Category: "Engine Machines"

Micrometer Calibration for all Kwik-Way Model Boring Bars

February 1st, 2012

From time to time it may become necessary to re-calibrate your boring bar micrometer. Kwik-Way can not calibrate  your micrometer here at our facility due to the fact that it must be calibrated to the boring bar that it is used in.

Please follow the the instructions carefully and your micrometer will be re-calibrated and accurate again within minutes.

Model FW-II Pictured Click Here for More Info

1. Using a scrap block, center the boring bar to the cylinder to be bored, and tighten the base clamp screw.

2. Raise the boring bar up to allow the tool holder and bit to be installed into the boring head.

3  With the tool holder and bit pushed back into the boring head as far as it will go, tighten the gib set screw. Now lower the boring head until the the tool bit is just into the top of the bore.

4.  Loosen the bib screw and allow the tool to carefully come out and contact the cylinerbore. Tighten the gib screw.

5.  Raise the boring head to allow the boring bar mike to be inserted into the boring head. NOTE: Have the micrometer adjusted large enough so that the tool bit will not contact the face on insertion.

6.  Slowly rotate the micrometer spindle untl the face of the mike JUST touches the tool bit. Now remove the micrometer and advance the reading by .010 to .015, then tighten the micrometer lock screw.

7.  Insert the micromenter back into the boring head and loosen the gib set screw to allow the tool bit to contact the face.(Use caution so as no to have the tool bit scratch the face of the micrometer) Tighten the gib set screw.

8.  Bore the cylinder.... now measure the actual finished size. DO NOT  loosen or remove the boring bar. Take the measurement with the bar in place.

9.  Place the stem of the boring bar micrometer into a vise with soft jaws so as not to damage the stem. Loosen the allen set screw found in the rear os the mike thimble in the knurled area.

10. Carefully rotate the thimble so that the mike now reads your bore size. Tighten the set screw.

11. Now loosen the micrometer lock screw and rotate the thimble either clockwise or counter clockwise, whichever direction is closer to thimble "0". Now re-tighten the micrometr lock screw at "0". If necessary, loosen the thimble set screw and slip the thimble up or down until the 0 is on the appropriate black line on the body of the micrometer then tighten the thimble set screw.

12. Loosen the micrometer lock screw and rotate the thimble to the reading of  the bore size in your test cylinder. Now add .010 to the reading and rebore the cylinder. Measure the cylinder to verify size, fine tune your micrometer reading if necessary.

Checking Valve Refacer Chuck Runout

February 7th, 2012

Valve Grinder Chuck Inspection

Chuck accuracy is critical to producing a quality valve job.

Most O.E.M.'s require a valve face run-out to be below .0015. To accomplish this, the chuck in a valve grinder must not only run-out below .0015, but must repeat this every time.

High performance engines require even greater accuracy. In some cases run-out must be below .0005.

How do you determine the accuracy of the chuck in your machine? There is basically one easy method that can be used which provides an accurate evaluation.

Start by finding a known round and straight part. A valve seat pilot, carbide if you have one will work very well. If you do not have one, use a section of drill rod that is straight and round. This will be your test piece.

  1. Insert the test piece into the chuck so that it is gripped correctly and has at least two inches of protrusion past the face of the chuck.
  2. Install a dial indicator (.0000 reading if possible) so as to have the plunger contact the test piece one inch from the face of the chuck.
  3. Turn the machine on and observe the indicator as the chuck is rotating. The reading at this point should not exceed .0015.

If the reading is inexcess of the .0015, you can first disassemble the chuck and clean it thoroughly. (Follow directions given in the machine manual). Examine the ramps on which the ball bearings ride, if wear is evident (grooves), the chuck will require placement. Kwik-Way provides new chucks that have less than .0005 run out and for the standard SVSIID and a Hi-Performance version with less than .0002 run out.

If you have any quesitons in regards to chuck performance, or if you need a replacement chuck, contact;

Kwik-Way Tech Services at 800-553-5953.

Flywheel Grinder Profits

July 19th, 2016


Our Van Norman Flywheel Grinders are one of the most profitable machines you could own.  They are not difficult to operate or maintain and tend to last a long time without the need for service if you do the few things that need to be done to maintain them. With a little instruction just about anyone in your shop can grind a flywheel successfully. The setup is easy and the job itself goes very fast. Typically, you should be able to get about $100 per hour if you have steady work for your machine.   Even if you don't have enough in-house work for it, you can likely get some outside jobs from other shops who don't have a flywheel grinder. There are also optional accessories available that allow you to do more than just grind flywheels.  It's becoming more common for Heavy Duty Trucks to have disc brakes with rotors that can be ground on our Van Norman Flywheel grinders with our Optional HD Truck Rotor Kit.

 

Here’s a quick overview of how to set up and use your flywheel grinder.

