Lapping and Checking Valves (EASY WAY)

Just lapping some valves
Update: Since of this video's release to 12/25/17, the engine has no major problem. The engine is used to drive around 30 miles a day, and yes, I know that too much Prussian blue was used.
Tools Used:
Drill/Driver
hex to 1/4 drive
Lisle 21200 Valve Lapper
CTA Fine/Coarse Lapping Compound
Permatex Prussian Blue
Dykem Steel Blue Layout Fluid
Digital Caliper
Note: A proper valve job is recommended to be done by a professional in a machine shop. I did this because this engine is not worth much and it is not a high performance engine. (LOW BUDGET)

[@DrDLightful]

I run a small engine shop, after the only machinist in the area retired I bought a hand set from Neway to cut valves and seats. They use carbide cutting bits and they make a very different finish than a stone cutter. I cut the valves at either 30 or 45 depending on spec. Cut the seat to a 46 or a 31 depending on spec, and use a maybe a 31 on a 46 at the top if the valve is seating too far outward. Once I get them seating pretty good I take a fine lapping compound and hand lap for no more than 5-10 seconds tops. Prolonged lapping will concave the face of the valve and destroy the new finish. For the lapping I take a piece of fuel line and push it over the valve stem and rub my hands together with the fuel line between them (like starting a fire with a stick). Finally I use a permanent marker and color the face of the valve, clean the seat really well and turn the valve no more than 5-10 degrees. This checks the contact all the way around the valve, note that turning the valve further would rub the entire face of the valve across any high spots there may be. Not the most professional way by any means but ones I've done 6-7 years ago are still running good when they come in for spring service.

[@jovedean6112]

I am a certified mechanic and use this method along with other shops. His seats are in spec. He did a great job! Thanks for sharing!

[@simonyoung1265]

Thanks for this comment mate..I'll be doing same when I get all the gear together..doing my diesel WL head..

[@natanyofsho]

Wow

[@DieselRamcharger]

you dont know what the fuck you are talking about.

[@natanyofsho]

@@DieselRamcharger all I said was “wow” what’s wrong with that?

[@DieselRamcharger]

@@natanyofsho i replied to the OP not to you. notice your name isnt tagged in. the youtube comment section is so stupid how it works.

[@66mustangguymoreau36]

I like to shine a bright light into the port area to make certain the valve seat will seal properly. Works very well. Good job

[@jcr8834]

lapped my valves today. used some of your info. I went back and forth with the drill rotating direction. My seats and valves came out great with no scratches. Holding gasoline as well within the chambers.

[@myintkyawmoe5373]

Thank you.

[@jcr8834]

@@myintkyawmoe5373 lol 3 years later.

[@norvigosracing6948]

Just catching up with the valve job. Is the engine still ok?

[@lusun8078]

@@jcr8834 Is your valve job holding up good?

[@jcr8834]

@@lusun8078 yes no problems. But sold the engine already

[@austinlemaster1150]

someone get this guy a beer. I like how you think and work. great video!

[@ryandavis6660]

Stratforward demonstration ! Brilliant.

[@vanillagoose4444]

I liked the Tap Dancing Squirrel ! He was getting his funk on while chewing them nuts !

[@jdmr.3346]

I lap by hand so you can hear and feel what is really going on. It takes much longer but it's very gratifying knowing it's done perfectly.

[@joet6990]

How long does it take to do by hand? I have a head off a dirt bike where the valves tapped the piston, the valve area where it sits looks alright but has a good bit of carbon build up. Would this get rid of the carbon also or do I need to get rid of that before doing this method?

[@Evolution_10_X]

@@joet6990ive lapped hundreds of valves get rid of all the carbon make sure it is completely cleaned first than get some engineers blue its good for beginners so you know where your at other than that its easy when you lap by hand it will get quiet the more u lap thats when u check

[@joet6990]

@@Evolution_10_X well I ended up just letting it sit in rust remover overnight and that removed almost all of the carbon buildup inside of it, I also watched a video on laughing valves which may have been yours. I kept going until all I saw was that silver line all the way around this seat and there are no black pits in it. when I blow into the intake hole and push my valve all the way in I can notice there is a small air leak. I put some soapy water onto everything and it looks like the air leak is coming from the new valve guide from the inside of it. Is that going to be sealed up when I put a valve seal on the end or is it still going to continue leaking? Will that cause compression issues?

