Well that didn't work out as planned.
I have some welds that are slightly higher than the deck. I don't want to file these down because these are the areas that had a leak and I had to run another pass over it to seal the leak. These welds are outside the actual head deck. A straight edge showed everything is good. The reason I got this issue with this particular cylinder is because of the way I built this one. When I did the other 4 engines I used 6" pipe that the machine shop had in stock at the time. This time they didn't have any aluminum 6" so I just rolled my own with the ring roller I made for this project. This time I also offset this ring a bit (you can see it in the photos) so that I could weld the area around the intake better. I had a hell of a problem with this on the other 4 engines. Got a leak there EVERY time and had issues trying to seal it. Funny thing is that I still had this issue with this cylinder but it was easier to fix it up.

Decided to play around with making the head tonight because the 14mm tap showed up in the mail.
Tapped a hole in the blank. Cut a sparkplug and used it to mount everything in the lathe. Installed the tool I used to make the bending die awhile ago (use the search box). This tool lets you cut a curve profile. Things started out ok but then I got a lot of chatter. What was happening is that you can't get a good grip on the sparkplug because it starts to collapse with no guts on the inside of it. So tomorrow I will have to make something so that I can hold this better in the lathe.
I also tried to use the compound slide and a standard lathe bit, but if you do that then the combustion chamber will not have the curved wall and will just have a 45' straight bevel. Also had some clearance issues when I tried this.
Not sure what I am gona do tomorrow but it's all experimental for me, I have never done this.
I don't have any high quality tools to work with like a "real" lathe or milling machine.
I really wish that my piston casting experiment worked out because you could cast a head a lot easier than what I am doing now. The piston casting idea was just a test to see if I was able to reasonably cast a product, but the real reason I did that was to try to cast liquid cooled heads. So you see there was an ulterior motive behind that coo coo idea.
If Methodical saw me do this crap tonight he would shut the whole company down. He would have called for an intervention or fired my azz.

I think you could improve the chatter issue if you triangulated the tool holder. Having nothing to support the top lets it flex too easily. I guess you could double the height of the base , but that may cause clearance issues as the depth of the cut increases. The more support you have closer to the cutting tool the more solid it will be. Slowing feed/rotation rate of the cutter, but increasing the speed of the lathe can sometimes help too. Experimenting with the depth of the cut could have an effect too.

"Good artists copy, great artists steal", Picaso & Jobs

That looks like a nice block you've got there. Why not make an outer shell and then use cylinder domes? If you did this you can increase the coolant capacity in the head by machining out the outer, and then machining the dome separately. Then they slide together, fitted and pressed somehow (Lightly) and the voids between the two pieces will contain the coolant.

Otherwise what were you planning for coolant passages? Without casting, I think you'll be better off this way.

Also if you plan to not use a headgasket - then you'll need to carefully machine a ring groove into the shell and dome.

Great minds think alike LOL.
I actually thought about that "machining the dome separately" thing last night after I had already started this. I was thinking of machining the dome with a step and then welding the dome to an outer coolant casing.
What I really need is to make a cutter that will cut this combustion chamber in one shot, like a drill bit for example. I am thinking of making a milling type cutter with those replaceable bolt in carbide tips. The bad part is that I don't have any curved carbide, only got triangle carbides.

Quote: "Otherwise what were you planning for coolant passages? Without casting, I think you'll be better off this way."
I was going to mill off the back side behind the dome and welding a casing and lid on.

This whole thing is just experimental for me. What I am doing right now may turn out to be a failure but who cares. Then I may try to do one of the above. Not sure where this is going yet.

CO, I thought that cylinder looked familiar. If I were porting a post recall cylinder I would not cut the port square. I would look to what RPM I intended to run the Engine at, then I would determine the exhaust, transfer and intake duration I need to run that rpm. I would cut the exhaust ports in a manner that increases the mean effective area in the appropriate location compared to the transfers. If you will, picture the exhaust ports cut larger at the top portion of the port, with a slightly arched top edge, that then tapers down to the bottom edge of the port. You want the exhaust to flow out of the cylinder as much as possible before the transfers open which aids in minimizing the charge blown out the exhaust. Remember that when determining the exhaust and transfer durations focus on blow down duration as this is an important part of power production. The attached pic is a port job in process but should show the idea of shape I'm referring to.

