790412 Ml13Al/Ml13AlEl Improved Cooling System Alan J. Samuel and Alan M. Loss FMC Corp., Ordnance Engrg. Div. David M. Latson u. S. Army Tank-Automotive Materiel Readiness Command Congress and Exposition Cobo Hall, Detroit February 26-March 2, 1979 New TextDownloaded from SAE International by University of Auckland, Saturday, September 29, 2018ISSN 0148-7191 The appearance of the code at the bottom of the first page of this paper indicates SAE's consent that copies of the paper may be made for persona! or internal use, or for the personal or internal use of specific clients. This' consent is given on the con­ dition, however, that the copier pay the stated per article copy fee through the Copyright Clearance Center, Inc., Operations Center, P.O. Box 765, Schenectady, N.Y. 12301, for copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. Papers published prior to 1978 may also be copied at a per paper fee of $2.50 under the above stated conditions. SAE routinely stocks printed papers fora period of three years following date of publication. Direct your orders to SAE Order Department. To obtain quantity reprint rates, p~rmission to reprint a technical paper or per­ mission to use copyrighted SAE publications in other works, contact the SAE Publications Division. Copyright © 1979 Society of Automotive Engineers, Inc. Downloaded from SAE International by University of Auckland, Saturday, September 29, 2018u.s. ARMY ANALYSIS OF ENGINE PROBLEMS in the Ml13Al Family of Vehicles (FOV) led to the conclusion that the largest single automotive cause of vehicle downtime was the engine, and the major reason for engine downtime was the result of cooling system deficiencies. There­ fore, an improvement program was instituted. Generalized work being done jointly by FMC Corporation, Ordnance Engineering Division (FMC) and the u.S. Army Tank -Automotive Research and Development Command (TARADCOM) in tracked vehicle cooling system design was applied specifically to the Ml13A1 FOV (and to the M1l3A1E1) (1). * The M113A1 Armored Personnel Carrier, the basic vehicle of the M1l3A1 FOV, Fig. 1, is full-tracked, diesel-powered, weighs appro­ ximately 12.5 tons, and is designed to trans­ port 12 troops or cargo plus driver. It is capable of amphibious operation across lakes 790412 Ml13Al/Ml13AlEl Improved Cooling System Alan J. Samuel and Alan M. Loss FMC Corp., Ordnance Engrg. Div. David M. Latson u. S. Army Tank-Automotive Materiel Readiness Command and streams, of extended cross-country travel over rough terrain, and'of high speed opera­ tion on improved roads. The Ml13A1E1 is a product-improved, up­ powered, standard length or stretched version of the basic Ml13A1, weighing up to approxi­ mately 16.5 tons, currently under development by the u.S. Army. The M113A1 propulsion system consists of the Detroit Diesel 6V53 Engine rated 215 HP, the Allison TX100-l Automatic Transmission with torque converter, the FMC DS200 SteeL Unit and Transfer Gear Case. The M113A1E1 propulsion system consists of the Detroit Diesel 6V53T Engine rated 290 HP, and the Allison X200-3 Power Train. *Numbers in parentheses designate References at end of paper. u.S. Army studies concluded that engine problems in the Ml13A1 Family of Vehicles re­ sulted primarily from cooling system deficien­ cies. This conclusion led to the development of an Improved Cooling System (ICS) which provides approximately l50F coolant tempera­ ture reduction under full load, low speed/high tractive effort conditions; eliminates the collection of the oil and dirt mixture which packs on the radiator heat transfer surfaces; provides a negative pressure engine compart­ ment for CBR application and reduction of exhaust fume le