[@Evolution_10_X]

@@joet6990 did you ream the valves? Or check the tolerances of the valve guides? I would check the correct bore hole and see if yours is in spec with what your manual says they could be worn out im doing valve guides on a triumph 650 right now and similar thing happened to me oil was seeping past the guides

[@jamiesimpson1786]

Generally lapping is back and forth and rotating the valve on the seat. It is normally used to fine tune the contact after both valve & seat have been refaced. This method maybe a little harsh.

[@richardalexander7089]

Ignore the *haters*. There are quite a few of these videos out there. You placed a disclaimer at the beginning. That should be enough. I learned a lot from this video. Thank you! I've also looked through the comments and found some good info. As well. If I combine your video and some of the comments, such as (paraphrasing here) "..the surface should be a dull grey and not really shiny. " has helped me a lot! Thank you again!

[@marty7922]

Lapping valves is not a machine shop only job, they usually grind, maybe replace stems. I use drill & hose on stem lapping, w/ finger grease to press the valve in & out lightly (let the compound do the work). Just push the compound back into the seat when it squeezes out. Prussian blue (or marker pen) isn’t necessary, you can easily see the gray resurfacing from the lap. If you’re really concerned, when done put alcohol on the valves and look for leaks in the ports. FYI Extra compound will not hurt the job, running it w/o compound can gall making scratches (same type metals gall). You can easily clean off the compound & not worry about grit in the engine. TIP - A wider contact surface on the exhaust is desirable, it pulls heat off the valve. A narrower contact on the intake helps prevent the seat from cooling (shrinking and dropping). Some valves have a 1º offset and not a solid contact (good for intake). Everybody has their own take on valve jobs, use what you feel’s best. You can get so perfect with stuff and still not have any better performance - just avoid burnt valves and dropped seats. If any of you are really that concerned, then replace the valve guides also. Nice video.

[@therandommech9099]

Thanks for the info.

[@henryfuentes3425]

0-Zone I like the alcohol idea . My papa told me to use gas to check if it was good. A little less fumes your way.

[@spooky3173]

@@henryfuentes3425 whats wrong with some fumes, makes the job more fun

[@lesglover6515]

Thanks for taking the time to upload this video to let average guys and girls know how to clean up a cylinder head. Well done.

[@timmclennan6616]

I've been getting great results for years using a variable speed drill on the valvestem and pulling it rather than pushing. Only tried it because my lappers suction cup had dry rotted.

[@DieselRamcharger]

you havent been getting good results.

[@roguepoops23]

@@DieselRamcharger got nothing better to do, eh?

[@geraldswain3259]

Preferably a lightweight one ,and then produces a hulking great 20v model !.

[@armaletalia3254]

LOL

[@garyclagett1848]

Very nice, easy to follow video. Do you ever reverse the drill? (Back and forth)?

[@bajanboyhood]

Seemed to grind those seats pretty long. How much were your shim Clarences out after your lapping process?

[@amacca995]

I tried a similar process myself except i used a hose on the other end of the valve and connected that to the drill. I changed direction of the drill a lot, not sure why but figured it might help. I did not have the suction thing you had. To my delight it worked much like yourself. Always satisfying to do your own work. Well done.

[@snowblind5151]

I tried the hose did it about 5 to 6 times sound didn't come clean and the hose wobbling scares me to think of whats happening to the guide. I would much rather try pushing the valve perfectly into the seat than bending or warping the stem and oval wear on the guide.

