3400 Piston specs.

[Fierobsessed]

Just need to know the volume of the dish in the 3400 pistons. If you have one to measure, the height of the dish and the depth from the deck of the piston will be sufficient.

Or, I can work backwards from the head chamber volume If you know it.

Thanks!

from the newest of newbies here!
What ever happened to my old account anyway?

[mfuller]

Gen III heads have 28cc combustion chambers.

[Fierobsessed]

ok, total cylender displacment is 558.4 CC (devide this number by 1 less then the compression ratio)
9.5:1 compression ratio
558.4/8.5=65.7CC total volume at tdc
-28 for the head
-12 for the head gasket
That leaves 26 CC's to the piston.
assuming a 2.6" diameter dish that would have to be about .3" deep! does that sound right?

3.4 DOHC has 64.2 CC's normal TDC volume
add approx 20CC's for the increased dish in the piston
that makes 84.2 CC's TDC Volume and 642.6 BDC volume thats 7.6:1 = way too low compression for me. DAM.

[mfuller]

Sounds about right.

[phantom505]

Aren't forged pistons about $600? How much would you really have saved going with the 3.4 DOHC?

[Fierofiend]

Heres some pictures of one I tore up...

http://members.cox.net/pbodymechanic1/3400/P2280212.JPG

http://members.cox.net/pbodymechanic1/3400/P2280214.JPG

dunno if it helps..

[RacerX11]

What are you trying to accomplish? I assume you are trying to lower your compression on a 3400? Using DOHC pistons in a 3400 will raise the compression, not lower it.

Your 20cc dish volume isn?t right for the DOHC pistons. I took a set of H684CP Sealed Power DOHC pistons and did some rough volume measurements with some clay. The equivalent dish volume came out to about 7cc.

Here are some piston specs from Silvolite: http://www.beckracing.com/slvpg24.htm

3.4 DOHC
Compression Height: 1.457"
No dish, but valve reliefs with approximate volume of 7cc (my measurements)

3400
Compression Height: 1.470
Dish Dimension: 3.15" diameter x 0.260" deep (~33cc)

3.4 Camaro
Compression Height: 1.457
Dish Dimension: 2.75" diameter x 0.080" deep (~8cc)

Using either the DOHC or Camaro piston in a 3400 will significantly raise the compression.

Marty