Jahns Pistons part# 1157

[chevyandpontiac]

I am trying to find out if these are open or closed chamber pistons.

I know they are 1965-1970 396 standard bore, 12.1 CR

Thanks Dan

[earntaz]

CLOSED ... I believe open chambers began about 71' ... TAZ

[67 Nova Boy]

LS6 454 were open chamber heads so maybe even 1970 so as Taz said...closed

Dave
67 Nova Boy

[chevyandpontiac]

Thanks everyone.

[earntaz]

Dan -- I just looked at a set of 1157's on EBay ... they are closed chamber pistons. TAZ

[67 Nova Boy]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: earntaz</div><div class="ubbcode-body">Dan -- I just looked at a set of 1157's on EBay ... they are closed chamber pistons. TAZ </div></div>

Taz...are the piston domes kidney shaped like the head?

Dave
67 Nova Boy

[earntaz]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 67 Nova Boy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: earntaz</div><div class="ubbcode-body">Dan -- I just looked at a set of 1157's on EBay ... they are closed chamber pistons. TAZ </div></div>

Taz...are the piston domes kidney shaped like the head?

Dave
67 Nova Boy</div></div>

Yes they are ... and look like at least a 12:1 CR ... TAZ