My block is at RS getting sleeved and bored to 84.5mm. Arias has three compression ratios available in that bore: 9.1:1, 10.9:1, and 11.9:1. I decided against 11.9:1 because my car will see a decent amount of city miles, retain A/C, etc. I told them to send me the 10.9:1 pistons but checking the specs on the Arias web sight it stated that this piston has a -3 dish as opposed to the 11.9:1 piston with a 1.4 dome.

Are there any negative effects to running a dished piston? The car will be seeing nitrous to make up for the lower comp. ratio I went with and I didn't know if using these pistons would be a bad idea. Any insight would be greatly appreciated. TIA

 

Id get the 11.9:1's..

 

That was my initial plan. I had been talking to the same person there evrytime I called. One time I called with some more questions and he wasn't working. Another person at the shop asked me alot of questions about how I'll be using the car, goals, etc. He suggested the nitrous and lower comp. I have a NX wet system on my 5.0 mustang that's less than 6 months old. I was going to get a dry nozzle, 440cc injectors, and a hondata s200 to control the nitrous.

 

bump. Anyone have a picture of one of these high compression dished pistons? I'm I'd like to see what they look like. I've always seen high comp. pistons with a dome that came up higher than the deck height and just can't imagine how a 10.9:1 piston could have a -3 dish. Any insight would be greatly appreciated.

 

Wiseco 11.8 comp pistons 84.5 mm

 

Looking at the right edge of the piston in the pics it looks like it has a slight dome. Is that really a dished piston?

 

O.K. I'm stupid. I figured out that the plus and minus numbers meant cc's not the hieght of the dome or depth of the dish.