Introduction: Valve Grinding 4 Engines

Does your head have adjustable valves
Does your head or motor have hydraulic tappets
Can you afford a Head Gasket set if so how much can you spend ?
Are you using a used replacement head is it rusty ?
Have you ever worked on cars motors or lawnmowers ?(experience)
How complex is your engine is it a simple old chevy or ford or : is it a newer OHC with variable
timing ( these can be tricky)?
Do you have enough Tools to remove the head sometimes special sockets for torx type bolts

Step 1: Get Ready to Grind Heads HAH!

A . to begin with do a compression check and note what cylinders are low 20 or 30 %,(example some are 85 and some are 120 lbs.) AND THEN
B .examine the movement of the valve lift before deciding to remove head see? if valve motion is moving like the higher reading cylinders valves,? movement look good" is the cam worn off? if so fix cam first
Is or has the valve clearance become too tight (by adjustment or wear?)if so "adjust if possible first ....see notation #2B down page below (then recheck compression)


engines with push rod motors (not overhead cam) i recommend caution if loosening any rockers are removed as some motors like Chevy v-8s and inline 6 motors have a certain way to set them ARE ROCKER ARMS IN THE WAY OF HEAD BOLTS?
when you remove any rocker arms pick one and determine(count as you loosen) how many turns the nut takes to be loose enough to get the socket squeezed into the head bolt then use this figure to turn any other rockers(when loosening). I usually only take as many rockers loose as i have to and then tighten them to the exact same amount of turns as you used to loosen the rocker arms (better a fraction loose then over tight)

1.To begin remove the head then clean it good
2. remove the valves springs ( use tool or make one) valve springs in box in a line maybe number the springs
leave the valves in the head in the same holes ( do not mix them up)
after this see if you can wiggle the end of the stem where it sticks through( valve guide) the head sideways if 1or two are really loose like .020 thousands beware you may to need have a guide installed at a machine shop for like 10 dollars o.k.?
4. place head on bench or piece of wood have a few small piece's of say 2x4x10" wood handy
5.hook up hand drill 1/4" or 3//8" best, too a suitable plug in a drill that can? run slower than 800 rpm is better i recommend 300 rpm is best
6. determine the size of the valve stem 1/4" or 5/16" 0r 9 MM. go to auto store buy the size of neoprin gas line that will squeeze onto the valve stem diameter tight or snug no more then 4 to 6 inches needed for several grinding job o.k.? cost around 1 dollar
7. get a small wood dowel or saw the end off a soft bolt 5/16" to say 3/8" it should be 3" long or 4" long ( nearly always)
8. take time to clean the valves one at a time if they have carbon caked onto them like wise remove any gunk carbon or rust from around the immediate area of the seat,it helps a lot when grinding
9. don't clean bent valves take them to auto store buy new ones for about 8 dollars each
10. if the car / truck ran good( 4 cylinders) and didn't backfire the intake valves may not need grinding, if v-8 engine they probably do so look at the faces and stems if there bright and show no signs of pitting maybe just grind the exhaust valves o.k.? used intake valves make better millage than freshly grind ed ones do
11. if the exhaust valves are burned bad they may need to be faced/ if there usable at all and to help with keeping efficient grinding time.
12 . i do not recommend buying all new valves as the installed height sometimes need to be set (so use original valves if u can) makes since" too measure a regular valves height with spring installed (not bent) the new valve must not be taller or longer by much (hint not even 1 thousandths generally more) with new valve replacement
and it is necessary to have the new valves Stems grind ed to be the same length as the old ones
so using the old valves might be better unless you know what your doing o.k.? and sand the stem ends to shorten them to whatever the old valve is on example (exhaust valve not bent from same engine when possible or a machine shop must be asked to measure the thing being any valve old or new when installed has not to be too long' understand ? and new valves sometimes... well! must be checked ! to be no longer when ground in and installed with spring/s hear this"

notation #1Exhaust Valves

BE IT Known !!! that exhaust valves get hotter :..and will wear ,or burn faster than intake valves: and therefore.. are to be expected" to be more likely to leak (power loss) and also and or on occasion be be bent dew to timing jump" if your motor is an >interference type motor< (ask auto zoin )
BUT if YOUR Valves are bent you will still be able to fix your car / engine:you just have to buy new valves, and follow these same methods after installing any new valve it will have/ need to be adjusted to the right length"... pay attention... to factory valve lash specs: if so.

***** notation # 2B Are Valves too tight (learn how to set em)

what i am cautioning is to be aware > how tight a valve assembly is / or has' become: <
This tightness or shall we say over tightness is something called >Lash"< or Stem end clearance.

