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How to: Piston / Rod swap, pressing pins - Uncle Tony

D

Danny Boy

Secret of life is enjoying the passage of time JT
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Hello,
Just saw Uncle Tony's Piston/Rod swap - he makes it look easy.
Have any of you done this instead of taking to a machine shop?
Pros/Cons?

PS - Not looking for comments on Uncle Tony, just your comments on DIY swapping piston/rods - Thanks in advance

 
You'd better make up a jig to center the pin in the assembly! If you don't, you won't know you've
screwed up until you put the pistons in the bore and put the rods on the crank!
 
Had my pistons assembled by my machine guy. I took the old pistons off the rods with my press. Sent the new pistons, rods and new wrist pins to him so he could assemble and balance everything sent with my block crank and all. I did final assembly of the engine. He just did all of the work I was afraid to do. lol

IMG_E1237.JPG
 
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Is Tony a metallurgist? For the cost I wouldn't gamble except on a low cost repair.
Mike
 
When I rebuilt mine last year, I had a couple that the pin was a little snug. I wanted to take them apart and hone them.
2 different shops told me there was a pretty big risk of damaging the pistons, so I used them as they were.
 
I don't know about removing pins with heat. But at my buddies machine shop we heat the rods with oxy/acetylene. But only to a straw color. The rods never get red or blue. And yes the pins are slid in and centered by hand.
Doug
 
As long as the rod doesn't get over 700 degrees you're O.K. you don't start changing the "Matrix" until 780 or so. Fast quick heat does the trick! If you take too long by using too small of a tip, it won't be good! I would never press a pin out because of damage to the piston and you don't want to scratch a pin. Just my 5 cents.
 
I am lucky enough to have a electric rod heater for my more stock type teardown or rebuilds, so much easier.
 
Keep in mind that my old 440 pistons were crap and not in good shape. Plus they were low compression pistons so pretty much worthless. The engine was so stuck I had to beat 2 pistons out of the cylinders. So they were not savable anyhow. Thus didn't have a problem throwing them into the press. Does anyone have a use for 8 440 stock wrist pins? lol I still have them in good shape.
 
BeepBeepRR said:
Keep in mind that my old 440 pistons were crap and not in good shape. Plus they were low compression pistons so pretty much worthless. The engine was so stuck I had to beat 2 pistons out of the cylinders. So they were not savable anyhow. Thus didn't have a problem throwing them into the press. Does anyone have a use for 8 440 stock wrist pins? lol I still have them in good shape.
Click to expand...
I always use my old used wrist pins for spacers on the head of my engine stands to bolt to the back of the block.
 
I’ve done this using the oven in the kitchen while the wife was out. Made up a fixture to stop the pin at the right point. Put the pins in the freezer too. Went pretty well. One pin stopped early so I used a press to nudge it the last little bit. No magic here, just CTE and care with the heat not to get burned.
 
zyzzyx said:
You'd better make up a jig to center the pin in the assembly! If you don't, you won't know you've
screwed up until you put the pistons in the bore and put the rods on the crank!
Click to expand...
B

Thank you zyzzyx for your comment regarding the jig.

Regarding other member comments and Uncle Tony's method, it doesn't appear that a jig was used(required)

Question? How critical is it that the pin and rod be centered?

Uncle Tony appears to center the pin relative to the piston sides (same amount of pin sticking out each side of the piston)

For myself, I'd like to use Uncle Tony's,(and FBBO members) method as it appears to be quite simple.

Hope this makes sense, and thanks for your comments
 
UT says heat it til it's dull red.
That's above the temp where you can change the properties, so maybe not the best way.
 
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UT said "dull red" not "Cherry red" see 7:02 on clip

If holding rod "too hot to handle, you've gone too far"

Appears that he's conscious about not over heating
 
Danny Boy said:
UT said "dull red" not "Cherry red" see 7:02 on clip

If holding rod "too hot to handle, you've gone too far"

Appears that he's conscious about not over heating
Click to expand...
I stand corrected, and have edited my post.
Dull red would not be above the critical temp, but probably is hot enough to change the properties, if the rod is originally hardened. By that I mean you would probably soften the steel.
 
You can buy a "temp-stick" to check the temperature for installing. For installing, you only need about 500 degrees. For removing, about the same, but "qiuck heat". Temp sticks come in a variety of temperatures, and when they melt when touching the part, that's it! They are on E-bay as Tempilsticks.
 
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If you use your oven you know the temp. As for centering, you shouldn’t be able to make the pin break past the radius of the piston when shifting the rod back and forth. For the jig, remember the rod will be all the way to one side.
 
I used gas stove in the kitchen. I would agree to have a jig to push against and set the pin placement.
Someone was yapping in the comments about not going over 500° or you will ruin the rod, they probably get nervous at 75mph in 70 zone.
Don't sweat it, just do it. If the rod fails it will be on the big end. The piston is still weaker than the rod.
 
With the importance of pressing the wrist pin either in or out, it would seem better to use full floating wrist pins, secured with EITHER Spirolox retainers OR Waldes Tru-Arc retaining rings. I realize that in order to use retaining rings, the pistons would need to have the retaining ring groove machined in the pin bore, whose dimensions (width, diameter and location) would need to be determined ahead of time. Some people prefer a Spirolox ring or others prefer the Waldes Tru-Arc type (usually 2 per groove per side to prevent push out). The only special tools required are the appropriate snap ring tools.
Out of curiosity, what is the advantage or dis-advantage of either method, other than perhaps a slight weight difference, due to the retaining ring(s) weights. Personally, I would prefer the retaining ring method....comments?
BOB RENTON
 
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