engine room blower

[jamie langstone]

Whats the forums thoughts on engine room blowers i.e I have a diesel engine in a searay 240 DA and do i need to have the the blower on at all times to get rid of the fumes or just before starting the engine and for a few minutes after the engine has started as when i am going along the air will be circulating through the air vents on the side of the boat.

 

[markspark7]

Whats the forums thoughts on engine room blowers i.e I have a diesel engine in a searay 240 DA and do i need to have the the blower on at all times to get rid of the fumes or just before starting the engine and for a few minutes after the engine has started as when i am going along the air will be circulating through the air vents on the side of the boat.

I have a fan running when ever the engine is. Carbon monoxides a silent killer. not worth the risk in my opinion

 

[Whopper]

+1...also helps to keep engine smells away.

 

[Momac]

My previous similar size/type of boat had a 170bhp diesel engine. The engine pumps far more air than any little 12 volt fan.

The fan is to extract any gas from the engine bay and should be run 4 minutes before the engine is started. You can leave it on after that but it will have no particular benefit as the air will be coming into the engine bay due to the demand from the engine.

There may be a benefit to the fan running when the engine is stopped or if you need engine access when the engine is hot. But on a small singled engine boat the engine hatch is relatively large so plenty of scope to allow heat and to rise when the engine hatch is opened.

Fans are more important with petrol engines.

I am sure others may disagree.

 

[GrahamHR]

My previous similar size/type of boat had a 170bhp diesel engine. The engine pumps far more air than any little 12 volt fan.

The fan is to extract any gas from the engine bay and should be run 4 minutes before the engine is started. You can leave it on after that but it will have no particular benefit as the air will be coming into the engine bay due to the demand from the engine.

There may be a benefit to the fan running when the engine is stopped or if you need engine access when the engine is hot. But on a small singled engine boat the engine hatch is relatively large so plenty of scope to allow heat and to rise when the engine hatch is opened.

Fans are more important with petrol engines.

I am sure others may disagree.

Not wishing to disagree for the sake of disagreeing, but I disagree ! I zealously used the blowers on my previous petrol engined boats ( 4+ minutes prior to stat up, after refuelling etc to get rid of any potential flammable/ explosuve vapours). Common sense, it would have been very foolhardy not to I don't see the need on my current diesel engined boat though. The dealer on handover told us we should, to make sure the air in the engine compartment was cool. ( his advice on the use of trim tabs was also a bit odd, compared to my experience of using trim tabs for 9+ years !), The engine bay is large with plenty of outlets for hot air to escape (upwards). The boat has no gas supply, any hydrogen from the batteries would diffuse naturally out of the vents Out of habit I would still switch it on, but I suspect the blower is there as the same boat has petrol engined versions ! Strange they fitted kill cords to all the petrol powered versions, but not to the faster diesel version !

 

[jimmy_the_builder]

Whats the forums thoughts on engine room blowers i.e I have a diesel engine in a searay 240 DA and do i need to have the the blower on at all times to get rid of the fumes or just before starting the engine and for a few minutes after the engine has started as when i am going along the air will be circulating through the air vents on the side of the boat.

Is it definitely an extractor fan? My twin-diesel installation has 6no engine room fans - which pump air _into_ the engine room, not out of it.

 

[SEARANGER ANCASTER]

Yes, it should be run for a minute or so before starting engine and thereafter. Even more important if you have a battery charger running as fumes from battery charger can ignite with a spark and a VERY loud bang ( ask me how I know !!!! , (forklift not boat thankfully). My old boat had a seperate fan on the battery cover but my current one doesnt so the fumes can gather in the engine bay.

 

[Chris_d]

Was the boat orignaly petrol? not many Searay 240DA's with diesels about, the extractor fan is mainly for clearing fumes (Petrol usually) before starting, poinless leaving it on as it will just be trying to compete with the engine to suck air!

 

[rafiki_]

Like Jimmy, my fans pump air in rather than extracting, and should be functioning while the engines are running.

 

[Rickard]

Not needed with Diesel engines

 

[Portofino]

Not needed with Diesel engines

Depends -maybe ---
With petrol boats -blow out -you suppose to run them a few minutes before start up -to remove potential petrol fumes .
Assuming the eletric componants in the fan ( s) are less likely to cause a spark then the engine ignition apparatus ? -probably so otherwise piontless ( just thinking aloud ) .

With Small medium diesels in a correct installation regarding adequate air vents -not needed agree .
The Air vents often design wise under estimated . Eg a boat hull designed for say 3.7 L Kad 44 ,s ventilation ,through developement ends up at 5.5L with Superchargers ( as well as st turbos ) then unless original moulds are changed -unlikely 'then that's why the fans pump air in !

Moving on to really big stuff say MTU 4000 series in a Managusta 120 then its more to do with cooling at low revs or tickover to cool the blocks -cos of " heatsoak "
These will have fans that both pump air in and suck out -not for engines but for to keep E room temp down .
At running speed the engines suck ( with an adequate designed intake ) enought air both to feed themselves ans cool the E room .

So really there are 3 situations all different for E room blowers

Complicating matters worse now factor in your emergancy fire extinguisher
Correctly done it should shut the E room vents ,as well as close tank fuel cocks, and stop engines ,and fire of the gas canister .
Do you really want air being pumped IN or your gas being pumped out ?
Of course it all may be interlocked together ? Or is it ?

 

[BartW]

in a searay 240 with diesel engines, you don't need to run engineroom fans,
I assume they are there because most seasray's of that size have petrol engines.

I have a 26ft boat with 2 x 190hp diesel engine, no fans
never had an issue with it on that point.

 

[Momac]

Engine bay fans are certainly fitted on some diesel engined boats even when the vast majority made had diesel engines fitted.
But it may be significant to note ....
The boats I am thinking of have batteries in boxes located in the engine bay
Lead acid batteries , if defective, can produce explosive hydrogen sulfide gas which is heavier than air.

 

[ip485]

Slightly resurrecting this thread, I have a Yanmar turbo 110HP diesel. In our cold climate the engine room stays reasonably cool even after hours at full chat, but I am a little worried that in a tropical climate the engine room temperatures may get a little high. Of course I have asked the manufacturers who helpfully say a blower is almost certainly not necessary but they have fitted a blower on some later boats.

This thred was interesting because it talked in terms of blwoing air in as well as out if I have understood. Now blowing air in is obvioulsy a great deal easier from am installation point of view (I think anyway). I am guess ing the disadvantage is the hot air is effectively squeezed out into the boat one way or another (or I do have the steering binacle immediately above the engine room) and which has a large caity connecting it directly to the engine room and could be fitted with a vent). Any thoughts?

 

[baylabayla3288]

On my previous Fairline the fans were on whenever the engines were running. Only way to switch off was to remove the fuse. The reason for this was to keep the er cooler. It had twin diesels.

 

[[164147]]

I have a bilge / engine room blower - it's a boat that only diesel engines were ever fitted to.

 

[Assassin]

On some craft its part of the design, especially where they have the option of petrol or diesel power options.