Select the proper stone

Not all stones are created equal. Make sure you’re using the correct stone for the material you are grinding – cast steel, billet steel or cast iron. If you aren't sure, you can ask your Irontite Sales Associate to help you determine the best stone for the type of material you will be grinding. There are also CBN wheels that you can use. These are much more expensive, but they also last about 10 times longer and some technicians feel they provide a better cut. CBN wheels are not dressed by removing material like traditional grinding stones. Instead, there is a cleaning stick that is used to remove any stuck-on material from the cutting surface of the CBN Wheel.

    

           
General Purpose Stone                                CBN Wheel

Mount and Dress the Stone

Follow our guidelines found in this section of the website for the correct dressing technique. The article was originally written for valve seat grinding stones, but the dressing principles apply to any grinding stone. You can view this Article here. The Van Norman Flywheel Grinders typically come with a Star Wheel dresser, but there is also a Diamond Dresser available. And, of course, if you are using a CBN wheel, then you do NOT want to use either of these dressing methods. Your dressing technique will influence how the stone reacts against the flywheel material. Basically, a quick pass dress will open the pores of the stone and deliver a rougher finish but cut more aggressively, and a more slow pass will close up the pores delivering a finer finish. You should vary your technique to determine which method is best suited for the flywheel you are grinding.

Coolant, coolant, coolant

Be sure to check your coolant reservoir and skim the tramp oils on a regular basis, especially during the heat of summer. Your coolant will experience some evaporation.  A good way to combat loss of coolant is to mix the coolant in a separate 5-gallon container with a lid so that as you need additional coolant it will already be mixed and ready to pour in.  This will also prevent altering the coolant mix ratio that can happen when you add a little more water here and there and then maybe a splash of concentrate and before you know it your coolant is too watery and things rust or it's too concentrated and your grinder isn't cutting like it should. 

 


The coolant you use and how it's mixed can greatly affect the effectiveness of your grinder.  Irontite has spent considerable time researching and experimenting with all different kinds of grinding coolant concentrates at differing mix ratios to come up with our recommended coolant concentrate product and the best mix ratio for most operations.  As always, if you have questions, your Irontite Sales Associates are knowledgable about our products and can help you make an informed choice.  They are at 800-553-5953 during regular business hours.

Ideally, you would just have a schedule for changing your coolant, but every shop is different and some weeks the grinder is busy while others it's not, so here are 3 ways you can tell if your coolant needs to be changed:

  1. The coolant is so dirty you can't see through it
  2. You find yourself dressing the stone more often than normal
  3. You can feel more than one inch of sludge in the reservoir

A great tip/trick is to get a powerful magnet (they have gotten inexpensive in recent years if you shop for one), something about the size of a drink coaster or a little smaller and place it in your coolant reservoir on the bottom as far away from the pump as you can.  This will attract the metal shavings and prevent them from flowing back up to the work site.   Another idea is to create your own larger reservoir with a sludge trap of some kind to continuously filter the coolant.

Be sure to inform everyone who uses the machine to never use any other chemicals on parts that are on or over the machining surface.  Using something like rust preventitive on a part still attached to the grinding table can contaminate the coolant in short order.   So it's best to just have a rule that you always remove any items from the machine and never use anything other than coolant while at the grinder.

Mounting

Remove any dowel pins prior to mounting the work piece using a dowel pin puller. Be sure to keep track of the dowel pins and return them to your customer. When mounting, use the crankshaft-mounting flange as your reference. It's important to clean and deburr the flange and table surface before mounting. Select the appropriate flange adaptor and a centering cone. Tighten the centering cone bolt to secure the assembly to the table. Insure there is no movement and rotate the table to be sure the grinding wheel is not going to contact anything that it should not.  When doing a stepped flywheel, keep in mind that the torque of the grinding motor can make the stone move slightly and you want to insure that the stone will not bump up against the wall of a step.  This could cause internal cracking in a stone that will lead to the stone breaking aggressively.

There are also many optional mounting kits to help you mount all different kinds of flywheels and other types of materal.   Here are several to choose from. 

Grind Away

Hand feed the grinding wheel so that it almost touches the work piece. Put on your safety face shield and position the machine’s grinding wheel safety shield and the coolant shroud protective shield. Turn on the coolant, then the table, then the grinding motor. Manually feed the stone into contact with the work piece. You will know the stone is about to touch when the coolant on the back side of the stone begins to foam slightly.  Now feed approximately .001 per revolution of the work piece. A constant spark pattern is necessary for efficient grinding. This will also cause the stone to break down and keep cutting more freely as well as keeping the stone from loading up. There will be times that you will need to stop grinding and redress the stone.  If you are using a CBN wheel and it's making a lot of noise (singing) this is typically a lack of necessary downward pressure. CBN wheels require fairly aggressive cutting pressure.  Or it could be dirty coolant or the CBN wheel needing to be cleaned with a CBN Dressing Stick.  Continue grinding until you obtain both the finish and specification required for the flywheel.

If you have the auto-feed option on your grinding machine, you can set the depth of cut you want and use the auto feed rate knob to adjust how aggressive the cut will be.

