Stock Pistons?

[Moparbob]

Hi,

Just pulled the heads off the 440 were fixin up to go in our charger. Everything looks pretty good inside but I have a question about the pistons. These pistons are totally flat topped. There is no writing on them anywhere. Can I assume these are stock pistons?

Thanks in advance 

[firefighter3931]

Bob, all factory 440 pistons are flattops with exception of the 6-pack slugs which came with valve reliefs. See if you can get a piston to deck measurement and i will do some compression calculations for you. 

* Just bring #1 up as high as it goes in the bore (TDC) and measure from the top of the piston to the deck surface. 


Ron

[Moparbob]

Bob, all factory 440 pistons are flattops with exception of the 6-pack slugs which came with valve reliefs. See if you can get a piston to deck measurement and i will do some compression calculations for you. 

* Just bring #1 up as high as it goes in the bore (TDC) and measure from the top of the piston to the deck surface. 


Ron

Hey Bud,

Don't have a mic but in true Firefighter Style I used a tape It measured 1/8"

[firefighter3931]

Hey Bud,

Don't have a mic but in true Firefighter Style I used a tape It measured 1/8"

That should be close enough....about what i figured it would be .125in below deck. I'll be right back with some calculations....stay tuned. 


Ron

[firefighter3931]

Ok making a few assumptions here :

stock bore + 90cc Chamber + .020 steel shim head gasket i come up with 8.2:1 static compression. That's about where they "normally" fall for a stock 73 vintage setup. The later 76-78 440's have even less compression....i've seen those pistons .170 below deck ! 

The VooDoo cam will work fine with this combo. I would have the heads milled .020 to true them up and bump the compression up a hair. 

With a proper tune this engine should run fine on 89 octane fuel. 



Ron

[Moparbob]

Thanks! You have been a great help!

[Moparbob]

Lets say, if,, If I wanted to up the compression but still run high test gas.. What pistons would you recommend? 

[firefighter3931]

Lets say, if,, If I wanted to up the compression but still run high test gas.. What pistons would you recommend? 

The Speedpro 2355 pisons are hard to beat for the price. They weigh almost identical to a stock piston so balancing will be an easy job. If you're going to replace the pistons you might as well balance the rotating assembly and install ARP rod bolts to bulletproof the bottom end. 

This is the same rotating assembly that i have in my own 440 that made 535hp/540tq on the dyno. As long as you keep the rpm's in check and the machinework/clearances are good it will live forever. With a hydraulic or even a mild solid cam you won't be making power beyond 6000 rpm anyway. If at some point you decide to upgrade to a closed chamber aluminum head your shortblock will be all set. 

With an open chamber 452 casting the 2355 pistons will give you ~ 9.3 static compression which is fine on pump gas. The #302 VooDoo cam will still work fine with this increased compression in case you were wondering. 


Mancini Racing has the best price on the 6-pack slugs : http://chucker54.stores.yahoo.net/440comdis20s.html


Ron



Ps. Here's a pic ; notice the valve reliefs 

[Moparbob]

Any problem boring a mid 70's 440 30 over? Also may I assume this set comes with rings?

[62 Max]

Any problem boring a mid 70's 440 30 over? Also may I assume this set comes with rings?

.030 won't hurt it.You'll have to spring for the rings.Spend a little extra and get a set of file fit Speed Pro Plasma Moly's.

[firefighter3931]

Any problem boring a mid 70's 440 30 over? Also may I assume this set comes with rings?

.030 won't hurt it.You'll have to spring for the rings.Spend a little extra and get a set of file fit Speed Pro Plasma Moly's.

Agreed, a .030 overbore will be fine unless the block has severe core shift. You could allways have the block sonic checked to be sure. The file to fit plasma moly's are in my engine. 


Ron