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View Full Version : 81 c 18 exhaust ?


lee
06-25-2008, 06:08 PM
when my boat sits in the water the bottom half of the exhaust tips and flaps sit in the water is that common have a 383 and alpha 1
MOP
06-25-2008, 07:57 PM
Need to know more, are your outlets set low on the transom? Or is the boat sitting at a very transom low attitude?
lee
06-25-2008, 10:25 PM
Need to know more, are your outlets set low on the transom? Or is the boat sitting at a very transom low attitude?
chicago my boat was set up with a 350 chevy and a alpha 1 drive exhaust is factory set is a 1981 classic 18
jstokes8407
06-26-2008, 08:15 PM
I have a 86 18 c and does the same thing it's normal
MOP
06-26-2008, 10:07 PM
For safety sake you should both run Salisbury flaps, you will be glad you did if someone stuffs a good roller up your butt.
MOP
06-26-2008, 10:08 PM
Ok tell me you both do!!!!
maddad
06-28-2008, 09:44 AM
Heh, heh heh, he said "roller up your butt", heh heh...
MOP
06-28-2008, 11:18 AM
One must be crafty to slip by the Censors! They might kick you in your Kockpit!!!!!
Lenny
06-28-2008, 01:14 PM
I do NOT think this is normal. The X-dimension (at 14 1/2") and a small block Chevy (24 1/2" apart center to center) WILL put the tips at about 2 1/4" BELOW the rubrail to the center of a 4" hole. As these two pics point out, if the exhaust tips were half submerged either the bow would be pointing to the MOON :eek: or the hull would be 5600 pounds instead of 2800.

I think you have some "other" exhaust manifolds on there that drop the riser lower than what we see nowadays. As you can see on my X-18 (new motor and $hit going in) that the SSM manifolds (same as stock Merc) the tips are up high, so that I will have to have the ring machined to get under the rub rail on these SSM 4" angle tips. The LE 18 (black one) actually has them cut into the rubrail flange for clearance but they have a 5" outside diameter. (Corsa)

As you can see, if these were half submerged it would be a little bit "odd" .
BigGrizzly
06-29-2008, 09:35 AM
Lenny, my 16 is original and exhaust sit low. the Corsican did the same befor I put on 4 inch hedders now it is even lower. Any way flaps are necessary. My Criterion has internal ones and are way cool even if you can't see them.