Grinding Valve Shims - Anyone tried it?

[Eli69]

I asked a friend, who owns a machine shop, if he thought he could take a little off the top of my valve shims. I told him they were probably really hard metal and their approximate size, and that they would have to finish up really smooth. He just said that it would be an easy job for him.

In case you were wondering, yes, I am very cheap and will try anyting to save a buck. I don't know how much it would cost but I do electrical maintenance at his shop so we'd trade work.

But I really need to know what you guys think. There's a lot of amazing insight on this forum. Thanks

[bwringer]

How is precision grinding and finishing cheaper than $5 a shim?

http://www.crc2onlinecatalog.com/

Even OEM shims are only $10 or so.

But theoretically, it should be possible as long as you always keep the ground surface down (against the bucket) and only allow the cam lobe to contact the hardened original surface.

You'll also have to find a machinist who can think in mm instead of inches. An awful lot of heartbreak can happen when someone confuses .01mm for .001 inch, but this happens all the time.

[onchiman]

I don't think I would do it. I may not seem like much, but those shims are "mission critical" components to these engines. I'd be concerned the grinding may introduce imperfections and or somehow change the temper of the steel. You'll also wind up with "odd" sized shims which might not be useful at the next adjustment and you probably won't even be able to trade them with anybody. Some food for thought.

[jpaul]

I had one ground down years ago, but it was only to create a thinner shim to allow an accurate measurement. For $5 a shim, I wouldn't run one that had been ground. The risk of running a shim that no longer has the proper hardening strikes me as false economy.

[Ghostgs1]

There is a machine that will accurately grind flat plates. It is a plate lapping machine and is a rotating table to which a light compound is added along with a lapping lubricant. The items to be flattened or trued ride inside rings that keep them centered on the table. We used to use them to repair worn plate type valves in large piston type compressors. Don't know if machine shops have them nowdays with the replacement of recip compressors by rotary screw. If they are still out there they would be capable of doing the job cheaply and accurately. Ray

[spchips]

magnet anyone

I would be concerned about magnetizing the hardened steel with the machining process. the manual warns against getting this from using a parts picker upper, but I bet a machining operation could do the same thing.

[renobruce]

My local Suzuki shop will do a straight trade on shims, no charge. And they have buckets full of them. You might check with your local shop and see if they do the same. It was SOP back in the day with the Suzukis and Yamahas.

[Nerobro]

Well... if he's going to use a "typical" grinder. They use a magnetic chuck. which WILL magentize the shims. That is not acceptable.

Go ahead and talk to the local suzy dealer. I"m sure they'll work with you on doing shims.

[bwringer]

My local Suzuki shop will do a straight trade on shims, no charge. And they have buckets full of them. You might check with your local shop and see if they do the same. It was SOP back in the day with the Suzukis and Yamahas.

You're lucky -- the surly pothead teenagers at my local Suzuki shop had never even heard of a GS valve shim, never mind that a current model (the GS500) still uses them. After many rolled eyes, dumb stares, blank looks, and heavy sighing, they were finally persuaded to look up the shims, whereupon they quoted me a price of over $15 each, then glared defiantly at me until I stomped out.

I called every single Suzuki dealer in Indiana. Every one. No shims. Prices ranging from $11 to $16 each, on the few occasions when they could be persuaded to look them up rather than hang up. Arrival times quoted as "uh, maybe a coupla weeks".

I called Suzuki dealers in Cincinnati. No love. I then started calling indpendent cycle shops within 60 miles of Indy. Still no luck -- they were all now building choppers and hoping for a TV crew to show up, or they just didn't work on "Jap Crap". Nice to hear good old American racism wasn't dead, fellas. Simply lovely.

Finally (this took a few days), I admitted defeat in my quixotic quest and zipped down to Cycle Recycle II over lunch hour. $5 each for all the shims I needed.

If you live somewhere where the Suzuki dealer hires someone other than Beavis and Butthead to run the parts and service departments, consider yourself lucky. Around here, they hire baggy pantsed teens for the summer at minimum wage and fire them before the first frost.

[renobruce]

WOW, I feel for you. My local Suzuki shop has been in business since the early 70's. The service manager has been working there since 1980. The salesman that sold me my 1150 still works there. When I pull up on my 1000, they know what they are seeing. The benefits of a small town, I guess.

[Eli69]

Thanks for the input everyone. I've been out of town all week and haven't been able to follow through on this yet, but, after I talk to my machinist friend again I'll post his response.

[rkubik]

Motion Pro makes shims

and every dealer can get Motion Pro stuff, including the little depressor tool thing you need for the job. The MP shims are about 1/2 the price of Suzuki shims - just found that out today.

[Canadian GS]

grinding valve shims - has anyone tried it?

As replied by Ghost GS1, there is a piece of machine shop equiptment out there that will accurately "lap" the valve shims. It is commonly used for lapping valve plates in oilfield equitment. It provides a wet lap[No heating]
without the use of a magnetic chuck. The material removal rate is slow and should not cause concern of potential for excessive thinning. The are lots of thicker gs shims out there that are of little use unless you are running high lift cams.
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Life is the trip, not the arrival at the end!!

Canadian GS

[feelergaugephil]

I did it, I needed a 245 size shim, so I ordered it from my local bike shop.
2 frikkin weeks later it arrived! only it was a 250!
So re order, 12 days later it arrives!! 255!
So, I got the 250 back off him, and used a sheet of glass and 400 wet and dry paper and eventually I got it down to were the feelergauge was at 5 between the shim and bucket!
Once in, it never clacked or flew out.
When I had run the engine in (rings) I went ahead and got the 245 shim.

[Eli69]

I like the using a piece of glass idea, pretty slick. I went to a local bike shop and they lent me the shim tool and traded me all the shims I needed. Didn't cost me a cent. The shop is in Perry, NY. Those guys are great, I really owe them.