Most manual machines will grind the average flywheel in about 10 to 15 minutes. Larger diesel type flywheels will take longer but you can charge more for those. The average labor charge for a flat flywheel is about $35 to $45. The labor charge for larger diesel flywheels averages $65 to $125

Maintenance … is key

It's critical the flywheel grinder is level for proper operation.  This is because the table actually floats on a bath of special lubricant called Table Lube.  If the table is not level, then it can leak table lube and/or set up an unwanted wear pattern on the under side of the table.  Eventually this can cause serious problems with the machine's operation and obtaining good flat grinds. Always keep the site jar located in the back right corner of the machine filled with table lube.  This keeps the level under the table up and also feeds the lubricating wick in the neck of the grinder column.  There is also a dip stick for checking your table lube, but, in most cases, if you keep your site glass jar filled you won't need to use the dip stick.

 

Cleaniness is....

Grinding is a dirty business.  It makes your grinder dirty.  However, you can extend the grinder’s life and profitability by wiping down the inside and outside after every job. A coat of wax for any painted metal surface will go that extra mile. The wax will make the wipe down go much easier too. The inside of the coolant shroud also needs to be cleaned and waxed to prevent crud build up. If you don't wipe after every job, the build up of all the stuff splashing around will attach and harden making it extremely difficult to ever get off and will also hinder a wipe-down by catching your cloth.

Use a deburring stone to knock down any dings or dents that occur on the grinding table when mounting flywheels. This little procedure will increase the accuracy of your flywheel set-up. Inspect all your tooling and adapter rings before using.  You are cleaning them anyway, why not pay attention to them and see if you have any marks that could introduce problems.  If so, get them replaced right away.

Use a wire brush on the threads of your hold-down bolts so they don’t carry debris into the threads of your center-mounting hole. It’s also a good idea to periodically replace the center bolt hole thread. Our EZ-Lok replacements make it quick and easy to keep your mounting threads like new.  These come with locktite red on them so you may need to use a little heat to get them free from the table.  But changing them on a regular basis will keep your table and its spindle in good shape for many, many years. Organize your tool board so you can quickly find the necessary tooling for mounting the next flywheel.

Check all Lubrication

Always double check your instruction and parts manual to be sure you use the recommended lubricants for your machine. 

Open the back of your machine and find the leadscrew. The leadscrew needs to be clean and well lubricated. It’s always best to use the leadscrew Lube specified in the owners manual. There should be a leadscrew nut that the leadscrew goes through. This nut also needs to be lubricated and has an adjustment procedure to keep your machine from having "head drop". The owners manual gives you step-by-step instructions for this.  It's a good practice to run your grinder column all the way to the top and all the way down at least once a week.  This is to help keep the leadscrew lube distributed over the entire leadscrew.  Over time, most operation takes place in the same small area of the leadscrew forcing the lube away.  Running the head up and down redistributes the lube.

The grinding head locking system only needs to be adjusted if after locking you can move the head.  Over time, the head may become difficult to move from side to side.  After you insure that this problem is not because the lock is engaged, there are 2 grease zerks on the opposite side of the column where you can apply regular automotive grease to lube the column top. 

Also, check to make sure the grinding head tilt is what the manufacturer designates and adjust accordingly. Inspect your dresser. Some machines have a star dresser and others have a diamond. Make sure the star is rotating and spins freely. If it doesn’t, it’s time to replace it. For machines that have a diamond, make sure it’s sharp and periodically rotated to insure even wear. Always replace if in doubt.

Always measure - never guess!

It’s a good idea to use a dial indicator when determining how much material is being removed. The leadscrews are very accurate, however, they are no replacement for actual measurement of how much of the stone wore away during the grinding process.  This is even more critical when you are working on a stepped type flywheel. You must insure you remove the exact amount of material from the pressure plate surface as you do for the clutch disc surface to insure the original geometry stays intact.

Taking care of your flywheel grinder will allow it to make money for you for many years. And if and when you do decide to upgrade or replace it for a new machine, it will have a higher resale value.

Remember, if you have more questions, contact  Irontite Products Inc at 800-553-5953

Valve Chuck Disassembly / Assembly Instructions

January 31st, 2012

4mm Valve Chuck Disassembly / Assembly Tool

PN: 012-1054-60

[This tool is required to perform the following operations]


Disassembly Instructions

STEP 1: Remove the chuck cover from the Chuck Bearing Assembly, being careful not to pull any wires from the cover.. Rotate the Chuck so that the Grind Mark on the front collar and the Yellow Mark on the Spring are Vertical as show in the photo below.

STEP 2: Remove the (3) three 8 x 32 x 5/16 slot head screws from the Chuck End Cap (Black) shown below.

STEP 3: Use the Disassembly Tool (picture at the top of this document) which is standard equipment with your machine, put the 8 x 32 screws (3) into the chuck shaft in a 1/4 of an inch. Put the 1/4 x 20 Hex Head Bolt finger tight against the End Plate.

STEP 4: Remove the Chuck Yoke.

STEP 5: Loosen the 1/4 x 20 Hex head bolt counter clockwise. As you release the 1/4 x 20 bolt, the spring pressure should begin to release.. NOTE: You may need to soak the chuck in Automatic Transmission Fluid to remove grit and make the collars slide easier.

