Flame Arrestor Connections

[pbv]

In doing some cleaning up around engines on my 2001 SeaRay 280 Sundancer with twin 4.3 EFIs I noticed that there was only one vent hose connected to the flame arrester. The other vent hose from the valve cover had a smaller diamator hose that was not connected to anything. This was the case on both engines. The arrestors do have a second input for hose two. Any feed back on the proper hose connections would be appreciated. I would also like to know if an aftermarket flame arrestor would give any benefit to engine performance. I was looking at the Holley. It's stainless steel and has a larger rise. Thanks all.

 

[rodbolt]

Re: Flame Arrestor Connections

can ya tell use who marinized the engines ?

 

[DHPMARINE]

Re: Flame Arrestor Connections

Good question rodbolt.If the boat was older I'd assume Mercruiser.But I don't know if that still holds true.I think Merc owned them.They even provided those white outdrives.<br /><br />DHP

 

[pbv]

Re: Flame Arrestor Connections

I would have no idea. I bought the boat used about a year ago. How would I find out who marinized the engines?

 

[tommays]

Re: Flame Arrestor Connections

it should say merc on the motor covers somewere searay likes to keep it in the brunswick family so unless there not orginal ?? merc it should be<br /><br /><br />tommays

 

[pbv]

Re: Flame Arrestor Connections

It does say merc on the covers. why the second hose not conected?

 

[trog100]

Re: Flame Arrestor Connections

it could be as simple as someone just hasnt bothered to connect the smaller of them.. i think they are only crankcase vents and only go into the flame arrestor to get rid of any smelly fumes..<br /><br />trog100

 

[rodbolt]

Re: Flame Arrestor Connections

hello<br /> some engines used a PCV valve some did not. most had two hoses running from the valve cover to the flame arrestor. sometimes them thar "smelly" fumes contain explosive vapors so the idea was to allow the incoming air to suck any vapors and blowby gasses into the intake. they need to go someplace. just laying around wont cut it. has anyone changed the carbs or repowered it ?

 

[trog100]

Re: Flame Arrestor Connections

another "boat" thing i have learnt rodbolt.. them thar smelly crankcase fumes are considered a fire hazard when in a boat.. and heres me thinking they were just smelly and best sucked outta the way cos of that.. he he<br /><br />i am learning dude.. i am learning.. he he<br /><br />trog100

 

[bigbrownbuku]

Re: Flame Arrestor Connections

you havent lived until a boat has exploded before your eyes. definately route that hose to the flame arrestor.

 

[rodbolt]

Re: Flame Arrestor Connections

having witnessed a few engine box blow offs and recovered a few more that burned to the water line I have a healthy repsect for fuel fumes in a bilge.its amazing the force when it goes poof.<br /> we had a fatality some years back at the fishing center. they figgure the man was alive till he landed on the boat ramp. lifted him and a section of the deck about 40 feet.<br /> a good friend of mine, crabber of course, had an old penn yann nboard. everytime I worked on it the fumes were bad, I kept telling him the tank had a leak. plus no blower and the engine and all accesories came out of his van. he was lucky the day it blew. but the boat was a total wreck. his newer boat has 2 bilge blowers

 

[Scaaty]

Re: Flame Arrestor Connections

Toward the end of the season I tossed out the Qjet on my 350 and put a new Edelbrock 600cfm on. The one hose (3/4?) from valve cover to arrestor no prob, but the EB has no front port for the old other side PCV hose (1/2?), like the Qjet did. So for the remainder of the year, I just left it off, with no prob. PVC would not let it vent anyway I think. Next is to reroute it to the rear port on the EB, where there is a port. This might be a reason for your loose smaller hose?

 

[Lou C]

Re: Flame Arrestor Connections

By definition blow by is combustion gas that gets past the rings and finds its way up the cyl head to the valve cover. Although most of that is combusted fuel/oil vapor, some could be unburned gas. So it has to be vented up to the flame arrestor or else what ever fuel vapor is in it can fall to the lowest point. What suprised me is tha on my oe OMC arrestor, the hoses go to a clamp that basically holds the hose up against the outside of the mesh of the arrestor. I would have thought there should be a fitting for the hose to slide on to to make sure all of the fumes really in to the arrestor. The older OMCs did not use a conventional pvc valve like a car does. Back in the real old days, cars used a road draft tube that let the fumes vent to the road surface. Bad in a boat!