Machining On the mill - Resurfacing (skimming) A-series cylinder head

Using my mill to resurface a cast iron a-series cylinder head. This one needs 0.040” removed.

[@user-vn8so9rf3d]

Great video and informative. The last head I did like this was at a tech college. Used a flycutter but we set the vertical head over about 1/4 degree off vertical. This gives you a single cut without a trace left on the exit side. Also better if your head is too long to give a full exit for the full rotation of the flycutter. Also interesting that the original machining for your head was from a planer.

[@garielgrenadius7564]

You're a true craftsman. You understand the workpiece, the tools and the job. Very nice indeed.

[@grahamharvey3]

Really enjoy all of your video's especially the machining ones, keep up the good work.

[@ACDodd]

Thanks for the feedback, I will continue to share, when available

[@triumphstu]

Great video this When I get to do the engine on mine I'll most likely be dropping mine off with you. It's brilliant watching people work who really know what they're doing

[@ACDodd]

Thanks for the kind words!

[@danielward-allen9825]

Top Notch. Thanks for that. Your mill is identical to mine. You are the machinist. Make it happen

[@ginjadesigns2325]

Nicely done. I’m a Toolmaker by trade and I spent some time in general engineering, including skimming many heads. I can smell the cast iron just watching the video!

[@ACDodd]

🤣🤣😁😎

[@Ph-vl1fm]

@@ACDodd 👍 how about RPM and feedind feed sir?

[@Radfordperson]

About 1969 I machined a 12G202 head on a shaping machine, that head is still good today.

[@ACDodd]

Nothing wrong with using a shaper, as long as it cuts parrallel all will be good!

[@sicks6six]

at 17 I did a miscellaneous machine course and the milling machine was great to use, we all made a precision set of dice as a test in measuring with all three dimensions 1/1000 difference but to look at all the same,

[@ACDodd]

Excellent, these skills are now in short supply, people will need these in the future if they want to be able to keep classic cars on the road

[@HaxbyShed]

looked great.

[@philipmyers583]

Like your work...would have loved to see you sweep the head to check geometry before milling.

[@ACDodd]

I would normally do that if I was taking a light skim with the fly cutter. In this case a bigger cut was needed and the face geometry did not matter as I simply needed it parallel with the bottom face.

[@donniceblakely1075]

Good looking job to be done with a mill. I enjoy watching sir

[@ACDodd]

Thanks for the feedback

[@prawny12009]

Would adding a support either end of the table travel help reduce droop? Perhaps a couple of studs on the bench with adjustable Teflon nubs for the table to slide/rest onto when at full travel.

[@ACDodd]

Droop is a factor of wear or poor maintenance in the slideways. This machine will mill parallel to 0.0005” Over the length of the head, droop is not a factor here.

[@keithgarland3404]

Top job AC.

[@ACDodd]

Thankyou!

[@stewartpeterson9090]

Thank you for great techniques using standard shop tools. Is the fly cutter shop made? Steel or alumnium. Diameter ? High speed steel or carbide cutter?

[@ACDodd]

Carbide tipped. The body is Mike steel around 8in in diameter. If you are going to make one use a large thick piece of Aluminium. It will reduce the ‘ringing’ when in operation

[@ganesankmg6409]

Super Very nice

[@bradonchishiko2449]

This is nice ❤❤

[@BigMikesGarage]

Nice work! I'm in process of making a fly cutter right now. Same style as yours. Started with a 8.5 inch diameter round steel stock at 1.75 inches thick. After machining, boring the center hole, and attaching an R8 blank arbor, it weighs about 24lbs. Just machined a slot for the carbide tool holder. Can't wait to try it out. Thanks for the great video! Approximately what are your feeds and speeds, just so I have a rough starting point.

[@ACDodd]

200 rpm and 60 to 70mm/min

[@mikiowino]

AC what set of sanders (manual or power) would you recommend for removing warp on an V- engine block while in the bay.

[@ACDodd]

Sorry I would not recommend doing this with the engine in the vehicle. It’s a remove, strip machine the decks adjust the inlet manifold to compensate and then clean and rebuild.

