One of the pistons i pulled out of my 460 has a broken skirt. I bought a new piston to replace it but i cant get the connecting rod off of the old piston. The wrist pin seems to be connected quite firmly to the rod, but floats fully in the piston. How do i get it out?
-kit

 

you need to have a machine shop press a new one on. you will also have to have the engine balanced because you have changed the internal mass and that piston may be way to heavy or too light.

 

What are the dangers of running a piston with a broken skirt?
-kit

 

The same dangers as having a grenade......

 

Well i mean specifically what should i look for that it may have caused? Aside from the obvious cylinder wall scratching possibilities, what other problems are likely to have been caused by the broken skirt?
-kit

 

If the piston is just cracked, about the only thing you have to examine is the cylinder wall for scores or scratches. If the skirt is broke and parts are lying in the pan, you need to examine the lower end to see if the rods, crank or oil pump has been damaged.
IMO, I know that the whole rotating assembly should be balanced when replacing a single piston, but if the cylinder wall is okay, put the piston in and run it. It won't be perfect, but will get you by.

 

To be safe with the balance just pull another piston and compare its weight to the replacement piston, chances are the are the same or too close to make a difference unless this is a 4,000 rpm plus motor. Wasn't that a semi-floating pin, you'll need a press plus a piston holder.
.....=o&o>.....

 

I just went to the machine shop and got the old pin pressed out and the new pin and piston put on the connecting rod and aligned. I asked them to weigh the piston and pins respectively when they were each off. The old weighed in at 34.625 ounces (982 g for you metric folks). The new was 34.5 ounces (977 g). If you check those conversions you'll find an error of about .1% (these are scale readings in both standards of measurement, not true conversions), about a third of the weight difference percent. Kinda cool.
-kit

 

Run it you'll never feel it. Ford did send out shakers even when brand new.
After the old pistons cleaned up and bead blasted I bet they would weigh the same. .....=o&o>.....

 

Those are the clean weights, and are definitely good enough for me. There's probably potential for enough variance in the rings to make up for that. Well i guess not, but just like tolerance stacking, theres always tolerance canceling.
-kit

 

I bet if you knew what Ford considered "within their weight production tolerance" you would be sick. Good to see you'll be up and running soon.
.....=o&o>.....

 

hahaha thanks beemer.
-kit

 

I'm running into the same problem. I'm kinda worried about the others breaking as well. I just bought a single piston for $8.50 but I'm having second thoughts and my just by a .030 set. Something had to break that piston and even though it seems tight I'm guessing it was piston slap. So either I put in the new piston and hope for the best or buy new pistons and have it bored, and new pistons pressed on and while I'm at it I'm gonna deck the block down to 10.300. All that is an extra $525.

 

tell ya what on worrying about that 5 gr. of difference in pistons, when I was still working for a shop had a customer that came in with a miss tore into it after determinning that one hole had zero compression and found that piston had a hole burnt in it. I wanted to put in a short block and redo the heads but this customer was too cheap only wanted to replace one piston but had to bore that one cyl .030 I tried, and tried to get him to let me bore them all and replace the pistons but no go (it was all I could do to get him to let me replace the bearings, and rings too) and balancing it was out of the question so I had the shop bore that one cyl and bought one .030 piston and redid the heads reassemble the engine. it actually ran pretty smooth infact it was smoother than a lot of factory engiens of the same size yet he complained about it until the shop finally paid to have a new engine put into his truck (this guy is a scam artist this way and I have since learned I won't even change oil in his truck and with this story he has a hard time finding anyone else in town that will) well the ending of this story is one of the other mechanics took that engine put it in his pickup and last I heard as of 3 yrs ago was still driving it that way, I did that 12yrs ago and the engine has 150,000 miles on it since that funky rebuild so they will work even if not ideal.

BTW because of that situation, I have gotten the attitude if I am working on your car the customer is not always right if you won't let me fix it the way I tell you it needs to be fixed, just take it on down the road cause I ain't doing it.

 

Sounds on the same line as my custom transmission friend (one man shop) were a customer tells him the symptoms and what needs to be replaced and worked on. He will answer "I can't do it as I see your smarter than me" he'll tell them he doesn't want to work on it then they leave. Many times they will come back but the answer is still no as are they the type that'll complain no
matter whats been done. "In business you must learn to read idiots" he said.
Back to pistons, weigh a good one and make the replacement the same (posted above) but find out why it failed in the first place.
.....=o&o>.....