Piston dish

Performance mods and Advanced Stroker discussion.
Brianj5600
I think I'll order a "tab"
I think I'll order a "tab"
Posts: 45
Joined: August 23rd, 2019, 10:49 am
Stroker Displacement: 4.7
Vehicle Year: 2004
Vehicle Make: Jeep
Vehicle Model: Wrangler

Piston dish

Post by Brianj5600 »

I was excited when I got my last box of stroker parts today. I'm building a 4.7 with around 9.5:1 and .035" quench. I was disappointed to see the "D shaped dish". I want to run 87 octane, but the dish is practically round. I don't think I want to use these. How much turbulence would I be giving up?
You do not have the required permissions to view the files attached to this post.
User avatar
Cheromaniac
I live here
I live here
Posts: 3290
Joined: March 8th, 2008, 12:58 pm
Stroker Displacement: 4563cc
Vehicle Year: 1992
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Cyprus

Re: Piston dish

Post by Cheromaniac »

Probably not as much as you think because the turbulence is induced by the kidney shape of the combustion chamber.
In any case, you need a 26cc piston dish to achieve the combination of a 9.5 CR and 0.035" quench. That's difficult to achieve without enlarging the area of the dish as well as deepening it.
1992 XJ 4.6 I6 Stroker - 5MT - 200rwhp 258rwtq - Sold :cry:
Brianj5600
I think I'll order a "tab"
I think I'll order a "tab"
Posts: 45
Joined: August 23rd, 2019, 10:49 am
Stroker Displacement: 4.7
Vehicle Year: 2004
Vehicle Make: Jeep
Vehicle Model: Wrangler

Re: Piston dish

Post by Brianj5600 »

Had I known the dish was so big I would have gone smaller and found a few cc's in the combustion chamber, which I might still do.
User avatar
Cheromaniac
I live here
I live here
Posts: 3290
Joined: March 8th, 2008, 12:58 pm
Stroker Displacement: 4563cc
Vehicle Year: 1992
Vehicle Make: Jeep
Vehicle Model: Cherokee
Location: Cyprus

Re: Piston dish

Post by Cheromaniac »

The sum of the combustion chamber volume and piston dish volume will need to be 83cc. If you can enlarge the combustion chamber to 62cc, you can reduce the piston dish to 21cc.
Russ Pottenger
Strong Poster
Strong Poster
Posts: 932
Joined: August 15th, 2009, 1:27 am
Stroker Displacement: 4.7
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: Piston dish

Post by Russ Pottenger »

Hi Brian,

Yeah that’s not a particularly well laid out reverse mirror dish.

I wouldn’t worry about it too much, but if there is ever a “Next Time” i’d be happy to send you pictures of my design which is much closer to the reverse mirror image of the combustion chamber.

~Russ~