Air cleaner/spark arrestor
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 14 of 17

Thread:
Air cleaner/spark arrestor

  1. #1
    Member
    Join Date
    May 2009
    Location
    Colorado Springs, Co.
    Posts
    74

    Default Air cleaner/spark arrestor

    I'm looking to increase the available air intake for the 466ci in my CV23, but have limited available height for a spark arrestor (like ~3"). I was thinking about possibly utilizing an old, lower profile air cleaner housing with dual snorkels, and running intake hoses close to the port & starboard air intakes.
    A pancake adapter with a single hose would be good also, but I haven't been able to locate something like that.
    Currently using a 2.75" tall, ~8" diameter spark arrestor.

    Either option feasible?
    1978 Glastron/Carlson CV23; 429, Berk jet.

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member 78_Tahiti's Avatar
    Join Date
    May 2009
    Location
    North Highlands, CA
    Posts
    110

    Default

    Many of the guys up in NorCal, with enclosed engines, like yours. Use a low profile 10 or 14 inch K&N air cleaner/filter. They are USCG Legal, free flowing, and more often then not, will fit under the engine cover.

  4. #3
    Off Road Badass Bonzen's Avatar
    Join Date
    Apr 2012
    Location
    San Diego
    Posts
    267

    Default

    I've noticed that these big block boat engines always seem to come with "small" air cleaners compared to the size of the engine. In the automotive world, these would be replaced by a much larger unit or at the very least come with a much larger unit factory. Is there a reason that marine applications typically use such a small filter? Can a small HP increase be gained from switching to a larger K&N style like stated in previous post?

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    I don't feel tardy Hallett Dave's Avatar
    Join Date
    Jan 2008
    Location
    Lancaster
    Posts
    845

    Default

    Quote Originally Posted by Bonzen View Post
    I've noticed that these big block boat engines always seem to come with "small" air cleaners compared to the size of the engine. In the automotive world, these would be replaced by a much larger unit or at the very least come with a much larger unit factory. Is there a reason that marine applications typically use such a small filter? Can a small HP increase be gained from switching to a larger K&N style like stated in previous post?
    Yes, because people that use them don't know any better. Use a filter that flows as much or more than the CFM rating of your carburetor.
    Call K&N and ask to speak to the engineering dept. They can provide you CFM flow ratings for every filter they make.
    Carburetors thrive on clean undisturbed airflow. Your engine internals will thank you for clean air as well.
    HD
    Quote Originally Posted by Futs View Post
    Im non induced and My turd leaves pretty hard as she sits.

  7. #5
    Off Road Badass Bonzen's Avatar
    Join Date
    Apr 2012
    Location
    San Diego
    Posts
    267

    Default

    Its that simple huh? I thought it could be something along those lines but I see engines in brand new boats come with these tiny little filters that wouldn't flow enough for a 22R Toyota lol so I figured there had to be some technical marine type reason...

  8. #6
    Senior Member
    Join Date
    Dec 2007
    Location
    New Jersey
    Posts
    307

    Default

    The reason is that they are NOT air filters - they are flame arrestors. Their Coast Guard required reason to exist is to prevent a back fire flame from igniting fumes or other combustibles in the bilge.

    They do not have any filter media and will only keep small logs and large sticks out of the engine. They flow more than a typical air filter of the same size but are known to be restrictive, you will definitely benefit from a good performance air filter from K&N. If you want to be totally Coast Guard legal, make sure to get a marine certified filter assembly. Costs more because they went through the trouble to get it certified, and the increased liability because they market it for marine.

    Doug

  9. #7
    Off Road Badass Bonzen's Avatar
    Join Date
    Apr 2012
    Location
    San Diego
    Posts
    267

    Default

    Ok thanks for the info. May be something we could all benefit from. Those factory spark arresters/air filters are tiny and we run some big engines.
    "I'd love to help you out wags, but there is larger issue concerning breast cup sizes on another thread that we have to work thru first. This subject suddenly became a non issue." - GN7

  10. #8
    Off Road Badass Bonzen's Avatar
    Join Date
    Apr 2012
    Location
    San Diego
    Posts
    267

