Good, basic introduction to lapping a cylinder head. Great thread of useful comments. This is certainly doable, however you have to have a good idea of how to measure the different types of warps. If I had to do this manually, like this I would try to set things up so I was wet-sanding it in effect. This would mean forgoing a flat horizontal set-up to something akin to a ramp. It would ~1.5x length of the head, and the top edge would have some soaker hose or garden hose with 50 pinholes in it attached to my spigot to allow water to flow over the wet sandpaper while stroking the head to remove grit and metal swarf. Additionally, I'd take a permanent magic marker and crosshatch the face of the head so I could occasionally stop and see where/how the head was scrapping in. Might have to reapply a few times. I'd also start at 200/400 especially for aluminum unless it was warped significantly. And, don't even start doing any of this until that head has had all gasket/rtv/etc scrapped off. Use a razor blade, solvent, whatever to get that 100% clean before starting else you're going to end up having to scrape even more and take more material off, lowering your deck height. You also have to know how much you can scrape off before it either start affecting compression or maybe valve height. I'm assuming a decent machine shop is ~$100 to do this, however if much more then it might actually be worth the sweat equity.

I’ve never done this before but I do work at a machine shop and there’s a couple things I’d do differently. First of all I’d get a larger piece strip of sandpaper and wet sand with machining oil. Start at a higher grit that 100. You’re likely working with aluminum and even 400 grit can get out of hand pretty quickly. Invest in some different grits, keep it clean, and above all else take your time.

@skullman0819

Жыл бұрын

I was hoping to see some additional tips in the comments and was wondering if wet sanding was a good option and I was also thinking that he was using sandpaper that is on the abrasive side I would honestly start with 400 and probably end with an 800

@tuckerburbank3422

Жыл бұрын

I have done it starting with 600 and ended with 2000. And WD-40 for lubricant

@breezentheosescapades8769

Жыл бұрын

Great comment

@joshuetortega3572

8 ай бұрын

@@tuckerburbank3422 how it go with those grits?

@joshuetortega3572

8 ай бұрын

what grit would you recommend to start and finish with? also can wd40 be a good lubricant when doing this?

I’ve used this recut before different setup but dykem dye or even market to see your true end results ensures you have no low spots or visible bows or other issues. But still thumbs up For teaching the youngins creativity

Looks like you need a larger sanding area so the ends of the head doesn't ever leave the sand paper.....the center of the head is getting sanded down more than the 4-5 inches of the ends. Idk.

@RATsnak3

Жыл бұрын

If it works it works lol

@rightsdontcomewithpermits7073

10 ай бұрын

​@@RATsnak3changing oil every 50k works too. You should try!

@RATsnak3

10 ай бұрын

@@rightsdontcomewithpermits7073 if your cylinder head needs to be resurfaced, an oil change isn’t going to cut it.

@ady-bdavid1173

8 ай бұрын

If you have a closer look you can actually see he moves the head far enough for it to get to be even. I had the same worry as you at first.

@damiann4734

4 ай бұрын

​@@RATsnak3noob always talks about changing oil. Its alright. We all know you can change your oil and filter. Good job. Leave the these sort of jobs to the expert, youtube warrior.

You have a big problem with your method that can be easily solved. If you watch your sanding process, you'll note that the end of the head overlaps the sandpaper each time you stoke to the left and back. At the same time, the center of the head strokes somewhat to the edge and then back, without overlapping the end. What this causes is the center of the head experiences more contact time with the sandpaper than the ends, and thus, you will sand a hollow on the center portions of the head. And you'll do it pretty quickly. The solution is to construct a larger sanding surface that will allow the entire surface of the head to be in contact with sandpaper at all times. As well, your glass substrate is actually quite flexible, so whatever you're using to support the glass should in itself, be very rigid and flat - a very large granite flat would work just fine. This will eliminate preferential material removal from the center. The process you're using is actually that used by amateur telescope makers to grind concave mirrors. With glass, the process is much slower and the amount of material is considerably less, with the same result.

That might work with a light head, but with a heavier one you might want to stick the sandpaper sheets to a large flat plank and also stick a 10 pounds weight on top for uniformity while you just do the back and forth movement (without applying any more downward pressure).

I always know I’m in for a good time when the video starts “This is probably the most dodgiest way you can do this at home…” You sold me. I’m in. 🤘🏻😎🤘🏻

I like the look of this method, though if I were to try that with my International 345 I’d give meself a hernia… I could probably adhesive some grip handles on the sheet and use it like a block plane though. Might give that a go.

Did you install a thicket cylinder head gasket? Or the same side?

