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In search of Lycoming ST-310 wobble test fixture

dan

Well Known Member
I have an IO-360-A1B6. Angle valve. Oh, also, it's an angle valve.

So I'm looking for a Lycoming ST-310 fixture to do a wobble test. Seems like a few sources will sell me one for just north of $2000. Sign me up for two.

I ran across Lycoming Service Letter No. L234B. Subject: Tool Rental Program.

"Lycoming Engines is pleased to announce a special tool rental program. This program is designed to support your need for special tools required for maintaining Lycoming reciprocating engines. Please check Lycoming Special Tool Catalog SSP-384 for proper tool application.

This tool rental program will be available through the normal Lycoming parts distribution network.

Contact your local Lycoming distributor to arrange for tool rental. Many tools are available for rental on a first come, first serve basis. A nominal rental fee per tool will be charged. The distributor will provide the factory with customer name and shipping address."

Score! So I contacted my local Lycoming distributor (Aviall in Cincinnati) and they had no idea what I was talking about. I've tried contacting Lycoming but haven't gotten a response.

I've of course seen this one: https://www.aircraftspruce.com/catalog/topages/valvewobble.php?clickkey=34395 ...for about $200, and it *says* it "will work on a angle vaule engine" (but should I believe the 4th grader who wrote that?).

Do I have a cheaper option? Anybody out there have an ST-310 in their possession, willing to part with it for a week or two? I'll pay shipping plus the cost of bubble wrap and a little extra for your emotional distress in its absence.

All you IO-390'ers out there, somebody's gotta have one of these puppies...

Did I mention I have an angle valve?
 
Maybe......

I machined a tool according to fig. 12 in SB388c, and purchased a suitable dial indicator. Supposed to work for angle and parallel valve engines, but I have not yet tried it on either. You are welcome to give it a try. I purchased some reamers that should work on my parallel valve, but I think the angle valve stems are larger. I did not machine the "post" to fit the angle valve engine yet. You would need a lathe to do something for that part. I could probably make one in a week or two (company visiting).

Let me know.

and once again, thanks for getting me started:D,

Terry
702 - two 7 eight - 0 two seven 3
 
I also operate an IO360 A1B6. I stuck a #2 exhaust valve at 320 hours since overhaul. I performed the wobble test about 100-120 hours prior to the sticking.

I hate to be cavalier about it, but if you simply pull the valve spring and "feel" the valve side play, you will know if it's getting too tight. Also, push the valve down the guide and look at the stem. If it's solid black carbon, I'll bet a dollar it's getting tight. If you have to hammer the valve out, like I did, it's too late...

I simply put a dial indicator on the valve stem and moved it side to side.

Having experienced valve sticking on 2 different engines, a couple of times lately, the key is finding it before it sticks. In my case, clearly 300 hours is the absolute maximum I can go.

In my operation, I will now simply clean the guide and valve stem, rather than take measurements. Takes me about an hour per cylinder, once set up to do it. I have the guide reamers, and I use a soft scraper, then Scotch Brite very carefully on the valve stem. Renewed to new tolerances, it's trouble free.
 
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