marking rod and pistons

David Lee · 06-18-2017, 09:07 PM

I am going to be pulling apart a bracket 340 and I am going to re-use the rod and pistons. And I have been told by very knowledgeable people not to use a numbered punch on the rods since they can induce stress risers. What is the best way to make these so they go back into the correct hole?

Jason · 06-18-2017, 09:32 PM

Sounds like a BS story. Most factory rods are stamped with a numbered punch and they hold up just fine.

Lew Silverman · 06-18-2017, 09:52 PM

How about one of those electric etching tools you can pick up at Sears or Harbor Freight for less than $20? That would solve the problem of being a little too "heavy-handed" with a punch and ball-peen hammer.

David Lee · 06-18-2017, 10:21 PM

Quote:

Originally Posted by Jason

Sounds like a BS story. Most factory rods are stamped with a numbered punch and they hold up just fine.

Jason, i want to return each piston and rod to the hole they came from, and no mopar rods are not numbered to go into a particular cylinder. And thanks Lew, I will look into that. I was also considering the pens that junk yards use to mark parts.

GTX JOHN · 06-18-2017, 11:50 PM

David: I am surprised....Every 340 production rod I have every seen
is numbered 1 to 8 to Cylinder. Never had a problem stamping including
pistons. Excepting Some Chinese aftermarket stuff (Re: 440 Source rods)

James L Miller · 06-19-2017, 12:00 AM

Quote:

Originally Posted by GTX JOHN

David: I am surprised....Every 340 production rod I have every seen
is numbered 1 to 8 to Cylinder. Never had a problem stamping including
pistons. Excepting Some Chinese aftermarket stuff (Re: 440 Source rods)

Almost all or all of the Chrysler V8s I've taken apart had the rods numbered (subject to old geezer memory). The number was maybe .09"-.12" tall as best as I can remember. I have a 340 on the engine stand, so I'll take a look tomorrow once the rain blows through. I probably wouldn't stamp the rods once the big ends were resized and new rod bolts installed. I think the rod bore only has a .0005" total tolerance on the bore size.

David Lee · 06-19-2017, 01:08 AM

guess I should have been a bit more specific. This engine was built by someone unknown and it is not my engine. It appears to have scat rods and kb pistons. I went down to an auto parts store and bought the pens and was able to mark the piston tops.

John Dinkel · 06-19-2017, 03:46 PM

Magic marker.

Fred D Bartoli · 06-19-2017, 11:52 PM

Dave,

Clean the area with lacquer thinner. Put dab of dykem on them, use a scribe to make the #. Been doing it for years stays on a long time.

David Lee · 06-20-2017, 03:04 AM

thanks for the idea

06-18-2017, 09:07 PM	#1
David Lee VIP Member Join Date: Oct 2007 Posts: 1,168 Likes: 487 Liked 346 Times in 126 Posts	marking rod and pistons I am going to be pulling apart a bracket 340 and I am going to re-use the rod and pistons. And I have been told by very knowledgeable people not to use a numbered punch on the rods since they can induce stress risers. What is the best way to make these so they go back into the correct hole?

06-18-2017, 09:32 PM	#2
Jason Member Join Date: Jul 2003 Posts: 235 Likes: 0 Liked 6 Times in 4 Posts	Re: marking rod and pistons Sounds like a BS story. Most factory rods are stamped with a numbered punch and they hold up just fine.

06-18-2017, 09:52 PM	#3
Lew Silverman VIP Member Join Date: Mar 2010 Location: Newport News, VA Posts: 1,435 Likes: 371 Liked 129 Times in 59 Posts	Re: marking rod and pistons How about one of those electric etching tools you can pick up at Sears or Harbor Freight for less than $20? That would solve the problem of being a little too "heavy-handed" with a punch and ball-peen hammer. __________________ Lew Silverman #2070 "The Wagon Master" N/SA

06-18-2017, 11:50 PM	#5
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,733 Likes: 2,799 Liked 2,483 Times in 697 Posts	Re: marking rod and pistons David: I am surprised....Every 340 production rod I have every seen is numbered 1 to 8 to Cylinder. Never had a problem stamping including pistons. Excepting Some Chinese aftermarket stuff (Re: 440 Source rods) __________________ John Irving 741 Stock 741 Super Stock

06-19-2017, 01:08 AM	#7
David Lee VIP Member Join Date: Oct 2007 Posts: 1,168 Likes: 487 Liked 346 Times in 126 Posts	Re: marking rod and pistons guess I should have been a bit more specific. This engine was built by someone unknown and it is not my engine. It appears to have scat rods and kb pistons. I went down to an auto parts store and bought the pens and was able to mark the piston tops.

06-19-2017, 03:46 PM	#8
John Dinkel Senior Member Join Date: Nov 2005 Location: Pinckney, Michigan Posts: 507 Likes: 399 Liked 263 Times in 68 Posts	Re: marking rod and pistons Magic marker. __________________ John Dinkel 3295 STK

06-19-2017, 11:52 PM	#9
Fred D Bartoli Junior Member Join Date: Dec 2008 Posts: 76 Likes: 0 Liked 1 Time in 1 Post	Re: marking rod and pistons Dave, Clean the area with lacquer thinner. Put dab of dykem on them, use a scribe to make the #. Been doing it for years stays on a long time.

06-20-2017, 03:04 AM	#10
David Lee VIP Member Join Date: Oct 2007 Posts: 1,168 Likes: 487 Liked 346 Times in 126 Posts	Re: marking rod and pistons thanks for the idea