| CYLINDER HEAD SURFACING LIMITS |
Allowable Head Stock Removal On
1984 Chrysler(Renault) Encore 2.5L (150 CID) Engines
Engine overheating and other causes that lead to warpage and
leaks may prompt more late model aluminum cylinder heads to start
appearing in machine shops. Care should be used in obtaining
correct machining specifications.
An unmachined cylinder head on the above subject engine is
allowed to have .020 removed according to Chrysler (AMC) before
it is considered to be scrap. In one particular case the dealer
organization told the machinist only .005 could be removed.
Many aluminum cylinder heads may be saved by following sound
straightening methods before machining, such as those suggested
in Straightening Aluminum Cylinder Heads, published by AERA and
sent to all members last year or those outlined in the 1982
Proceedings.
The AERA Technical Committee
May 1985 - TB 349
##END## |
| CYLINDER HEAD SPECS. ON AMC/RENAULT 1.7L ENGINES |
Cylinder Head Specifications on
Chrysler (AMC/Renault) 1.7 & 2.0L Engines
The following machining and installation specifications should be observed when remanufacturing cylinder heads used on Chrysler (AMC/Renault) 1.7 & 2.0L engines. These engines are used in AMC Alliance, Encore and GTA automobiles.
According to Renault the cylinder head thickness is 6.673 +/- .007 (169.5 +/- .2mm). The maximum acceptable warp of the cylinder head deck face is .002 (.05mm). The cylinder head should not be resurfaced. Both intake and exhaust valves should be recessed .031 - .043 (.8 - 1.1mm) below the deck face of the
cylinder head.
Use the following procedure when installing a remanufactured cylinder head.
1. Clean head bolt threads. Apply oil to the threads and underneath the
head of the bolt.
2. Position the cylinder head gasket and mount the cylinder head.
3. Install the cylinder head bolts and tighten all bolts in sequence to
22 lbs.ft. (see illustration below)
4. Tighten all bolts in sequence to 52 lbs.ft.
5. Wait at least 3 minutes, then loosen all bolts completely.
6. Tighten all bolts in sequence to 15 lbs.ft.
7. Turn all bolts in sequence by 123o +/- 2o.
The AERA Technical Committee |
| CON. ROD & FLYWHEEL BOLT, ALLIANCE & ENCORE |
Connecting Rod And Flywheel Fastener Replacement On
All AMC Alliance And Encore Engines
American Motors Corporation advises AERA members that connecting
rod bolts and nuts used in its Renault engines (found in the
Alliance and Encore models) are not to be reused. American
Motors also advise that the flywheel, or driveplate, bolts should
not be reused either.
The engines affected by this warning are the C2J, C3J, F3N, 843,
A7L, J8S, and the J7T.
The advisement was issued because the connecting rod and flywheel
bolts in these engines are a torque to yield design that must not
be reused because of the bolt's stretching characteristics.
Erroneous torque values and in-service bolt breakage may result
from reusing a torque to yield bolt.
The AERA Technical Committee
June 1986 - SPB 133
##END## |
| 1980-86 CYLINDER HEAD SPECIFICATIONS |
Cylinder Head Specification for
1980-86 Chrysler (AMC Renault) 1.4L (85 CID) Engines
The following cylinder head specifications are for the Chrysler
1.4L (85 CID) C2J and C3J engines. Both engines are used in the
AMC Renault Alliance, Encore and Renault LeCar. Be sure to
verify the engine model number before surfacing the cylinder
head.
Type Cyl. Head Thickness
C2J Engines 2.866 +/-.002 new
2.846 +/-.002 minimumafter surfacing
C3J Engines 2.850 +/-.002 new
2.830 +/-.002 minimumafter surfacing
Cylinder head height (thickness) is measured from the deck
surface of the cylinder head to the rocker cover rail (A). The
cylinder head must be surfaced when distortion is in excess of
.002.
The two engines can be distinguished at the identification plate
attached to the cylinder block above the oil filter. If the top
line contains the number seven (7) immediately to the left of the
slash (/), then it is a C3J engine. All others are the C2J
engine. AERA members have found most vehicles equipped with the
C2J engine.
The AERA Technical Committee
March 1991 - TB 533R
##END## |
| VALVE LASH SPECIFICATIONS |
Valve Lash Specifications On
Chrysler (AMC Renault) 1.7 & 2.0L (105 & 122 CID) Engines
The Chrysler (AMC Renault) 1.7 & 2.0L (105 & 122 CID) engines use
a puck with a replaceable pad to adjust the valve lash. With the
engine cold, the recommended valve lash for the intake valves is
.008 (.20mm) and .015 (.40mm) for the exhaust valves (Figure
1).
