Originally Posted by Catmando (Post 3039704)

Not having water cooled exhaust can be dangerous. What are your plans to minimize the danger of fire?

Originally Posted by 999JAY (Post 3039676)

I have been thinking about this, so far I have rigged it with a 1.25" hose double clamped. I went with a large circulation pump originally because I was going to water cool the exhaust.

I decided to keep it simple for a first project and ditched the water cooled exhaust due to the work needed to pull this off.

Looks like I will have to fit a pressure dump to the stariner to keep the hoses in place.
Not sure if I will be running at speeds of 140+ but we will have to see how stable she is when in the water. I am little concerned about the torque steer on a single engine setup.
But there is only one way to find out!

Originally Posted by KNOT-RIGHT (Post 3039757)

This is a misconception in a turbine application it is actually
safer to have dry exhaust preferably stainless 321 or 430
for its heat resistance with the correct pyro wrap and fire
containment blanket suited for the temperature.
Keep it simple.

Ask the turbine boat owners who do have water cooled exhaust
what happens when the big 140lb DC electric motor fails
that operates the water flow to the exhaust.
How much does a 18inch diameter double walled stainless
exhaust pipe weigh that is 6 feet long?
Turbines don't need water so why use it.

Originally Posted by KNOT-RIGHT (Post 3039757)

This is a misconception in a turbine application it is actually
safer to have dry exhaust preferably stainless 321 or 430
for its heat resistance with the correct pyro wrap and fire
containment blanket suited for the temperature.
Keep it simple.

Ask the turbine boat owners who do have water cooled exhaust
what happens when the big 140lb DC electric motor fails
that operates the water flow to the exhaust.
How much does a 18inch diameter double walled stainless
exhaust pipe weigh that is 6 feet long?
Turbines don't need water so why use it.

Originally Posted by J Arruda (Post 3039974)

Well, to start with the pump and DC motor is 32Ibs, not 140.
The pipe is 14", not 18".
We are on on boat 37 right now of which 30 have water cooled exhaust.
Only our race boats have dry exhaust, due to the unstable water pressure at speeds over 190 Mph. Every other boat we have completed have been outfitted with wet exhaust due to the benefit of unlimited cooling water.
With regard to reliabilety. We have had two electric motor failures in over 10 years.

Originally Posted by 999JAY (Post 3039993)

Hi Dave
I am going to run a centre pod down the boat to deflect the water away from the bottom of the drop box, this s something else I will have to fabricate at a later date.

Knot-right
On your build I noticed you went with a pneumatic over hydraulic brake actuator for your free power turbine brake. There is a unit called a brakerite electric actuator that uses a simple 12v supply to activate you caliper.
Turbine Marine use these by the looks of it on there builds to simplify the braking system on gearshift.

Originally Posted by KNOT-RIGHT (Post 3039665)

What size water pickup are you going to use?
I used one inch and had so much water pressure it blew
the double clamped hose right off and began to sink the boat
at 140mph.


I ended up adding a 1- 1/4 dump with check valve right out of
the strainer.

Another note I never really have had to use the manual
circulation pumps.
Even in long no wake zones the oil temp would be below
190 degrees.

Originally Posted by Sean H (Post 3040115)

hose clamps? wouldn't a -20 or -24 be much more reliable?