Flame arrestor

[toger13]

do any of you use the K&N marine flame arrestors?

i have a 1999 mercruiser 350MAG EFI and am thinking on getting one it prob wont make any difference but looks as though it will filter the are as well as doing the normal job the standard thing looks pathetic lol

any way on the K&N website the one listed for the 5.7 efi engine has a hole in the centre and looks like a carb air filter rather than a clamp on filter what do you think?

http://www.knfilters.com/search/product.aspx?Prod=59-3364

Thanks
Si

 

[a70eliminator]

Re: Flame arrestor

The original is a flame arrester not an air filter, boats don't need air filters, you could probably buy some wires and spark plugs for the price of that K&N?

 

[Bondo]

Re: Flame arrestor

you could probably buy some wires and spark plugs for the price of that K&N?

Ayuh,... Or a tank of Gas...

 

[toger13]

Re: Flame arrestor

ye your probabley right but imo an air filter is cheap insurance there shouldnt be any dust or debris about but you never know lol

so what do you think about the mounting of it?

Si

 

[HT32BSX115]

Re: Flame arrestor

Howdy,

K&N always sells their automotive products with the idea that they"flow' better hence "more HP" This also means that they can allow more particulate matter into the engine since they do flow better (than a standard paper filter)

For a marine flame arrester application I would be willing to bet that they do not "flow better" than the OEM screen that Mercruiser puts on all their engines. There is no dust that would be a problem in your engine compartment (unless you regularly dump a shovel-full of dirt in there).....and the OEM flame arrester will prevent any "debris" from passing thru it.

If you think you're extending your engines life by putting a filter on it, consider that marine engines rarely wear out (My last boat had a 150 Mercruiser [GM L6] in it and went 39 years without a rebuild with literally the same flame arrester that my 97 454 has on it now)

My suggestion mirrors The above suggestions, although you can put any air "filter" on your engine. It's an un-necessary expenditure of money.


Cheers,


Rick

 

[toger13]

Re: Flame arrestor

ok i will steer clear then and save for a switch able through transome exhaust

Si

 

[Zackman]

Re: Flame arrestor

ok i will steer clear then and save for a switch able through transome exhaust

Si

You do know that won't improve performance either on that engine. Don't waste your money unless you just want to make more noise? I've got the same year and model of engine and I bought it used with the captain call exhaust. I wish it didn't have it. Also, you may want to check local noise laws before you add it.​

 

[toger13]

Re: Flame arrestor

it was more for noise to be fair we dont have noise regs for boats in the uk there arnt that many boats about

all the performance parts seam very expensive and hard to get hold of i was looking in to some ss manifolds (headers) as you guys would say, for abit more performance and to hopefully eliminate the chance of the old ones leaking in to the engine

Si

 

[wca_tim]

Re: Flame arrestor

I was somewhat surprised when I swithced from a factory style merc flame arrestor to a performance model (Gaffrig) and had to rejet the carb again... surprising how restrictive those things can be

 

[ziggy]

Re: Flame arrestor

i just don't see how it can be much less restricting than just flat slats on a oem fa. maybe your oem fa is different than mine though, i don't know..

 

[HT32BSX115]

Re: Flame arrestor

I was somewhat surprised when I swithced from a factory style merc flame arrestor to a performance model (Gaffrig) and had to rejet the carb again... surprising how restrictive those things can be

That's very surprising. I have run with mine on and off and couldn't tell the difference........... "A difference which makes no difference, IS no difference" [Mr Spock, Stardate 3145.3]

The way to tell would be to put a vacuum gage on each and measure it.

 

[toger13]

Re: Flame arrestor

i emailed k&n before i posted on here they dont do a filter for my 350 mag any way just the earlier ones

Si

 

[wca_tim]

Re: Flame arrestor

That's very surprising. I have run with mine on and off and couldn't tell the difference........... "A difference which makes no difference, IS no difference" [Mr Spock, Stardate 3145.3]

The way to tell would be to put a vacuum gage on each and measure it.

umm... not sure why neeed to try the vacuum gauge, I switched back and forth several times and wot was consistently a little lower with the (fairly new) factory slotted flame arrestor than with the other. not a huge difference, but one main jet / needle larger required or the same color plugs...

 

[Mkos1980]

Re: Flame arrestor

When I did my top end rebuild I tried the Stock merc setup, K&N, and nothing for data reasons only. I consistantly gained 2.3 MPH with the open setup vs the stock FA. When I went with a 9x3IN K&N I gain 1.8-1.9 over the stock setup. That was good enough reason for me to switch.

When the motor was bone stock, I couldnt really see a differance.