Yeah I see what you have done there.
I am not an Engine guy, I am a hack n whack guy and have never studied anything related to porting so bear with me on incompetent questions:
1) Is it not desired to have the exhaust blow out as quick as possible as soon as the port opens ??
2) The pressure in the combustion chamber when it lights up is about 750 psi. Therefore if the top of the exhaust port is square wouldn't it allow the exhaust to blast out quicker with a bigger area at the top because it is square ?? What I see in all the cylinders is the exhaust port oval shaped and yours shown there is similar. Why not square the top end ?? I'm missing something here on the theory.

Edit: I just read your post SLOWLY this time. I guess what you are saying is that if the port is square a lot of the fresh intake charge blows out the big exhaust hole. Makes sense now. As soon as the transfer ports close you want to start choking off the exhaust hole to prevent the new charge from escaping.

CO, you have more great ideas then you give yourself credit. A round hole always has more volume then a similarly sized square hole. The exhaust port size is relative. I make the widest part of my ports 90% of the bore diameter. The top of the port where I mentioned mean effective area is made larger so more exhaust blows out quicker, prior to opening the transfers You nailed that idea, but by widening the port to 90% you take even more advantage of moving expelling gases. The pic below is an example of a ported pre recall cylinder. The ports as you've shown are square, when these cylinders are ported look how wide the top part of the exhaust port is made. Also notice how all edges are rounded to keep the rings from snagging.

Meth -- my brothers Engine looks like that last pic. I call them cats eyes ports. That machine was bought years ago and at one time was a California machine because I saw some cali stickers on it. The Engine had 2mm milled off of the cylinder and a bunch of port work. It's a strong Engine.

Got some time tonight to play.
Made a cutter shaped like the combustion chamber out of an old planer blade I had here. These are the industrial kind that we had at a place I worked. They get thrown in the garbage after a while so grabbed a few. This is high quality high speed steel. I didn't do a very good job on this tool but tried it anyways. Turned out better than expected but still not right. Below is a pic of a test piece and then I tried to fix the head I did on the lathe. The shape of that combustion chamber was definitely no good so I had nothing to lose. At the end of the day this piece is probably junk.
Also of note is that if you use a sparkplug to hold anything keep in mind that the hexagon part your socket fits on is just friction welded on the body of the sparkplug. This is probably why I was having trouble holding that piece in the lathe. Tonight when I tried to remove the sparkplug from the homemade head it just peeled off. See pic.

CO, how bad did the cutter chatter when plunging to cut the chamber? I've seen some guys on other boards do something similar. That actually doesn't look bad.....

Chatter was bad because I couldn't get the cutter in line with center. I did trim it a bit the other day and cut the wings off for the squish band cut. This all helped a lot with regards to chatter. One of the keys was gently cuts. No hogging. At the end of the day my northern skillbilly solutions will require some buffing with a flap wheel. Got a long way to go with respect to making my own heads. If I do get there then I will have to cut the squish band manually in the lathe. I wish I had the skills and machines you got.

I am very happy with what just happened in my shop.
I cut a piece of aluminum round stock and cut a combustion chamber in it with that cutter I made.
Learned a few important lessons. One lesson is that you DO NOT CUT A PILOT HOLE for this homemade cutter. When I tried to do this same thing on that piece of 6" round stock the other day, that I had already cut and tapped a sparkplug hole, I ended up getting bad chatter marks as well as it tried to "run off". That piece is now junk. This new piece of 4" round stock I did tonight has NO chatter marks. The marks you see in the picture are the actual rough grinding I did to make the cutter edge.
The second lesson I learned was to apply a lot of pressure to the drill press handle until the cutter actually stalled. Then back off a bit. As you can see the chaff is nice and curly .
It only took about 10mins to cut this, but another almost 20min to make sure is was deep enough to hold 30cc of water. How did I chose 30cc ?? Well because earlier in another thread I calculated that the squish band holds 5cc. An oddy head is about 35cc. If I am out a cc or two then fire me boss .
Now I have to manually cut the squish band on the lathe.
Like I said this thing is experimental and it's about a challenge and having fun. A positive end result will be awesome with this project but it is not a prerequisite.

