Valve Grinding Machine Comparison
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The Evolution of Balancing
July 21, 2016
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Valve Grinding Machine Comparison

OK guys. You will see shortly that this is not a sales pitch. I can’t get involved in this discussion without being thorough and answering a lot of questions no one asked. I’ll apologize now.

KwikWay (US made)
I began selling valve grinding machines back in the mid eighties when I took a territory for KwikWay. Back then the battle was between KW and Sioux and the machines were traded in about every two years. The normal price was around $2,500. Times have changed and so have expectations…
The finish on the KW was, and is still, superior to anything I have seen since. There are more grades of wheels available and more sources for those wheels than any other machine. The diamond dresser is the best thought out system of any valve machine. There were some true design geniuses when KwikWay came into existence back in the 20’s.
The KW has an inherent problem in the six-ball chuck design. Even if the chuck starts out near perfect the ramps wear quicker than the hardened balls so any attempt to reclaim the original accuracy is futile. The one hope is that the operator will keep the grinding oil/grit out of the chuck so it doesn’t prematurely wear. That said, there is a benefit to the six-ball design if it runs true.
The chuck stem turns true regardless of the condition of the stem. The head of the valve is round even if a few tenths off-center. Fortunately KW has learned a lot about making a precision chuck since the eighties. The design of the KW refacer is good if the chuck runs true. KW has had about ninety years to get this right.
The price of the KW is the best in the US market.

Sioux (US made)
I used a Sioux valve grinding machine as far back as 1978 and was forced to sell them when I quit KW and went to work for Kansas Instruments in 1990. Again, many wheels are available and many sources for the wheels. Sioux was, at one time the leading supplier in the US of valve grinding machines.
This machine had problems with the finish (never equal to the KW) as well as inherent problems with the chuck design. As cool as some of the features appeared, I was not impressed with the accuracy or finish. To grind a valve true on the Sioux it was necessary to first chamfer the stem. The machine was supplied with a stamped steel chamfering fixture for this purpose. The end stop had a conical end that centered the chamfered end of the valve (a novel feature until it wore in the area where the stem rode) and the three rollers centered the stem close to the head of the valve. This design was a hybrid centerless/roller chuck design. As cool as this was, it was not any more accurate than the KW (usually less accurate) and more difficult to set up properly. This was a cumbersome design and finally scrapped when SnapOn purchased Sioux soon after the turn of the millennium. More on this later.
There are no new Sioux machines.

TobinArp (US made)
The TobinArp was probably the best design (as with much of their line) in the market but, probably because of the price, only popular in the higher end race shops. A good variety of wheels are available for this machine but not as many varieties or sources as KW or Sioux. The TA used a collet style chuck and a pivot arm so the grinding was accomplished on the end of the wheel instead of the side. The finish was superior to even the KW. It was not as versatile as the KW or the Sioux (for different valve stem sizes a collet change was necessary) so many shops generally would prefer the KW or Sioux. The collet Chuck was superior in accuracy to the KW or Sioux. This machine was ahead of its time. Sunnen eventually purchased TobinArp and it was manufactured as a Sunnen machine until Sunnen chose to dump anything other than honing equipment. Still today this machine is preferred by many performance shops for good reason. There is no better machine for grinding titanium valves.
There are no new TA machines.

IDL (Canadian made)
Ingenious Devices Limited in Canada decided to take a stab at the valve grinding market sometime in the mid eighties.
There is a limited source for wheels for the IDL compared to KW and Sioux.
They were the first to build a ‘centerless’ chuck design. Centerless in the valve grinder market refers to a valve rotating on rollers on its own stem as opposed to the stem being fixed in a chuck of some sort.
Like TobinArp they decided on a pivot design for the traverse and ground on the end of the wheel. This machine had good success with the racers although it was expensive in comparison to the KW or Sioux. But it was inferior in finish to the KW and even the Sioux. The chuck design was complicated and it was a cumbersome machine. The finish was never the quality of the KW refacer. Sunnen purchased IDL and continued to manufacture the machine and, because it was now labeled ‘Sunnen’, it was accepted as the best. In my opinion it was never the quality of the Sunnen/TobinArp design.
There are no new IDL machines.

Comec (Italian)
Comec designed a Machine that is a mixture of the weaker designs of the foregoing machines. There are few sources and choices of grinding wheels available.
They use the pivoting traverse. They grind on the end of the wheel and use a chuck design based largely on the ‘centerless’ IDL machine. A good finish is difficult to achieve and the chuck has the complications of the IDL machine. Most customers with this machine don’t seem to care much for it. I do understand there are exceptions.
The Comec is closest to the price of the KW machine. It is sold through Baker Sales.

