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VALVE REUSE GUIDELINES |
Valve Reuse Guidelines On
Honda Engines
The AERA Technical Committee is informing members of suggested valve reuse specifications on Honda engines. Unless service manuals provide specific measurements, the following guidelines for valve margin thickness should be considered:
Engines older than 1987: Discard the valve when the valve margin reaches .008 (.2mm) less than original thickness.
1987 and newer engines: The minimum valve margin is
.045 for intake and exhaust valves.
The valve stem and keeper grooves should also be inspected for wear when considering valve reuse.
AERA Technical Committee |
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SEIZED CAMSHAFTS |
Seized Camshafts On
1984-93 Honda 1.5L Engines
The AERA Technical Committee offers information that may reduce the possibility of seized camshafts on 1984-93 1.5L Honda engines. This engine uses a metered oil supply to the cylinder head by means of a restrictor located in the deck of the cylinder block.
Through time, the small hole in this restrictor may become partially blocked and limit the amount of oil flow to the cylinder head. Eventually, after many engine starts, a dry start condition may exist and cause a journal to score its camshaft bore.
Some AERA members are increasing the opening size of this oil restrictor anytime the cylinder head is removed from the block. Drilling the existing restrictor to .062 (1.575 mm) in size will increase the volume of oil to the cylinder head and camshaft. This should not overwhelm the cylinder head with oil, providing all other oil clearances are within specifications. This procedure has been done many times and should help prevent a seized camshaft journal in
this engine.
The AERA Technical Committee |
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VALVE GUIDE REPLACEMENT ON HONDA 4 CYLINDER ENGINES |
Valve Guide Replacement On
Honda 4 Cylinder Engines
Some AERA member machine shops have adapted the following technique for replacing valve guides on Honda cylinder heads.
Honda recommends heating the cylinder head to 300oF to ease removal and installation of the valve guides. Removal of the guide is best accomplished by tapping the whole inside of the guide for an appropriate bolt that can be attache to a slide hammer. Even if the guide breaks off in the center during
removal, the other end is ready for a second attempt.
Honda replacement guides are generally semi-finished and need to be honed or reamed to size after installation. Some members have reported great difficulty reaming the guide after installation. This may be caused by the heat treating process the guides are subjected to as part of the manufacturing process.
One solution is to chuck the guide into a lathe and using an ordinary shop drill bit, drilling the inside diameter almost to size. Guides prepared in such a way are very easily reamed or honed to size after installation.
The AERA Technical Committee |
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OIL PUMP PRIMING ON HONDA 4 CYLINDER ENGINES |
Oil Pump Priming on
Honda 4 Cylinder Engines
AERA members have reported difficulties in priming the oil pump on Honda 4 cylinder engines when starting the engine for the first time.
There are two simple steps that can be taken to overcome this problem. Remove the oil filter and inject oil into the center of the oil filter base while slowly baring the engine over backwards. Fill the oil filter with clean engine oil and reinstall.
This problem can also be guarded against during engine assembly. Before installing the oil orifice into the cylinder block and mounting the cylinder head, inject oil into the passage that contains the orifice. Be sure to install the oil orifice to prevent excess oil from filling the rocker cover during normal
operation.
The AERA Technical Committee |
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OIL LEAK ON 1989-91 HONDA 1.5 & 1.6L ENGINES |
Engine Oil Leak On
1989-91 Honda 1.5 & 1.6L Engines
The AERA Technical Committee offers the following information regarding an engine oil leak on 1989-91 Honda 1.5 & 1.6L engines. Some vehicles that were produced during the mentioned years may have an oil leak around the spark plug well. The spark plug area of the camshaft holder casting could be porous and may leak.
If normal diagnosis and repairs do not fix the above-mentioned concern, installation of a new cam holder kit, Part #041 01-PM3-308, H/C: 3046497, will be required. To properly install the new kit, removal of the spark plugs and valve cover need to be done. Upon removal of the valve cover, inspect valve cover rubber seals. If any signs of damage have occurred, replace rubber seals as needed.
Turn the engine to TDC and remove the timing belt adjuster and remove the timing belt and the rocker arm assembly. Check clearance between the new camshaft holders and the camshaft by coating the new cam holder with oil and install them without the rocker arms and shafts. Install the required bolts and torque them to 16 ft/lbs. While using an INCH lb torque wrench, turn the camshaft and check the amount of force. If the turning torque is greater than 112 in/lbs, the camshaft holder may need to be polished.
If the holders need to be polished, rotate the camshaft several times to establish contact marks inside the holders. Remove the holders and inspect for contact marks on the surface. Polish the marks with a #500 grit emery paper and then finish with a #800 grit emery paper. Wash the camshaft holder and install so that turning torque can be checked. If turning torque is still not acceptable, continue with the polishing process.
