sizes continued into 1933, and these were sold by Sears along with the J models, which were introduced in 1930. Production of the smaller size X model engines was discontinued in 1930.

TABLE ONE:

Comparison of Casting Dates, Serial Numbers and Brand

Serial Number

Casting Date

HP

Model

Brand

1,461

4-21-28

2-

XK

Economy

1,540

5-14-28

1-

XK

Economy

7,128

1-1-29

6

XK

Hercules

7,298

1-14-29 (head)

1-

XK

Economy

1-31-29 (block)

8,024

2-27-29

1-

XK

Hercules

8,669

1-26-29

3-

XK

Hercules

9,032

4-11-29

6

XK

Unknown

9,897

3-28-29

1-

XK

Economy

12,063

7-6-29

3-

XK

Economy

13,069

8-15-29

1-

XK

Hercules

13,970

4-25-29

1-

XK

Economy

14,544

9-11-29

1-

XK

Economy

15,557

9-20-29

1-

XK

Economy

15,889

10-22-29

1-

XK

Economy

17,740

3-25-30

8

XK

Economy

TABLE TWO:

X Model Production Breakdown by Size

HP

Number Known

Percentage

Estimated Production

1-

110

51

8,925

2-

24

11

1,925

3*

2

1

175

3-

21

10

1,750

4*

6

3

525

6

39

18

3,150

8

12

6

1,050

Total:

214

100

17,500

These 3 HP and 4 HP sizes were simply re-rated 2- HP and 3- HP sizes. They are seldom seen and came out very near the end of production.

An unrestored 1- HP Hercules Model XK, serial number unknown. These engines were produced from 1928 to 1929.

The second table represents a breakdown of sizes and production of X model engines, as near as I know. While all these numbers might seem confusing, and perhaps even boring, these bits of history are important to have generally available - they don't do the gas engine hobby any good if they're just written down in a book in my house. Any additional information on X model engines or casting dates is welcomed and will be added to the list.

Glenn Karen is a noted authority on Hercules engines. Contact him at: 20601 Old State Rd., Haubstadt, IN 47639, or e-mail at: glenn.karch@gte.net