Ok this isn't new at all, but I'm not sure if anyone was aware of it. It comes from the FT series of motors. It's the Silvolite 3139.

Here's the specs:

1. Compression height: 1.882"
2. Dish volume: 18cc
3. Rings: 3/32", 5/64", 3/16"

Lets see what this thing does for an old 360. Here's what most people use when they them:

Silvolite 1131 piston, with:

1. Compression height: 1.760"
2. Valve relief volume: 8cc
3. Rings: 3/32", 5/64", 3/16"

So with a little math, assuming factory dimensions on the block, crank, and rods, in a 360, the 1131 piston sits 0.120" below the deck. The 3139 piston, on the other hand, sits .002" above deck, more than making up for the dish!

Now lets see what the compression would be on a theoretical 360, with 72cc chambers and a .038" thick Mr. Gasket head gasket (Fel-pro would be slightly lower):

1131 piston: 7.51 to 1 compression.
3139 piston: 8.57 to 1 compression.

Now 8.57:1 compression may not seem like much, but it's a lot better than 7.51:1! For someone looking to build an FE, and starting out with a 360, staying with the 360 may now be worth it depending on the priorities for their build.

The question is, is this piston still available? I saw it listed here:

http://www.beckracing.com/slvpg50.htm

From these guys:

http://www.beckracing.com

Thoughts, comments? Am I insane?

 

aren't FT pistons full skirt? if so then it wouldent work becuase the counter weight would take out the piston in an FE.

 

Remember, some early 360's had full skirt pistons. I think it would work fine. Where you have problems is running full skirt pistons with a 390 crank. Neither of which we're doing here.

Also, here's a picture of an FT piston. Not a 3139 like I was saying, but this is the 3142, also used in FT's.

 

lots of FT pistons are not full skirt but lots of 360's had full skirts and they cleared the counter weights

 

I don't see why it wouldn't work...352s had full skirts and its the same crank as 360..so they could be used in 352 rebuilds also, I'm not familiar with FTs, are the pistons weights the same as FE??

 

I have no idea what they weigh! My guess is that it would be somewhere in the ballpark, maybe a little heavier, but you'd want to have the whole thing balanced anyway. Good practice on any rebuild when any bottom end component is changed.