NOTE: Incorrect turning torque can result in camshaft seizure due to insufficient clearance.
The AERA Technical Committee |
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TIGHT DRIVE BELTS CAUSE CRANKSHAFT DAMAGE |
Tight Drive Belts Cause Crankshaft Damage On
1992-94 Honda 1.5L Engines
The AERA Technical Committee advises members of an installation procedure on Honda 1.5L engines that may cause damage to the crankshaft. Subsequent to most engine repairs that may be done, one of the final procedures required is the installation of the accessory drive belts.
If an accessory drive belt is overtightened, excessive side loading will result on the crankshaft pulley bolt causing it to loosen or break. Side loading can also cause main bearing damage and wear in the crankshaft keyway.
Honda indicates the most accurate method of adjusting their serpentine drive belts is to use a torque wrench. First, with the idler pulley nut finger tight, rotate the engine in the direction of rotation two complete turns. Then, torque the belt adjusting screw to 40 in. lbs. (see figure 1). Finally, torque the idler pulley nut
to 35 ft. lbs.
The crankshaft pulley bolt mounting torque is equally as important at installation and should not exceed 83 ft. lbs. Be sure to lubricate lightly with engine oil the underside of the bolt flange and bottom threads only, as indicated in figure 2 below.
The AERA Technical Committee |
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CYLINDER SLEEVE REMOVAL & INSTALLATION PROCEDURE |
Cylinder Sleeve Removal & Installation On
Honda 750 cc Motorcycle Engine
The cylinder sleeves on a Honda 750 cc motorcycle engine may be
removed from the cast aluminum body by heating the assembly to
275^ F. At this temperature the liners will literally fall out
of the casting.
WARNING: The fins on this casting are very thin so, if possible,
use an oven rather than an open flame to heat the
casting. A too hot flame will cause the fins to
collapse.
To install new cylinder liners, reheat the casting to 275^ F, and
you will be able to drop the liners right into place.
The AERA Technical Committee
November 1978 - SPB 48
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BALANCE SHAFT & BUSHING SPECIFICATIONS |
Balance Shaft & Bushing Specifications For
1991-97 Honda 2.2L Engines
The AERA Technical Committee offers the following information for 1991-97 Honda 2.2L engines. This information should be used anytime the block is being serviced.
Measure the shafts and compare to the chart below. Measure runout on the No. 2 journal of each balancer shaft to make sure the balancer shafts are not bent. The balance shaft total indicated runout should not exceed .001" (0.02 mm).
Location Shaft Housing Oil Clearance
#1 Front 1.6820-1.6824 1.6850-1.6858 .0026 - 0.0046
#1 Rear (oil pump) .8243-.8248 .8268-.827 .0020 - 0.0030
#2 1.5241-1.5246 1.5276-1.5283 .0030 - 0.0050
#3 1.3670-1.3675 1.3701-1.3709 .0026 - 0.0039
Measure the inside diameters as shown if Figure 2. below and refer to the chart above. The engine manufacturer does not provide service limits for the oil clearances listed in the above table. Experience has shown, however, noise and loss of oil pressure will result if clearances are beyond limits listed.
The AERA Technical Committee |
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OIL CONSUMPTION ON 84-93 HONDA 1.5L ENGINES |
Oil Consumption On
1984-93 Honda 1.5L Engines
The AERA Technical Committee offers information on oil consumption on 1984-93 Honda 1.5L engines. Honda considers oil consumption when the rate is in excess of one quart to one thousand miles traveled. This engine uses a metered oil supply to the cylinder head by means of a removeable metal
orifice located in the deck of the cylinder block.
The orifice shown below, meters a certain amount of lubricating oil to the cylinder head components. It often times is stuck to the cylinder head during the removal process and may be misplaced during cleaning and handling.
If the orifice, Part #15140PM3000, is not reinstalled during assembly, excessive amounts of engine oil will enter the cylinder head. This additional oil will then collect under the valve cover and overwhelm the valve stem seals. The oil
will then enter the combustion process and the exhaust system, causing oil loss.
Some AERA members increase the opening size of this orifice slightly, anytime the cylinder head is removed from the block. Drilling the existing restrictor to .062 (1.575 mm) in size will increase the volume of oil to the cylinder head
and camshaft. That procedure has been beneficial during cold starts when ambient temperatures are very low.
Increasing the orifice hole size slightly should not overwhelm the cylinder head with oil, providing all other oil clearances are within specifications.
For Additional Information See AERA Technical Bulletin TB 1376
The AERA Technical Committee |