This is great indead

Thanks COOP ...

Good idea

I hand lapped my head and block together with grinding paste, does an even better job as both surfaces are flat to each other. Can only do that if the engine is out and you clean the entire head and block after though

@holymichelo1138

11 ай бұрын

Shade more light on this method please.

@intraterrestrial69

6 ай бұрын

I could see that being a good method, if there was no head gasket failure or overhead event to begin with. I would maybe do this if I were just upgrading valve springs on an otherwise healthy engine.

@skylined5534

26 күн бұрын

I've heard of this method before, usually for single barrel set ups.

I have done two alloy heads using this method on laminated glass with the spray bostik adhesive trick like you used. But I used 220-240 paper with running water from hose, it cuts plenty fast enough. After a few minutes work the 220-240 has lost its sharpness and is like a 400 so you have already got a nice final finish without changing papers :)

@justinw523

5 ай бұрын

@michaely6665 I’m working on a 2002 5.3 LS with MLS head gaskets which the head surface needs to be near mirror, how long do I sand with the 220 before switching to the 240? or do I just choose one over the other? And do I keep sanding using water until they wear down to around 400 grit?

@michaely6665

5 ай бұрын

I used 220/240 whatever shop had, maybe for iron heads you could try 150/180. Water flushing paper helps stop loose stuff scratching alloy heads. After 5 minutes the 220 has already lost the best sharpness. The finish was dull smooth, 220grit is about 17ra, and MLS gaskets needs 30ra from a list I found.

@justinw523

5 ай бұрын

@michaely6665 Alright thanks. The cylinder heads I have are aluminum 862 and are not In really bad of shape they mainly need a once over but I’m going to buy a straight edge and get some bright markers to check any high and lows as I go along

@justinw523

5 ай бұрын

@michaely6665 I believe they say 50ra to 60ra for aluminum heads with MLS gaskets and the chart i found says 120 grit leaves a 40ra to 60ra finish does that sound about right?

@michaely6665

5 ай бұрын

All I can say is 220 grit cut fast enough, and leaves a nice smooth finish. Only if the heads are really bad would you need to go lower, 120 grit is aggressive for aluminium, I tried 180 once and it really cuts in.

That's fkn clever, nice

Nice Ford 351c 2v cylinder head!!

Yes this actually works.,yes many people have done it exactly like this for many years with much success. Not everyone has an automotive machine shop around the corner.

Honestly this looks like it would be fun if I had 2 cars and one of them ran. Not your fault though thanks for the information.

How grit you use.

I picked up some thick laminated glass stereo / shelf panes. I picked the smallest for my motorcycle head needs. Coffee table & dining table glass is great too. Yes a finer grade of wetable sand paper huh.

@chrisguzzy3732

10 күн бұрын

That works for motorcycle heads? I always wanted to try it

@BroomysGarage

10 күн бұрын

@chrisguzzy3732 any head that has valves.

Straight lines are the worst thing you can do. Also, no lubrication or cutting oil to clear the shavings. Iron heads are different than aluminum of course, but they still need confusion on the milling marks to seat. Smooth isn't the key. The gasket needs something to bite into. I use 220 for first cut and 320 for final and work in figure eight motion. I have a video posted as well.

@Pocketbassist

Жыл бұрын

not for MLS gaskets, smoothness is key

@jimkruse74

Жыл бұрын

I guarantee the edges are a few thou difference just because of the momentum of the strokes. I checked it at the machine shop. Completely right about a very smooth finish with MLS but you take that head to the head shop and you'll see the corners or off. 220 grit is far from a smooth finish for an MLS gasket. It will work...but for how long

@BlackwaterDSM

Жыл бұрын

Meh, I watched your videos, with all 17 likes and comments DISABLED. Red Flag number one. Then I saw you pull out a Home Depot 4’ level as a “straight edge” to check a 2-thousandths factory tolerance on a Subaru head (notorious for head gasket and ring land groove motor failures)… Red Flag number two. Then you stated in your video that if someone didn’t have a sheet of glass or certified flat surface to “Just use the floor if you know it’s flat”. I lost it and died laughing. When I went to install my new flooring in my house, my floor had highs and lows of 1/4” to nearly 1.5” differences. If you’re recommending to use the FLOOR to machine a motor because “Your dad has a machine shop”, you are part of the problem. 👍🏻 Edit: Not to mention in your comment here you stated that “Smooth isn’t the key”, when in fact, it is on almost every gasket made now which are primarily MLS gaskets because they are far superior to Carbon/Cork and are the best way to fix a factory-flawed cheap gasket setup. Just the 2 cents of a someone who builds 1500hp+ engines quite frequently and my own personal 1638hp Whipple blown LS7 has 80,000mi of pure abuse on it and has needed NOTHING other than standard maintenance.