[@billholt174]

@@snowblind5151 I had similar thoughts. It would seem to be much more accurately done with the control permitted by direct feedback of the feel if you were to use a low-cost hand-held lapping tool. That gizmo is essentially a time-tested standard. I can't imagine an advantage to sleeving the stem with hose and having to pull it backwards or upwards against gravity to do this with acceptable precision. I'm not hatin', just statin'. As well, people who use power tools for more finesse-dependent work like this are the impatient horn honkers who pass cars to be first in line at the next light. : ] Unless you can work with the exactness of a CNC machine on a job like this I don't think that a drill is your friend for anything other than getting this done in a hurry, as in a busy dealership shop or a half-assed Sal's Garage. It's easy enough to make a mistake by hand, and the force inherent in a drill is a mere extension that can take a correctable mistake to the level of irreparable fuck up.

[@wetcmonkey]

I did something similar, I use a smallvacuum hose attached it to the opposite end of the valve stem and pulled up instead off pressing into it. I didn't have the lapping tool as you did but worked just as well. If it works it works

[@road2ziondesign988]

Excellent job and great detail thanks for sharing.

[@joeabels3931]

I tried this and it worked great. Thanks so much for the post.

[@davidmiles4394]

I've been doing mine the same way but I've been doing the water and air test and still got a couple valves that's leaking

[@gibamec7636]

Good job, Master!

[@MrHandy-hz5ju]

you can measure the seat like that to be accurate.. you have to check runout. which is a measuring tool you can you in a circular measurement. look up measuring valve runout. its basically a dial indicator..

[@dickJohnsonpeter]

I looked around with a boroscope into a 4.0 L6 in a 97 xj I had just purchased, with 197,000 and everything looked brand new, I mean, barely any carbon, cross hatching on cylinder walls looked new valves/seats all shiny and smooth, I was not expecting this from a vehicle clearly driven through 20 years of harsh northern winters. Best $500 I ever spent. It now has 210,000 and runs like new.

[@AmicosBarandgrill]

Great video! I would also use the drill alternately forward and in reverse and at a lower rpm.

[@Midnight_Rider96]

The best way to do a diy valve job is lap the seats until pitting is gone, then have the valves ground at a machine shop to restore a perfect cone shape, the do a final light lap with fine compound. Cutting the seats is where most of the money goes, and hardened seats tend not to wear as quickly as valves anyway. More importantly, the valve needs to be able to expand from heat and still seal. You only get that back by grinding the valve. Lapping a worn valve will make it seal only in the exact position it was lapped, which won't matter when it heats up and expands

[@ThomasJeppesen]

Alistair B what would be the consequences of a too large contact area between seat and valve? I’m changing the valves on my motorcycle, and after lapping it looks great, but the contact area is right around service limit on exhaust side. It’s not that I’m lazy to go have the seats cut, but I live in Vietnam, and I really don’t want to have the machine shop molest the head. If it’s a question of longevity, I can live with that, but I wonder if there are other issues? Cheers

[@borna430]

A valve that goes to the machine shop is much more expensive than a new valve :)

[@Midnight_Rider96]

@@borna430 not necessarily. I worked in a machine shop we always ground the valves if they weren't too damaged. New valves can be pretty expensive or hard to find for vintage or exotic engines.

[@vadski3469]

Would I be okay lapping new valves with used, unlapped seats?

[@vadski3469]

Aftermarket valves that is.

[@sleezymechanic]

The service manual made it very clear I was suppose to 1/4 turn with the prussian blue. To turn or not to turn.

[@lamewarrior]

Where are you finding suction cups that stick? I bought new, genuine "made in China" rubbers and finally had to rotate the valves with my fingers. (they didn't need lapping anyway, just a "feel good" exercise)

[@prophaniti1]

Great way to socket the seats....

[@hacwa]

what does this mean? - don't actually expect a reply but worth a shot :D

[@bottmar1]

Just be sure to use grease based lapping compound as the water based crap doesn't spread very evenly since the valve likely has some oil residue on it. Also water based compound dries up in it's container. Grease based stores forever.

[@carlescarles4112]

what size grit did u use of the grinding paste?

[@patriciasparks6740]

The cta lapping compound is it in two parts? All I can find it f/c black that seems to be like permatex valve grinding compound. Where did you get yours??