Checking this (lash) is sometimes simple" :on non hydraulic lifters or barrel tappets a quick check
i will mention is simple checking to see if a tiny space is measurable between the
tappet or in some cases cam follower /rocker arm all non hydraulics require a small space
in the line of lift force it is there to compensate for the expansion of hot valve
stem expansion " it (the space mentioned valve lash") it can be .006"(six thousands)
an inch.or it can be .010"(ten thousands) or rarely more,
ok if the valve is over tight it will hold the valve open" and that will cause a low compression(psi)
too mention further the effect
of said over tightened valve lash include 2 symptoms low/r compression and :
if on the intake valve : this causes backfiring into the carb or intake manifold (fi eng-plenum)
on the other hand an overtightened exhaust valve will become overheated
and that is very bad as more damage will concur as result!
knowing if a hydraulic lifter or hydraulic valve adjuster is too tight is a little more complex
let me say check any adjustment nuts if their are any as these type of settings are often described as non adjustable that is not to say they cannot be adjusted or even rarely become to tight occasionally explain takes time
just try to see if you can compare any difference to any of the normal compression cylinders... If your car isn't (didnt) miss or backfire and has hydraulic lifters or adjusters
then don't worry" assume there set right ( this is 4 hydraulic lifted valves only)


Does your head have adjustable valves
Does your head or motor have hydraulic tappets
Can you afford a Head Gasket set if so how much can you spend ?
Are you using a used replacement head is it rusty ?
Have you ever worked on cars motors or lawnmowers ?(experience)
How complex is your engine is it a simple old Chevy or ford or : is it a newer OHC with variable
timing ( these can be tricky)?
Do you have enough Tools to remove the head sometimes special sockets or torx type bolts

what do pistons look like after removing head ?

inspect pistons if you have the head off do you see oil? or do? some look very clean ?...the clean ones may have a steam clean pattern if the pistons black with a clean ring around its top edged it may have a bad ring so it is relevant
if all pistons have the same color and no oil gunk it should be alright

LETS SAY Difficult "

Okay old Chevrolets or old ford v-8s that are push rod type engines are the simplest to
to manage The next group would be the 4 cylinder imports that either have push rod
engines or only 1 overhead Cam

following these would be the belt type duel overhead cam with belt type motor and with
adjustable rockers
4 cylinder motors with chain cam drive and and 2 cams also with balancer's
After this it would be assumed that motors with duel over head cams with barrel tappets
Then possibly the worst might be the duel overhead cam v-6 with a chain drive
Beware of variable timing cams they can slip as they have 2 gears on one sprocket
above is in reference to order of difficulty "

over tightened valves effect lets us say slightly over tight might make a rough idle when hot or even when running when cold (engine temp a valve grossly over tightened will miss on that cylinder said" grossly over tightened valve may hit the top of a piston and rattled or bend or simply loose compression .I will not expand what all could go wrong. A rounded camshaft will cause a popping' sound in the intake manifold when its on the intake valve cam lobe. Rarely a defective rocker arm or cam follower will effect some similar noises and compression lose

causes of over tightness usually are confined to wear of the seats and faces thus the valve is drawn closer to the cam reducing the correct dimension (valve lash or op range) otherwise an adjustible valve train has provision to set the valve lash tightness (various ways) non adjustable then you hav to custom tailer the valve lash dimension through grinding or modifications to the rocker body or position otherwise ther is no recourse then some head work, hints and helps are scattered through this article ! elsewhere .

Step 2: Get Down to Grinding

put your(the) valve keepers out of the way in a corner where they wont spill ( stick on magnet?)and then
begin next to grind valves ,after cleaning ,and if necessary facing ( see pic) of exhaust valves, if you have the valve grinding compound "? is it water based ? ( ask auto store?) or is your grinding compound grease based?) if water based get a small bowl of soapy water nearby and a paper towel or cotton rags ,....water based compound is simpler and dont smell bad.!
if you have the grease based grinding compound then you will need some charcoal lighter fluid or lamp oil or some petroleum ( like kerosene) don't use much of the stuff you might catch on fire
and maybe you should have a small art brush to dab it
1st.. Turn head so you can see valves like on its side use a wood shim to block it so it wont roll
get the dowel mentioned and put it in the 300 rpm capable drill ( best)Battery drills? it can takes hours to do 1 head if valve/s badly burned so a 15 minute battery drill isn't necessarily effective here"
2. Then put the short piece of the neoprene (rubber hose) onto the dowel push it on say 1/2" too1 inch ok? (do not use a drill bit to turn the hose! use a dowel or metal shaft only) using wood be careful not to over tighten( see Note #3 below

