530 Engine room venting

[aussie530carver]

Hi all i have a 1999 Carver 530 and on a long run on the Easter weekend i went down to check on the engines whilst under way and noticed it was as hot as hell in the engine room.... surely the engines must be also breathing in this hot air..
So i have noticed on some later 530s they have vents right down near the Gensets but nowhere near the engines.
Has anyone added extra venting on the hull into the engine room. I have looked at this and before cutting into the hull would like to see how others have got around this issue... i know i can constantly run the bilge blowers but there must be a better answer... maybe some nice lazer cut vents on the outside of the hull.. but what and where would be the best way to drill or cut holes into the hull...Cheers Paul

[Alaska 530 Voyager]

Hi Paul,

I had a 99 530 for almost 10 years. I'm not positive on this, but I believe Carver added vents the next year or so, to the sides of our 530's. Take a look at some 2000 or newer 530's and see what you think... You can see the added vents on their sides in various pictures.. Maybe you could copy the vent system on the later models... good luck, Dave.

[Alaska 530 Voyager]

Sorry Paul, I just realized I didn't read your post entirely the first time and already proposed this...

[km1125]

On a diesel engine, the air temp that the engine breathes is not really a big deal. That intake air gets compressed a lot which heats it plenty. Much of that excess heat gets removed in the aftercooler before the air gets stuffed into the cylinder.

It would be interesting to run some calculations to see what difference it could make, but I'll bet in the end it's "none", as the wastegate and aftercooler ultimately determine how much air is in the cylinder.

[bud37]

Those big engines are constantly changing huge amounts of air in the compartment....into the engine then out the exhaust.....I doubt the air would have much chance to heat up enough in the process to be a detriment.

What you may feel many times is radiant heat from all the equipment....are all the insulation blankets/pieces in place ?

They may have added the larger/extra vents to cool the compartment down after shutdown perhaps...just a guess on my part, but if you don't have clouds of black smoke and power issues the engines are most likely getting the air they require for proper combustion.

Consider the placement of extra vents as to rough seas conditions.

[Viper]

"Hot as hell" is subjective. Engine rooms get hot. The ambient air in the engine compartment is very important. How much hotter than ambient air is the question. The differential limit is lower than you'd think. Relatively speaking, the cooler the better in both gas and especially diesel applications for best performance.

Intake and exhaust fans/blowers are sometimes used to remedy hot engine rooms that would otherwise affect performance. Don't confuse these with bilge blowers, they're not the same. They move way more volume and are usually mounted higher up where the hotter air is. Some have both exhaust and intake blowers while others have only exhaust. They're meant to help bring in cooler air to improve combustion. They work much better than increasing the size of hull venting which is usually designed to minimum spec by the boat manufacturer. The more venting the better of course but you have to take other things into consideration such as wash while underway, aesthetics, etc. Most air moving systems will have delays on them so they run for several minutes after engine shut down to help cool the compartment faster.

You'll know you're not getting enough air or it's too hot if you take her for a wide open run with the genny operating and watch the tachs, they should remain steady once you're at top speed. If they start dropping off a bit, chances are you're not getting enough air or the air is too hot for optimal performance. If the tachs start to fall off, open the engine hatches and see if that makes a difference. If it does, you have your answer.