Setting the valve lash requires mounting the camshaft and
camshaft caps to the cylinder head. Using the sequence outlined
in the illustration (Figure 2), torque bolts #11 & 12 (6mm
diameter) to 7 lbs.ft. and the remaining bolts (8mm diameter) to
15 lbs.ft. Apply a small amount of RTV sealer on the parting
face of each end camshaft bearing cap before installation. This
will guard against external oil leaks.
For additional information see AERA Technical Bulletins: TB 654,
395 & SB 36
The AERA Technical Committee
March 1991 - TB 747
##END## |
| VALVE CROSSHEAD CLEARANCE |
Valve Crosshead To Rocker Lever Clearance On
NH, NT & V-1710 Series Cummins Engines
Valve crosshead nose to rocker lever clearance on the subject engines must be checked during engine rebuild and at any time valve crossheads are replaced on engines using crossheads No. 123416 & 3000326. A minimum of .020 (.51 mm) clearance must be present as illustrated in Fig. 1, on the cylinder being checked with valves completely closed and crosshead in the upmost position. After installing rocker lever assemblies, check crosshead to rocker lever clearance as follows:
1. Turn crankshaft slowly in direction of rotation until the valves are closed on the cylinder being checked. With rocker lever held firmly against the stellite pad of the crosshead, a .020 (.51 mm) wire type feeler gauge must pass between the crosshead nose and the lower beam section of the rocker lever.
2. If the feeler gauge does not pass through:
a. Remove the rocker lever and/or crosshead and grind the nose of the crosshead or rocker lever beam in the area circled in Fig. 1 until enough clearance is obtained.
b. If the rocker is ground, grinding should cover the complete area illustrated in Fig. 2 in a continuous arc. Do NOT grind just the contact area.
Caution: A sharp depression in this area will cause a stress riser and eventual failure of the lever. Grind only enough material to achieve the required clearance. If grinding enters the oil passage, the rocker lever must be junked.
c. Grind sharp edges smooth.
The AERA Technical Committee |
| |
|
| CRANKSHAFTS INDUSTRIAL |
Crankshafts Used In Industrial Applications On
GM (Chevrolet) 5.7L (350 CID) Engines
When the GM (Chevrolet) 5.7L (350 CID) industrial engine is used in some applications such as lift trucks, the only crankshaft that is applicable has the forging number 1182. Dimension A of the rear flange is slightly smaller than that of other crankshafts used in General Motors 5.7L (350 CID) engines.
The larger flange crankshafts will not pass through the center hole of the bell housing. This is very critical when an oil clutch system is used.
The AERA Technical Committee |
| BURNED EXHAUST VALVES |
Burned Exhaust Valves, Low Power & Hard Starting On
Cummins NH & NT Engines With Jacobs Brake 25B & 30
Cummins Engine Co. reported that if the following complaints are experienced in the NH and NT engines equipped with Jacobs brakes, the slave piston clearance should be checked:
A. Exhaust valve burning
B. Low engine power when at operating temperature
C. Engine hard to start or will not start at operating temperature
A standard slave piston adjustment of .018 +/- .001 has been established. The .018 clearance setting is a cold setting which results in zero slave piston to crosshead clearance when the engine is at operating temperature.
Should the slave piston clearance setting be less than .018, the following conditions outlined in A, B or C above may result as well as affect breaking power.
If the slave piston clearance is greater than .018 +/- .001, the following problems may occur:
1. Engine injector train component problems
2. Injector carboning
3. Bent injector push rods
4. Worn injector adjusting screws
5. Decreased camshaft life
6. Cam follower and follower shaft failure
7. Delay in breaking action
If the above problems are experienced and the engine is equipped with a Jacobs brake, the slave piston clearance should be checked with the latest Cummins specifications.
The AERA Technical Committee |
| NEW CYLINDER LINER O-RINGS |
New Cylinder Liner O-Ring Seals On
Cummins NH/NT 6 Cylinder Engines
Cummins Engine Company has released new O-ring seals for the cylinder liners in NH/NT 6 cylinder engines. The new seals are made of an EP material and have a smaller diameter cross-section.
The new seal replaces both the old center seal #3008998 and the old lower seal #183049. The new seal carries Cummins part #3032874 and is black in color with one blue dot.
The new O-ring seals are not to be intermixed with the former seals on the same liner. Cylinder liner deformation will result. You can use the former seals and new seals in the same engine as long as they are used in the correct combinations on each liner. The illustration below shows the correct combinations.
The AERA Technical Committee |