STEP 6: Remove the Chuck Disassembly Tool.

STEP 7: Begin to remove the outer collar from the chuck shaft. Next, remove the Loading Cup with the Four (4) springs. The large spring and inner collar will be removed along with the Thrust Step Washer. As you take the Inner collar off the steel chuck balls(9/16) may fall out of the chuck shaft.

STEP 8: Remove the Chuck Handwheel and belt from the chuck shaft. Remove the chuck from the chuck bearing assembly. Clean all parts with a parts cleaning solvent.


Assembly Instructions

STEP 9: (1) Put the shaft back in the chuck bearing slide, use transmission fluid only and coat the chuck shaft. Make sure the keys are vertical.

(2) Put the thrust washer, spring, and (3) three rear balls back on the chuck shaft, making sure that the Yellow mark is lined up with the Keys. hold on to the bottom balls so they don't fall out of the shaft.

(3) Slide on the Inner collar, so all three rear balls are inside of the collar.

(4) Put the front set of balls in the shaft. Install the loading cup with four(4) springs facing out.

(5) Install the outer collar, making sure the grind mark is lined up with the keyways.

(6) Reinstall the Disassembly tool. Put the three screws (8 x 32) in one quarter (1/4) of an inch. Begin to tighten the 1/4 x 20 bolt, making sure that the collars are still lined up with the keys. Run 1/4 x 20 bolt in until it is tight.

(7) Reinstall the Chuck Yoke.

(8) Remove the Disassembly Tool and reinstall the chuck End Cap with the three 8 x 32 screws.

(9) Reinstall the chuck Handwheel and Belt, making sure the chuck and chuck handwheel are snug to the chuck bearing slide.

(10) Reinstall the chuck cover. Make sure there are no wires touching the chuck.

VALVE FUNCTIONS

April 20th, 2012
by Kwik-Way Products Inc.

For the past three or four decades the automotive industry witnessed substantial reductions in the number of valve servicing operations being performed. Leaded, high octane fuel burned in high compression engines developing high horsepower was the reason.

Even when these engines did need valve service the car owner might not be aware of it because his car's engine had a great excess of power which he hardly ever called upon.

Today the picture is changing. Lower compression ratios and unleaded fuels are the order of the day. They are the result of the need to reduce air pollution. And with these new conditions comes the need for maintaining high engine efficiency if performance and emission control standards are to be maintained

Valve misalignment can occur in a comparatively new engine of any make. How many car operators know or understand this? The service shop operator must begin to develop new means and methods for selling service, and especially for selling car owners on the importance of servicing valve and valve seats. He can easily do this by explaining the benefits that will be effected from a valve realigning operation.

Above is a new valve, true and mechanically accurate in all its proportions — the condition in which it is installed in an engine. The valve face and the valve stem are concentric with the same center line — the center line of the valve stem itself.

Above is a warped valve. The warp- age occurs only in that part which is subjected to extreme heat — the portion above the guide — and in the valve head. The valve face must be restored to concentricity with the portion of the stem that operates in the guide.

ENGINE BLOCKS CHANGE SHAPE DURING SEASONING PERIOD — USUALLY WITHIN THE FIRST FIVE THOUSAND MILES

Years ago it was customary for engine manufacturers to stack engine blocks out in the weather so that they might become seasoned. These were corded up like wood. Tracks were laid between the piles and workmen were kept constantly busy bringing in the blocks and facing off first the top and then the bottom; then placing them out in the weather again for another period of seasoning between machine operations. All of this was done to eliminate casting strain. This seasoning operation as a rule took from six months to a year after the casting was made.

Compare this with our present day method of pouring iron ore into an electric furnace and having it come out of the plant in from forty-eight to sixty hours — a complete running engine. These blocks are normalized or heat-treated to eliminate casting strains. But remember! When these blocks are heated and cooled over a period of time in the operation of an engine, or when the head nuts or bolts are not drawn down evenly with a torque wrench, the different shapes and radii of the manifold near the valve guide will cause misalignment of the guide to the seat, and must be corrected in order to get maximum performance from the engine.

HARDENED VALVE SEATS PREVENT VALVES FROM HAMMERING IN

Since the introduction of hardened valve seats it is impossible for the valve to hammer in as before. Therefore, the misalignment caused by warping of or changing of the shape of the metal in the block will set up a friction between the valve stem and the valve guide. This will soon wear the valve guide as well as the valve stem and to a point that will partially destroy the effectiveness of the valves. A normally worn valve guide is illustrated above. It is worn at points A-B at top left hand and at bottom right hand for the reason that the valve seat is higher at the right hand side. The valve strikes the high side of the seat first, then bounces to the left. As the valve spring pulls the valve down, valve stem friction causes the wear as shown.

BLOCK IS DISTORTED IF HEAD NUTS ARE TIGHTENED WITHOUT USE OF TORQUE WRENCH

Another factor entering into valve misalignment is the distorting strain set up in the block or head due to the unevenness of tightening which results when a torque wrench is not used. Due to differences in stance of the operator, and other human factors, some of the head nuts or bolts are tightened excessively if torque is not measured. This always happens when a torque wrench is not used. In tightening head nuts or bolts, follow factory torque recommendations.

