TM 5-2420-230-24-2
Glossary of Terms
Section i - Introduction
Page i-12
B Series
Glossary of Terms
Definition
A.C.:
Alternating Current
AFC:
Air Fuel Control; a device in the fuel pump that limits the fuel delivery until
there is sufficent intake manifold pressure to allow for complete combustion.
ATDC:
After Top Dead Center; refers to the position of the piston or the crankshaft
rod journal. The piston is moving downward on the power stroke or intake
stroke.
BDC:
Bottom Dead Center; refers to the position of the piston or the crankshaft rod
journal. The piston is at its lowest position in the cylinder.
BTDC:
Before Top Dead Center; refers to the position of the piston or the crankshaft
rod journal. The piston is moving upward on the compression stroke or ex-
haust stroke.
Circumferential Direction:
In the direction of a circle in respect to the centerline of a round part or a
bore.
Concentricity:
A measurement of the difference between the centers of either two or more
parts or the bores in one part.
CPL:
Control Parts List; this listing identifies the specific parts that must be in-
stalled on the engine to meet agency certification.
Cummins Sealant:
This is a one part Room Temperature Vulcanizing (RTV) silicone rubber, ad-
hesive and sealant material having high heat and oil resistance, and low
compression set.
Some of the equivalent products are Marston Lubricants, Hylosil, Dow Corn-
ing, Silastic 732, Loctite Superflex, General Electric 1473, and General Elec-
tric 1470.
D.C.:
Direct Current
Dye Penetrant Method:
A method used to check for cracks in a part by using a dye penetrant and a
developer. Use crack detection kit, Part No. 3375432, or its equivalent.
End Clearance:
The clearance in an assembly determined by pushing the shaft in an axial
direction one way and then pushing the shaft the other way.
E.S.N.
Engine Serial Number
Hammer:
A hand tool consisting of a hard steel head on a handle.
I.D.:
Inside Diameter
Loctite 290:
A single component, anaerobic, polyester resin, liquid sealant compound that
hardens between closely fitted metal surfaces producing a tough, hard bond.
An equivalent product is Perma-Lok HL 126.
Loctite 609:
A single component anaerobic, liquid adhesive that meets or exceeds the re-
quirements of MIL-R-46082A (MR) TYPE1.
Some of the equivalent products are Loctite 601 and Permabond HL 138.
Lubriplate 105:
A mineral oil base grease with calcium soap (2 percent to 6 percent), and
zinc oxide (2 percent to 4 percent) additives.
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