[@szbalogh]

Did You wash the lapping compound in the valve guide? :o

[@norain31]

When valves arent flat and suction cup wont stick i use a 1/4 fuel hose . I slide the hose over the valve stem from back side and i put a short peice of dowl in the drill side of hose . Clamp on drill then do the lapping . just another way i thought id mention .good job there bud .

[@algonzalez8798]

This is a good Old School trick we "Budget Racers" used. Might use less lapping compound and keep the speed as low as you can.....save the valve guides. Also, the marking dye should be transparent when applied properly.....but, all in all great information to help those that can't afford those machine shop fees which now are just crazy!

[@dirkrosslee796]

I just use the 2 stage compound .clean off nicely. Assemble and pour some feul to check for leaks.

[@martinez1701a]

Machining is outrageous now adays $90 for a simple crank polish or few hundred to resurface a set of heads is bullshit!

[@martinez1701a]

@@dirkrosslee796 yeah gas or acetone is great for checking seats.

[@ColdWarVet607]

I used soapy water (lots of dish washing soap) over my valves after pulling the head, then blew compressed air under the valve and watch the bubbles grow. After a good lapping no more bubbles.

[@2andrewd]

transparent marking dye. you just won a patent.

[@davidsundquist1845]

try a leak down test-fill the chamber with clean solvent-should hold over nite without leaking.

[@NKPGarage]

Great job. And very good to see you check the spec.

[@kevinbui5280]

It’s really easy way, I’ll try for my car at home, i hope I’ll successfully. Many thanks for your interesting videp :)

[@Nunya_Beezwax]

Prussian Blue is totally unnecessary. The lapping compound will leave a dark ring around the valve face when it's seating correctly

[@juntjoonunya9216]

What is that noise?? And I don't mind it

[@user-wc3sl4xs6l]

Sitting here laughing at all the tapping complaints 😂😂😂

[@carl_marks1626]

It went from a 3 angle to one big angle valve job.

[@charlesbrewer6552]

My aircraft engine manufacturer recomends (during an engine maintenance course where we did it) to cut the 3 angles and then lap to achieve a minimum seal. Checked with prussian blue to about 1mm or less, but a continuous, definit seal. The lapped seal was to be in the middle of the valve seat and the valve face. They said "BY HAND", do not give it to engine shop who will put it in a machine to do. The method shown here appears to destroy valve and seats angles. Well, that's what I was taught by the manufacturer of my aircraft engine. But, what would they know?

[@jacquespoirier9071]

@@charlesbrewer6552 it is the best way to confirm a good valve contact, I never use a machine of any kind to lap valves after grinding. On modern engines, it happens frequently that the valves and seats are in a very good condition so just a very light lapping to clean the contact is required.

[@carlosruiz9963]

But do they have to seal ?100 percent cos a still have very tini air comprecion los even after polishing 😢

[@theunknownone5663]

What is that backround noise?

[@waynep343]

HUGE HINT.. if your valve seats are 44 or 45 degrees.. take an extra valve and grind it to 60 degrees so you can narrow the seats up from the bottom with lapping compound. you may need a slightly larger valve to grind a 30 degree seat on that to narrow valve seats from the top with the 30... you will have to do this with exhaust and intake valves.

[@jrlopez7874]

a pro grinded valves by hand

[@molliarti]

Companion,I think that make this don't good,I was learn when put a compound,the movements of valve its right-left right-left right-left. Why you use the drill in a one direction? Thanks for your time.

[@Taydrum]

You need to do this by hand, never with a drill, because you need to listen to the sound of the valve on the seat. You also need to go both directions

[@bendude6748]

I think both will do the job but I also prefer to do the job by hand I think you get a better feel for it.

[@Michael-lg4wz]

how does your suction cup work so well ive tried cold water warm water, a little detergent, CRC,dry,light sanding

[@AndresLopizesuno]

Silicone lub works great

[@fatboysonny]

Nice video, thanks. I have a compression issue with my WR250F. I'm almost certain it's valves, as the piston and rings were new and in tolerance. I already tried to lap the valves once, but don't think they were in spec. I will attempt again with a few of your hints, cheers!

