K&N spark arrestor

[Autotech1]

Well we wanted a air cleaner cause the spark arrestor we had didnt look like it would filter much atol. Found that K&N had line of marine approved air cleaners. Marine SAE J1928 approved.

This one measures 9"x2 3/4" tall.

I found a real good price a JEGS. they wanted $20-30 less than a "discount" marine .com outfit.

$87.99 +shipping

 

[bruceb58]

Re: K&N spark arrestor

I am curious why you think you need an air cleaner.

 

[Gary H NC]

Re: K&N spark arrestor

Well,it looks cool. As far as performance does it make any difference?

 

[John_S]

Re: K&N spark arrestor

Thats the one I have, but won't be running it till spring time. I got it new off ebay, around $50, but had to spend some time to keep looking and watching. The fittings for the breather hoses are a bit pricy, though. About $12-15 each at Jegs. I wouldn't expect any noticable gains.

 

[Reel Poor]

Re: K&N spark arrestor

John S brings up a good point. Be aware that the marine engine application you are working with does not use a PCV valve. You will need the ventilation hose adapter kit has mentioned. You may also need the fittings and rubber grommets for the valve covers, avaliable from Mercruiser. Parts 19, 20, 21, 22, requires two each, as they route from each valve cover to the flame arrestor

 

[Autotech1]

Re: K&N spark arrestor

Yeah im aware of mercruisers retarded setup, and were gonna modify it. well be running single pcv valve to intake vacuum as in an automotive application. From my understanding this is a factory configuration on other marine applications.

pcv valve in one valve cover, breather in the other. just letting the crankcase vent is the wost you can do for sludge and carbon. PCV (positive crankcase ventilation has been the standard for 50 years for a reason.

If anyone has compellingevidence or a reason this wont work please let me know. well be mosly on small lakes where dust is still an issue and we really dont like the idea of running an engine on unfiltered air.

 

[ziggy]

Re: K&N spark arrestor

got me a buddie that did one of them on his 4.3. breather hoses and all. he likes it i guess. put it on to filter out dog hair, which seemed like a resonable reason to put an airfilter on. don't know maybe he had dog hair on his FA. + it does look cool.. but did cost him money....

PCV (positive crankcase ventilation has been the standard for 50 years.

that may be true. for cars. is that a true statement for boat engines? if not, i would want to find out why the difference. ya'd think that if mercruiser thought a pvc valve was good for their engines, they'd put one on it oem. sorry i do not know the answer, but it would be a question that i would want to know the answer to prior to modin my marine engine to be more like a car engine.......hopefully a marine tech will chime in and let us in on the facts on this pvc vs ccv thing.....who knows, maybe it aint that big a deal even......i do question the change to a pvc valve though. but have no compeling evidence........hope it works out good for ya......

 

[Autotech1]

Re: K&N spark arrestor

yeah we'll see how it works out, it might not but if it works itll be a cleaner setop. ie no black oil covering the air cleaner/spark arrestor.

No its not true of marine, i was refering to autos.

I just dont see why it wouldnt or couldent be the same. our factory job actually used 2 pcv valves with hoses going op to the stock arrestor.

Just as you sig claims xiggy..

 

[John_S]

Re: K&N spark arrestor

I believe newer Mercs have PCV. The experts here will know. Possible negatives? ....more opportunity for vacuum leaks....slightly more unburnable gases reinducted. minor stuff I think.

 

[Reel Poor]

Re: K&N spark arrestor

our factory job actually used 2 pcv valves with hoses going op to the stock arrestor.

If your setup has two PCV valves with hoses going to the flame arrestor someone installed those valves by error. The Mercruiser fittings do look simular to PCV valves but they definately not PCV valves. They are just a hollow fitting, looks like a PCV valve that has been gutted.

I can't give you a positive answer on why, but I can tell you that I know of (personally) several cases where PCV valves have been used and it has caused ventilation problems. The difference between old style w/out PCV and the new style with PCV could be a simple as cam grind. Marine engines are run under constant heavy loads which means the engine vaccum is very low for trying to control vaccum operated devices. You may find with the low vaccum that the PCV valve cannot open/operate properly.

 

[mtnrat]

Re: K&N spark arrestor

Dennis Moore in Small Block Chevy Marine Performance describes it as "the finest marine flame arrestor available"

 

[John_S]

Re: K&N spark arrestor

Most 4brl SBCs in boats are not restricted by the carb, let alone the flame arrestor. If it did flow allot better, you would need to re-jet. My guess would be 5hp or less.

There should be plenty of vacuum to open PCV valves. If that was the issue, Merc would only need to have them made with a lighter spring.

 

[Reel Poor]

Re: K&N spark arrestor

There should be plenty of vacuum to open PCV valves. If that was the issue, Merc would only need to have them made with a lighter spring.

You know John, it's not about what Mercruiser should have, could have, or needed to have done. It's about what they DID or DID NOT do.

I don't know of any carburated small block GM based Mercruiser I/O engine that came with a PCV valve. Why ? I still don't have the exact answer. The origional marine carbs didn't have vaccum ports to support PCV valves either. And we should all know that the way Autotech1 said his is hooked up, will not work. Quote form Autotech1 ("Our factory job actually used 2 pcv valves with hoses going op to the stock arrestor.") If he actually has two PCV valves there, some clueless sole replaced the factory fittings with PCV valves, and they need to be removed and replaced with the proper parts.

