Identifying bushed and press fit pistons

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Bronze Barracuda

Bronze Barracuda

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I have two sets of connecting rods both out of 318's
Both the 318 rod have casting numbers 3418645
Trying to determine if they are press fit or floating.
One set has a retainer clip? The other does not.

Please note the picture with 2:sets of rods and pistons 1 is the 318 with the retainer clip (3418645) the other is a 273 rod and piston (2406782) also with the retainer clip. I am hoping/assuming the retainer clip ones are floating?

IMG_20220115_224235.jpg


IMG_20220115_222054_01.jpg
 
Yes, retainer clips= floating wristpins. Remember though, even if the wristpins are pressed onto the rods, that could still mean the pistons have grooves for retaining clips or Spirolox. If that makes sense.
 
Couldn't you just remove one of the clips and see if you can push the wristpin out?
 
MOPAROFFICIAL said:
The pistons are honed for either press or float. The rods pin bore is the interference fit, not the piston.
Click to expand...
The piston bores are the same diameter, press or floating. Just look at the description on all of the KB pistons. Their description says something like "can be pressed or floating".
 
RustyRatRod said:
The piston bores are the same diameter, press or floating. Just look at the description on all of the KB pistons. Their description says something like "can be pressed or floating".
Click to expand...
What I said was the piston floats regardless because it is the rods pin bore that is either interference fit 'press' with no bushing...or bushed for 'floating'. The piston floats on the pin no matter what. With press rods you dont need clips..the rod centered on the journal , pin doesn't move only the piston..n keeps it from hitting the cyl wall.
 
I guess 'either' through ya off?

I have a press fit rod I honed so I could slide a pin through to a get ROUGH piston to deck check for a build.
 
At the risk of stepping on someone's toes and/or looking like a dimwit myself.
So I'm guessing the rod hole is the same size as it does not determine the design, it is either press fit of floating? Press fit would just be a slightly larger wrist pin?

So the wrist pin hole on the piston would need to be slightly larger as well. Correct?

Part of my confusion as to why I didn't just remove the retainer clip, is both rods having the same casting number yet both have different pins.
Another point of interest in regards to bushings. I believe I read somewhere in a FABO thread that some people have put the floating pins in without bushings. So it is possible that the ones with the retainer clip was originally a press fit.
I'll take one apart this evening to see if it has a bushing.

Thanks everyone.
 
The pin size is the same for press or push. It's the rod small end that has a different diameter depending. You should be able to see the bushing in the rod if it has them. If not, try rocking the rod back and forth to see if it turns on the pin. Hold the pin from turning if necessary while you move the rod.
 
MOPAROFFICIAL said:
I guess 'either' through ya off?

I have a press fit rod I honed so I could slide a pin through to a get ROUGH piston to deck check for a build.
Click to expand...
Stupid as I am anything can throw me off.
 
Ok got the piston apart easily. Looks like that's a bushing. Everything came apart very easy. Standard bearings came out of them too.
It's a good day.

PXL_20220117_011614863.jpg


PXL_20220117_011720576.jpg


PXL_20220117_012102501.jpg
 
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