If you will check the valve seat nearest the bolts that are tightened excessively you will find the part of the seat nearest the bolt will be worn shiny; while the side of the seat opposite to or away from the bolt will be pitted or burned. It therefore follows that a properly aligned valve job may easily be spoiled by improper tightening of cylinder head nuts or bolts.

A properly aligned valve job may easily be spoiled by improper tightening of cylinder head nuts or bolts. The remedy is simple. It is as easy to use a torque wrench as any socket handle.

LOCATING FOR REALIGNING VALVE SEATS

Several mei.iods are being used today to locate the grinder for realigning and resurfacing valve seats. There is, however, one accepted method that engineering practice has never improved upon. As an illustration, it has been common practice in machine shops for the past thirty or forty years to use what is known as a "machine arbor." This is a piece of hardened and ground steel microscopically tapered from end to end. Whenever a piece of precision work having a hole in the center was brought back to a lathe for machining, such an arbor was used to keep the machine work concentric with the hole in the center of the piece.

The Kwik-Way Manufacturing Company recognized the infallible accuracy of this procedure and designed a Tapered Arbor to be used for centering the valve seat alignment operation. The application of this arbor to the operation of servicing valve seats is covered by patents owned by the Kwik-Way Manufacturing Company and although widely imitated, it is not or should not be made available for this use by other manufacturers.

NONE BUT A TAPERED ARBOR WILL PROPERLY ALIGN A VALVE SEAT RECONDITIONING OPERATION

The Kwik-Way Tapered Arbor, commonly known as a Pilot, is microscopically tapered throughout the stem (the part that enters the guide). When inserted in the guide it takes its alignment from the least worn portion of the guide, which is towards the center, and not from the bell mouth portions on either end. Note (illustration at right) that the arbor does not contact the worn portions A-B at top and bottom of the guide and is not misaligned by those worn portions. It is accurately aligned by the unworn part. The Kwik-Way Eccentrimeter (below) measures the concentricity of the valve seat with relation to the guide. Some of the imitations have a straight surface for the greater portion of the stem with a conical or cork- shaped part for about an inch at the top. Since the valve has been crowded over to one side of the valve guide due to misalignment and the peculiarities of valve spring tension, the wear caused by this crowding of the valve stem to one side makes the top portion of the guide a most unsatisfactory point from which to locate for reconditioning of the seat. The seat cannot be reconditioned and realigned so it will be concentric with the actual center line of the valve guide.

CHECKING FOR WEAR IN VALVE GUIDE

In reconditioning a valve seat in an engine that has had considerable use, it is first necessary to determine whether or not the wear in the guide is beyond the point where the guide will be satisfactory for further use.

Through the use of the Kwik-Way Tapered Arbor the amount of wear can be determined. Kwik-Way Tapered Arbors are manufactured in steps of one-thousandth of an inch in undersize and oversize. By using a range of arbors, the amount of guide wear may easily be determined. The arbor, when inserted in the guide, actually becomes a plug gage for the worn guide. It is not good practice to use guides that are worn more than .003".

Insert another type arbor in a valve guide where there is considerable wear at the top and bottom. Try such an arbor as mentioned in preceding paragraphs and there will be an excessive misalignment due to the wedging of the cork or conical-shaped part of the arbor into the worn portion of the guide. Note (illustration left) that the conical or cork-shaped upper portion of that type arbor or pilot will contact the upper worn portion of the guide which also causes the lower portion to contact the bottom worn section of the guide. It is, therefore, misaligned by these worn portions. By checking such an arbor with an indicator, it is easy to prove this point as it is almost impossible to get the same reading twice. The Kwik-Way Tapered Arbor may be reinserted any number of times and checked with an indicator, and it will be proven that it will properly align itself each time it is inserted. It will be found that a seat trued up from a Kwik-Way Tapered Arbor is concentric with the actual center line of the valve stem guide.

ENGINE VALVES PERFORM FUNCTIONS OTHER THAN SEALING COMPRESSION

The valves in an engine have numerous functions. First, they must permit the intake of fuel and air. Then they must seal compression. After the explosion the exhaust valve must permit the burned gases to leave the combustion chamber. Then there is one other function that valves must perform. They must streamline these gases and make it possible for them to move into and out of the combustion chamber as rapidly as possible, and, when the gases leave the combustion chamber, they must be so directed that they will not swirl or congest in a manner that will prevent the complete scavenging of the cylinder. The terrific pressure at which the gases pass through the exhaust manifold will normally create a vacuum in the cylinder, which in turn will assist in the complete scavenging of the cylinder.

