Low Profile Flame Arrestor

Hey MMaxx,
Bumping the thread to see how the K&N is working for ya??? I need to make a switch as well and was just wondering if the CFM's were the same, restricted or otherwise... Since you haven't reported, I'm assuming that life is good???

Moj'

TRB...Thats the place, it was $119 with free shipping, and it looks way better then you can see in the PIC, its real shiney,it comes in three diffrent designs,(Electic)(flame)(scalloped) its a heavy billet, not cheap at all. The low profile one thats on the boat now is going to jbear, but I do have the originl taller one somewhere!

backfoot..thanks, we will see if does anything on Sat when you guys get here!

the next thing is a air vent handle for better airflow, also from (rex marine)   

MM; That is sweet lookin' Am I gonna need one of them?

john

Maddmarxx, how much did that cost you? That is a sweet looking arrestor.

Just got it today, this thing is SICK

I ordered a K&N custom-66 flame arrestor from Rex marine its dimensions are 11-7/8 x 8-3/8 x 3"hi Its low but I dont think air flow will be restricted!!

TRBenj
Did you see the flame arrester on 87BFN's that eric is working on? The 454 flame arrester looks bigger in dia.,lower in profile and has a fuel vent!

TRB, the PCV can be plumbed into the intake ,you don't have to use that spacer.a simple fitting is all that is needed on the rear of the intake.Have done several with no problem.Chose to do away with the PCV on my stroker,just used two vented breather caps on each v/cover ran these to the flame arrester.Works great w/ no blow by....................boat dr

TRBenj wrote: Raising the motorbox would interfere with the pylon, so that wasnt an option.

TRBenj;
You might be surprised. The boat actually still gets a rearward cant when underway. Even though the rope may be even with the top of the motor box at idle, as soon as you take off, you would probably have a couple of inches to spare for raising the motor box if that's the interferance measurement that you're referring to.

boat dr wrote: I may be out of line on this question but here goes.... Install a high lift, longer duration cam ,taller and better breathing intake,GT 40 or good heads match the ports upgrade the ignition system,longer and hotter spark the list goes on and on.... Then i install a low profile flame arrester that does not list the CFM flow rate.How well and how much will this restrict flow??????       boat dr

Doc, I looked at a lot of marine flame arrestors, but never saw a single one that lists a CFM flow rate. Like I noted earlier, this arrestor was installed on many big blocks straight from PCM, so it shouldnt be overly restrictive. Although the overall height is lower, the filter area is larger than the one it replaces.

Raising the motorbox would interfere with the pylon, so that wasnt an option. Removing the 1" spacer creates another problem (where to plumb the PCV) and could potentially hurt performance as well. What other options should I have considered?

Good question Doc. If you read anything into K&N's site, performance increases as the air is smoothed and turbulence decreases. Now I also understand that they're trying to sell product, but I've also read that same thing in performance books. Low profile air filters can normally (but not always) produce lower performance because the air has to turn a sharper corner to get into the carb and they generally have a smaller surface area for the air to get through unless you get a significantly larger diameter. This can be smoothed somewhat by installing a stubstack but really the best performance gains can be achieved with a larger diameter and slightly taller filter as a general rule (as it relates to carburated or TBI type applications). I'm certainly no rocket scientist though. That's why I really wanted to try one of these things if I could get one to fit under my engine cover. All I would need is another couple of inches.

TRBenj wrote: Theyre pricey too, at $15-20 ea.

I hear ya. What the hell isn't pricey from K&N. They have some good stuff though. Interesting about what the Donzi boy's think about 'em. Those are some Go Fast dudes so I would a$$ume they know what they're talking about.

Holy crap, it worked!!!!! Thanks for the posting tip BKH!!!!!!

I thought I would bring this thread full circle. I found an arrestor on a boat being sold on ebay, and the owner let me swap with him. This is the same SS flame arrestor that SkiDIM used to sell as their "low profile" unit, but was discontinued a year or 2 ago. I discovered the same arrestor was also offered on several Nautiques in the mid-late 80's, primarily big blocks and for some reason, many '88 Ski Nautiques. I wanted this arrestor in particular because it was slightly shorter, larger in diameter, stainless steel, and had both fittings I need (5/8" breather and 1/4" fuel line).

It is 8" in diameter and 2" tall, with no neck- so the element is a full 2". The original arrestor on my boat was only 6.5" in diameter. It was 3" tall, with a 2" element and a 1" neck. I expect the new unit to flow just as well (maybe better?) due to the increased filter area. Best of all, I can now close my motorbox!

Before:


After:

Thanks 79, thats actually the same one I linked to in my original post- it appears we are back where we started!
I actually found one that is 2" tall with all the fittings here. You have to scroll down about half way and look for part number 3745649 for a Chrysler (short type).

Thanks to everyone for their input!