343 pistons in 360, don't fit...

[PaintedRat]

NOTE: For those using this for search info, the Egge 343 pistons are listed on their site under Rambler, and are slightly shorter than listed. These will provide CR over 10, but quench isn't perfect, read for details.

I tried install my pistons into my block today. The bore is fine, and the rings fit. The counterweights on the 360 crank contact the piston skirts at the bottom of the stroke. What do I do now?

I'm thinking the easiest would be to have the counterweights taken down, then rebalanced, but I don't know if you can do that. One suggestion was to machine the pistons, but that sounds like it would take more effort and money.

[jeepsr4ever]

This is common when your fitting a custom set of pistons. You will need to cut the skirts either grind them or mill them doesnt matter.

[PaintedRat]

Is this something I can do with a dremel and file or should it go to a shop? How much clearance do I need? Can it be done on the rods, and should I remove the rings (both for the purpose of not trapping debris in bad places)? During removal/reinstall of rings, I'm afraid I'll break another ring and have to order new ones.

[jeepsr4ever]

at least .035 of relief...you can use a dremel. How bad is it?

[PaintedRat]

It is solid contact, but at the very bottom of the stroke. I think a hair off and it will pass. I will try to do this today on the first piston and see if I have any trouble.

Oh, and I see a lot of orange/red, blue, and black blocks, so I thought the green shown above would be a fun color for my first engine build.

[jeepsr4ever]

Sweet looks like AMX Big Bad Green

[AMX69PHATTY]

Interesting.
I have a stock 343 4V piston sitting here beside
a TRW replacement cast 360 piston.
On the TRW 360 piston, the part of the skirt that goes
from the side of narrow part farthest down on the skirt 90* from the pin
to the cresent shaped flat surface 90* away, below the pin
is what differs from the stock 343 piston.
On the 360 piston this area comes down almost flush with the cresnt shaped flat.
Looks like on each 343 Piston, in ( 4 ) places, you would need to blend / grind this area
so the skirt transition from the 2 skirt "tips" becomes almost, but not quite,
flush to the cresent shaped flat area above the pin.
May I ask if you have 360 pistons to sit besdie and compare to the 343's ?

[PaintedRat]

I had the machine shop chuck the 360 pistons after they were removed from the rods, so no side by side comparison. I'll try to get a pic of the 343. I don't know what brand they are, they were bought through the machine shop.

[AMX69PHATTY]

Not the greatest pictures, but the camera I have is really old.

[73hornut]

I would have them rebalanced afterward. Your going to change the weight of each piston.