Years ago, before engines operated at a high rate of speed, the matter of streamlining the gases was not considered an important one. When it is considered that at an average speed of fifty miles per hour there are twenty intakes, twenty explosions and twenty exhausts in each cylinder every second, it is not difficult to realize the importance of streamlining the gases. Automotive engineers today recognize this and in many instances have changed the shape of the valve towards the tulip design or designed them with a large fillet on the under side of the valve. The purpose of this fillet is to streamline the gases so they will pass freely out of the exhaust manifold. Most poppet valves are made at an angle of forty-five degrees, and being round they permit, (provided the valve is properly aligned), the exhaust gases to rush towards each other in a circle and under terrific pressure at an enormous velocity. This actually creates a vacuum that completely scavenges the cylinder. If the gases are not guided by the fillet under the valve, they collide and swirl, so to speak, which will cause a congestion in the manifold. This congestion will work against the proper elimination of the gases.

DO NOT ALTER SHAPE OF VALVE PORTS

For this reason service mechanics should avoid cutting away the port below the valve seat and should be very particular not to destroy the radius that may be above the valve seat in diesel- type engines especially. This radius was placed there for a purpose by the designer of the engine.

MISALIGNMENT OF VALVES AND VALVE SEATS AFFECTS STREAMLINING OF GASES

Inasmuch as the shape of the valve and stem have the effect of streamlining the gases, a valve that is misaligned or a valve seat that is distorted by unevenly tightened head bolts will very seriously affect the operation of an engine. The timing will be changed as a result of the valve contacting the high portion first, then later being pulled into contact with the seat by the tension of the spring. The time that elapses between the contacting of the high spot and of the valve being pulled into contact with the seat, while of exceedingly short duration, is really of considerable importance, due to piston travel. Consider an exhaust valve that has been misaligned, or a valve seat that has been distorted by lack of torque control whereby the valve contacts one side of the seat first. This causes the valve to cool more quickly on that side — contracting the fillet — causing the valve to press harder on the seat at one point while the remainder of the valve is cracked open. It is common for such a crack to be opened as wide as .015 of an inch. Therefore, the hot gases rushing out of the combustion chamber pass a portion of the valve only, cause the fillet to expand on that particular side which opens the orifice even wider, further maligning the valve.

Since the gases that pass this leak do not meet the gases that should pass from the side that is closed, they strike the exhaust manifold on one side causing the stream of gas to swirl (see page 11). This will cause a congestion which will prevent the complete scavenging of the cylinder, so that when the piston

reaches the top of the scavenging stroke, there will be a slight compression in the cylinder. This can be compared to turning a high-pressure hose into a drain in a basin. The stream striking the bowl "head-on" will swirl or boil and the basin will fill up and run over. By directing the stream slightly to one side, it will be found that the drain will take care of the flow of water satisfactorily. It is obvious, therefore, that the piston will have to travel partially back down again to relieve this slight compression before the intake of gas can begin (see page 14). This would be the equivalent of shortening the stroke of the engine, with the resulting loss of power, to say nothing of the results that would arise from exhaust gases being left with the combustible mixture that is drawn in with the intake stroke.

This shows the piston at "Bottom Dead Center" just at the beginning of the exhaust stroke. The misaligned exhaust valve is causing the gases to begin to swirl which will cause a congestion in the exhaust manifold and prevent proper scavenging of the cylinder.

This shows the distance of piston travel during the first 45° of exhaust stroke. It also shows the ideal condition with valves in correct alignment. Note the streamlining of exhaust gases for rapid and complete scavenging of the cylinder.

This shows a warped exhaust vaive fully open, intake valve closed, at the beginning of the last 45° of the exhaust stroke. The continued swirl of gases in the exhaust manifold is retarding the rapid scavenging of the cylinder.

Distance of piston travel at the first 45° of intake. Congestion in the exhaust manifold has prevented complete scavenging, leaving a slight compression in the cylinder. The piston must, therefore, move slightly downward to relieve this compression before intake of gas can begin. This is equivalent to shortening the engine stroke.

The piston keeps on Traveling while the valve is sliding improperly off or on the seat

A piston may have completed one-fifth of its travel by the time the misaligned exhaust valve completely contacts the seat. In an ordinary engine a valve is lifted about .001" by the cam, while the fly wheel is traveling from two to three degrees, depending upon the make of the engine. If the valve is cracked open as much as .015" on one side, we therefore would have a piston travel of three degrees times .015", or forty-five degrees of crank travel. Consider this in connection with the fact that when a car is moving at the rate of fifty miles per hour, the reciprocal action of the piston is approximately twenty times a second, and when the valve port is not entirely open all the way around, the piston goes to the top, creates a slight compression as has been previously described, and will return approximately a distance represented by forty-five degrees of crank travel before intake gases can enter the cylinder.

RESULT OF LATE VALVE ACTION

In case of extreme misalignment of both intake and exhaust valves, some of this slight compression in the cylinder may be forced into the intake manifold causing pre-ignition. This is noticeable at higher speeds and is indicated by an occasional cough or backfire of the engine.

