Where to buy a cylinder

[swedishcub]

I probably need to buy a new cylinder due to a broken exhaust stud.
I first broke the exhaust stud and after that I broke an extracting pin in hardened steel inside the exhaust stud. So I'm so to say stuck with it.
Does someone have any suggestion about where to find a cylinder to a fair price. The engine is a O-320 A2B with narrow deck cylinders and with +010" OD. The engine has 1830 hours so a brand new one is not an option.
When you Google on cylinders you get so many answers on companies, so it would be nice if someone of you can give me some recommendations on some.
Thomas
"swedishcub"

 

[jay heil]

take that cylinder to a machine shop they can get that old stud and extracter out of there dont know what the machine is they use but they can do it where I work I will ask them what its called tomorrow

 

[Aviator]

Hi Thomas,

I'll check in the hangar tomorrow, I should have a PN 75184-85 +.010 with about 100hrs since repair (according to the logs). I pulled the 4 jugs about 2 years ago for new ones so I don't remember if I still have all of them. Can you check if this PN works for you. I should also have a PN 69387CP and a 71118CP. Have the pistons, too and the repair tags. If any of these work for you, you're welcome to it. Don't know about shipping cost to Sweden, though. You'll have to look after that.

Cheers

 

[Steve Pierce]

I have one also if Aviator's doesn't pan out. Mine would be an unknown on time etc. but I know they are .010" over. Is there enough sticking out that you can weld a nut to it. We broke one three times recently and got lucky and were still able to get it out by welding a nut to what was left.

 

[Gordon Misch]

When I had my machine shop business I removed a lot of broken easy-outs for folks. Thing is, they were rarely simple.

The quickest way (that doesn't always work) is to rapidly heat the easy-out with an acetylene flame to red-hot then let it cool. It expands, pushing out on the surrounding metal, which compresses it while it is soft. Then when it cools it will often be a little bit loose (and the high-carbon steel will be a bit softer). Same thing with the hole drilled in the stud - a flame directed into the hole (not the surrounding metal) can loosen the stud - making it easier to get out with the easy-out - after it cools.

The other way, that almost always worked but is time-consuming, is to setup the part in a milling machine (drill press is not rigid enough to get through the easy out without radial deflection and damage to the threaded hole) and use a solid carbide combination drill/countersink to drill out the easy out. The carbide drill frequently breaks, but it is brittle enough that it can be broken up with a punch and the pieces removed from the hole. Then, much to my surprise the first time I tried it, the broken drill will rub its way through the easy out, which can eventually be removed. Then, of course, it's back to square one getting the stud out.

The biggest mistake I saw with easy-outs was folks using too small a hole in the stud. A good size hole, then flame inside, followed by cooling and then easy-out with some penetrating oil seems to work the best. Steve's idea of electric welding on a nut, the inside of the nut to the end of the stud, can work also, and also will shrink the stud slightly at the top.

By the way, it's important to heat the stud as rapidly as possible, so the surrounding metal stays cool, forcing the stud to shrink while it is hot enough to deform.

 

[jay heil]

the machine they use to take it out is called an EDM [non-wire] they said they could take it out without hurting the cylinder its cuts it with electricity if you can find one around your area they could do it fer you

 

[Gordon Misch]

Yep, EDM would be perfect if you can find one -

 

[swedishcub]

Thank you for all your advices. I got to know today of a machine shop in my town that have a EDM, so I will try with that first. If it doesn't work out well I'm pleased to know that there is a chance with Steve or Aviator.
Thanks so far.
Thomas
"swedishcub"

 

[swedishcub]

Just to let you know that it worked out very well with the EMD machine. The stud is out and the threads was unhurt. So now is everything back on its place and the plane is back in the water for another float season. Thank you all for your advices and offers.
Thomas
Swedishcub

 

[12Geezer2]

I have had pretty good luck by welding a flat washer on the stud if it is broken flush then weld a nut to the flat washer. Best to use an under size washer. Sometimes takes a couple attempts. Dan