3.Then push the other end onto the end of a valve ( start at one end) or just do the exhaust or do all in order you decide "!
4 . Take the tube or bottle of valve grinding compound in one hand' then lift the valve by pushing
on the end where you have the hose and drill that will give space to put some grinding compound into the seat(valve) area ,i recommend putting small dabbs ...say.. like 2 drop dabbs ..onto the seat or the edge of the valve face in a radial fashion first probably not as much as 1/8 a teaspoonful ok?
Thar's a reason to use small amounts(grind compound) because it will get into the valves stem and ruin the dont get it on the stem at all just the face and seat "

5 .pull the valve with the drill back into the head until the valve just touches the seat

6 start the drill slowly at first keep the valve pulled to the seat for the first 30 seconds then let the valve lift for 1 instant then repeat the same if possible stay around 100 rpm for a minute
after say 2 minutes then began to let valve lift off ( just 1/16"to 1/8" max) every 5 seconds let the slight pull pressure( 1/2 a pound approximate is fine for 90 % of the process but the end shall increase the final cut pressure to 1 too2 lbs pounds if the connection allows) you are using to keep the valves face and seat together with the compound grinding between the 1 rotating surface( valve) and the stationary valve seat .:

grind for 5 minutes.... then look at the valve... lift it enough or out thy taking the hose off the stem wash it see if the valve is showing a perfect grey white circle around the middle of where the seat is contacting the face when its smooth and say 1/32 to 1/16" an inch(wide) for intakes valves and or 1/16-1/8" th an inch for exhaust valves (wide)?
You may clean both surfaces of the used compound with towel and appropriate liquid ( i use the tip of my finger covered by the rag or towel that is wet in water or petrol respectively as needed )

Then put the drill and hose onto the next valve in order too be ground "ok? if your ?using petrol dont catch fire with sparks or drill ...cigarettes ***CAUTION ****
if you do blame the product and you i warned you here to use the water based grind compound

7. one thing is it could possibly take you 10 to 25 minutes to grind a real bad valve or if you didnt face the exhaust valves first ( see face valve illustration instructions)
If your valves is smooth and grey in a narrow line all the way in a circle in 6 minutes of grinding you are very lucky . >point here is to change the valve compound every say 8-10 minutes of grinding< and use 1/2 pound pull force to grind with ok"?

Don't try to pull more pressure then 1 and a half pounds because your hose will mess up and the grind will be to coarse and wont seal near as good"! so engine wont be as good ",,,
Remember if the grinding compound is too course it may gouge the finish also dont let the valve bounce off the seat higher than the recommend 1/8 " because compound will sling into the stem and mess the stem and guide up pretty bad, avoid that, watch for it ,use compound sparingly if prone to ok? and have a little oil on the stem itself not the seat

8.when done grinding but before putting the springs back on? look (test your work) if you have any doubt about the surface squareness of the seat or on heads with high millage ? or ,over heating before? ,( if car over heated ask machine shop if that model head needs checked for cracks and warpage nix this last statement if engine ran cool with thermostat installed ) remember a cracked head isnt likely to work if it is so....but some times certain heads do/ can have the tiny cracks and it isnt harmful it all depends, so ask a head pro shop ok?

Grinding compound it shouldn't take you a whole tube of compound( 3 dollars) for 1 or 2 heads, but if they are impossible it can ".i use permatex brand but that are other brands!

When all the valves are done first wipe excess compound out with damp rag or paper towel then spray each valve port and guide out with carburetor spray(1 at a time dont get confused on position) and put oil on stem then new seals ( if) and springs and retainers everything just as it was before you may use paint to number the pieces with dots or something so you know or make cardboard rack
with numbers however just dont mix stuff up certainly not the valves ok? several small cleaning rags or paper towels at hand moistened ?yes ?soggy no" small bowel of soap water or can of
charcoal lighter fluid if using grease base grinding compound

**** note #3 if using a wood dowel be certain it is rotating without a wobble if it tightens crooked
get another piece of dowel: center it in the drill chuck not to tight here ok ?
***** precaution"
a simple suggestion is to keep things in order and dont let anyone mess the order up or u b sorry!

Step 3: Whats Need to Grind Yer Valves Good"!

General directions for grinding valves on most engines with out expensive tools and with the know how to accomplish a very good job you will need a few simple things like
1.hand drill ( 300-400 rpm)is best
2. valve grinding compound
3. a glass or bowl of water
4. cleaner for parts ( carburetor spray helps)
5. oil or grease
6. paper towels or cotton clothe
7.Possibly a sheet of 180 carborundum wet /dry sandpaper
8. probably new valve stem seals
9. a lot of time if you are doing the whole head
10. may bey 2 hand drills can speed grinding
11. basic comprehension of physics involved
12. safety eye lenses
13. Awareness of which valves you intend to grind if not all

Step 4: Testing Seats and Valve Faces Quality

Some where : i need to mention the way to check the seat's of any valves that might be poorly fitted or how to see if your valve is going to grind well'... Remember i said it helps to know if their were any certain cylinders whose compression was too low "...So You Can Be Extra CAREFUL of those valves, and inspect the results of your grinding ok?

