Reconditioning Cast-in-Block Engines and Fitting of Sleeves

[Reconditioning Cast-in-Block Engines and Fitting of Sleeves]
[From the U.S. Government Publishing Office, www.gpo.gov]

RECONDITIONING CAST-IN-BLOCK
ENGINES AND FITTING
OF SLEEVES
Prepared for vehicle maintenance section
DIVISION OF MOTOR TRANSPORT
OFFICE OF DEFENSE TRANSPORTATION
by MAINTENANCE METHODS COORDINATING COMMITTEE OF TRANSPORTATION AND MAINTENANCE ACTIVITY SOCIETY OF AUTOMOTIVE ENGINEERS, INC.
GOVERNMENT PRINTING OFFICE - WASHINGTON - 1943
SAE Maintenance Methods Coordinating Committee
w. J. Cumming, Chairman, Chief, Vehicle Maintenance Section Division of Motor Transport
Office of Defense Transportation
E. P. Gohn, Test Engineer The Atlantic Refining Company
M. E. Nuttila, Superintendent, Motor Vehicles Cities Service Oil Company
G. W. Laurie, Manager, Automobile Transportation Dept. The Atlantic Refining Company
J. Y. Ray, Supervisor, Automobile Equipment Virginia Electric & Power Company
S. B. Shaw, Automotive Engineer Pacific Gas & Electric Company
W. A. Taussig, Automotive Engineer Burlington Transportation Company
E. W. Templin, Automotive Engineer Los Angeles Department of Water & Power
D. K. Wilson, Superintendent, Automobile Equipment New York Power and Light Corporation
A. M. Wolf, Automotive Consultant
Subcommittee on Reconditioning Cast-in-Block Engines and Fitting of Sleeves
D. B. Erminger, Chairman, Assistant Service Manager International Harvester Company
E. H. Blakelock, Shop Superintendent • Quaker City Motor Parts
H. L. Eberts, Assistant to General Manager Small Electric Motors, Ltd.
A. W. Lines, General Manager Sealed Power Corporation
J. R. Nelan, Shop Foreman County of Los Angeles, Road Department Floyd Patras, Manager Maintenance Southwestern Greyhound Lines Edwin W. Whitman, Superintendent of Shop K & G Auto Parts, Inc.
E. P Gohn
Project Chairman
RECONDITIONING CAST-IN-BLOCK ENGINES
AND FITTING
OF SLEEVES
INTRODUCTION
In considering cylinder sleeves, the Committee found it necessary to divide this report into three parts:
(A) Salvaging and reconditioning cast-in-block engines by installing dry-type cylinder sleeves.
This section treats the subject of installing dry cylinder sleeves in an engine not designed for the use of sleeves as a means of salvaging the engine when damage or wear to one or more cylinders makes such a step necessary.
(B) Reconditioning and replacing dry-type cylinder sleeves in replaceable cylinder-sleeve engines.
This section is an outline for the installation and maintenance of dry cylinder sleeves when used in an engine designed for their use and originally equipped with them.
(C) Reconditioning and replacing wet-type cylinder sleeves in replaceable cylinder-sleeve engines.
This section is an outline for the installation and maintenance of wet cylinder sleeves when used in an engine designed for their use and originally equipped with them.
(A) SALVAGING AND RECONDITIONING CAST-IN-BLOCK ENGINES BY INSTALLING DRY-TYPE CYLINDER SLEEVES
Taking up each division of the subject in the order stated, we can report in connection with the first division that this practice is believed to be entirely practical and advisable when any of the following conditions exist:
1. The diameter of the oversizing required will be greater than the safe maximum specified by the engine manufacturer or will necessitate the removal of more than Xe-inch (0.062) of metal from the cylinder bore, which is the limit except where cylinder wall thickness is known to be sufficient to permit greater oversize.
2. The cylinder walls are deeply scored or cracked, necessitating the removal of more than %6-inch (0.062) of metal.
3. The porosity of the metal is such that leakage is visible under test.
Note.—Despite the widespread misconception among truck users, the use of cylinder sleeves of any type has never necessitated, and does not now necessitate, the complementary use of special pistons or rings. Standard pistons and rings are entirely satisfactory.
PREPARATION FOR INSTALLATION OF DRY-TYPE SLEEVES
The paramount consideration when installing drytype sleeves in cast-in-block engines is to obtain the best possible fit of sleeve to block. Only a close and uniform fit will assure adequate transfer of heat from piston and rings through the sleeve to the cooling section of the block.
