Through-hull exhaust?

[scottveazie]

Had an interesting idea, I know this was done on v8 OMC applications, but I was thinking, could these be used on my Buick V-6? I don't see why they couldn't, maybe a performance boost? Also...the coolness of the sound could play a factor. Just an idea....

http://portland.craigslist.org/clk/boa/1792062090.html

~Scott

[Peter_Crowl]

Had an interesting idea, I know this was done on v8 OMC applications, but I was thinking, could these be used on my Buick V-6? I don't see why they couldn't, maybe a performance boost? Also...the coolness of the sound could play a factor. Just an idea....

http://portland.craigslist.org/clk/boa/1792062090.html

~Scott

Hmmmmm...I dunno...you'd have to cap off the exhaust ports on the intermediate wouldn't you?
As for the sound...I'm not a fan of loud - but it certainly would be.

I guess you'd have to get them and try it!

[JimAndros]

I don't think you would gain anything but noise. The exhaust passages are the same size as the ones on a V8. If the V8 can push a larger volume of exhaust thru them, the 6 banger should breath with ease.

I think the only factory thru-hull exhaust was a few years in the '74 to '77 time frame. It was an upgrade that raised the HP from 235 to 245 if I remember correctly.

[bchowk]

Jim and Peter are all over it... as usual....Like you, I have wondered about though hull exhaust as well, but then start thinking about how big that exhaust port on the intermediat really is, then how much gas can those exhaust manufold REALLY move anyway...then break out in cold sweats thinking about cutting the holes in the hull.....So I guess I'm no help, huh, would love to see it done out of curiosity, but not on MY boat

I bought a set of replacement exhaust manifold for mine (my origionals had some holes and were crumbling at the head flanges). The replacements were just a little bit different from the origionals in the way the cooling water exits, same idea (they even look basically the same) but wonder if it gives some sort of venturie effect drawing hot gas out...blah blah blah...i'm not sure if it was just a good repair move or if they flow better than origional but can tell you getting them on there really helped.....however I did notice that they are not really well matched to the exhaust port on the head...since we are talking about improving breathing...I've been telling myself that one of these days I'm gonna take the exhaust manifolds of and gasket match them, smooth the runners a little, maybe even get them ceramic coated (mostly for looks, but might help performance)

cheers,
B.C.