" described here" first is when you have grind ed for 5 minute intervals(**small valves smaller then 3/4" can sometimes be ground in a minute or two!**) remove the valve and wash the Grind Compound stuff off ,or wipe it enough to see if you think its dune ( good enough)

You will decide this! depending on the amount of tiny pits still remaining on the two surfaces( both valve face contacting area and valve seat area see pic) after you have followed STEP 2 :

When thar is a smooth grey white line (circle) extending around the total circumference
of the valve and no major pits that completely cross that line you may then clean and put it back
into the head and proceed to the next valve this valve is finished grinding .

Notice that if their is only half a grey white (50%)circle present showing on the valve face( not seat) then you should know that valve is bent or warped ,and you may have to get a replacement (valve)

same goes for the seat face their should be a complete circle of grey white metal showing the full circumference ( not halfway) of the seat if not then you will most likely have to do 1 of two things

1 . if its a cast iron seat ( not inserts) you might just need to grind more
2. if its those hardened seats mentioned elsewhere you may need to perform the additional task of squaring the seat as described in the paragraph on squaring hardened seats .(step 5)

now to mention how to test how good any freshly grind ed valve procedure is !!!! you can do this

TEST procedure ( see pics) take a pencil ( no2#) is perfect ( not to sharp dull is fine )
ok too test any valve grind ed job with a pencil
with the seat and valve perfectly clean and dry of anything take the pencil and mark lines every ( like 20 degrees) across the grey white grind ed line space(on seat) , draw the pencil lines radially only the seat circle is pencil lined ok? then put the proper(mating) valve into the head and push it down till it touches the seat
LISTEN UP HERE" to do the test right the valve will be twisted only a short twist say 1/4" or 25 degrees back and fourth in this limited fraction of motion it is necessary to push downward as hard as possible with out loosening the slight twist control coordinate ( 25 degrees) back and forth....use fingernails to help to hold the valve edges tight twist valve 10 times in this slight back and forward motion ( pushing down) is enough and the valve is removed look at the lines you drew on the seat now
has every line been smeared, by the valves contact ,partial twist if so the seat and valve are perfect go on to next one
if only half the lines are smeared check the valve to see if its bent ?

and retest maybe if say? only 3/4 to 7/8 of the lines are smeared the seats probably crooked or carbon worn on one side you will have to perform and additional procedure to level that seat ( see pic and carborundum square method) or the valve will still leak probably bad ( unacceptable)

between the two tests you can figure out which valves "mite need more work "but if you know the cylinders that were normal to begin with ( because you measured compression) then this will not be the case with thos particular valves so it helps to know where your leaking ones where to start with",...
The other thing is.. if your repairing a head that jumped time on the belt or chain ect?. then you may be buying some new valves? for the exhaust valves in question? most likely all or half will be bent from timing jump! those heads usually wont need this pencil test but the new replacement valves still have to be lapped (ground)in to the seat the same grind method applies ok
Valves break when the are out of time or when they are rusted to tight to move (stuck)
The most common cause is when a timing chain or belt or cam gear slips or
malfunctions it is possible that a head can be ruined when broken valves are jammed between
the moving piston and the surface of the head also pistons and even blocks sometimes
are ruined if obviously when that happens you need more then a valve job


Prussian blue for a valve test Prussian blue may be used to see how your valve job is going
to test valve seats get Prussian blue? put very thin layer on on the face of the valve
then turn that valve 1/4"inch(20 degrees) if the seat shows a clear line of blue extending its full perimeter
contact pattern it is assumed to be ok unless there are areas where you don't see blue then you have a worn valve seat or miss match of grinding progress
or warped condition on the seat or valve its self
or the just need grinding if slightly
or also repeat this dye test to determine proper contact of meshing faces ok? using Prussian blue may be tricky so practice or you will not know how but don't despair most likely you will be able to manage to get your valves in working order!

