Author Topic: Valve Seat Cutter D-Bit style  (Read 1151 times)

Offline 90LX_Notch

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Valve Seat Cutter D-Bit style
« on: March 04, 2017, 01:41:10 AM »
I started my first IC engine this summer, Arv's Tiny.  The time finally came to cut the seats and I needed to make the cutter.  Everyone uses George's proven cutter; but, I don't have  the means to accurately do the necessary indexing.  I decided to try it as a piloted D-bit.

The required pilot and port diameters were turned along with the 45 degree angle.  A .225 diameter was also turned as a concentricty reference since I was going to try and make George's style originally.  The tool was heated locally at the 45 degree angle until it was carrot orange and was then quenched in water.  The tool was then set up on the surface grinder and the 45 and adjacent areas were ground to one half.  I wound up grinding more of the .136 port diameter section of the tool then I had originally planned.  This was necessary because I was trying to measure off of the .225 reference diameter. The length of this diameter was too narrow for the micrometer spindle to measure and I needed to widen it.

The tool seems to have worked well.  I need to make the valve assemblies next and make a test fixture to check if they seal well.

-Bob


Picture 1 is the tool geometry.
Picture 2 shows the tool cutting the first seat.
Picture 3 shows one seat cut and one uncut.
Picture 4 shows both seats cut.
Picture 5 Is looking through a 25x microscope at sections of both seats.
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Offline gerritv

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Re: Valve Seat Cutter D-Bit style
« Reply #1 on: March 04, 2017, 03:30:25 AM »
That is a great use of D bit style. A single lip version of the real engine valve seat cutters.

The pilot makes the difference, not relying on the machine/work mount rigidity. Plus of cours ethe seat is concentric with the valve stem.

Gerrit
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Offline Roger B

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Re: Valve Seat Cutter D-Bit style
« Reply #2 on: March 04, 2017, 07:52:48 AM »
Nicely done  :praise2:  I have previously made simple versions of the full size versions with hand filed flutes.
Best regards

Roger

Offline steve-de24

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Re: Valve Seat Cutter D-Bit style
« Reply #3 on: March 04, 2017, 10:44:09 AM »
Bob,
A nice piece of work - thanks for sharing.
The 'Tiny' is on my short-list for a future project.
Steve

Offline gbritnell

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Re: Valve Seat Cutter D-Bit style
« Reply #4 on: March 04, 2017, 02:01:56 PM »
Great idea Bob for those that lack the indexing capabilities. The end result looks just fine.
gbritnell
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Offline 90LX_Notch

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Re: Valve Seat Cutter D-Bit style
« Reply #5 on: March 04, 2017, 02:53:03 PM »
Thank you gentlemen. 

Thank you George.  99 percent of the credit goes to you and your tool design.

-Bob
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My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos