1986 4.3L same as 1991 4.3L????????

[customcar2boat]

just wondering if these are the same motors and ccan be swapped? thanks guys

 

[Lark40]

Re: 1986 4.3L same as 1991 4.3L????????

Do you have a Merc or an OMC?<br /><br />Basically, a 1991 4.3 Cobra engine should bolt to a 1986 Cobra outdrive.

 

[customcar2boat]

Re: 1986 4.3L same as 1991 4.3L????????

the 91 is a 4.3L Merc and the engine i want to replace it with is an 86 chevy 4.3L(out of a van)

 

[Bondo]

Re: 1986 4.3L same as 1991 4.3L????????

I'm not sure what year Chevy came out with the 2nd Gen 4.3... You'll see the difference in the timing cover(extra hump on the top, for the 3rd shaft).... Either way, It Shouldn't interfere with what you're doing.... I Know the 86 is a 2 shaft motor(crank + cam).... The accessories Should bolt right on anyway.....

 

[jee70611]

Re: 1986 4.3L same as 1991 4.3L????????

If it is compatible, you should try and make sure you use marine head gaskets(stainless steel I think). Also, DO NOT I REPEAT DO NOT use ANY of the electical system or fuel system parts from the engine out of the van. Re-use the marine grade starter, alternator, distributor, carburetor, fuel pump, and any other electrical or fuel system components from the engine originally in the boat. You don't want any explosions. Also, change the freeze plugs and replace them with brass ones. The cam may also need to be changed out. Someone else should know what to do about the cam because I'm not too sure what specs would be best. You may be able to use the one out of the old engine. Good Luck!

 

[customcar2boat]

Re: 1986 4.3L same as 1991 4.3L????????

hey guys. . .started tearing into these motors. . are we sure these are swappable. . They dont look the same to me. . Maybe I am just paranoid. . or maybe the van engine still has too much SH*T on it still. . van is 1986 rebuilt 4.3L and boat is 1991 merc 4.3L. Any help thanks

 

[Bondo]

Re: 1986 4.3L same as 1991 4.3L????????

Just What do you See that's Different ??????

 

[chris in va]

Re: 1986 4.3L same as 1991 4.3L????????

Don't know about the issue on boats, but the '86 4.3 is different from the '91 4.3 in the Astro vans.

 

[akriverrat]

Re: 1986 4.3L same as 1991 4.3L????????

91 probably vortec. non vortec manifolds wont work. intake and exhaust.

 

[Bondo]

Re: 1986 4.3L same as 1991 4.3L????????

Vortec didn't appear till the Late 90s.....<br />I ask again...<br />Just What do you See that's Different ??????

 

[customcar2boat]

Re: 1986 4.3L same as 1991 4.3L????????

well, now that I have taken more of it apart, the only major things I have noticed was a bunch of extra sensors and the intake has a different set of mounts for the water pump and has a vacuum pump or something on it. . I havent decided to use it just yet. . while i have the old out i am going to tear it down and have it checked. . see if it is salvagable before i waste my new engine. . keep ya posted. . long weekend of work but going in the right direction

 

[Bondo]

Re: 1986 4.3L same as 1991 4.3L????????

I Think, Once you get down to the long block, They'll be the same....