wwholden asked...Three questions:
QUESTION #1
1.) I saw in your photos you cut into the sealing surface of the head to get the head gasket to sit flush with the squish band. I didn't see you do that in your videos. Were you not happy with the results of sitting the gasket inside of the head?
ANSWER...
That was an experiment that turned out very well. I was trying to close up the squish without machining material off the top of the cylinder. A cylinder is expensive and a cylinder head is cheap. I can screw up quite a few of those and still not feel bad. I could have done the same thing NOT running a head gasket,and yes that works too,but its not the same thing as machining the head (its fun machining things). The head in the video is a different head than the one with the step cut. Thats why you didn't see it in the video
QUESTION #2
2.)And in your videos you cut from the sealing flange into the head. While sivic says he cuts from the dome out. So that you can correct your mistakes without screwing up ones that are fine. Do you think you will change your process?
ANSWER...
My method works the same way. I rarely,and I mean rarely, have to correct anything. This is why I tell you to take your time when machining. Its easy to take material off, but hard to put it back on. Everybody has they're own technique. Your going to have to take about
.130 off the head sealing surface to begin with anyway,just to make a squish band head. I like my method better. Both methods work well. I've tried both methods. I prefer mine. I also won't be changing my process for any reason. Why, because somebody else does it a different way? Thats like saying I put my pants on with my left leg first and you put your pants on with your right leg first. As long as your pants get put on thats what counts. To each his own. What you assume about it being difficult to correct any mistakes is incorrect...I have no problem correcting any mistakes using this method. I find it way easier to get the correct the chamber size (last cut) than anything else.That way,you can easily adjust the CC's of the chamber as you see fit,and all the other cuts are finished before hand. With the method I use,I can change my mind at the last minute about the CC's I want to run and go from there. If everything is finished,and all you need to do is cut the chamber,you can easily cut a little and remove the head from the arbor to check the CC's then re-mount it on the arbor and re-cut,and then repeat as many times as you see fit until you get the desired results (CC's). When you start cutting heads of your own,try both methods. You might prefer one over the other.
QUESTION #3
3.)In my machining classes I've taken we have not cut any spherical domes like that yet. Didn't even know it was possible. Can you shed some light on how thats done since that wasn't covered in the videos?
ANSWER
REMEMBER THIS>>> Anything is possible!
The reason it wasn't in the video,is because I need to get or make a camera mount,so I don't have to use one of my hands to hold the camera. The camera wanted to keep falling off everything I was putting it on. I need both hands to cut the hemi chamber. This is why >>>
In the real world you would use a "Radius cutter",or "Radi cutter". They're relatively easy to make,but I still haven't made one. They are the bomb!
However...you can get the desired results your looking for by using the X and Y axises (longitudinal feed and cross feed) at the same time. The first time you try doing this, its like spinning around in a circle until your dizzy and then trying to walk in a strait line. If you go SLOW you will get fantastic results! Its not as hard as you think after you do it a bit. You basically get it really close then hand sand it with course sand paper to get the results your looking for (cover those ways!). This is where you get a chance to make templates of stiff cardboard or aluminum that match the dome every time you CC that head. That way you have templates of given CC's to check your work as you go on the next head you create. Or ....just get one of those radius tools.I'm going to end up making some custom carbide cutters(dome shaped with desired CC's) that fit in the tail stock. That way it can be quick and easy.
In case your wondering...it takes me about 45 minutes to cut the head start to finish,and another 5-6 minutes to CC the chamber. It goes pretty quick.
Here's a radius cutter in action...
I hope this helped to answer your questions.
QUESTION #1
1.) I saw in your photos you cut into the sealing surface of the head to get the head gasket to sit flush with the squish band. I didn't see you do that in your videos. Were you not happy with the results of sitting the gasket inside of the head?
ANSWER...
That was an experiment that turned out very well. I was trying to close up the squish without machining material off the top of the cylinder. A cylinder is expensive and a cylinder head is cheap. I can screw up quite a few of those and still not feel bad. I could have done the same thing NOT running a head gasket,and yes that works too,but its not the same thing as machining the head (its fun machining things). The head in the video is a different head than the one with the step cut. Thats why you didn't see it in the video
QUESTION #2
2.)And in your videos you cut from the sealing flange into the head. While sivic says he cuts from the dome out. So that you can correct your mistakes without screwing up ones that are fine. Do you think you will change your process?
ANSWER...
My method works the same way. I rarely,and I mean rarely, have to correct anything. This is why I tell you to take your time when machining. Its easy to take material off, but hard to put it back on. Everybody has they're own technique. Your going to have to take about
.130 off the head sealing surface to begin with anyway,just to make a squish band head. I like my method better. Both methods work well. I've tried both methods. I prefer mine. I also won't be changing my process for any reason. Why, because somebody else does it a different way? Thats like saying I put my pants on with my left leg first and you put your pants on with your right leg first. As long as your pants get put on thats what counts. To each his own. What you assume about it being difficult to correct any mistakes is incorrect...I have no problem correcting any mistakes using this method. I find it way easier to get the correct the chamber size (last cut) than anything else.That way,you can easily adjust the CC's of the chamber as you see fit,and all the other cuts are finished before hand. With the method I use,I can change my mind at the last minute about the CC's I want to run and go from there. If everything is finished,and all you need to do is cut the chamber,you can easily cut a little and remove the head from the arbor to check the CC's then re-mount it on the arbor and re-cut,and then repeat as many times as you see fit until you get the desired results (CC's). When you start cutting heads of your own,try both methods. You might prefer one over the other.
QUESTION #3
3.)In my machining classes I've taken we have not cut any spherical domes like that yet. Didn't even know it was possible. Can you shed some light on how thats done since that wasn't covered in the videos?
ANSWER
REMEMBER THIS>>> Anything is possible!
The reason it wasn't in the video,is because I need to get or make a camera mount,so I don't have to use one of my hands to hold the camera. The camera wanted to keep falling off everything I was putting it on. I need both hands to cut the hemi chamber. This is why >>>
In the real world you would use a "Radius cutter",or "Radi cutter". They're relatively easy to make,but I still haven't made one. They are the bomb!
However...you can get the desired results your looking for by using the X and Y axises (longitudinal feed and cross feed) at the same time. The first time you try doing this, its like spinning around in a circle until your dizzy and then trying to walk in a strait line. If you go SLOW you will get fantastic results! Its not as hard as you think after you do it a bit. You basically get it really close then hand sand it with course sand paper to get the results your looking for (cover those ways!). This is where you get a chance to make templates of stiff cardboard or aluminum that match the dome every time you CC that head. That way you have templates of given CC's to check your work as you go on the next head you create. Or ....just get one of those radius tools.
I'm going to end up making some custom carbide cutters(dome shaped with desired CC's) that fit in the tail stock. That way it can be quick and easy. In case your wondering...it takes me about 45 minutes to cut the head start to finish,and another 5-6 minutes to CC the chamber. It goes pretty quick.
Here's a radius cutter in action...
I hope this helped to answer your questions.
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