36 21 stud Pistons with buttons

[Ggmac]

I'm working on the 21 stud I've been stepping over for years . Stell Pistons , no ridge . Now here is what I found , piston pin buttons , is this ford ? The Pistons have no cut for snap rings . The ring ( 1st. And 2nd ) have diag ends . No expanders on any .
Any insight is appreciated , Gary

[Kurt in NJ]

probably center lock ----if you look in the small end of original rod there is a groove in the center, a clip fits in there to grab a groove in the wristpin, originally there was a tool that screwed through the pin at each end ---then hit with hammer

[Ggmac]

Thanks Kurt . I'll see if some pics will help .
I have used SBChevy Pistons with buttons and this is like those . If I remove a button ( pressed washer ) the pin removes easily .
Thanks , Gary

[Ggmac]

Originally Posted by Kurt in NJ

probably center lock ----if you look in the small end of original rod there is a groove in the center, a clip fits in there to grab a groove in the wristpin, originally there was a tool that screwed through the pin at each end ---then hit with hammer

Kurt , I took some pics but don't know how to post them . I can email .
My e mail is [email protected]
Thanks , Gary

[rotorwrench]

Aircraft engines use several types of what are referred to as piston pin plugs since most have floating piston pins. Some plugs have a light push fit outside of the piston pin and fill the whole pin bore. Other types fit into each end of the piston pin with a piloted stub and can be either a light push fit or a tighter press fit. Most of these are only a bumper plug and don't fill the whole bore. Some are made from harder aluminum alloys and others are made from a softer copper aluminum alloy and have a gold color to them. All of them work pretty well as long as they are replaced at each overhaul.

I don't know what Ford used with their steel pistons since I haven't worked on any that old yet. An engine rebuilder that works on a lot of old flatheads could likely add more to the story than I can.

[Ggmac]

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Originally Posted by rotorwrench

Aircraft engines use several types of what are referred to as piston pin plugs since most have floating piston pins. Some plugs have a light push fit outside of the piston pin and fill the whole pin bore. Other types fit into each end of the piston pin with a piloted stub and can be either a light push fit or a tighter press fit. Most of these are only a bumper plug and don't fill the whole bore. Some are made from harder aluminum alloys and others are made from a softer copper aluminum alloy and have a gold color to them. All of them work pretty well as long as they are replaced at each overhaul.

I don't know what Ford used with their steel pistons since I haven't worked on any that old yet. An engine rebuilder that works on a lot of old flatheads could likely add more to the story than I can.

Thanks , these aren't like the Teflon plugs I've used on the SBChevys . These are a washer looking convex plug , hollow center , full pin diam and seem to expand like a Welch plug when compressed in center .
This engine also has rings (1-2) that have diag ends . I've seen this type before but can't remember on what . I'm thinking on motorcycle or import .
Thanks again .