 

[mkpj1]

Re: K&N spark arrestor

Am I missing something? PCV is exactly what it stands for positive crankcase ventilation. It's early emissions system required for early model cars. Ventilates crankcase gases to be burned so they don't go into the air and burn a hole into the ozone...I think. My concern is that you could create backpressure in your crankcase? Why do that? Just leave it open like Merc did. Better yet, just get another breather? Those look cool too?

 

[Tail_Gunner]

Re: K&N spark arrestor

Am I missing something? PCV is exactly what it stands for positive crankcase ventilation. It's early emissions system required for early model cars. Ventilates crankcase gases to be burned so they don't go into the air and burn a hole into the ozone...I think. My concern is that you could create backpressure in your crankcase? Why do that? Just leave it open like Merc did. Better yet, just get another breather? Those look cool too?

Bingo boat motor's are not subject EPA guideline's, This airfilter should be a very good addition to most fair weather boater's, dust, pollen, what ever dont know there not supposed to stay away from water or hang around......... Im in for one but i would like to know how the marine engine a PVC works, Umm where's Don or Bond-o when you need a relialbe answer? ...........o


Hmmm i like the retro high rise look.......8) with efi......

 

[mkpj1]

Re: K&N spark arrestor

Ya, nicer for the evironment but you would need to be cautious you need to be ure you have the right application as you could create back pressure in the crankcase, push out on seals and gaskets. See, Merc didn't design that earlier year to run with one. Plus it's marine. Also, Ditto what John S. stated, carb isn't jetted to work with it either. Just use another K&N breather? those look good and you will stil filter out the hydrocarbons.

 

[John_S]

Re: K&N spark arrestor

ReelPoor,

I agree with your assessment on Autotech1's configuration. If he didn't look carefully to see there was "no guts" to the part in the valve cover, he would think they are PCV valves. And if they were true PCV valves they would never draw enough vacuum to open, only being attached to the arrestor.


I was not trying to attack what you were saying, but the marine explaination didn't make sense to me.

Look at part #8, it is listed as a PCV valve.

8 21-861476 VALVE, PVC $5.05 $4.95 1

http://www.mercruiserparts.com/Show...bnbr=100&bdesc=Cylinder+Head+and+Rocker+Cover

If you check the camshaft in that engine, you will see it is the same part # as what has been used since '87. No special vacuum cam. From the diagrams I am not sure where Merc picks up the vacuum souce, but suspect the intake manifold (but didn't find a port on that diagram).

There is nothing special in the engine blocks for PCV. Prior to PCV, there was just a foam filter on the valve cover, 60's. I believe PCV started on GM smallblocks sometime in the 70's. I had a 1970 nova w/350 which had no PCV just foam, and a '72 Impalla w/350 that did (I think). Too many years to be absolutly positive.

 

[Reel Poor]

Re: K&N spark arrestor

I was not trying to attack what you were saying, but the marine explaination didn't make sense to me.

Look at part #8, it is listed as a PCV valve.
8 21-861476 VALVE, PVC $5.05 $4.95 1

http://www.mercruiserparts.com/Show...bnbr=100&bdesc=Cylinder+Head+and+Rocker+Cover

If you check the camshaft in that engine, you will see it is the same part # as what has been used since '87. No special vacuum cam. From the diagrams I am not sure where Merc picks up the vacuum souce, but suspect the intake manifold (but didn't find a port on that diagram).

No problem John, I really didn't take it as an attack, sorry if I sounded like I did. I am just trying to tell the man how Mercruiser designed his particular application.
He's working on a pre 1986 model GM Base carburated Mercruiser setup. He may be able to run a PCV valve without any problems. It's just not Merc design and I was trying to make him aware of a potential problem.

Your link and picture does not apply to this application. The link you provided is for 1998 & up model TBI applications, not carbed.

As for the cam, I know there is no "special vaccum cam". But, cam grinds and engine load can and do greatly affect the avalibility of engine vaccum for controling vaccum operated componants. I'm not saying this is why Mercruiser didn't use PCV valves, Just mentioned it because it could play a factor in their crankcase ventilation design.

 

[Autotech1]

Re: K&N spark arrestor

sorry guys, I looked the other day and they are in fact hollow.

 

[Boomyal]

Re: K&N spark arrestor

Yeah im aware of mercruisers retarded setup, and were gonna modify it. well be running single pcv valve to intake vacuum as in an automotive application. From my understanding this is a factory configuration on other marine applications.

pcv valve in one valve cover, breather in the other. just letting the crankcase vent is the wost you can do for sludge and carbon. PCV (positive crankcase ventilation has been the standard for 50 years for a reason.

If anyone has compellingevidence or a reason this wont work please let me know. well be mosly on small lakes where dust is still an issue and we really dont like the idea of running an engine on unfiltered air.

With you here AutoTech. My friend and I both own near identical BeachCraft 18' runabouts. Mine is a Merc 888 (ford) his is an 898 (chev). Now my friend is a mechanic of some accomplishment and he was appalled at the lack of a PCV setup on his 898. So, like you intend, he rustled around, found the proper components and Voila, like the ford, his chev now has a PVC.