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Installing Pistons backwards in 1991 302 mustang

7625 Views 9 Replies 7 Participants Last post by  FoxChassis
I ran into a guy yesterday that does alot of work with 302's and 289's. He told me that i could take my stock 302 and swap the pistons from one side to the other ( like put number one where number five is and so on) and pick up a good 30hp.. I see how this could lenthen the stroke of the engine but how would it add that kind of power? Also my car is going to be a weekend car so driveablility is not really that much of a problem. He told me that i would not have any problem with the engine like this is this true?
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I've never heard of that, and I don't understand how it would add any power. I don't see it lengthening any stroke either. maybe that is just me...
by turnning the wrist pin a different angle it would add .300 to the rod length
Personally, I would just install the pistons the right way.
Im asking about the theroy not trying to get bashed for a idea..
In theory it would work by raising compression. only if what you said about it increasing the stroke by .300, but that seems kindof odd to me.

i would be extremely cautious and make sure the valves won't crash into the pistons, infact i would not do this. Unless i had a junker 302 i could try it on, to see if it would cause any issues, before i would do it to an engine i was building
but when you think about it if you have 4 valve reliefs it should not change the positon of the valve reliefs
im pretty sure that switching the pistons to the other side will do nothing as the stroke of the crank on all 8 pistons are the same as well as the connecting rod length. When you build an engine the pistons and connecting rods dont come numbered you can put them in any cylinder you like as long as the arrow faces the front of the engine. If you just think about it the engine is balanced so both sides must be doing the same exact thing thats why there are running mates and other such things that make the engine more balanced. Also switching the pistons around costs no extra money so i do beleieve if its 30 free hp ford would of did it on their own because the 302 is not a new engine that they wouldnt have known
LMAO change to gt40p heads if you want 30 hp way easier. The pistons come to the top of the motor deck perfectly parallel to the deck how would reversing them do anything
It's an OLD trick, and yes it's true.

You may or may not experience some piston noise on cold start up, until the engine warms up. Cylinder wear may increase as well.

Claimed power gain is anywere from 10 to 30 HP.
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