1987 5.7 omc exhaust manifold/risers

[shhh]

i have a 87 omc with a chevy350. I am looking to replace the old log style exhaust manifold with new center rise ones. My question is has anyone done this before. I found a site http://www.michiganmotorz.com/generic-exhaust-manifold-package-years-p-249.html that has them but the problem is they said they fit all 5.7 engines. I know this might sound stupid but i been looking online for this package for a coouple of days now and all the ones i looked at they all look the same but with different risers. Does anyone know if there is any differents or r they the same. If so what is the differents? Does anyone know where else i could find them at? Im trying to do a thru hull exhaust but i need the risers to come straight out not point downward like they are now. Could i just make my own risers. Thanks -Anthony

 

[Bondo]

Re: 1987 5.7 omc exhaust manifold/risers

i have a 87 omc with a chevy350. I am looking to replace the old log style exhaust manifold with new center rise ones. My question is has anyone done this before. I found a site http://www.michiganmotorz.com/generic-exhaust-manifold-package-years-p-249.html that has them but the problem is they said they fit all 5.7 engines. I know this might sound stupid but i been looking online for this package for a coouple of days now and all the ones i looked at they all look the same but with different risers. Does anyone know if there is any differents or r they the same. If so what is the differents? Does anyone know where else i could find them at? Im trying to do a thru hull exhaust but i need the risers to come straight out not point downward like they are now. Could i just make my own risers. Thanks -Anthony

Ayuh,.... They'll all fit a 350, but some bolt holes will be different, for the accessories, from different manufacturers,....

Other than the various bolt holes movin' about, the risers are different angles, 'n diameters...

'n,... No, I really doubt you could craft a set of risers...

 

[Nivekt]

Re: 1987 5.7 omc exhaust manifold/risers

So, is the sole purpose for wanting to do the swap to center risers to accommodate a through hull exhaust? What about using the log style and just crafting your own elbow tubes to come from the outlet of the risers through the transom? Would that work Bond-o?

 

[Bondo]

Re: 1987 5.7 omc exhaust manifold/risers

So, is the sole purpose for wanting to do the swap to center risers to accommodate a through hull exhaust? What about using the log style and just crafting your own elbow tubes to come from the outlet of the risers through the transom? Would that work Bond-o?

Ayuh,... Generally speakin', log manifold risers point straight down,... Not conducive to thru-hulls...

If ya could bolt on angled risers, there's no space to the transom to plumb 'em...

Btw,... Thru-hulls Ain't what they're cracked up to be,...

I've Hated the fact I put 'em in years ago,...
until I sunk the tips underwater, the rumblin' drove ya NUTS....

Now, it's quite at idle, but Roars at anything over displacement speeds...

I Won't do thru-hulls again,..... Ever.... least not on a fishin' boat....

 

[Nivekt]

Re: 1987 5.7 omc exhaust manifold/risers

Function over form, I always say.

 

[HT32BSX115]

Re: 1987 5.7 omc exhaust manifold/risers

Function over form, I always say.

Yeah. I had Corsa "Capts Call" (exhaust diverter valves) on my Four Winns Liberator when I had the OMC 460 installed. SO I could switch anytime I wanted to go "Thru-hull" it was just a flip of the switch....... EVERYBODY ELSE HATED IT!!

If there was ANYONE else in the boat, they would quickly say "TURN IT OFF TURN IT OFF!!!!!!!"





When I swapped out the engine and drive for the Mercruiser engine and drive, I left the Capts Call on the floor. It seems to work better there!!