what' up with these CATs - Page 3

anthony · 10-02-2008, 05:33 PM

Quote:

Originally Posted by Agitated88

I don't mean to hijack this thread, but JD's comment brought to mind a question I've had for a while. I have noticed on a few...VERY few boats the exhaust vents out the side vs. the stern. Is there a reason this isn't done more often?? Is it due to overall structural integrity of the hull or stringers, does it cause engine performance issues by creating extra bends in the pipe, or maybe it reduces floor space for box's, etc...just wondering. Obviously it would solve the sooting transom problem, and I've heard/read somewhere that this setup is even quieter. Thanks ya'll...good thread!!

It doesn't cure sooting of the transom because there is still the same baffling effect. Got a buddy that has a Carolina Classic that exhausts out the side and it still soots the transom. Any boat is going to soot the transom to some degree...I stopped waxing my transom because the soot seemed to stick to a waxed transom better. I use Roll Off on the transom after every trip and use Collinite Fiberglass Cleaner every couple of months to really get it good.

costaricasportfishing · 10-11-2008, 08:09 PM

I have 3126 CAT 420hp but was having the same problem. Cleaning the aftercooler and turbo seems to have fixed it for me.

seapower · 10-11-2008, 08:49 PM

Aggitated88, this is just my opinion. I'd stay away from them. They are OK if your engine is always running. Most boats when you take away power will lay side-to the sea unless anchored. If you lay side-to with your engine shut down, exhaust side to the swell and you pitch enough, the exhaust water can roll down the exhaust hose, through your mixing elbow and into your exhaust manifold. When your engine is shut down some exhaust valves will be either open or in some state of open. This will allow water into your cylinders. This will in turn give you a hydraulic lock when you try to re-start. While cranking the piston will travel up, the exhaust valve will close and you can't compress a liquid. This equals evacuating the water at least or a rod through the side of the block at worst (sometimes called "venting" the block). Either way no good. Not many boats will lay stern-to.Frank

Parker · 11-18-2008, 10:08 PM

I have 3208's 1990's and what I did find was that Purple power takes it right off. And believe me I tried everything. Get it in Walmartlike $11. for 2 gallons. Such a deal

10-11-2008, 08:49 PM	#23
seapower Sit down Shut up And fish Join Date: Feb 2008 Location: Bath,NC Posts: 495 Credits: 2,161.8 Boat: 25' DownEaster Home Port: Bath, NC Best Catch: My wife Occupation: marine diesel service owner	Side exit exhuast, Aggitated88, this is just my opinion. I'd stay away from them. They are OK if your engine is always running. Most boats when you take away power will lay side-to the sea unless anchored. If you lay side-to with your engine shut down, exhaust side to the swell and you pitch enough, the exhaust water can roll down the exhaust hose, through your mixing elbow and into your exhaust manifold. When your engine is shut down some exhaust valves will be either open or in some state of open. This will allow water into your cylinders. This will in turn give you a hydraulic lock when you try to re-start. While cranking the piston will travel up, the exhaust valve will close and you can't compress a liquid. This equals evacuating the water at least or a rod through the side of the block at worst (sometimes called "venting" the block). Either way no good. Not many boats will lay stern-to.Frank

11-18-2008, 10:08 PM	#24
Parker #1 Lurker Join Date: Nov 2008 Posts: 2 Credits: 143.2	Same Problem I have 3208's 1990's and what I did find was that Purple power takes it right off. And believe me I tried everything. Get it in Walmartlike $11. for 2 gallons. Such a deal

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10-11-2008, 08:09 PM	#22
costaricasportfishing Crab mustard is good Join Date: Sep 2006 Location: Jaco, Costa Rica,by way of Rodanthe NC Posts: 600 Credits: 1,808.7 Boat: Miss Behav'in Home Port: Los Suenos, Costa Rica Best Catch: Grand Slam, Blue(400+),Black(500+),4 Sails Occupation: Sportfishing Capt	I have 3126 CAT 420hp but was having the same problem. Cleaning the aftercooler and turbo seems to have fixed it for me.