3SX Custom Ross Pistons for 6G74 3.5l Block
Turbo & Non-Turbo
For 3.5L NON-Turbo Conversions in 3000GT / Stealth
Go BIG or go home! These are the pistons used in Eric's big 6G74 conversion that yielded the highest horsepower ever pumped out of a FWD Non-Turbo 3000GT/Stealth! The "95mm Flat Tops" available here yielded a 13:1 compression ratio in his engine. Understand that his engine features mega-decked heads that have shaved the cylinder bowls down to a mere 42cc. The stock heads measure about 52cc. These shorter heads obviously increase the compression ratio using the same piston. In a non-decked head, the compression is closer to 11:1 (increasing with decked heads, which is typical of a fresh build) - still higher than the cast pistons that come stock in the engine.
These pistons were specifically designed for this build and feature a flat-top with about -3cc volume in the valve pockets, 1.5/1.5/3.0 ring pattern, wrist pins that are 0.866" x 2.3" using wire locks, and thicker wrist pin bosses that are closer together.
We used and recommend the 95mm MLS Head Gaskets.
Upgraded pins and custom Total Seal rings are included with these pistons.
The following dyno graph shows the end result of the 6G74 engine built using these pistons. That churned out over 280 hp at the wheels directly compared to a stock 3000GT (with an intake filter) that rolled out 159 hp - which is fairly typical for a stock DOHC 3000GT/Stealth.
The complete details of the build and modifications on Eric's car are featured here.
For 3.5L Turbo Conversions in 3000GT / Stealth
These are custom Ross pistons made for 3SX and designed to work in the the 6G74 block for those owners doing the 3.5-liter conversion in their 3000GT/Stealth. These are lower 8.5:1 compression sets for those doing a twin turbo 3.5l conversion.
Pins and Hastings chromoly rings are included with these pistons.
The pistons are designed to use pins that are 2.500" long x 0.866" diameter (included are 0.125" thick wall) and use Spiralox. Should you want to get alternate pins - we offer Tool Steel Pins and uberstrong H13 Pins.
NOTE: We HIGHLY recommend that you have your pistons PRIOR to boring your block, so your machine shop can bore to the proper clearances for the pistons. The listed piston sizes are approximate, and as there are different tolerance requirements between different piston manufacturers, and even exact size variations between piston production runs, you should never bore your block without having the pistons that are going in the block. 3SX is not responsible for pistons not matching a bore - this is the responsibility of the machine shop.
NOTE: These items are custom made and take 3-4 MONTHS to process and ship. Please take that into consideration when purchasing.