@zdravkomomci7570

8 ай бұрын

​@@jimkruse74you right I did this method and was out like .003 on each end with the straight edge ended up getting the surface milled

@boots7859

2 ай бұрын

Figure 8 is what you use for small things like cpu heat sinks, etc. Kind if hard to do quite the same with a 30-50# head, but one could try a bit. And no, most modern engines and gaskets need flat as possible unlike older cork and 80's-90's gasket that need some 'bite'. Work in an area that can be wet and position a hose to spray water onto your wet sand paper to flood the debris out and away from the scraping area. If I were doing this, I'd get a range of quality wet sandpaper from 200/400 up to 2000/3000. A mirror finish isn't required, however the closer you get the better the seal will be.

This is gangster

I have a sr20det with a blown head gasket. Wil this hold turbo pressure or with it be too much?

@donwest5387

27 күн бұрын

the gasket and the torque "hold" the head gasket. Use studs

What finish grit sandpaper would I need for a near mirror finish for MLS head gaskets? Working on a 2002 GM 5.3 LS engine

@eenokk6711

5 ай бұрын

Theirs no sand paper in the world that'll give you a mirror finish.

@cleveland2286

4 ай бұрын

2000, 4000, to get a mirror finish you'd need metal polish compound

what type of glass or surface was it that you used? sorry if I missed it somewhere

@daspinmonkey

7 ай бұрын

He used perspex, or Acrillic. It's plastic.

Just the thing i need for my Gemini intake manifoldsssss

I clicked looking for any info on the Townado!

OH MY GOODNESS! 😳 YOU WERE NOT KIDDING ABOUT BEING "DODGEY" 😅

Can you do a video on cheap way to lap a rotary center/end plate.

@BroomysGarage

4 жыл бұрын

Possibly. The cheap way is to get a thick piece of glass, cutting paste compound, and to rub the plate in circular motions over the glass. Takes a long time and only really good to give the plate a bit of a clean up.

@RedBatRacing

3 жыл бұрын

To lap an end plate, I used an old centre plate as the base that are typically flat because they have more material in them, I then used valve lapping paste. Just did a circular and figure of 8 motion and it came out incredibly well. Took the grooves in the plate down to within tolerance

What size filler gauge did you use?

@BlackwaterDSM

Жыл бұрын

Not sure what he used, but I would go with a 2-thousandths feeler. I’ve built some pretty hardcore motors performance motors, and 2-thousandths is the industry standard “tolerance”.

@CharlesLease-ei1ee

5 ай бұрын

Long as you have no more than 3000 warpage, you’ll be OK

can you coat it in prussian blue, sand a tiny bit to find the highs & lows?

@dooo679

Жыл бұрын

Or even coat the whole surface with a sharpie if the theme is go cheap under $50? I never used prussian blue marker, maybe it dry out and sand off.

@zdravkomomci7570

8 ай бұрын

I used pressure pack spray acrylic as a guidecoat I ended up ruining the ends on the head like .003 on the straight edge cos of clog in paper and motion go to a shop you risk leaks doing it like some youtubers show you

@boots7859

2 ай бұрын

@@zdravkomomci7570 The point is that you have to use your head and realize nothing is ever as simple as it seems. Its called basic research. Using a pencil or magic marker to verify as you are scraping in is normal in machining. Where you got the idea to use some sort of spray acrylic is just nutz as its going to be 1-2 thousands... Get decent wet sand paper and get water flowing over as you scrape, and check flatness/finish often.

I worked at a shop where I was told to do this on a large belt-sander. (!?)

For 120.00 my machine shop nearby will re-surface my head to perfection!

It would work better with a flat stone, and the head turned upside down. I've seen it done before but time has to be taken to make sure the passes are even. That would only work if the block was totally fine and the head was only out a few .000

Id use a wide flat piece of 18mm mdf with the grit wrapped around it. Place the head on your bench and pass the wood with grit paper firstly lengthways then side to side to finish so that no score lines are in line with the cylinders.

What's the name of the material you're using please? You said it's not glass.

@matts.8342

Жыл бұрын

Perspex. It's plexiglass. Plastic.

@renejacques8288

Жыл бұрын

@@matts.8342 It's been a while, lol. But thanks!

