Ok as I was working on getting the motor out of my parts boat for my chaparral and I had a thought.  The chaparral is equipped with thru hull exhaust and the connections are still there for the hub exhaust.  My daughter doesn't seem to be into loud things right now.  So should I hook up the thru hull or the hub exhaust?  Which would you chose? And does anyone know of an available switch gate that can switch between the two?  Thanks nathan

nathan wrote on May 8^th, 2010 at 11:41pm:

Ok as I was working on getting the motor out of my parts boat for my chaparral and I had a thought.  The chaparral is equipped with thru hull exhaust and the connections are still there for the hub exhaust.  My daughter doesn't seem to be into loud things right now.  So should I hook up the thru hull or the hub exhaust?  Which would you chose? And does anyone know of an available switch gate that can switch between the two?  Thanks nathan

I love the sound of through hulls, but I think it would get old if it were on my boat and I had to hear it all the time.  Corsa makes a system that switches between through hull and through prop, but it ain't cheap!

http://boatstoreonline.com/corsa.html

Yeah, it would definitely get old. Having a Captain's Call is an awesome way to go. I'd like to have one. But yes, they are very expensive and I don't think they should be.

It sounds like you are pretty handy, I'm sure you could take an automotive kit and make it work for your boat.

Something like this to start with:
http://www.summitracing.com/parts/SUM-670150/?rtype=10

My next boat will definitely have a Captain's Call.

I would love to have both.  but right now there is not enough money to sped on the exhaust if I want some other goodies.  I may just make my own.  nothing fancy just a mechanical gate that I can open by hand when I want to be loud.

I have the Corsa Captain's Call exhaust on my boat and I love it.

Next boat will definitely have it also.

I love the sound, but being able to turn it off is an added bonus.

My buddy had a IMCO switchable thru hull exhaust installed on his Baja runabout and it has performed well.   I believe it's a little less expensive then the Corsa system.

Is there a difference in performance between the two?

yes the thru hull offers less restriction and better horse power.  but it is a lot of noise.  its kind of like an open header hot rod.  i am thinking of doing the thru hull right now because I can always change it.

If that's the cheaper, faster way to get on the water, that sounds like the way to go. Maybe your daughter will learn to like a loud nice sounding engine.

Both connections are there so it just a decision on which will get hooked up and which get will be capped.  I am leaning toward the thru hull because I love a boat with a good sound to it.  Plus that the engine we are starting with is a 188 hp ford 302 mercrusier but when we are done it will be a little more hp.  Mainly due to parts and pieces we have left around here and the 1150 CFM holley that is a 4 corner adjustable, mechanical secondary race ready carb and a set of big heads  ;).  And the boat may end up with a hot foot to control the gas.  When it’s done I will see what my daughter says and if it’s too loud then I will cap the thru hull and connect the hub exhaust.  It’s just too bad I don't have the boss 302 heads that my grandfather had but we have the next best thing.  Should have the motor out by this weekend.

I may be a Chevy guy, but it's extremely hard to beat the sound of a Ford 302. Plus the aftermarket for them is incredible.

I would perfer to run a chevy.  Perferably my race motor but I need all the accessories around the motor and the first donor I picked up has a ford in it.  but thats ok it is easy to get hp out of a ford.

That should be enough HP to get it moving at least and that's a great first step. How heavy is that boat? Will that be enough to plane?

188 is the lowest recommended by chaparral.  when we are done the hp should be closer 300 to 350!!  right now the motor has a two barrell carb when done it will have better heads, intake, cam and a 1150 cfm 4 barrel holley carb

I think this is a great way to get started on the project. It at least gets you out there and then the 302 is a f*cking good foundation to build with. Used parts are dirt cheap, so your goals are pretty attainable.

we have built a 500 hp 302 motor for a mustang before.  the main difference in a boat motor and a car motor is thats in a boat. we are going as radical with this motor just want a good and strong motor

If you use a radical cam with a lot of valve overlap, definitely go with thru hull exhaust.  At idle, you can actually suck water through the prop into the exhaust ports.

for that reason I am only going with a cam that is factory or a little bigger but not too much.  the big power gain will come in the heads, intake and card I am going to use.  the motor is fighting to stay in the boat it is in now I broke a craftsman socket trying to get a bolt loose.  so know it is soaking in jb80 and I will try tomarrow with a new socket.  ;D

I guess it's cordless drill time! :)

Owtlaw wrote on May 14^th, 2010 at 7:50pm:

If you use a radical cam with a lot of valve overlap, definitely go with thru hull exhaust.  At idle, you can actually suck water through the prop into the exhaust ports.

As a car guy, I'd never think of that when building an engine. I wonder how many people have soaked motors because that's never occurred to them? Boats are such a different world lol

a cordless is not big enough.  if i have to use anything cordless it will be a sawsall. lol