DIY flame arrestor?

soggy_feet

Senior Chief Petty Officer
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Oct 10, 2009
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Swapping my GM 250ci straight 6 for a Chevy 350 with a 4 barrel carb. I don't plan on reusing the skinny little arrestor from the I-6, but I'm even less interested in spending $50+ for what is essentially a screen door for my carb.

Anyone ever make one?

Doesn't look like it'd be too hard to use the top and bottom pieces from the old arrestor and layer some stainless or aluminum expanded metal and screen.
Disclosure: I do have welding/fabricating/machinist background

I'm having trouble finding the details of UL Standard 1111 or SAE J-1928 to know exactly what I'd need to build it to if I were going the detailed route with documents to back up my work, but the quick and dirty is to grab my calipers and measure the spacing in the wire cloth used in mass produced ones, and duplicate that.
 

Bt Doctur

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How much do you want to spend for one, messages still are not working here, find me at marine engine dot com, same screen name
 

achris

More fish than mountain goat
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I've just done a quick search on 'Marine flame arresters' and $50 is very cheap. It would probably take you longer than $50 worth of your labour just to collect the parts to make your own... How much have you spent on the conversion so far? And you baulking at 50... :facepalm: I'll bet you spend more than that on fuel for a day out... :noidea:
 
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soggy_feet

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I bought a 1984 Chaparral 235XLC for $500 on a tandem axle trailer.
Engine was cracked from ice, drive had the skeg broken.

I bought another complete 350 that turned out to be a backup motor for a local circle track team for $125. Motor has seen 16 races. Also a replacement skeg for $25.

I plan on selling the trailer for at least what I have into the project, also all the lights, and the stainless cleats, rail, etc.

So what I have spent so far? $650 and I plan on getting that back. So, $50+ for a screen isn't really fitting the theme here. I have scruples.

http://www.mcmaster.com/#9305t92/=sd92v3
http://www.mcmaster.com/#9227t63/=sd93uh

I could make one for $30 with material left over. Probably less, as I have some stainless screen somewhere around here already.

Also, I like making things. I cut the front 8ft off my steel hull a couple years ago and redesigned, fabricated and installed a new one.
Made a pair of 12 LED arrays brighter than most underwater lights for about $20 rather than spend $100 on a purchased set, installed them in the new bow.
 

Outsider

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I have scruples.

You might, indeed, but what you don't have is a USCG approved flame arrestor ... ;)
 

Bt Doctur

Supreme Mariner
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you still interested in the flame arrestor
DSCN2429_zpse74c4ff9.jpg
 

Lager

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Jan 19, 2014
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While I admire your fabrication skills any flame arrestor you can make will not pass coast guard regs.IF you get pulled for any reason and they happen have you pull your engine cover, the right one has to be there,otherwise you get the ticket. Why do we need one? Its not really a intake filter, its just there to help prevent a fire ball coming out from your carb if you have a burnt intake valve or possibly a real lean fuel mix. It wont prevent it, just suppress it a bit.
Just one on of those things you gotta have, IF the LEO checks for it.
 

soggy_feet

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While I admire your fabrication skills any flame arrestor you can make will not pass coast guard regs.

Unless it meets UL 1111 or J1928. USCG isn't even certifying them anymore, they just maintain that they need to meet one of those two standards. Done right, there's no reason it shouldn't satisfy an inspection on the water.
 
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achris

More fish than mountain goat
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Unless it meets UL 1111 or J1928. USCG isn't even certifying them anymore, they just maintain that they need to meet one of those two standards. Done right, there's no reason it shouldn't satisfy an inspection on the water.

Then go ahead and make one... I'm not sure why we have this thread here. It's not really asking a question, seems more like bitching about the cost of a commercial arrester. We can let this thread die, or I can close it... Your choice.
 

soggy_feet

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Well, had someone made one before, then maybe I'd have a little help knowing what I can/cannot do.
If I'm the first, maybe I can add what I learn to the knowledge base here.


Really a love/hate relationship with this forum.
Bunch of info here, but if you're not asking what the mods allow, it's locked down or pushed off to some sub-forum where the thread will see 15 views a year.

Lock it if you want, I don't think I'm breaking any rules here.
 

midcarolina

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Thread seems ok to me ( but what the heck to I know ) I bet the admins have orders out to shut down non essential threads to help save room on their new defunct server........I say this cause I don't recall ever reading a thread with achris acting as such!
 

achris

More fish than mountain goat
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Nothing like that... I just see this thread going nowhere, just in circles. One says I'm going to build, the other says it's not USCG, first says so what.... You get the picture. We have far more important things to deal with.
 

DaveG55

Petty Officer 2nd Class
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Jun 17, 2012
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Well, it may be going nowhere but I'd be curious to know what the USCG specs say and what testing is done to determine that the specs are met.
 

soggy_feet

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Coast Guard requirement:
Device must be marked to show compliance with SAE J-1928 or UL 1111 Standards.


They don't do testing (any more) as far as I can tell.
 
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