@BlackwaterDSM

Жыл бұрын

Do NOT use plexiglass. It’s nowhere near imperfection. If you can’t afford a machinist’s block or precision tools, your 2nd best bet is to use a piece of precision machined glass about 5-6mm or 1/4” thick (or greater). Glass is created in a much more precise manner than plexiglass. Edit: That’s not as expensive as you think. A small enough piece to cover the size of your head/block is probably about the same price as this ultra thick piece of plexiglass.

@matts.8342

Жыл бұрын

@@BlackwaterDSM Would a piece of marble or granite tile work? I have one I use to flatten the back and sharpen woodworking tools with various sandpaper grits, almost exactly like this guy is using the plexiglass.

@BlackwaterDSM

Жыл бұрын

@@matts.8342 Technically it would work, but you have to look at the tolerances with which things are considered “flat”. Granite and marble are “precision cut” (using that term loosely) on a wet saw which can have small variations of well over 10-thousandths just due to the fact of how it’s cut and polished. Glass is manufactured by mixing the product components and heating to 1200 degrees celsius before it is “floated” on top of a molten tin pool, thereby creating an essentially flat surface due to gravity’s force on liquid objects. Tile and marble would do the job just fine probably, but a sheet of glass would do much better and it’s not to expensive to purchase a small sheet a little bigger than your deck. Just get a reasonably thick piece to prevent breakage.

I'm sure Holden Bogans out there have much more Dodgey methods than that my man.

Could this work on a 6 syl bmw e60 also?

@thisislargemouth5566

2 жыл бұрын

Of course you just need as much longer piece of glass

I surfaced a head last week that someone Sanded, it was more then .030 out.

Some wd40 helps but good way to do it for sure

@zdravkomomci7570

8 ай бұрын

Not really all it does is render the paper useless making it slippery and unable to cut

That is an opel Astra Top

does this work on a aluminium head sorry to bother you

@BroomysGarage

4 жыл бұрын

Sure, however it depends what the head gasket material being used is made from. Paper or graphite based gaskets will take up some imperfections on the surface, but multi layer steel gaskets need a mirror finish to seal properly.

@michwas7270

4 жыл бұрын

@@BroomysGarage cheers for the reply mate ripper I'll bear this in mind

@LosSerpent

Жыл бұрын

@@BroomysGarage I'm not sure what gasket i have. It looks like steel on the inside but outside it's black, rubbery like?

@joshuahenrichson9001

Жыл бұрын

@@LosSerpent That sounds like a multi layer steel(mls) gasket. How did the job turn out? What material was the head and block? What finish did you use?

@LosSerpent

Жыл бұрын

@@joshuahenrichson9001 it actually ended up sealing without resurfacing, already did 7000km on it and no leaks. Bmw f650 funduro

Youd soon find out if it was warped,on a dead flat surface of course.

Yes. 100-grit only takes up all the grime... along with all your compression.

@LabSkaterPussies

2 жыл бұрын

what grit sandpaper would you use

@amounifnd

Жыл бұрын

How ? The more you take off you increase the compression.

Way too much work mate. Good on you for it though.

Hopeless set up... Get a big plate glass table and a bigger area of sheets glued on... And for christ sake make it rigid !!!

That's a cleaning not resurfacing

While this is a good way to check and clean the surface of your cylinder head, this is in no way machining or re-surfacing. Nice try but no cigar.

@boots7859

2 ай бұрын

I'm not in love with the idea, however it certainly is resurfacing. Do what the OP did, and you can easily take n thousandths off your head depending upon how low grit you start with or how long you want to push a lump of iron around. Will it generally be as accurate and good as a proper resurfacing with a mill? Nope. Will you possibly ruin your head? Yep. But you are resurfacing it, and Bugatti was reknown for doing almost exactly the same thing, albeit on a surface stone.

Please don’t do this

@mrspoopy3227

Жыл бұрын

The alternative would be paying $500, I'll try anything before I dish out that kind of money

@TheYotaDen

Жыл бұрын

Redoing a head gasket is gonna cost you more time and money than just paying a machinist to resurface it right the first time🤷

@chibba5418

Жыл бұрын

@@TheYotaDen if it works, it works. Buy a used head if you really mess up

@whiplashmachine

Жыл бұрын

@@mrspoopy3227 where do you live that charges 500 bucks to resurface a head?

@mrspoopy3227

Жыл бұрын

@@whiplashmachine shitfornia

I just did it with a 6 inch belt sander 😂

@justcause266

7 ай бұрын

How did it turn out and is the engine running ?

There is a tool That goes over the surface instead of having to move the whole head ! I found this ridiculous

@boots7859

2 ай бұрын

Yes, its called a mill, and can cost minimum 5K to start if not more considering the size.