Inasmuch as the sleeve outside diameter contour always conforms to the contour of the block bore and reflects any irregularities therein, it is essential that the bore of the block be as true as careful workmanship can make it. The greatest accuracy must be observed in boring and machining if distortion of the sleeve, with subsequent corrective honing, is to be avoided. The machining can be done with either a precision cylinder grinder or a boring bar. More than one grind or cut should be made to obtain the finished size.
The specification for the fit of the sleeve to the bore depends on which type of sleeve is being installed, whether it be the cast iron sleeve of comparatively low Brinell rating (200 minimum) or the steel sleeve with high Brinell rating (460 minimum). The usual fit for the cast iron type of sleeve is a shrink or press fit of 0.002 to 0.003 inch whereas a line-to-line fit is considered satisfactory in the case of the high Brinell type steel sleeve (except in rare instances where extremely thin sleeves are used, in which cases a slightly tighter fit is necessary). Where a plain sleeve of this type is to be used, it is recommended that a shoulder be left in the bottom of the bore in order to lock the sleeve in place between its shoulder and the cylinder-head gasket. Where it is possible to install a sleeve with a shoulder at the top to register with a groove at the top of the
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bore, a shoulder in the bottom of the bore is not necessary.
INSTALLATION METHODS
The practicability of three methods of installing dry-type cylinder sleeves in cast-in-block engines has been well demonstrated:
1. Use of puller assembly (as illustrated).
2. Use of air hammer equipment.
3. Expansion of cylinder bore and contraction or shrinkage of cylinder sleeve.
Figure 1.—Use of sleeve puller assembly for installing sleeve with use of suitable lower plate.
1. USE OF PULLER ASSEMBLY
The first of these methods, the puller method, requires that, prior to insertion in the bore, the outside diameter of the cylinder sleeve be given an even coat of thin white lead or hydraulic brake fluid. This precaution prevents scoring of the sleeve as it is pulled in.
Care should be exercised to start the sleeve in
squarely, in order to prevent “cocking” or distortion. It should be drawn down with an even pull until it is flush with the top of the cylinder block.
When a number of sleeves are to be installed, say 6, they should be installed in alternate bores as, for * example, 1, 3, and 5 followed by 2, 4, and 6. This procedure, permitting the block and sleeves to normalize themselves gradually, is a safeguard against distortion, with implied complications.
Upon completion of the installation of sleeves in a block, the inside diameter of each sleeve should be measured with inside micrometer and dial indicator for possible distortion resulting in a taper or out-ofround condition which would impede piston travel. If either condition is indicated it should be corrected by reboring or honing.
In order to remove all abrasive particles, the installed cylinder sleeves should be washed out with soapy water, flushed with clear water, and dried with air. When dry, the cylinder sleeves should be lubricated without delay to prevent rusting.
Running clearance between piston and cylinder wall should be checked with steel ribbons or feeler blades of specified thickness and tension pull.
2. USE OF AIR HAMMER
The second installation method, the air-hammer method, is the same in principle as the puller method just described in that the cylinder sleeve in each case is forced into the block bore under strong pressure. The air-hammer method, however, does differ in the following detail: •
To use the air hammer it is necessary to make up a “driving” plate that will fit the inside diameter and outside diameter of the cylinder sleeve and take the blows of the hammer. The plate must be strong enough to withstand blows of half the operating pressure of a small air hammer and must be secured in some way so that it will remain in constant contact with the sleeve (to prevent damaging the end of the sleeve).
In all other respects the installation technique given in the previous section for the puller method applies throughout the air-hammer method and need not be repeated here.
3. EXPANSION AND SHRINKAGE METHOD
This third sleeve installation method for cast-in-block engines differs from the preceding two in that it does not demand the exercise of force. Under this method the engine block is filled with hot water to bring about expansion or enlargement of the bores, while the cylinder sleeves are chilled by dry ice or other refrigerant to bring about shrinkage and a a reduced outside diameter. Ordinarily under this method the sleeve can be installed by hand but may sometimes have to be tapped in (with a soft wood block).
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Under this method sufficient time must be allowed for the block and sleeves to normalize themselves as to temperature before the bores are checked for taper and out-of-round, running clearance, etc., as described in connection with the puller assembly method.