Malfunctioning Tappets or rockers Followers / cam lobes ect

IM mentioning this because occasionally" and aside from say.... over tight valve adjustment '
its worthwhile to know that hydraulic tappets or hydraulic adjusters even, solid tappet" clearance
cause some problems that mimic or promote valve leakage .
if a hydraulic lifter pumps up to much and do-sent return to the proper length> it holds the valve
inappropriately open< and that will be enough to.. effect the fuel mixture on that cylinder
possibly even other cylinders(flow pressure question)
If so a miss or partial miss will be noticeable (loss of power and balance)
if it is the intake valve that's delayed or not shutting completely
its worse as a noticeable effect when this is on the intake side of things(valve)

such things on the intake valve side will cause popping through the plenum or carburetor
sometimes even backfiring , ITS IMPORTANT not to mix up any valve parts taken from the head
or engine
Know what the wear is on your camshaft if the cam is in the block
such as when you have a push rod engine then attempt to measure and inspect how much
each lift movement of the cam lobe is actually lifting all intake lobes and each exhaust
lobe must lift only as much type
check the lifts of the 2 types of lobes as exhaust lifter usually higher then intake lobes
determine which lobe type your comparing
if a worn out cam lobe is found then you will need a new cam and set of tappets

on older motors tappets can be stuck in the block anyways dont mix up the tappets
put any removed tappets in a box place them back the same way and direction
if you are using a new cam use new tappets if you are installing a used cam (not
recommend) then the same lifter must be installed onto the exact same lobe as in
the replacement as a rule i would say its possible to change a 4 cylinders cam
but 8 cylinder cams wear more then 4 cylinder cam lobes ect.


Having a head off and just to see what valves are leaking worse
you may with all valves installed and with springs on them, turn the exhaust ports up
then pour a small amount of kerosene or charcoal lighter fluid into the open port & see
how much kerosene or charcoal lighter fluid comes out around the valves head
if it comes out fast...... then its leaking ,and will leak compression
you cant use this test for dirty valves as dirt will make you think its worse then it is
also inexperienced grinders will most likely leave grinding compound that will cause the
kerosene to slip through! Were this test is handy is pre dis-assembly of head, leak tests
or testing thoroughly cleaned reassembled heads see picture about poring kerosene ok?
this method is not perfect but can be used along with the process in general

Step 5: Testing for Bad Valve Seats for That Need Squaring Ect

when necessary to square hardened seats( make concentric) i sometimes am able to do so by using petal shaped pieces of 180 grit carborundum wet and dry sand paper ( see pics) i place the trimmed and sized carborundum paper over the valve the push the valve into the bad seat to be worked
and twist the valve back and forth with the sand paper sanding the valves seat not the face? it usually takes like 5 of those prepared pieces of carborundum 180 grit dont waist your time with any other grits or types if you dont have 180 carborundum forget it! use as much force to sand grind the seats as you can(muster) with out wrecking your delicate paper ( petal shaped) be prepared to spend 15 minutes of work and thats each one you attempt to repair 5 minutes is useless its just that hardened seats are so hard also when finished with the carborundum you have to re lapp( grind with compound) the valve back in ( might want to use a new valve now sometimes?) then do the pencil line perimeter contact test out side of this i have gave you some ideas you can work with otherwise go to the machine shop for service, thanks. Do not assume this carborundum sanding step is complete valve grinding job",.. it is".. only a part(step) of the process the above grinding is totally necessary

Step 6: The Rest of the Pictures

To remove valve springs" first remember if the spring keeper fly's off "! when removing the spring it will hit you in the eye!!!(ouch) and it will most likely destroy it so wear plastic glasses when removing the valve springs. Ok first off DO you have a valve spring compressor tool? to work on heads JC Whitney has them for like $20...if not you might make your own tool from steel in my illustrations their are some examples, i assume no express nor implied indication of the safety of any tools show , for or not for usage"! .. Using valve tools can be demanding difficult and you can possibly get hurt, so don't let anything slip or hurt your" body parts" like your eyes ok?
If you? have no drill or electric? see hand tool for hand grinding, it works but takes all day and practice .

Keep head work on floored area the valve keepers are hard to find if they are dropped or fly off .

I showed a piece of chain" in illustration of spring tool pics ok? ...The chain is to be used with one of the two pry fork type tools, you can make out of 5/16th x 1.1/2" steel bar stock it will need a
small hole about 3 inches from fork end to put a 1/4"screw through this attaches through the
chain link itself and the chain which will be screwed snug to the head by using the screw holes
already made onto the head providing a fulcrum point to pries the springs into the compressed
position" where you may then remove the keepers with a small magnetized screwdriver ( sometimes only use this for like removing springs while head is on the motor)
you may then remove the keepers with a small magnetized screwdriver
greased) or your fingers .
   The small steel pipe in the pic is for valves set down in the head casting and you have to use a screwdriver with grease to hold the keepers when trying to put them back onto the valve stems when working on those heads where the valves are set low into the head also it might be mentioned to compress springs it mite be possible to place a small jack under a
car on top of the pipe thing ( in pic or) use a length ( say 4-5' feet)2x4 and prize down onto the
valve spring with the pipe tool you-ll need something pretty heavy to hold the one end of you

prizeing ( ie 2x4 wood) device such methods will require a suitable helper sometimes if so.
remember if you grind the valve a lot ( ie more the .010) you might need to grind some off the tip of the stem so it isn't to long for the necessary clearance perimeters of certain nonadjustable valve clearance head designs ,but most of the time not