Awesome. So impressive regardless of out come.

Later tonight (about midnight west coast time) I will try to post a pic of the combustion chamber with the squish band cut and what the final plan is for this. Also why I am doing it this way.

Well I got finished a bit early.
Unfortunately I cut the squish band slightly wider than I wanted but it's close enough for me.
I guess I could trim it a bit to get the squish band correct width but then I will have to trim out the combustion chamber a bit more. Not sure yet.
I measured the head volume and it came in at 33cc approx. But I still have to radius the edge of the squish band where it ends inside the combustion chamber. In the pic you can see the sharp edge where the two meet. Then I should be able to get the 2cc I need or at least close.

Earlier I mentioned I would tell you why I did it this way.
Originally I started with a piece of 6" round stock that was 2" thick. The problem with that was several fold.
One is that it would not fit in my mickey mouse mini home hobby lathe. We have to work with and around the tools we got -- right ?? So I had to tap the sparkplug hole and then try to hold it in the lathe with the sparkplug. It worked ----- sort of. Until the sparkplug hex came apart. You can see that earlier in this thread.
Second reason is that, let say I was able to get a good cut combustion chamber. Now how do I liquid cool it this head ?? Yup I would have to spend hours cutting all the excess off the back side so that I could make a water chamber. It was a stupid idea but that's how we learn.

So now with this new piece I have a small piece of 4" (trimmed down). This is much easier to handle. I plan on cutting a step in a piece of aluminum plate that is about 3/8" or so and inserting this combustion chamber. I may weld it in or just use the plate to hold it onto the cylinder. Not sure yet what I am going to use because I'm not there yet. As for the water chamber I will weld on sides and a lid. This has an advantage that I wanted all along. Since I am a square head (German), I wanted to make a square head. Get it ?? . That's the plan.

Mystery pic.
Anyone wana guess what the plan is ??

I did end up trimming the squish band and cut a bevel where the squish band and combustion chamber meet. Still have to buff it with a flapper wheel and re-measure the cc's.

CO, I'm also absolutely impressed. You are very persistent! Keep going, I know we are all looking forward to the finished product.. If you want I can make a vinamold form of a Rands head I have here and send it to you. Maybe just as a reference of a comp chamber that has a centered plug. let me know.

Thanks for the offer meth but I am just screwing around here and having fun.
I don't even know what vinamold is. If it is like that two piece rubber molding liquid I use to make intake manifolds and Engine mounts, then I don't know how that would help me. This head is made very crudely. Everything is done manually but if it works I'm good with it and the time was well spent. If you saw some of my workmanship you would fire my azz.

EDIT: I just looked up vinamold. Cool. Looks like a guy could probably use the yellow or the blue to make Engine mounts. https://extruflex.com/product/vinamold

Houston ----- we have a problem .
I cut the o-ring groove tonight and running about .020" of crush.
Took a good reading on the cc's of this head.
Unfortunately it comes in at 30cc.
A stock head I believe is 36cc.
Am I going to have to recut this head or can I run 30cc ??

Meth -- check your mail when you get a chance.

Looking good CO. Keep it up!

Well Meth must be busy, so since I have a stock head here that I took off of the black Engine I had on the shelf (used this to make a template of the combustion chamber), I think what I will do is just make the 30cc head and then bolt both of these on the R401 Engine and see what kind of compressions I am getting. I need to pressure test this Engine anyways because I don't know if the seals are good.

Sorry if you already addressed this, but can't you take the jaws out of the chuck and turn them around? So you could grab a larger diameter chunk? I'm able to do this on my 4 jaw chuck. The 4 jaw has independent jaws though.

Not sure what you are asking but yes I do have jaws that are installed the other way around.