Author Topic: Engine valve and seat grinding..  (Read 172 times)

Offline oldcarguy

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Engine valve and seat grinding..
« on: April 11, 2024, 07:14:05 PM »

My Sioux Valve Grinder # 645L and Portable Seat Grinder 1710S
Sioux made valve grinders since the early 1920's. A must have single use machine for any antique car enthusiast such as myself. In the early days, up until the 1970's and introduction of unleaded gasoline, the valves on cars needed resurfacing between 50,000 to 70,000 miles. And it was cheaper to grind the old valves rather than purchasing new.









After cleaning up the valves. The flat end is ground square to the stem. Then a small 45 degree chamfer is added flat end. Making for easier insertion in the head of block. But most important for truing the valve in the Sioux grinder head. Along with setting a stop making all valves the same length. Only old timer's know and understand this. I have read several poster's saying that they cannot get the valve to run truer than .005”. Saying that the three jaws in the work-head is not enough to hold the valve stem true. When in practice The back end of the work-head has a stop with a reverse taper. That center's the valve stem. And the three small jaws grabs 4” of 5” toward the valve head.  And indeed makes for quick and accurate setup. Putting a test indicator the revolving valve reveals the TIR (Total Indicator Reading) of less than .001”.

This is a Sioux Portable Valve Seat Grinder. The kit contains the power unit, numerous grinding wheels, positioning shafts, and diamond wheel dresser. This tool in a must have for quick and accurate valve seat grinding of flat head engines. The seat can be resurfaced without removing the engine from the car. Being that most early cars were valve in block design this was a very popular tool to own. However it's still can be used in valve in head engines. But many home mechanics just drop the heads off at a machine shop for someone else to do all the valve work...   




Offline john k

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Re: Engine valve and seat grinding..
« Reply #1 on: April 11, 2024, 09:39:16 PM »
Have run a Sioux valve grinder and seat grinder since the late 60s.  One shop had an air powered seat grinder, which was easier to run than the electric model.  Selecting the size stone, facing it, getting a good contact via prussian blue was a part of shop work I really miss.  Later on a shop had a Quik-Way valve set up, just it was all set left handed, opposite the Sioux.

Offline The Magic Ratchet

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Re: Engine valve and seat grinding..
« Reply #2 on: April 12, 2024, 05:59:36 AM »
When I had my shop, we had a Black & Decker seat grinder. I can't remember which valve grinder we had, it might have been a Sioux, but I bought it used from our local NAPA parts store machine shop. It was said to be worn out but once I cleaned it up the only thing I could find wrong was excessive play in the guides that were used in the mechanism to slide the valve back and forth across the grinding stone. My father-in-law was a tool and die maker so I asked him to take the guides to work and remove the clearance plus a little more. When I got them back, I installed with some shim stock to get the clearance just right so the table slid smoothly without any chatter when cutting the valve. That grinder served me well up until I sold the place. I wish I had a setup now as this sort of work is getting hard to get done as the automotive machine shops close up one at a time.

Lou Manglass


Offline goodfellow

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Re: Engine valve and seat grinding..
« Reply #3 on: April 12, 2024, 07:52:03 AM »
When I had my shop, we had a Black & Decker seat grinder. I can't remember which valve grinder we had, it might have been a Sioux, but I bought it used from our local NAPA parts store machine shop. It was said to be worn out but once I cleaned it up the only thing I could find wrong was excessive play in the guides that were used in the mechanism to slide the valve back and forth across the grinding stone. My father-in-law was a tool and die maker so I asked him to take the guides to work and remove the clearance plus a little more. When I got them back, I installed with some shim stock to get the clearance just right so the table slid smoothly without any chatter when cutting the valve. That grinder served me well up until I sold the place. I wish I had a setup now as this sort of work is getting hard to get done as the automotive machine shops close up one at a time.

Lou Manglass



Same here -- B&D made a good machine, but in my humble opinion it was not as versatile as the Sioux. I learned on the B&D as a young mechanic, and about 20 ago I saw one on Craig's list for sale. Couldn't pass on it -- and the wife actually encouraged me to get it. It was a complete kit, and included a pneumatic valve seat grinder, a complete set of stones, and a nice slew of valve guide reamers. All housed in the OEM cabinet.

I posted the original link to the machine way back on GG version 1.0 -- that's quite a few years ago. Glad I saved the write-up and reposted on GG 2.0

https://garagegazette.com/index.php?topic=65.msg499#msg499
« Last Edit: April 12, 2024, 07:55:57 AM by goodfellow »

Offline john k

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Re: Engine valve and seat grinding..
« Reply #4 on: April 12, 2024, 08:53:53 AM »
This brought up a memory, from the first shop I worked at.  Was grinding the seats on a Ford flathead V-8, in the case with the stones and shafts were a set with a valve stem diameter of 1/2 inch.  Just huge in comparison to the rest.  Discovered they were for a commercial Ford engine that used sodium in a hollow valve stem.  The sodum sloshing inside cooled the valve in an attempt keep the seat from burning.  We found an article saying to dispose of them carefully, as the liquid sodium could  burn or explode.  Watching for a Sioux set now.

Offline john k

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Re: Engine valve and seat grinding..
« Reply #5 on: April 12, 2024, 11:17:21 AM »
This brought up a memory, from the first shop I worked at.  Was grinding the seats on a Ford flathead V-8, in the case with the stones and shafts were a set with a valve stem diameter of 1/2 inch.  Just huge in comparison to the rest.  Discovered they were for a commercial Ford engine that used sodium in a hollow valve stem.  The sodum sloshing inside cooled the valve in an attempt keep the seat from burning.  We found an article saying to dispose of them carefully, as the liquid sodium could  burn or explode.  Watching for a Sioux set now.

Offline goodfellow

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Re: Engine valve and seat grinding..
« Reply #6 on: April 12, 2024, 03:42:59 PM »
I remember the sodium filled valve stems. Pretty cool technology given the times in which they were implemented.
 

Offline muddy

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Re: Engine valve and seat grinding..
« Reply #7 on: April 12, 2024, 08:48:43 PM »
Always fascinated by it, never got to run one probably never will.

Sent from my twisted mind of the mudman


Online slip knot

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Re: Engine valve and seat grinding..
« Reply #8 on: April 13, 2024, 03:28:44 PM »
I spent a lot of time with one of these working on the little flat head Fords. A lot of the early Ford tractors came with non adjustable tappets. you set valve clearance by moving the seat face around. I learned pretty quickly that buying the adjustable tappets made life much easier.

Offline 34_40

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Re: Engine valve and seat grinding..
« Reply #9 on: April 14, 2024, 06:36:22 AM »
We ran one of those setups back in the middle 70's.  All Sioux equipment in the Vocational HS I went to.  We were doing 3 angle valves even then!  I got pretty good at lifting the driver and the tool holder at the same time in one smooth motion.  Our teacher that year was an old guy who always told stories of him and his brother crossing the country in a model T Ford.   :)