 Be certain to check all installed valve clearances before starting you motor where applicable ( ask a machine shop man if he thinks your motor has hydraulic tappets that can compensate for changes in valve height . 
                                                VALVE SEAT WIDTHS ARE IMPORTANT

A useful Paragraph about the valve seat width", ok "after or  before grinding valves the way im showing" with the drill and hose ? your achieved result has a dimension",   in other words you are possibly going to have to alter the finished or prior width of the valve seat to come within a (necessary) width parameter ok"? For most valve sizes on common car engines im going to suggest 2 possible sizes for the 2 types of valves ( intake and exhaust) the finished valve width that is very close too this width> 1/16" <for intake valves or not over >1/8" <or less for exhaust valves .
For instance 1/32 is way to narrow for intakes and 3/16 isn't going to work for exhaust widths
its to wide. Also these sizes are for car or small truck valves bigger then say 3/4" in diameter ok lets say for instance that you ground the valves and it looks like now the intake side seat is just under 1/8" WIDE NOW , (especially of cast iron seats) your going to need to reduce that to 1/16 or just under ok ?
Wear some safety glasses when doing this...One simple way this can be done is with a small grindstone about 1/2" -5/8" in diameter (see pic) ok put the stone in the drill chuck ( or dremell tool ect. or die grinder)the idea is to grind a slight amount of seat width away from the inner lower edge of the seats perimeter.
                                     TRIMMING SEAT WIDTHS WITH SMALL GRINDSTONE

 Its a matter of keeping the stone carefully in the hole while the stone is spinning, do not allow the grindstone to come up or out of the pocket while it is spinning, its to risky. If you nick the upper seat it can be damaged severely i recommend a suggested rpm of 300 to 800rpm for cast seats maybe 1200, but a 10,000 rpm die grinder will not be necessary for beginners .
i usually start grinding at 12 o'clock( imaginary positioning point) and move the stone in a clockwise direction (circle) taking about 11 -15 seconds to complete the full 360 degrees (circle)... stop the grindstone, then remove it from the pocket (port where the seats at) look at the resulting grind ed spot is it close to the inner diameter of the seat?( suggested width) if so fine if not ? continue repeating the grinding as stated keep a very firm grip on your drill or whatever you hook to your grindstone(use) move slowly and deliberately as possible do not let you stone come to close to the 45 degree of the good seat angle instead keep you alignment within 20-30 degrees is better (for reasons) once again for hardend seats use as high a speed as possible like 1200 or more and probably go with the 30 degree "throating" angle otherwise youl waste your stone, also keep loose clothing away from your tool. Cast iron grinds easy so don't over trim that seat and dont mix up your valves while Thar out ( paint numbers?) and chances are you wont need to do any "INTAKE" valves with HARD SEAT inserts AT ALL they will probably be close enough to correct width ..... thanks "

Step 7: This Is Something Totally Expeiramental!

Ok last year while grinding a 3 litre head with the drill ... i came up with the idea of useing a spool
too attach to the valve itself ... Whereby a great deal of torque could be mustered into the grinding process by kwick arm movements while at the same time adding the advantages or a reciprocating method
wel here it is in picture you wont see this any where else its a first and im shareing it with you faithful readers "lol" youl have to work out the particulars of the large yoyo like(lath turned?) wooden spool(4"?) and the sizes of the hole(1/2"-5/8") that holds the 1 inch section of neoprin hose (suggested) also the hose fit will be somewhat tricky to size mite need fileing maybe even a clamp i recond lawnmower sized rope be used for reliability and size and fited to two small wod handles or maybe metal rings to be pulled quickly back and forth to get the spinning motion for your grind job awwhhgh go... ahead... try it youl love it

Step 8: Makeing Marks Befor Disembly"