Definitely, there is much more to a valve's performance than the function of sealing compression. On one of the popular makes of engines, when the crank pin moves from top dead- center to a point equal to forty-five degrees, the piston has traveled down approximately twenty percent of its entire stroke. The piston in the same engine when moved forty-five degrees from the bottom dead-center will travel up only thirteen percent of its stroke. In other words, the piston is moving a greater distance at forty-five degrees of travel from top dead-center (see page 14), than it does in the same distance from bottom dead-center (see page 12), and it is when the piston is at the top that the exhaust valve is closing and the intake valve is opening. If you will consult late "Valve Timing Data," you will find that in some of the engines the intake valve opens twenty-six degrees before top dead-center and in the same engine the exhaust valves close at thirty-four degrees after dead- center. This means that both valves are open at the same time for a period of sixty degrees.

When these factors are taken into consideration, it must be admitted that misalignment of .001 of an inch on a valve is one of the most important dimensional elements in an engine.

Actual tests have proven that if the ordinary valve struck the valve seat on one side .001" sooner than it did on the other, it would take .010" of clearance between the valve stem and the guide at the bottom of the valve guide to let the valve rest on the opposite side of this seat without bending the stem. Truly then, valve alignment is exceedingly important.

Many service shop operators claim they are perfectly satisfied with the results they are getting. They also claim they are having no trouble. They may not be having trouble, but the owners of the engines they service do have trouble. In most instances they do not know where the trouble exists or where to place the blame, because they have never learned that engine performance can be restored to the equivalent of new after an engine has been run for some time. Many mechanics think because they have .002" or .003" clearance between a valve stem and valve guide they have that much to play with as the valve stem when cold is .003" and sometimes .004" smaller than the hole in the valve guide. This clearance was left there by the engineer to allow for expansion of the valve stem at the top of the guide so there will only be room for a film of oil when the engine is warm and running. There are engines that employ valve guides tapered as much as .004 of an inch, but it was the intention of the engineers that this clearance be reduced to normal clearance when the valve stem itself becomes heated and expands.

PROPER ALIGNMENT ESSENTIAL

In correcting a warped or misaligned valve so it will function properly when placed in an engine, the valve face must be restored to concentricity with the center line of that portion of the stem that operates in the valve guide. Wet grinding is considered a necessity for today's valves and all newer valve facers include a coolant system.

The above illustration shows the effect of holding a valve in a chuck that grips the end of the stem in a cone, and, as indicated by the check marks, in the distorted portion above the guide travel. A valve chucked in this manner cannot be refaced concentric with its original center. Note the valve face is eccentric to the center line of the stem. It is impossible for such a valve to seal compression.

In this illustration we have the effect of holding a valve in a chuck that grips it only on the distorted portion, as indicated by the four check marks. Note the true center line "AB" and the false center line "CD" established by this refacing operation. As this valve is refaced at a tangent to the true center, it will leak compression.

To properly correct a warped or distorted valve it is necessary to grip the valve stem in two places, with a three-point grip, within that portion of the stem that operates in the guide, as shown in this illustration. We know of no other way of accomplishing the proper results. Note that this finished valve face is concentric with the true center line of the valve. The shaded portion "E" shows metal removed. The Kwik-Way Chuck (illustrated below) was designed to accomplish these results. While it has been imitated in many ways, it has never been definitely copied.

Any valve face that is not concentric with the part of the stem that operates in the guide will contact the valve seat on only a small portion of its circumference. It will slap, bounce, be noisy, leak compression and affect valve timing. A properly corrected valve will contact the valve seat throughout its entire circumference and the valve stem will "float" in the guide, free from valve stem friction. Fuel economy and utilization of all possible power will be the result.

GRINDING COMPOUND

The fact that the use of grinding compound will not secure effective results in a valve reseating operation has been accepted for a number of years by the authorities in the industry. It is possible, through the use of compound, to effect a joint between the valve and the valve seat when the engine is cold, but as soon as the valve becomes heated from the natural heat of the engine, the portion that has been ground with compound will not contact the seat due to expansion of the metal. Here is the reason why.- A valve head 2" in diameter heated to 1450° (the normal temperature of an exhaust valve in operation), will expand .016", or .008" from each side of center. This means the valve will rise on the seat. The illustration below shows a valve and seat "ground in" with compound. When the engine is cold the valve and seat apparently form complete contact; but when the valve is heated and has raised, the portion ground in with compound is actually not in contact with the seat at all, and it is impossible for it ever to be when the engine is functioning. Through the use of the Kwik-Way Tapered Arbor for aligning a valve reseating operation, a compression-tight joint may be secured between the valve and the valve seat and this joint will be effective whether the valve is hot or cold. The use of compound on a valve so realigned would really prove detrimental.

DIESEL ENGINES

Diesel engines occupy a very important position in the service field today. Knowledge of diesel engines should be acquired by everyone in the service industry and as rapidly as possible. In diesel engines of the two-cycle type any tendency for the burned gases to collide or swirl as they are passing out will delay the expulsion and carry the timing over to a point where harmful results will occur, since in this type engine there must be a complete intake of fresh air, compression and ignition in one revolution of three hundred and sixty degrees. In addition, the burned gases must be expelled from the cylinders and the exhaust valve cooled for the next operation. The exhaust valves are cooled while resting on the seat. It is interesting to note that the exhaust valve in a two-cycle engine has sixty per cent less time allowed for cooling than the valves in a four-cycle engine.

