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Topic: Question about 3,8 ltr engine pistons (Read 664 times) previous topic - next topic

Question about 3,8 ltr engine pistons

I have 1986 3,8ltr V6 engine. Can I use in this engine pistons for 3,8ltr V6 1988-95 ?
Pistons heads (top) are visually same design.
Ring grooves of new pistons are smaller, but I also will use rings for new type pistons (88-95).
Piston pin is by measurements same size.
Piston skirt is little bit different design (shorter). But in my opinion, it will be not matter so much.
The only difference, what I found, is distance from pin to top of piston. New type piston are about 0,016 inch (0,4mm) shorter. It will probably decrease compression ratio. But how much?
Does anybody had experience with new type pistons in old type engine?

Cougar 86 3,8ltr TBI

Question about 3,8 ltr engine pistons

Reply #1
its not the compression decrease that is important but the possibility of the decrease in quench area. maybe use the newer rods also.
louie  :birdsmily:
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Question about 3,8 ltr engine pistons

Reply #2
Quote from: dudeman351;152764
maybe use the newer rods also.
My local parts dealer told me, that by their catalog/database, connecting rods for 86 and 89 engines are same. They have same part numbers.

Cougar 86 3,8ltr TBI