i am including a suggestion for marking timing marks that on overhead cam engines will need to reassembled the same way to the correct marks
   i will mention here any push rod engine is not effected timing mark wise but the distributor will need to be marked on those (most likely) as you sometimes have to remove it to remove head/s
  of course newer engines don't have distributors they have coil packs ect .
     i have used  paint of various types but i always clean a small spot near my intended marks
   with something like carb spray you can most likely use acetone or turpentine , maybe  finger nail polish remover , this will insure the paint stays on the timing gear  or belt and the area near the mark
  (block / casting gear or cog) 
   keep most of your paint marks to the visible side so you wont turn the belt backwards by mistake
     IN general take time to find out what the marks are supposed to align with by looking in a manual for you engine or ask auto zone . maybe visit a library get a copy made or draw a good picture as if you are working on a v6  0r v8 with a lot of cams and balance rs you will really have to 
   know where each one is marked 
 On small 4 cylinder motors with no in block balance rs or maybe a single cam you can probably get by with just painting the marks onto the chain link and gear or on to the belt and its cog for belt
 type drives(cam).
     I will say in the absence of timing alignment marks: it is possible to make your own with paint . 
                                          TRY TO FIND THE MARKS (timing)
       A lot of the time i will begin my work (valve job) by turning motor to top dead center on the number 1 piston  this usually brings the timing marks into there normal position were you can verify exactly where each of the 3 or 4  marks are aligned(on gears). If you find the  cam or cams aligned but cant see the crank mark just wash a spot on the chain and sprocket  with solvent ( mentioned  earlier)   
      Paint a spot of paint across 1 tooth and onto the mating chain use the tooth and mating link as to be careful to use a small enough paint spot as to not be confuse to which link it is on ok?

         when you are ready to re instal the heads you can move the marks just a little to get them to the same spot use you hand and a wrench remember to put the cam back into the same position before
   putting or bolting the cam onto the head or when the cam is already bolted to the head ( overhead cam engines)

 **** if your motor is an interference motor don't turn the motor over keep crank and cams the same spot when separated 
    Have 2 cams on a  engine or 4 cams? mark them put a paint spot on the front and rear ones or a tag wired with ef if - er=ir ect
   dont mix them up . ( ie front exhaust cam front intake cam, or if you have a 2 head motor the back 2 cams) 
    After you  have you marks then take the bolts holding the head on most likely you will need to
       if you are uncertain about a caps position (numbers?)try to match the scratch marks seen on the lower cam
             journal they are like finger prints
    there may me a set of numbers and a letter like E on one cam (CAP) and a similar number and letter N

     if the numbers and letters are invisible make your own letters and numbers do so like this
     take a screwdriver or ice pic number the cam holders (boss) starting at one end say 1 through 5 then additionally speaking of twin cam heads  put an e or x for the exhaust cam ones? only beside the exhaust cam caps (dual cam requires more marks)

    More then 1 cam ? do something similar (last paragraph) for the rear head but keep the parts away from the 1st heads cam/s (store it so you don't mix em)
     Cam caps   i lay the caps in the valve cover after checking my  cap numbers keep them in order to replace the same spot on the cam journals
     Take any necessary intake manifold bolts off the head and remove to one side take any exhaust manifold bolts off and remove exhaust manifold to one side
   take any brackets off the manifold that bind you from removing the head and connected parts .

( a pneumatic impact wrench is helpful removing big bolts if they are tight  but should not be used for small bolts like 1/2 0r 13 mm just  on 17 mm or bigger ) AND LOOSEN THE CAM GEAR RETAINING BOLT /S BEFORE TAKING ANY CAP BOLTS LOOSE
    LAY YOUR HEAD BOLTS IN THE VALVE COVER OR A CAN PUT SMALL BOLTS IN A DIFFERENT CUP OR PAN DON'T DROP THEM INTO THE AREA BETWEEN THE CHAIN AND THE BOTTOM OF THE OIL PAN  YOU DO NOT WANT THEN IN YOUR MOTOR"! IF YOU DO DROP ONE IN CALL AND ASK A MACHINIST  ABOUT WHAT HAPPENED use a large pair of vise grips to lock the cam and hold it or if you can try to get the cam and gear off with out removing i have used a pipe wrench to hold a cam
   but it can slip and remember you cant let the cam turn (on interference engines ) if  your can gear has large holes  you can sometimes stick a metal bar through the hole to lock it just so it do sent turn ( when loosening cog bolt)

    if you are uncertain about a caps position try to math the scratch marks seen on the lower cam
             journal they are like2 halves and sometimes  are matchable by wear scratches pa terns
    if you have damage to a cap or journal you may be able to smooth it a little(slightly) with 320 grit sandpaper stretched around a socket of a very close size (clean all dust after).

                                                 CAM CAM WONT STAY PUT ON MARK BECAUSE SPRINGS 
     If you find the cam when set to correct mark is jumping to a different spot, it will be necessary
        to hold or lock it while your finishing positioning any remaining gears / chain ect use a pair
      of vise grips clamped to the cam at some spot UN-machined.
                                                   CAMS WITH  ALIGNMENT HOLES
         Some motors like
            the GM 2.4 use holes in the cam gears that you stick a bolt or drill bit into to  while aligning
         beware of the gm 2.4 variable cam gear/s as there are 2 gears stacked and  you must not
         allow the 2 gears to slip to another tooth or it will not work (seriously)

         the 2.4 is a difficult motor to lean their are hidden bolts behind chain tension er ect 
            On iron blocks and or heads i use permatex Indian head shellac to seal rust spots 
         even though it may not be altogether necessary it can stop rust from forming on the
          metal that will cause pitting and lead to gasket failure (use your own judgement).