[@firstnamelastname7352]

Cant lap valves on dirt bikes. Replace only

[@MotoBuilds]

I think the wr valves may be stainless. In which case they can be lapped in. However it is very likely your valve shims. Not the seat and valve itself...

[@samdraper9340]

How did you get on.. currently having some problem on my sherco 250

[@ralphbrown2714]

You were right ,not done by a professional.

[@aliibrahim2618]

Good job 👍🏾

[@samlorca7974]

This is manual process, don't use an electric tool!!!

[@motleymenace]

I've personally done it this way a couple times so far during my apprenticeship and have not had any problems, however I can see why you personally may choose the original way over this as it could be easy to make a mistake like this, however I feel if you take your time it can still do the job right and save you a lot of time.

[@llewvirtue861]

I wanted to cringe when I say that power tool, I started my trade doing heads in cummins engines. The face of that valve and the seat should both should have been faced. This is a short term solution

[@55chevytruck]

Bob Glidden used to use a food mixer back in the day and I seem to remember his pro stock motors ran pretty well.

[@jackm5213]

That valve and that seat are so bad that the valve should have been faced and seat cut to ensure apropriate angle and back cut lapping fucked valvles like this will cut its own angle and destroy CFM

[@TakeDeadAim]

BS. I build/rebuild roughly 20 heads of all makes per week. I use a drill on every one of them to lap the valves. Been doing it that way for roughly 7 years. You deal with the Doodle stick if you want. I'll do the same job...better...in 1/10th of the time. Also, no need for prussian blue. After you've don't enough you'll know by sound and feel. You can also use a sharpie if you really want. And yeah...that was WAAAAAY too much!lol!

[@k2one9]

Do you have a typewriter?

[@TheWolf047]

thats what i thought to!!

[@michaelcwilson2]

Great video. A little advice, go way lighter with the blueing. Cheers mate

[@carlosarce5013]

Can't wait to try this technique, thanks bro.

[@SvcGlobal]

Great, great, great video! Thanks a lot!

[@torque395]

What engine is this head for?

[@Rashid-ee5ig]

Valve hand grinding machine kaha milegi link send me

[@ylwgtr]

Is predator hiding in your shed there?

[@J__C__]

ylwgtr glad I'm not the only one that noticed that annoying shit

[@Mattmorro67]

Sped up sounds like an old 22R turning over

[@desertrider325]

How do I clean the carbon stuck on the valves and head? Tried brake clean and a rag still stuck.

[@MotoBuilds]

T R, why would you ever have carbon deposits on your throttle body....the intake valves should be sealed at the time of combustion.

[@Spudderr]

Berkebile 2+2 gum cutter

[@Rashid-ee5ig]

Lapping tool ka link bhi send karna

[@Turbogto_guy]

To any of the people saying this won’t work and this isn’t a good job, I’ve done the same thing on engines many years ago that are still running perfectly. All you need is the valve to seal against the seat. If the valve has a coating and you wear it off then the valves won’t last. So in that case you replace the valves and lap new ones in that aren’t coated.

[@JAVTROOPER]

Thank you 🙏🏻😊

[@michaelhayward7790]

Always remember to put the lapping compound on the valve stem and rotate whilst installing.. good as new right?

[@slickricktheruler]

Great how for the DIY person. Thanks man.

[@897473]

Great video. Well done!

[@andrewnardo1021]

I’ve lapped valves with a drill more times than not and have had literally 0 issues. From small engines to large agricultural diesels. Never had wear issues or leaking issues. Would I use it for a high performance application, no, but for re lapping good used valves during a rebuild there’s no issue.

[@joshcallaghan9432]

People like to bag out what they've never tried and love the "oldskool way". That may be better but could you feel the difference? I doubt it. I did this the other day and it seemed to work. My Exhaust valves leaked air, now they dont. Gotta be happy with that!

[@greggoldie2351]

Wet test is best!

