ford exhaust

[biggercb]

Hello, I have a Mercruiser 888 outdrive with a 188hp 302 engine. I would like to get a little more power out of this motor. I was looking for a less expensive alterantive to the 1500-2000 dollar exhaust systems (most of which dont even list a part number for a SBF). My question is, if I leave the engine compartment open, can I run upside down automotive headers? Will this create any problems? Thanks for any advice.

[Squirtin Thunder]

What do you have now ??? My father ran Nicson manifolds and it would turn 5500RPM and real quick !!!

[LakesOnly]

Does this engine have a 2-bbl carburetor? If so, I would suggest a mild-mannered aluminum intake manifold and a small 4-bbl carburetor. Let the little sucker breathe.
LO

[biggercb]

Right now I have the stock cast iron manifolds. I have the stock two barrel holley carb on there also. Just finished freshening up the heads (which were 351 heads and the firing order is also 351, dont know if that is stock or not). An aluminum intake manifold is on my christmas list. The first carb that I plan on trying is a predator carb. Buddy of mine slapped it on his 304 v8 cj7 and the way it made the jeep run makes me think it will be an excellent boat carb, it wants to run wfo. Talking about letting it breathe, thats why I was looking at the exhaust because they way they come together in a y-pipe and go out through the bottom sure looks very restrictive. Since Im not real worried about making it louder (its pretty quiet now) I was thinking that headers would be a nice compliment to the bigger intake and much bigger carb. Let me know what you all think.
Thanks,
Clay

[biggercb]

Will the heat from automotive exhaust be a fire hazzard? Are the guys who run their exhaust dry have any input?

[SoggyJet]

.....My question is, if I leave the engine compartment open, can I run upside down automotive headers? Will this create any problems? Thanks for any advice.
My answer would be no you should not do it. The uncooled pipes create a safety hazard due to potential for burns and increase the risk of fire. Dry headers are (should) only used for racing and are not coast guard approved.
To help open up the exhaust you could change over to the newer style center riser exhaust manifolds and convert it to thru transom exhaust. As you suspect, sending the exhaust out the outdrive is a significant exhaust restriction. The center riser manifolds are available in cast iron (same material as your original Merc manifolds) from Osco and other aftermarket vendors at an almost reasonable cost.
Between going to the thru transom exhaust and the 4 bbl aluminum intake you should wake it up pretty good. A bigger cam would help too.
You need to open up both the intake and the exhaust, as the engine will only breathe as well as the worst bottleneck.
Doug