Engine room air intake blower replacement 2001 34 convertable

Since you are monitoring temps, roll the dice, see what you get. You can always remove it. I would rely on the heat probe closest to the engine air intake.

https://www.lowes.com/pd/AcuRite-Digital-Wireless-Indoor-Outdoor-White-Thermometer/50425270

My cheap solution to engine room temp monitoring, I realize it is not exact but I figured it would let me know if it was above 120 or not.

I wouldn't roll the dice on my "iron".... Start cutting engineered compartment air flow, you'd better be down there with an infrared heat sensor monitoring all your engine surfaces. That little "sears" temp gauge ain't gonna tell you nuthin' but the temperature around it. You could have a nice comfortable 125 degree forward while the back of your your exhaust manifolds and mixer are charring their paint.

This started with replacing an exhaust fan - now we are reducing air flow? Hmmmm.

I am not the OP,
Different question but same topic, sort of.
I probably should have started another thread.
I do not have fans , only large vents that allow quite a bit of the engine room noise to enter the cockpit.

You're noise is not coming from the air vents. Your engines are sucking air in through the vents when running at cruise and keeping the noise in. The noise is coming from the deck itself directly under your feet and the hatch seal of that deck, as well as the exhaust. I did a lot of this testing with Cabo back in the day. Ironically, the new Cabo 41' with the Volvo's are super quiet as far as engine noise goes, but the exhaust itself is noisy and you hear that at the helm, BUT it's clearly a different sound and totally different than the earlier 40's with man's or cats.

J, Yes there is a lot of turbo and engine noise coming out of the vents, easy to hear it while engines are running. The vents are quite large I am sure there was an elaborate set attached at one time. There are the " boxes " behind the vents. They are open on 2 sides.
I have moved the remote temp sensors around in the engine room and my temps seem to be fine.
I may experiment with a couple of simple ideas , if I find a simple idea that helps I will share it.

Start with applying quality acoustical material? If you can find the material that had a thin lead sheet in the middle those work very well. Start with the sides of two sides of the vents as you describe and any other surface that could transmit the sound wave via vibration to the cockpit. Not a fan of reducing that air flow. You have no outboard hull vents? Diesels?

As an experiment, you can put several layers of moving blankets from China Freight (Harbor Freight) on the helm deck floor and run the boat at cruise to experiment. From what I've found, A lot of noise come from the exhaust due to the flat transoms on SF and the 3 sided shape of the helm window area and tends to suck the noise back (station wagon effect).

The 41' Cabo is almost erie in this situation, if you've run a lot of the old ones. At cruise, you hear almost zero engine noise from the engine room. The Volvo's are very very quiet (and really smooth,fuel efficient, and fast engines in that boat, REALLY good match), but you hear the exhaust from the transom clear as day, like driving a sportscar with loud exhaust.

Did Hatteras add a Cockpit engine room intake/exhaust vent to the Cabo 41 Express? They typically have them on their SF’s.

I never paid any attention, but think so.

Capt J- "As an experiment, you can put several layers of moving blankets from China Freight (Harbor Freight) on the helm deck floor and run the boat at cruise to experiment. From what I've found, A lot of noise come from the exhaust due to the flat transoms on SF and the 3 sided shape of the helm window area and tends to suck the noise back (station wagon effect)."

Why? I already told you that I am addressing the noise coming from the vents. My deck is already insulated with Aqua Traction.

Thanks, I will try a few quick experiments and get back to everyone.

Sorry for repeating myself, try to absorb that noise before it gets to the vents with good acoustical materials made for that purpose. Placement is also important so I've read. There are a number of good articles on the internet about attenuating noise.

Good luck and let us know ....

How is the gasket where the hinged deck meets the deck?

The gasket was crappy, fixed that. I also made a huge difference.