Seat and valve seat are freshened up but the stem is shot..

[@pauljanssen2624]

When you over lap a valve into the valve seat you around the seat and don't have a true interference fit it will work for a short time but you'll end up burning a valve a rounded angle and not a true 45 flat angle worst thing you can do is use electric drill

[@fretzmaler7591]

You Are absolutely right here, the drill method is for the lazy Boys and wrong seat fitment, this drill method is harsh.

[@FordTechATC]

I spent today lapping a cylinder head from a 6.4 ford diesel. I cleaned the entire cylinder head. Removed all carbon. Purchased new intake and exhaust valves. There 2 intake and 2 exhaust valves per cylinder. I lapped the valves using the hand tool and lapping compound mixed with grease from Permatex (it comes premixed). I doubled checked my work after finishing the cylinder head using water into the ports. Some water flows from the valves. A couple of drops here and there. The valve seats and the valves sealing surface looks perfect. Is this normal after lapping a cylinder head.

[@jmonaghan6496]

FordTechATC yes from the research I've done just now. It seems to be completely normal. Your good to go and good job ;)

[@FordTechATC]

I did my research as well and it is normal to have wetness. The correct way would be with the Prussian blue and measure seat and sealing surface. Called up a bunch of machine shops to make sure I was good to go. I reused that cylinder head and engine runs like a champ. The other cylinder head had a cracked exhaust valve seat. Had to replace it.

[@jacquespoirier9071]

it is normal because you don't have the 1 degree interference in a worn out seat, this will not cause issues ad the volumes involved in the engine sweeping process are much much larger than that and as your engine will run, there will be a final match between the valves and their seats.

[@kenchorney2724]

At 6:12 it looks like there is a crack between the valve seats.

[@automotivejunk5291]

that is just a build up of carbon within the chamber

[@MotoBuilds]

What is that weird tapping noise in the background...

[@codytessmer]

ETX MX that noise is driving me Fuck! I can't finish the video

[@jankindl915]

Camera focus.

[@bustyboy123]

Cody Tessmer lol yes

[@MrFredsAdventures]

Sounds like those teeth chattering zombies on World War Z

[@LadyJesterSurfer]

I'm guessing a fan

[@Anenome5]

Light coat of prussian blue? That was about 20 times too much PB!!! It cannot act as a surface contact indicator if you put giant gobs of it on that like!

[@therandommech9099]

sorry about that, I know it was a fail..... forgot to mention that I did wiped most of it off camera.

[@jdubcbr600]

Good video! There's always someone on the Tube that knows how to do it better than you and wants to tell you all about right? I wanna know why the hell are they watching if they know how to do it already? Self entitled pricks!

[@joeeastman]

JoshW817 EXACTLY, everyone has to call him out on the same shit someone else has already addressed rather than read through the existing comments to see if their comment is even necessary. All those "pros" should just make their own - "this is the right way to do it" videos, then we will all be so impressed that we would be inclined to remove any video we've ever uploaded.....good video btw.

[@grahamlangston2101]

Using a drill in only one direction will cause lining Mark's lazy way of doing a job

[@ominguti6345]

You're using way too much prussian blue. Those dabs with the tube you make along the radius of the valve, one would suffice. Then you should smear the prussian blue around the valve with your finger so there is a very thin even amount. It should look even, then you press the valve into its seat and you give it a "slight" whack with a piece of wood or plastic. This transfers the blue sufficiently. This method will show you half a thou out of round, while your method will probably show great transfer with 10 thou out of round.

[@jacquespoirier9071]

totally agree

[@mikerieck306]

......and sometimes you need to do a Serdi valve job and replace the valves. Like right at the beginning of the video.

[@Just1Spark]

The background noise is the cameras auto focus lol. Not a mouse.

[@haiqalazree]

if i just switched off the light and just shine through the hole to check for the valve seat is it ok?

[@youthised58]

Wouldn't it be wise to replace the guides first befrore lapping. Worn guides causes valve stem wobble. I mean, if you're looking for perfection why not start with perfect guides and not worn ones? If there's wobble at the end in the guide, the wobble at the valve end would be even greater. Equipped machine shops cost a lot but they can save you the trouble of starting over again.