    Default

    Went ahead and got this bad boy for my 750-ish cfm TBI. According to K&N tech line, this filter flows 845cfm. Part number 59-3370. Marine approved. 9" diameter, 5" total element height, and 6.750 total height. The stock spark arrestor looks puny next to it, I'll post up after I run the boat with mph/rpm results or seat of pant feel haha.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	20150518_191520.jpg 
Views:	210 
Size:	14.6 KB 
ID:	734145  
    "I'd love to help you out wags, but there is larger issue concerning breast cup sizes on another thread that we have to work thru first. This subject suddenly became a non issue." - GN7

  11. #9
    Member Dave01's Avatar
    Join Date
    Sep 2008
    Location
    NH
    Posts
    66

    Default

    I know the obvious answer is "filtered air is better than not filtered". But, is there any evidence that marine engines run 100 hours a season have their life shortened at all from running flame arrestors and not filters? I've run every inboard I've owned with just arrestors and rarely have seen any with a filter. A lake or river isn't a dusty environment at all, though I suppose pollen in the air might get filtered out. I'm not against making the change to a filter, that's why I'm asking, just am not sure it's needed.
    '86 Eliminator Sport 20, Chevy 454, Berkeley 12JG w/jetovator

  12. #10
    Junior Member
    Join Date
    May 2015
    Posts
    15

    Default

    I just ordered a new flame arrestor from Holley. It dwarfs the stock one from the 70s. It is at least 3 times the size. Now its too tall for my hatch to close :/

    Oh and it was ridiculously over priced at $100. There is nothing to it but a little sheet metal and mesh.

  13. #11
    Junior Member
    Join Date
    May 2015
    Posts
    15

    Default

    Here is the link to the one I got. It is about 3.75 tall, if that is what you are looking for. Rated to 800 cfm.

    https://www.holley.com/products/acce...s/parts/720-13

  14. #12
    Off Road Badass Bonzen's Avatar
    Join Date
    Apr 2012
    Location
    San Diego
    Posts
    267

    Default

    It's not really about filtration...well yes but not as crucial an issue with boats especially motors in closed hatches that keep dust/pollen/bikini tops away from the air cleaner. Although my stock spark arrestor routinely needed cleaning from built up "fibers" that I assume come off the interior carpeting around the motor. My stock spark arrestor had only 1.75" of actual mesh height to breath air through. It was 8" total in diameter too. The mesh is also 3 layers thick...fairly restrictive. So by comparison the new K&N (also $100) has 5" of element height and is an inch larger in dia. It has to be better for a BB motor that has a larger than stock throttle body, modified internals and .030 over. Maybe a bone stock mercruiser BB with a current year advanced EFI system wont benefit from more air but that's not what most of us have. If I get 200rpm for $100 that's money well spent. Some guy on another forum put this exact same filter as I just bought on his 500 Mag and it dyno'd around 35hp more than the stock spark arrestor! So like I said it has to be "better" than stock.

  15. #13
    Member Dave01's Avatar
    Join Date
    Sep 2008
    Location
    NH
    Posts
    66

    Default

    I'm surprised to hear that, I figured arrestors with open mesh flowed more air than larger air filters with the restriction of the fiber filter.
    '86 Eliminator Sport 20, Chevy 454, Berkeley 12JG w/jetovator

  16. #14
    Senior Member bp298's Avatar
    Join Date
    Dec 2007
    Location
    LHC
    Posts
    6,570

    Default

    I've been running these for 17 years on 3 different engines. k&n's slip fit over 5 1/2 x 3" "modified" spark arrestors. this is the second set of filters on the same arrestors. these were perfectly clean/red at the beginning of the season. this is after 3 races. i'll clean them again before the end of the season. for those of you that believe there's no dirt that gets to the engine because it's a boat? all I can tell you is that after one season, these things are filthy. and it's primarily run only on race tracks, and a few runs on lake havasu. if you prefer to let all that crap run through your engine, your choice.



    for those that think these are "too small". these two filters have been run on 2 different engines on the dyno, back to back pulls, several times. I have run with/without on back to back track passes more than once. there was no difference in performance either on the dyno or on the track. there is no measurable difference with them vs without them.

    having said all that, standard barbon spark arrestors are restrictive to air flow. like doug said, they do not "filter" the air. these k&n's are NOT spark arrestor filters. they are standard k&n air filters, part E-3403, that just happen to be the perfect size to make a snug slip fit over the barbon 5 1/2 x 3 spark arrestors. I do not know what the results would be with k&n spark arrestors.

+ Reply to Thread
Page 1 of 2 1 2 LastLast

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in


Tags for this Thread

Digg This Thread

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95