[@1crazypj]

Did you modify the combustion chambers as per David Vizard's A Series instructions? I've seen diagrams in various magazines over the last 40(?) yeasr plus it's in some of his other porting books

[@ACDodd]

In this one no, it was not in the budget.

[@philphil4459]

what rpm and feedrate do you use???

[@ACDodd]

200rpm and 60 to 70mm/minute

[@Swilling]

nice video mate - i am curious about the stop you used for the depth gauge - the end of that steel stock looks rounded - would that not cause a problem for repeatability with the depth mic ? - im working my way up to surfacing a set of iron heads on my own so just trying to learn - thanks for sharing a great video. Cheers

[@ACDodd]

It is rounded for a reason, I simply measure to the highest point.

[@dm-zx7xb]

Which gives you the best reading and quicker to setup since it doesn't have to be perfectly level.

[@ACDodd]

@@dm-zx7xb not sure what you are referring to?

[@dm-zx7xb]

@@ACDodd was stating that the piece being rounded allowed for quick mounting without needing to be true to anything. A non rounded piece would need to be squared to the head otherwise you would get a different reading depending where you measured from if it were mounted at an angle.

[@ACDodd]

@@dm-zx7xb gotchA

[@rtwynn24]

I am impressed

[@ACDodd]

Thankyou

[@zisdeadbaby]

Thinking of making a fly cutter like yours AC. Did you go to EN 8 steel for that one

[@ACDodd]

Don’t use steel, use a big Chuck of aluminium. That will dampen the vibrations and make a better cutter.

[@OnlineHousehusband]

Very neat work. Some great interesting videos you're putting up. I've recently had my head done a CST so interesting to see the process. Although I had my chambers completely reworked and larger inlet and exhaust valves installed. Surprised this head isn't breathed on as the chamber's are so restrictive? Subscribed!

[@ACDodd]

In this case the customer only wanted the seats recut no blending. Thanks for the comments, my intension is to show how things are done, and sometimes not always with full on commercial equipment.

[@darrendean21]

@@ACDodd Great videos, thanks for sharing. I do similar work on a mill and my thoughts are that commercial equipment concentrates on speed/profit over quality. A good condition mill can often do it too good ...

[@diesel-ks2zv]

How much does it cost to build a fly cutter like this? What inserts do you use?

[@ACDodd]

Depends how much scrap material you have lying around. The tool holder is a TNMG 22 left hand turning tool which was purchased the rest was machined including the R8 taper spindle mount

[@zisdeadbaby]

Nice one AC. Do you surface mini blocks the same way?

[@ACDodd]

Yes.

[@CamUlmer01]

Awesome job! I do have a question, why go for the single point flycutter rather than a face mill? I have access to some rather large face mills that could skim the head in one pass. Is there a benefit of the use of a flycutter/single point tool that I'm not seeing?

[@ACDodd]

You would need a more rigid machine to run a large face mill. In use a 3 inch one for taking large cuts when I need to remove lots of material. Then I switch back to the fly cutter for finishing

[@CamUlmer01]

@@ACDodd Okay sounds good, my other question is what difference does back dragging the tool make? Is it something that is going to cause an issue with the finish for the surface?

[@ACDodd]

@@CamUlmer01 I have set my head so that the tool is 0.002” difference in height between the front and the back, therefore there is only contact on one side

[@CamUlmer01]

@@ACDodd Right, I'm just wondering why one would do that instead of leaving the head of the mill alone and letting the tool drag? Better gasket sealing surface? Sorry for all the questions, looking to try this out myself and don't want to miss any details on it

[@ACDodd]

@@CamUlmer01 the surface finish is poor unless you tilt the head slightly

[@diesel-ks2zv]

Very neat finish,what fly cutter are you using?

[@ACDodd]

Home made

[@adamdiaz8442]

Hi there mr Dodd did you buy that cutter here in the uk I’ve been looking for a long time but can’t find anything that size

[@ACDodd]

Custom made.

[@adamdiaz8442]

@@ACDodd thought as much I will have a go one day cheers

[@moon_splain7178]

I've seen loads of these videos but if it's a spinning tool, how does it only cut on one side and be level? Is that the "back cut"? Is the tool angled to do that?

