wiseco piston port side or starboard side

[tvpear12]

Hi, and how are you all? This is my first rebuild and as you all know lots of money here so i dont want to mess up. i bought new wiseco pistons for my 1989 evinrude 90 horse v-4 crossflow.The wiseco instruction paper that is in my piston box says to look for a p or s on the dome of the piston for port or starboard side.my piston #3173p2 all 4 of my pistons have the same number. my question is, are wiseco pistons offset at the pin location? should i have 2 piston numbers3173p2 and 2 piston numbers 3173s2? please help it almost looks like i have 4 port side pistons. any help would be most app.

 

[Hotrods]

Re: wiseco piston port side or starboard side

Welcome to iboats pear<br /><br />the slop goes towards the exhaust ports..all should face in. I hope this helps. And I hope you are using a manual.<br /><br />

 

[tvpear12]

Re: wiseco piston port side or starboard side

Thanks hot rod but my manual says look for a p in the part number for port side and a s in the part number for the atarboard side and all 4 of my pistons have a p in the part number.I know how they go in the block but are the pistons offset at the pin location causing me to need 2 of one number and 2 of another number.

 

[Hotrods]

Re: wiseco piston port side or starboard side

An expert should be along any minute.. lets see..

 

[Hotrods]

Re: wiseco piston port side or starboard side

Im showing that pertains to looper engines.

 

[tvpear12]

Re: wiseco piston port side or starboard side

my manual says v-4 and v-6 but most importantley it says this in the instructions that are in my wiseco piston box. I think if these are not offset at the piston pin it would not matter but as you know, it can be offset to where the naked eye cant see. if the pin location is dead center, i would think it does not matter. but i dont know for sure and have a grand tied up in this rebuild.

 

[Hotrods]

Re: wiseco piston port side or starboard side

You are "for sure" in the right place. I spent the same on mine just completed it. these guys here are great!!! search "sticky rings". alot i learned there.. give it some time someone will have your answer.

 

[P.V.]

Re: wiseco piston port side or starboard side

Looper motors have pistons that are "specific" to the port or stbr side. Cross-flow pistons are not! Look at the picture above, it is a cross-flow and has the "deflector" offset to the intake. This "deflector" takes the incoming air-fuel mixture and moves it "upward" as it just enters the combustion chamber. The exhust side is more flat and allows a quick exit of exhust gases after they're burn'd.

 

[Walker]

Re: wiseco piston port side or starboard side

Do your pistons look like the ones in the picture or are they flat on top. If they are like the picture then they can go on either side, just orient them like the picture. There is a small hole in the connecting rod that must face up when installed.

 

[tvpear12]

Re: wiseco piston port side or starboard side

hotrod,pv, and walker you guys are the best. now i can build my heart out. thank you guys a billion. wish i could say more, but you guys know your stuff. and thanks iboats for all your pros on here.

 

[Hotrods]

Re: wiseco piston port side or starboard side

Glad to hear you got it figured out.. lol And im not a pro. just a reader...I can honestly say ive only read 2 books in my life time. 1 Moby **** and 2 about 687 pages of 2 rude repair manuals...LOL And I liked the manuals better/..look i can't spell out the title of Moby---->younowhat

 

[Dhadley]

Re: wiseco piston port side or starboard side

The guys are right. Crossflow pistons dont take sides. They're a very easy going bunch and dont care where they live as long as they're facing each other like in the pic. <br /><br />Looper pistons are a very independent lot. They're so odd about where they live that if you try to put them in the wrong neighborhood they will revolt. <br /><br />There is no S in the 3173 series so you're good to go.<br /><br />Good luck!