[@snowblind5151]

Where do I get the suction cup?

[@rb3166]

From the stick. You can buy it at Napa.

[@TunerFaction]

Though this is an old video I thought I might try and steer some people away from lapping your valves. Though it may seem intuitive, lapping your valves will actually produce negative effects for your engine. This is because when you lap your valves, you do it when the block is cold. This means the valve may seat well when the engine isn't warmed up, but when you are up to operating temps, your valves will no longer seat correctly. This is why it's always best to get your valve seating done at a machine shop.

[@owaind-g678]

Are you suggesting that a machine shop would heat up your head and valves to lap them together? If you were to send a head to a machine shop for a valve job its likely going to be more than just lapping valves, maybe cutting angles onto valve faces/seats, installing new valve guides/seats, Lapping would be done as the final step of a valve job sure, but it wouldn't be the sole reason to send it. I regularly see vehicle manufacturers explain how and why to lap valves in the vehicle manuals quite often. I personally believe your advice is not based upon any evidence, its just more of an opinion. Valve lapping is not that difficult and if you managed to dig them out of the engine your probably competent enough to rub em together a bit. just my opinion though.

[@TunerFaction]

@@owaind-g678 Hey Owain thanks for the reply good sir! I appreciate the respectful disagreement and thought I might respond to your response. So I don't think a machine shop heats up the head and then laps valve seats. Like you said, when you get a valve job done at a machine shop they cut new seats at various angles and then as a final step, they very briefly lap the valves to remove any peaks from the valve seat cutting. In the research I have done, lapping your valves without getting new seats cut is a bad idea and can cause problems down the road. There is a great video from HP Academy on KZbin that explains exactly why lapping your valves is not a great idea. If you were interested, just search up "Can I lap my valves at home?" By HP Academy. There are a few other reputable sources that also say the same thing and the conclusion that I have come to is that lapping valves without getting new seats cut is a bad idea. I also agree with you in that it's an easy job to lap your valves by yourself, I'm simply saying that even if you do it correctly, I don't think it's healthy for your engine. This is obviously just my opinion, and I could be wrong! I just thought I would share what conclusion I have come to given the research I have done on the topic!

[@owaind-g678]

​@@TunerFaction Thanks for your reply and expanding on your idea, I understand your point better now and i agree freshly cut valves will always be the best option, but not always the viable option. Although there is a big difference between racing and road engines and id like to focus more on every day street engines for the at home "DIY" valve work we see in these videos online. Engines will still run even in awful conditions with pitted valves and bad compression and weak springs, could have your timing off and the things still run like a hot damn. Most the valve work I have had to do is on older vehicles with higher mileage, the parts aren't always available and can cost a small fortune if you can get them at all, sometimes resorting to second hand parts or donor engines, sometimes you just gotta do what you gotta do to get by and a lot of the time it means the parts will get cleaned off and put back together as they were, machine shop time is expensive and not always within the budget at this point i dont think you would be doing any real harm to the engine by improving the mating surfaces of the valves or seats, as long as your careful not to damage the valve guides should all be fine and dandy. I am still curious about the expansion of valves and seats to the point of failure to seal but in a racing engine with forced induction it may be the case, It's an interesting idea and i will do some more research into it regardless. Thank you for the heads up on HP academy channel i will be taking a look at their videos.

[@TunerFaction]

@@owaind-g678 Owain thanks once again for being so civil about our conversation. Too many people on here would have just called me an idiot and moved on. I think you have a good point, I had crafted my opinion looking at this topic purely from a racing/forced induction engine standpoint where the best option will always be to have a machine shop cut your valve seats. On an older engine where parts are few are far between, I don't think their is as much of a problem lapping your valves at home to get rid of some pitting or worn out valve seats. In a case like that, you would likely improve the seating of the valve overall! You are also right that it's not in many peoples budgets to get a valve job at a machine shop, heck, I didn't even get a valve job at the machine shop because it would have cost me north of 1500 buckaroos. I would say that there is no "correct" answer, I think it changes from situation to situation. If you want to build a high horsepower race engine, lapping your valves at home is really not the way to go. If you are just rebuilding your daily driver or rebuilding an older engine with no intention of pushing big power, I don't think there is anything wrong with lapping your valves at home. Great conversation!

