I happened upon this guide to ID TEC engines. Hope this of some use!
Tecumseh" engine code decipher list.
V = Vertical Shaft
LAV = Lightweight Aluminum Vertical {engine}
VM = Vertical Medium Frame {engine}
TVM = Tecumseh Vertical {medium frame}
VH = Vertical Heavy Duty {cast iron}
TVS = Tecumseh Vertical Shaft
TNT = Toro N' Tecumseh
ECV = Exclusive Craftsman Vertical
OVM = Overhead Valve vetical Medium Frame {engine}
H = Horizonal Shaft
HS = Horizonal Small Frame {engine}
HM = Horizonal Medium Frame {engine}
HHM = Horizonal Heavy Duty {cast iron} Medium Frame {engine}
HH = Horizonal Heavy Duty {cast iron}
ECH = Exclusive Craftsman Horizonal
An Example is: TVS90-43056A serial #8310C
TVS = Tecumseh Vertical Shaft
90 = 9 Cubic Inch Displacement
43056A = Specific number for parts identification
8310C = Serial number
8 = Year of manufacturing {1978}
310 = Calendar day of the year {310th day in year of 1978}
C = Assembly line and shift when the engine was built.
SBH = Short Block Horizonal
SBV = Short Block Vertical
OH = Overhead Valve Heavy Duty {cast iron}
Examples: OH160...OH120
Overhead Valve 160 equals 16 horsepower
Overhead Valve 120 equals 12 horsepower
Recommended oil viscosities for Aluminum Engines:
Above 32 degrees: 30 weight or 10W30
Below 32 degrees: 5W30
Below 0 degrees: 5W30 or 10W
Recommended oil viscosities for Cast Iron Engines:
Above 32 degrees: 30
Below 32 degrees: 10W
Spark Plug Gap: .030 inch
Older model engines using points and condensers:
Ignition Point Gap: .020 inch
Valve Clearance: Refer to note below
============ ========= ========= ========= ========= ========= ========= ====
> > ========
>>>>>NOTE PLEASE READ<<<<
".005 int/.010 ex refers to OHV engines (OH and HH models), while .010/.020 refers to HH100 & HH120 L-Head models. What may be confusing is that some of the older OHV models had an HH150, HH150 designation, and later become OH numbers."
Tecumseh" engine code decipher list.
V = Vertical Shaft
LAV = Lightweight Aluminum Vertical {engine}
VM = Vertical Medium Frame {engine}
TVM = Tecumseh Vertical {medium frame}
VH = Vertical Heavy Duty {cast iron}
TVS = Tecumseh Vertical Shaft
TNT = Toro N' Tecumseh
ECV = Exclusive Craftsman Vertical
OVM = Overhead Valve vetical Medium Frame {engine}
H = Horizonal Shaft
HS = Horizonal Small Frame {engine}
HM = Horizonal Medium Frame {engine}
HHM = Horizonal Heavy Duty {cast iron} Medium Frame {engine}
HH = Horizonal Heavy Duty {cast iron}
ECH = Exclusive Craftsman Horizonal
An Example is: TVS90-43056A serial #8310C
TVS = Tecumseh Vertical Shaft
90 = 9 Cubic Inch Displacement
43056A = Specific number for parts identification
8310C = Serial number
8 = Year of manufacturing {1978}
310 = Calendar day of the year {310th day in year of 1978}
C = Assembly line and shift when the engine was built.
SBH = Short Block Horizonal
SBV = Short Block Vertical
OH = Overhead Valve Heavy Duty {cast iron}
Examples: OH160...OH120
Overhead Valve 160 equals 16 horsepower
Overhead Valve 120 equals 12 horsepower
Recommended oil viscosities for Aluminum Engines:
Above 32 degrees: 30 weight or 10W30
Below 32 degrees: 5W30
Below 0 degrees: 5W30 or 10W
Recommended oil viscosities for Cast Iron Engines:
Above 32 degrees: 30
Below 32 degrees: 10W
Spark Plug Gap: .030 inch
Older model engines using points and condensers:
Ignition Point Gap: .020 inch
Valve Clearance: Refer to note below
============ ========= ========= ========= ========= ========= ========= ====
> > ========
>>>>>NOTE PLEASE READ<<<<
".005 int/.010 ex refers to OHV engines (OH and HH models), while .010/.020 refers to HH100 & HH120 L-Head models. What may be confusing is that some of the older OHV models had an HH150, HH150 designation, and later become OH numbers."