[@ACDodd]

Yes the head of the mill is angled such that the trailing edge of the tool is 0.002” lower than the leading edge. This also Produces a head which is not perfectly flat but at 0.0002 to 0.0003” this has no effect on sealing.

[@jamiesimpson1786]

Hi, are the fly cutters for the mill available to purchase or did you make that one?

[@ACDodd]

It’s a home made one

[@jackrichards1863]

That certainly worked well in your hands. Your mill is so parallel I will add I've seen worse results in machine shops. Leave it at that ...!

[@ACDodd]

The point is people need to maintain there machines. Parallel cutting is certainly possible on a machine in good condition that is set correctly

[@madaxe79]

What feeds and speeds do you run the fly cutter at? I’ve got a customer dropping in a pair of heads this week to do, I’ve never machined heads before so I don’t really know what Ra to go for. I assume they don’t have to be super smooth. Im thinking say 0.1mm/rev with an 08 nose should be fine.

[@ACDodd]

0.3 to 0.35mm/rev, 150m/min speed.

[@madaxe79]

@@ACDodd you’re a legend…

[@madaxe79]

@@ACDodd what insert you use? My “fly cutter” takes CCMT, But I can really put anything in it, it’s just set up with a CCMT holder at the moment

[@ACDodd]

@@madaxe79 I use a TNMG220408 insert for aluminium

[@madaxe79]

@@ACDodd sweet.

[@ozr2222]

how can you use the a flycutter so that it only cuts on the backside? you dont tilt the spindle i guess? nicely insightful video though!

[@ACDodd]

The head is tilted, the rear side of the cutter is 0.002” lower than the right

[@ozr2222]

@@ACDodd so if you put the cutter in reverse you can have cuts on the other side of the flycutter? and why would that be better?

[@ACDodd]

@@ozr2222 no, it’s not in reverse.

[@e34boat88]

can you make surface finish good for mls gasket on that setup?

[@ACDodd]

Yes

[@Ph-vl1fm]

nice..btw is that alumunium cylinderhead?

[@ACDodd]

No cast iron

[@Ph-vl1fm]

@@ACDodd ok thanks..whats the insert type?👍

[@ACDodd]

@@Ph-vl1fm insert for aluminium

[@user-px5uv1qw1r]

Is it difficult to use the machine to resurface a cylinder head for beginners?

[@ACDodd]

No, as long as you understand all the machining aspect you need to be considering. Practice is key, I started by machining old heads that were scrap till I could get the finish as required

[@jamesdungan6198]

How do you know the face of the head is parallel to the mounting Surface or are you just presuming that the top of the head is flat

[@ACDodd]

I check it with a micrometer after skimming its usually within 0.0005”

[@rogeronslow1498]

That machine sounds like it's bearings are shot!

[@ACDodd]

Trust me they are fine.

[@robertoudokrapf453]

OLA. Se a máquina tiver condições, sem dúvida conseguirás o cruzamento. Some 0.05 do cabeçote com 0.05 (ou mais ) ABRAÇOS... Roberto Udo Krapf

[@TheTechGuider]

What are the attachments called your using in you’re mill for doing heads.

[@ACDodd]

Which attachments are you referring to?

[@TheTechGuider]

@@ACDodd the cuter heads

[@ACDodd]

@@TheTechGuider the first cutter is facemill, 3inch diameter with 5 carbide inserts, the second is a fly cutter and it’s homemade.

[@dieseldes6578]

Very good. I made a similar fly cutter for my Bridgeport, but the surface finish is only just "OK", i wouldn't use it with a steel multi layer head gasket. Probably fine on a cast head with a old style fibre gasket. What feeds and speeds are you using on iron, and alloy? I even tried a PCD insert on alloy, which helped, but it still isn't perfect. Maybe my expectations are too high for a old Bridgeport. I even added weight to the back side of my 10 inch alloy fly cutter "disk" to balance out the cutter, which helped, and from a distance on alloy it looks like a mirror, but it isn't good enough... Have you measured the RA?

