Correct ventilation in engine compartment of runabout

Iceguy1

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Mar 13, 2016
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I am planning to re-upholster my 1985 21’ Chris Craft bowrider this winter. (350 I/O Mercruiser) I’d like to build wrap around seating on one side and a solid upholstered side panel on the other side (instead of the open storage areas that are there now). As is, there is lots of added airflow into the engine compartment through these side storage areas while underway (in addition to the vents from the outside of the boat)

So my FIRST question is... Is it ok to block this airflow from inside the cockpit with panels and seating?

I know there are lots of runabouts with engines tucked away, completely seperated from the cockpit. I just want to make sure what ever I do is safe.

2nd question... If vents alone will be sufficient ventilation, what is the correct layout? Both my vents have openings facing aft. The starboard vent has the blower and hose goes down into the bilge, under the engine. I assume the port vent should be facing forward to act as an intake. Am I correct? Is it installed incorrectly on my boat with both of them facing aft?



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Scott Danforth

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unless you spend lots of time trying to seal off the bilge, it will pull air from the gunwales no mater what you put in front of them.
 

Iceguy1

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unless you spend lots of time trying to seal off the bilge, it will pull air from the gunwales no mater what you put in front of them.
So are you saying that it would be ok to close of these openings with upholstery? (Assuming I have correct ventilation set up just using the bilge vents)
 

Scott Danforth

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there is more than just the area that you are thinking. you would have to work at making your furniture air tight. your bilge blower vent wont be enough for a motor, however the engine will get enough air everywhere else (like under the dash and along the gunwale, etc.
 

tpenfield

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Are you sure those side panel storage areas are actually open to the engine bay? It would seem that things stored in them may fall into the engine bay, if they were.

More ventilation is better, so come up with a plan that gets you the re-upholstering you want and does not suffocate the engine. To Scott's point the engine will pull air from all kinds of places, but why make it struggle?

Sound deadening may be a consideration, but not sure if the current design is noisy to begin with :unsure:
 

Rick Stephens

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Are you sure those side panel storage areas are actually open to the engine bay? It would seem that things stored in them may fall into the engine bay, if they were.

Made me laugh Ted. I'm always digging around the battery box or hydraulic pump for seldom used stuff that fell out of my side panel gunnel storage into the engine bay.
 

Iceguy1

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Mar 13, 2016
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Are you sure those side panel storage areas are actually open to the engine bay? It would seem that things stored in them may fall into the engine bay, if they were.

More ventilation is better, so come up with a plan that gets you the re-upholstering you want and does not suffocate the engine. To Scott's point the engine will pull air from all kinds of places, but why make it struggle?

Sound deadening may be a consideration, but not sure if the current design is noisy to begin with :unsure:
Not for sound deadening, just going for a sleeker more modern layout. And just like Rick said, yes my gunwale storage compartments definitely pass air through into the engine bay. Have had to fish things out of the engine bay on occasion when I find I’m missing something.

Thanks to all for the opinions. I’ll plan on incorporating some openings in the new upholstery to allow for some extra airflow into the engine bay
 

tpenfield

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Are your having the upholstery done at a shop or are you DIY? Just curious . . .
 

Iceguy1

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Are your having the upholstery done at a shop or are you DIY? Just curious . . .
Going to give it a shot myself. Have a pretty beefy all metal vintage grandma sewing machine. Been planning for years and studying with how to videos from sailrite.com. My only sewing experience is making a pair of boxers in home ec. in middle school 30 years ago, so we’ll see how it goes.

Planning on replacing most of the plywood with new marine grade plywood. Aiming for a more modern look, doing away with the 80’s stripes, piping on seams and carpet matching the accent color.

The base color of the gel coat is beige, so I’ve picked three tone beige and browns. Adding lots of polished mahogany accents to honor the Chris Craft name. Lots of improvements... I’ll be making a one piece hinged engine hatch instead of the typical 80’s three panels that lift out. Hinging all the seat cushions over storage areas. Replacing the jump seat with wrap around seating. Making the back rests of the bow seats more plush and practical. And MOST important.... lots and lots of stainless steal cup holders!

Got some pretty fancy plans with some complicated sewing involved. Wish me luck. Haha
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tpenfield

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Going to give it a shot myself. Have a pretty beefy all metal vintage grandma sewing machine. Been planning for years and studying with how to videos from sailrite.com. My only sewing experience is making a pair of boxers in home ec. in middle school 30 years ago, so we’ll see how it goes.
. . .
Got some pretty fancy plans with some complicated sewing involved. Wish me luck. Haha
There are a bunch of us (myself included) who have done upholstery on our boats. lowlysubaruguy, resurector_, Woodonglass, sphelps, bruceb58, corjen1 . . . to name a few :D

Study up on sewing machines . . . to do a really good job, you will want/need a 'walking foot' / 'needle feed' (aka compound feed) machine. Regular sewing machines just don't cut it for upholstery work. Look for brands like Consew, Juki, Highlead, Chandler/Adler. Sailrite has a couple of machines at the top of their line ( '111' and 'Fabricator') that would be OK. I got a used Consew 206RB-4 for $500 . . . worth every penny. Also, you will want a servo motor rather than the older style clutch motor and possibly some 'gear reduction' on the machine.

I did the upholstery and canvas on my 33 footer over last winter. I got most of my stuff from Sailrite . . . they seem to have good stuff at decent prices.

Expect to find some rotted base material (boards) when you take the seats and sides apart. I had to re-fabricate about 1/2 of the seat frames on my boat.

I suggest you start a thread about the upholstery when you get going on it. You'll get lots of help/advice along the way.
 

alyssagrey93

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Oct 23, 2020
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Huh this looks really good. My hubby wants to re-upholster his boat too. But we are going all white
 

JackBronson

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Regarding your vents I assume you have a blower in your engine compartment. On my prior boat, an '87 Starcraft bowrider, the blower was connected to an intake and an exhaust hose.
The vent on the intake hose side should be facing forward so as the boat is moving forward air is being forced into the engine compartment. The exhaust hose side should be pointing aft.
I had an overheat problem on the Starcraft that had a pretty tight engine compartment. One thing I discovered was that someone had put the vents on backwards. Reversing them helped the issue.
 

alyssagrey93

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Oct 23, 2020
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I have actually been in the process of restoring my own boat and it has been a very fun journey. The only thing that I have left to do is get a new upholstery. I have found the necessary leather and I have talked with a friend who has something like an industrial size sewing machine that would be ale to do the outlines that I needed. I have asked my friend who is a seamstress if she knows how to do this and she said that she never did it before but she is sure that she can manage. She also said she found a really good website with a lot of tips when it comes to sewing. I'll link it below. I am still waiting for the prototype thingies but I think that it will look great. Wish me luck. I will post pics of the finished results later I promise :p




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Yo guys can check it here: http://sewingmachinebuffs.com/how-to-thread-a-singer-sewing-machine/
 
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