Lapping and Checking Valves (EASY WAY) 

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?

@@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

@@Snorky_88 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?

@@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

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.

@@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.

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

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

@@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.

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

Aftermarket valves that is.

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?

@@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.

totally agree

thats what i thought to!!

Camera focus.

Cody Tessmer lol yes

Sounds like those teeth chattering zombies on World War Z

I'm guessing a fan

Auto-focus motor in the camera constantly re-adjusting.

Dodd Garger it's the internet you know all the morons will believe and continue to think that this process is a basic valve job when it is simply not as you stated this process is absolutely pointless without a valve job but like I say it's the internet and there be 20 other people doing the same garbage You and I know that this is done after a valve job is done to check to see where the valve and the seat meet There's different purposes for where they want the seat and valve to meet up is the only purpose for lapping compound

Many will disagree with you, and many more done valve lapping with success. I've done this before myself and I know it works, never had issues. I didn't do it quite this way but nonetheless I've done it. Perhaps you didn't lap the valve right? Or perhaps you took too much off? This trick will work, however you have to make sure the seat and the valve is good enough for it. Too much pitting and this is not the idea solution. It's only good for minimal grinding.

I second that! You're only supposed to put a stain on the valve and see where it transfers to! And you are supposed to turn/rotate it. You aren't supposed to glob it on the piece like tar on a leaky roof!

That's not how you use ANY of the products shown on this video. It's more of a "how NOT to" video! Some people are idiots. (The squirrel sounds were annoying too)

I wouldn't let him touch anything of mine this is so wrong!!!!

Just enough blue for a good splash check! Lol

Yeh

3 angle valve job on a v8 = buy a new head

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

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.

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.

Yeah what he said!

Thank you.

@@myintkyawmoe5373 lol 3 years later.

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

@@jcr8834 Is your valve job holding up good?

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

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

Wow

you dont know what the fuck you are talking about.

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

@@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.

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.

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

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

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

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!

you havent been getting good results.

@@DieselRamcharger got nothing better to do, eh?

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.

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

Thanks for the info.

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.

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

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

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

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

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

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.

transparent marking dye. you just won a patent.

LOL

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

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!

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.

Aaron Frazier finally someone with commen sense.

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

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

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

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

@Red Pilz hey , first of all im not a valve lapper by trade and I've never lapped a valve . That being said , I am a tool maker by trade , I make lost wax injection mould tools for turbine blades and have made various other tools such as plastic injection mould tools and rubber mould tools , I can diamond polish to a mirror finish and blend die forms out to name but a few of my skills in my set , so I use all the same stuff in this video but in a different application . To best answer your question , the lapping paste in this video is quite "dry" , my diamond polish I get is much the same , if you just use it as it is , it will kind of "clog" up and also get hot with the drill., I dont think you need to drill it , better twist by hand , but each to there own , I would personally add a touch of cutting oil if available to the lapping paste when applied , or any oil or wd40 you can get your mits on , your lapping paste will last you longer and you will get a better finish , obviously the more oil you add the more you "water it down" so will take longer and take less material off , but a little wont hurt and you will find it just makes everything better and nicer , and if your lapping valves , use some engineering blue like in the video but use x100 less than him and apply evenly , press valve in , don't twist , and remove , it will take practice to "read" the blue on the valve but its not rocket science , hope that helps you , good luck on the lapping , if you need more help with the blue just ask

Atleast you know that camera is constantly focusing. Thats what all the clicking is about. Auto-focus

Wrong. What you describing is a way out of round valve seat. Once it is close, even fine lapping paste will score both surfaces yet 'bearing blue' will show it is still way out.

@@johnwoodrow8769 if you wanna get down to specifics, it depends on the year of the head, the material of the valve and seat, and experience. When using a titanium valve, sure Blue will show up imperfections lost to the untrained eye that lapping compound will not. I'm not about to get into all of the specifics with someone who has probably never even removed a valve from a head

@@Nunya_Beezwax You may be right, and have my experience than a qualified mechanic who has been in the trade for nearly 60 years, working on everything from lawn mowers, D9 Bulldozers, outboard motors, and now just content to rebuild motorcycle race engines. I've been in the trade long enough to see from the 1960's when it was necessary to lap valves due to the accuracy of the equipment being used (pilots fixed in the valve guide) to the advent of 'syncro' equipment where lapping became an obsolete and actually negative practice. P.S. I haven't lapped valves in race engines for at least the last 40 years (steel or hi-tec). The majority of modern performance oriented motorcycle engines use lightweight coated engine valves.

Yup that's def6 a crack

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

Lmfao this dude got roasted

Because the Prussian blue should be applied so thinly it is absolutely necessary to slightly twist the valve to transfer some of it to the valve seat to get a reading.

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