[@ACDodd]

I only cut cast iron, 200rpm and feed rate I don’t know as it’s a variable speed drive and not geared. Never needed to know the Surface roughness, the a-series heads I work on are very forgiving.

[@jeffrawe6486]

I would have put two end stops, one at each end, and pushed it up against tenon stops to prevent ant movement…..

[@ACDodd]

The reality is there is so much surface contact, and so little force from such a small cut it’s not necessary. However if I were using a facemill and taking big cuts this is a sensible precaution.

[@Ratridez]

👍👍

[@robertoudokrapf453]

OLÁ. PARA QUE SIMPLIFICAR SE DA PARA COMPLICAR. ABRAÇOS... Roberto Udo Krapf

[@bumblebeeuk3904]

when you back cut you are cove cutting making the head not flat . why ?

[@ACDodd]

It’s about 0.0003” over the width of the head, it has now effect on service life of the gasket

[@tonyharding5336]

Never wore gloves in my day lol

[@MahmoudMohamed-vx5vb]

Great work but i think u need to trim ur milling machine

[@ACDodd]

If you mean tram my mill, then no I don’t, I have set it deliberately like this.

[@hankpb1]

my mill hasn't got auto feed..still possible ?

[@ACDodd]

You need to invest in an auto feed unit to get consistent results

[@robertoudokrapf453]

OLÁ. A aparência é de ser uma ótima maquina. O primeiro ferramental usado é totalmente inadequado. O segundo equipamento eu diria ser de melhor precisão. Infelizmente a demonstração é muito falha. A regulagem da "torre'" DEVE ESTAR A EXATOS 90º em relação à "mesa" da máquina. A ferramenta de corte tem de cortar o corte feito de lado a lado mostrando CLARAMENTE O CRUZAMENTO DE LINHAS NO CORTE.. (para que isso ocorra é necessário que o ferramental de corte ultrapasse totalmente o comprimento do cabeçote). Na demonstração feita dá para notar a falta de planicidade no cabeçote. O operador esqueceu ou não sabe da importância do cruzamento. ABRAÇOS..., Roberto Udo Krapf

[@ACDodd]

I am well aware of the head tramming and this adds a few tenths of a thou curvature across the head. Which in practice causes no issue. The head is deliberately tilted so that the trailing edge of the cutter is 0.05mm lower than the front. You can therefore calculate the amount of curvature.

[@user-mechanicalmusic]

more than 1 way to skim a cat

[@ACDodd]

Indeed

[@circlejerk6861]

Crank that spindle speed up!

[@ACDodd]

Nope, tool life is unacceptable

[@circlejerk6861]

@@ACDodd I’d sacrifice tool life for a better finish any day of the week

[@turhanjansimail8009]

hallo

[@adrianobastardi]

Wouldn't it be more professional to use foam sandpaper blocks from Poundland?

[@user-zz5yv8vx5l]

You do it when you do your video....don't interrupt

[@adrianobastardi]

@@user-zz5yv8vx5l lmao, no need to get upset and start crying and by the way I will say and do whatever I want whenever I want. And if you don't like it you are going to have to continue crying and bedwetting.

[@derekkchung]

When a head is warped, it is like a banana, that means the cam bore also warped? If u shave off the gasket side surface to make it flat, the cam bore still not straight, am I right? U do not want a cam bending and rotating. Too much resistance and it will weaken the camshaft. The only way is to use heat to straighten the whole head and that is expensive process, am I right? With that being said, to what extent we can resurface (skim) the head without a concern of cam bore not straight? 0.002"?? To what extent we should not even bother fixing? over 0.008? (...for a 4 cylinder head.)

[@ACDodd]

I am showing an overhead valve head here there is no cam in the head.

[@ACDodd]

In your application the head must be straightened first and the alignment of the cam tunnels returned to straight before any skimming, refer to manufacturers data for cam tunnel alignment for the engine you are working on

[@cyciminski6147]

M

[@barenekid9695]

Waste of Time $$$ and effort on a piece of Iron Ballast

[@ACDodd]

The owner did not think so.

[@xl250mon5]

There's always one " expert" who has no idea and has never done it.