           I f you are working on the ford SOHC V-8 the Gas TYPE chain Tension-er is behind 
               the timing cover it will be very difficult to squeeze  if you remove the gear so if you
             have a piece of oak wood you may be able to make a wedge and pound it 
              against the chain to scotch the tensiner from springing out when you take the top
              cam gear off. If it does come out you will have a hard time to get your gear back on.
             cam loose .
                                                                        Pressurized Gas Tensioner

               Be aware of  what type of Tensioner you have on your engine if it has a gas pressure
                   type Tensioner you will need to in most cases remove it because you will not be able 
               to get you chain/s or belts onto the cams as it will expand and make it to tight a fit 
                 If you do take the gas pressurized Tensioner off to reuse it you will need to slowly
              re compress it back into the cylinder housing so you can get it in far enough to put 
               a pin into the retainer hole on the side near the rubber boot to be removed like
                a grenade pin only after all the gears and chains / belts are in place and screwed on.

              It takes a lot of force to push the Gas pressure Tensioner in : you will have to
               put it into a large shop vise and the slowly over  say 4 or 5 minits screw the vise
               tight until the pin hole is aligned  to much weight and you will ruin the end of the 
                tensioner i have put them under the car and used a jack to slowly compress them
                 remember to give them time it will need to move slowly over say 4 or 5 minits .

                 when replacing a rocker arm assembly on the Honda civic 4 cylinder engine, be careful when the
                 assembly starts to tighten watch to see if the rocker arms are all contacting there
                  respective valve stems if the high  lobe end valve gets sideways it will bend the exhaust valve 
                sideways BEWARE just push it to the top of the stem so it don't bind as you get it close to pulling down 
                even as some lobes are high and push on the assembly as your tightening it to the head cam inplace
                 understand ?

                A Nissan 4 or v-6 cylinder uses a hydraulic tensioner if your chain is makeing a zizing 
                   noise when engine heats up it could mean the main bearings are wore out ! a chain job
                   will not help this you have bigger troubles  so check oil pressure" with motor hot first .

                 Got an older front wheel  gm motor with a bad cam?  don't want too take the motor out 
                 because of side fender frame? then jack the motor up remove  intake and push rods 
                  and all lifters (use vise grips to pull lifters)  timing cover and gear .Then slide the cam 
                  sideways till it hits the metal above the box frame (jack the motor a little ) the use 
                    a drill to drill a series of holes in a semi circle slightly larger then the cam from 
                    and through the tin behind the wheel well ,bend the metal back (wheel removed)
                     and pull the cam out through the flap , it  will save a lot 
                     of work and sometimes an engine change. Install new cam and lifters".

                  Have a leaky crank seal up in side an area where you cannot prize it  out with a 
                    screwdriver ?  it may be necessary to drill a small hole in the seal shell through
                    the thin tin shell (  caution don't over drill into the main bearing )
                       and put a fairly long enough sheet metal screw into the hole so
                      you can pull on the screw  ( seal attached)to get the old leaky seal out 
                   These few cars with a sunken seal will be hard to align the new seal to push it in
                       i have at these times cut a small section of plastic from the side a plastic pop
                      bottle and wrapped it around the crankshaft nose(temporarily) so that the rubber the new                 lip on the new seal can slide over the plastic sleeve like a shoe horn and the new
                     seal doesn't flip under when you push the seal into the recessed area 
                      always put grease or oil onto a new seal.

                                                              LEAKING OIL SEALS AND TIMING BELTS
                       If the cam seals or crankshaft seals are leaking and your motor has a belt /s 
                         you will need to replace any and all seals on the effected cam or crankshaft
                        other wise if you allow the oil to continue to leak onto your timing belt 
                          it will sometimes ( depending on the belt) cause the belt to break soon possibly
                         in as little as 2 months and potentially within a year it could break 
                         best to always use a new belt but if your not then wash the oil of the belt 
                         with degrease r or then use tide soap, or oven cleaner ect.

                  Time saver when taking certain heads off that "head bolts" can be removed
                   without first removing cam? simply take bolts out: when ready lift end of head
                 farest from gear/cog that will allow you to slip the belt off the gear/ cog  & remove
                  head and cam in one chunk, !  leave adjustment alone Unless its loose going
                 back  on? if you mill the head it may become loose so then adjust the belt if 
                 it has a manual belt idler ( see above for info of pressurized gas tension er !)ok