(B) RECONDITIONING AND REPLACING
DRY-TYPE CYLINDER SLEEVES IN REPLACEABLE CYLINDER-SLEEVE ENGINES
RECONDITIONING DRY-TYPE SLEEVES
It is accepted practice, when required, to oversize dry-type sleeves for larger pistons up to the limit of manufacturers’ recommendations, which run from 0.040 inch to 0.060 inch. Sleeves which cannot be oversized within specified limits definitely should be replaced.
The method of oversizing dry-type sleeves depends on the material in them. If the sleeve material has a low Brinell rating, a boring bar, grinder, or hone can be used very satisfactorily. If the sleeve has a high Brinell rating, a boring bar cannot be used and the sleeve must be oversized by grinding or by use of a hone with stones of special grit. Naturally the oversizing of a high-Brinell type sleeve involves considerable work, for which reason only the minimum amount of metal should be removed.
No measurements for distortion, running clearance, etc. should be taken before the bore has had time to cool and normalize itself.
REPLACING DRY-TYPE SLEEVES
Whenever sleeve oversizing requirements exceed the manufacturers’ recommendations, the sleeve should be replaced.
Pullers which are available or can be made up locally are very satisfactory for the removal of used sleeves.
It is recommended that, following removal of the sleeves, a hone with fine-cutting stones be passed through the bores of the block to polish the surfaces. The polishing not only facilitates installation of the new sleeves but assures maximum contact of sleeve to bore for most efficient transfer of heat.
Before installation the outside diameter of each sleeve should be measured to make sure it is the right size for the bore in which it is to be installed. Installation of sleeves will be further facilitated and scoring prevented if the outside surface is given an even coat of thin white lead or hydraulic brake fluid.
As the three commonly approved methods of installation have been described in detail in another action, the reader is referred to that section for particulars.
(C) RECONDITIONING AND REPLACING WET-TYPE CYLINDER SLEEVES IN REPLACEABLE CYLINDER-SLEEVE ENGINES
For various reasons manufacturers of wet-type replaceable cylinder-sleeve engines have in the past been reluctant to approve the oversizing of wet cylinder-sleeve bores and installation of oversize pistons as a remedy for cylinder-sleeve wear or damage. The three main objections cited by the manufacturers are: First, the general unavailability of skilled mechanics and the precision reboring equipment necessary for a good job; second, the
Figure 2.—Use of sleeve puller assembly for removing sleeve with use of suit able lower plate.
frequent dissatisfaction of owners with the jobs turned out as compared with a straight replacement job; and, third, the much longer time the truck is “down” as compared with straight-replacement “down” time.
Today, however, owing to the necessity of conserving metal required for the country’s war effort, the practice of oversizing wet-type sleeves is favorably regarded so long as all necessary precautions are
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taken in reconditioning the sleeve. The oversizing must of course be held within the specified limits of 0.040 inch to 0.060 inch, except in the case of extremely heavy sleeves, when larger tolerances are permissible.
Regarding oversizing procedure we make the following recommendations:
As experience has proved the impracticability of grinding, honing, or boring out wet-type cylinder sleeves in their original block or case, it is definitely recommended that sleeves be removed from the block and placed in a special fixture affording at least a line-to-line fit. A line-to-line fit will prevent movement of the sleeve during the operation.
It is the absence of a line-to-line fit between a wettype sleeve and the block which makes it impracticable to oversize these sleeves in their original blocks. Clamping the sleeve at the top to prevent movement during oversizing strongly tends to distort the upper section of the sleeve while failing to prevent movement at the lower end, owing to the resilience of the rubber seal ring or gasket. Consequently,
it is almost impossible to make a straight or round bore in this manner.
Removal of sleeves is accomplished by means of a puller (see illustration) or a hydraulic jack or press. Usually wet-type sleeves need be forced only about one inch, or until the sleeve breaks loose and clears the seal ring. A sleeve can then be lifted out by hand.
The rubber seal ring should be removed immediately, before it hardens. The ring groove should be thoroughly cleaned, as should the retaining flange and lower end of sleeve-support surfaces and the entire outside diameter of the sleeve.
To facilitate installation, the new seal ring should be coated with white lead or a mixture of heavy soap suds and glycerin. The sleeve should then be pushed gently into place, care being taken to prevent damaging the rubber ring. In the majority of cases no pushing tool is necessary.
It is finally recommended, that the manufacturers' instructions covering sleeve replacement be followed in all cases.
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