Rottler (Indian made)
IDL copy
When Sunnen dropped the IDL refacer, and maybe a little before, Robin Chera made a copy of the IDL (by then, Sunnen) refacer. There are a few changes but the chuck is the same complicated centerless system and most features are the same. There are still less options on the grinding wheels than KW or Sioux.
Robin added a digital readout for the angle and made a nice base for the machine to set on. Robin offered (or possibly made it at Rottler’s request) the machine to Rottler. The machines I have had my hands on did not have a good finish and the DRO was not working soon after they were put in place. These are pretty machines but I don’t care for the complicated chucks or the electronics.(Maybe prejudiced, or simply my opinion). I have talked to many people who don’t care for this machine.
Rottler’s IDL copy is ridiculously priced. Even Sunnen didn’t charge as much.

Rottler (Indian made)
KwikWay copy
Robin decided (could be at Rottler’s request) to make a copy of the KwikWay refacer. He made the same chuck and used the same wheels and almost all duplicate features as the KW. This is beneficial when choosing wheels for titanium and stellite valves. The chuck still has the limited size range of all the KW’s. It also has the same concerns when it comes to the expensive maintenance down the line.
A big mistake was made in the choice of roller ways for the spindle traverse. The original KW used a dovetail way and a spring-loaded gib plate. This is a very good system for longevity. The roller ways on the ‘Rottler’ version are impossible to seal. It does feel very free when it is new but will be a big and expensive problem with time. We purchased these same ways for testing and decided they were the worst choice.
I assume the finish and concentricity are good with Rottler’s KW copy. I don’t believe it will be better. The price of this style machine has been established by KW. Rottler’s copy is ridiculously more.

T&S 2075 Valve Grinding Machine (US made)
Around 2005 or ’06 we decided to make a valve grinder. We started with a blank piece of paper (SOLIDWORKS page) and first put both extremes of valve sizes on the screen (length and diameter). We then designed a unique centerless chuck, cast base, form-fitted cover, Sioux size wheel and copied the bearing design of the KW spindle. This machine was light-weight, small profile, easy serviced had we wasted no effort on frills. The cost to manufacture was low but we did not attempt to market it well. We did not spend enough time on the stem end and the machine was messy to use.
Our goal was to make a function/cost over form machine that was easy to use and cheap and simple to service. We sold a few of these machines and, in retrospect, have seen that they were actually very good machines for grinding the valve face quickly and easily.
When Sioux/SnapOn discontinued the 2075 machine we saw it as an opportunity to expand this machine design to use common parts with the Sioux and our simple centerless chuck design and the design of the KW spindle for a superior finish. We also added a DRO for the angle and linear ways for the traverse and wheel in-feed.
We made a mistake in our choice of the encoder system for the DRO and made our own electronic interface. The interface worked well, taring to 44.5 degrees but the encoder had the same problem as the Rottler design. It was not well sealed from the coolant and had the tendency to fail quickly. We changed to a US made encoder/DRO and sealed the encoder to rectify this problem.

Sioux Retrofit Chuck
Since we made a copy of the Sioux machine it seemed to make sense to make a retrofit centerless chuck for all of the Sioux 2001 and 2075 machines. This made an improvement in the concentricity and range of the chuck for the Sioux but did nothing for the design of the spindle so the finish on the old Sioux machines was still inadequate. We did find a way to change the spindle design to improve the finish but by the time all of this was done it made more sense to simply sell a complete new machine. We couldn’t find a really efficient method of retrofitting these old machines.

2075 Epoxy/Granite Machine
We decided to take the design a step further and make the ultimate valve grinder with the following concerns, 0-90 degree angle for facing, best finish in the industry, common wheel design for versatility of finish on different materials, linear ways for lifetime longevity and little maintenance, Sioux stem grinding design, and $40 rebuild for the chuck. The centerless system was rotated to the side so the angle would be the same regardless of the size of the stem. (This is not the case on the add-on centerless design using the original chuck to drive the rotation).

I feel we made the best valve refacer in the market today, but even at $10,500 it was not a profitable machine for us. We have shelved the design until we are more efficient in manufacturing this machine.

Summary
Unfortunately, I don’t care for any of the overly expensive and complicated refacers being offered today. Many people are laying out a lot of money for the Indian and Italian machines even though KwikWay is offering a great value and a really good US made machine with a guarantee of performance. It baffles me why someone would pay extra money for Rottler’s KW copy.
We have decided to continue to watch this market and jump in when we can be more competitive and profitable.
If I were to recommend a valve refacer today it would be the US made KwikWay Machine.

I already apologized for the offense my comments will probably cause. But these are my honest thoughts.

Tim Whitley
President
T&S Machines and Tools, Inc.

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