A check-up was recently made of a two-cycle diesel engine used in transportation service. This particular engine was operating on a fuel consumption of approximately forty gallons per hour at wide open throttle and at full load, whereas the engine was rated to perform satisfactorily under these conditions on about nine gallons per hour. The engine had been in service intermittently for twenty-three days. As a theoretical analysis of the reason for excessive fuel consumption, let us consider the following:

Upon removing the cylinder heads it was found that the misalignment of the seats was about .01 6". The misalignment of the valves was not checked. Excessive consumption of fuel was the result of valve and valve seat misalignment. The injectors were checked and found to be o.k. Compression appeared normal and the blowers to scavenge the cylinders were producing their normal pressure to blow the burned gases out of the cylinders. In this particular engine the fuel injections take place at 5° ahead of center at an idle speed. The power stroke is complete at about 100°, at which time the exhaust valves open in the cylinder head to permit blowing off the terrific pressure in the cylinder. The exhaust valves are open for a period of

VALVE TIMING OF A 2 CYCLE DIESEL ENGINE

137°. About fifty times the normal capacity of the cylinder at atmospheric pressure in compressed gases has to be eliminated through the exhaust valves, since the piston travels down to expose ports in the cylinder and admit air for scavenging. These ports are open 50° each side of the bottom dead-center. From the time the exhaust valves open and the air ports are exposed by the piston traveling downward, 30° of crankshaft travel has taken place. In other words, when 130° is reached on the crankshaft, the piston has traveled down and exposes the ports in the cylinder and admits air to scavenge the cylinder. These ports are closed by the upward movement of the piston. Then the exhaust valves close and the piston travels up, compressing the gases at a ratio of about sixteen to one.

This particular engine had a maximum r.p.m. of seven hundred and twenty. This means that it made one revolution in 1/12 of a second, and since thirty degrees is 1/1 2th of a revolution, then the equivalent time allotted to blow off the high pressure was equal to 1/144th of a second.

The manufacturer's valve chart shows that the exhaust valves open .008" during six degrees of crank-shaft travel. Therefore a valve that was misaligned .016" or twice .008" would equal approximately twelve degrees of crank travel, partially delaying the opening of valves. Twelve degrees from thirty degrees leaves eighteen degrees, and eighteen degrees would equal 1/240th of a second instead of 1/1 44th as it should have been. In the design of this engine thirty degrees was considered ample time to blow off the high pressure gases. It is obvious if there is any pressure in the cylinders when the ports are exposed that the gases will blow out into the air manifold if the pressure is greater than the pressure in the air manifold or the amount maintained by the air blower. (The air blower maintains a pressure of only three pounds.)

If some of these gases are trapped in the cylinder due to the delay when the exhaust valves close, then if the engine travels around until it gets the next injection of fuel and the resultant explosion is not ample or sufficient due to faulty mixture, the governor will open the injector and admit more fuel. It will explode again on the next revolution and if it still lacks sufficient power, the fuel will be increased more and more which will throw the ratio out of proportion and increase the fuel consumption to a point that will be prohibitive. Since the fuel is coming into the cylinders from one place and the air from another, a very bad situation can occur that would not take place in a four-cycle carbureted engine.

This illustration tends to show the enormous volume of gas that is compressed into the cylinders of a diesel engine — about fifty times the normal capacity of the cylinder at atmospheric pressure.

Remember that the valve seats in this particular engine were misaligned at an average of .016" each. The misalignment of the valves was not checked. With the Kwik-Way System of Scientific Valve and Valve Seat Correction, the valves and valve seats in this engine were restored to proper concentricity and alignment, which sealed compression at the valves. As a result the fuel consumption was restored to the manufacturer's rating which was only about one-fourth of the fuel that had been used during the period of valve misalignment.

It can be definitely seen that if valve misalignment will cause a diesel-type engine to increase fuel consumption from a rated nine gallons per hour to forty gallons per hour, this same condition will to an equal or less extent affect other engines of the diesel type. Again, use of a torque wrench to tighten cylinder head bolts or nuts is necessary to insure against block distortion which can cause misalignment and valve seat distortion.

The engine of today is a marvel of perfection. It will perform satisfactorily in temperatures ranging from one hundred and twenty degrees above zero to from twenty to forty degrees below zero. It has fast acceleration and speed beyond the margins of safety and thousands of miles of satisfactory service. But it has been truthfully said that the engine has not been built that cannot be improved by the service that may be rendered by a well-trained mechanic who uses the proper equipment.

Kwik-Way Products Inc.

PRECISION ENGINE RECONDITIONING EQUIPMENT INCLUDES

  • VALVE FACERS
  • VALVE SEAT GRINDERS
  • CYLINDER BORING BARS
  • ENGINE BORING FIXTURES
  • SURFACE GRINDERS
  • BRAKE SERVICE EQUIPMENT


Copyright 1948, all rights reserved
Kwik-Way Products Inc.,500 57th St., Marion, Iowa
Revised Edition 1979