[@Dylans503]

Dear, Owain. Are you still there?... I miss you. ~ Your lover always, Tuner Faction.

[@drdrakeramoray6738]

6.14 I can see the crack between valves seats

[@bryanoverlin839]

Yup that's def6 a crack

[@garyr7027]

Does look like it... I'd say it is.

[@KushaTarantino]

Lmfao this dude got roasted

[@memadmax69]

Ouch. Scratched the hell out of that valve.

[@pantherplatform]

I'm halfway thru restoring a 1990 Ford 300-6 but the head and valves are like brand new still. The head is cast iron so I don't have to be as careful cleaning the seats as if it was aluminum. Looks like your a pro.

[@jacquespoirier9071]

lapping must be light !!! heavy lapping as you do creates a deformation of the contact seat and promotes a failure at a less than desired interval. Many times, I had to replace valves on low to moderate mileage engines because of a failure of the timing chain and most of the time, I seat the new valve by lightly lap them in their seat and i never had a comeback on those jobs

[@simssimms6522]

Does the valve need to be sanded and perfect clean before the suction cup? Mine wont suction

[@Michael-lg4wz]

I have the same problem ive tried cold water, hot water,detergent,dry,400 grid sandpaper thats why im looking at the drill methods

[@christinetokyo5125]

Use a hose on the other end

[@tomassosaoconnor]

@@Michael-lg4wz I did polished the combustion chambers with the valves in, so the valves where polished as well, completely recommended

[@myintkyawmoe5373]

Good thank.

[@themotorlawcompany4673]

Good vid. Some voiceover explaining why you would do this would be helpful.

[@Eddie-cw5mi]

great vid. thanks for the info!

[@BigJsgarage]

You have enough lapping compound on one valve to do the hole head.

[@therandommech9099]

just getting rid of some old compound.....

[@bikejunk1]

Problem with using too much is getting it all out of the valve area and seal it is like throwing a hand full of very fine sand in your engine not good

[@therandommech9099]

True.... But I did pressure wash the head in the end

[@macncheese1991]

its his build he can do whatever he wants.

[@lesglover6515]

BigJsgarage w maybe you could put your own video up if you don't like his.

[@blueonblueracingnova]

thanks for the vid i have this to do on my new race motor yet . not so keen on the drill idea but the checking idea is great . and i will deffo be using this way in the future.

[@75L48]

It must be bent to a degree no prussian blue is needed to see its bent before your method will read results. :D

[@ShenaniganZone]

thanks. you helped me big time

[@untraditionalministries4588]

everybody on here complaining, whu font you do your own videos, he already said hes not a professional

[@Elipro427]

Aaron Frazier finally someone with commen sense.

[@J__C__]

Aaron Frazier English much, Aaron? Jeez. Whu font? Wu Tang for life! Lmao

[@jacquespoirier9071]

this is good to confirm the contact on the valve seating area but there is a reason to rotate the valve in alternate direction, when the guide is not perfect, you end up with an egg shaped seat. and gouged valves. the best use of lapping compound is to confirm a seating contact on a freshly reground valve and seat and it should be done very lightly as there is an angle difference of 1 degree between the valve and the seat to promote an initial tight gas seal and this angle interference should not be destroyed

[@fortuner123]

If he is doing a bad vid then he should expect corrections knuckle head.

[@TonaldDrump686]

Jacques Poirier : 👈 This guy is 💯 percent correct. Y’all should listen.

[@MiKa-fu2wi]

Thank God for squirrel camera men...

[@sudhirtirkey3234]

It would have been better if the grinding was clockwise as well as anticlockwise, intermittently.

[@sandbiker]

Fantastic video, thanks.