Wow !

Speaking of which, I just looked this up, the 565EFi uses the same flame arrestors....but of course 2 of them per motor.

http://www.mercruiserparts.com/bam/s...1361/15970/100

the throat on this FA is 3.75, the TB is 3.5. I will simply take one of the silicone couplings from the 4" tubing connector, cut it down to about 0.75", take a few mm out of the diameter and it should work well. I did get a note back from Michigan Wire(who bought Barbron), and they said that COOPS FA is actually a Volvo design. So...for me to get one made, I would have to get their permission. I think that the one SB recommended and I eventually picked is the best decision. Glad I bought these, and hope to get them on this weekend. BTW, Volvo 5.7l engines use a FA that is clamped on(per schematics)...so, I am not worried about doing this. It is the same TB, and with the silicone gasket to make up the space difference, it should more than stay put.

Latest from Kai. Looking good!


Well, the new FAs are on, and I have the easy side fresh air done(port side has the horn right I the way...fire extinguisher etc.). The new FA fit nice, and now have about 0.5" clearance to the sun deck. The fresh air inlet now comes in, drops and does a 180, and then simply points air to the top of the engine from the side. Not sure if I will add more piping to put the air closer to the intake yet...but at this point, it will be a huge improvement, and unobtrusive. Most likely, I could get the Bimini top shelf back in with a little work too. Tomorrow I will do some testing on the lake and report back.

Well, today during a medium speed cruise, temps were does to 115 with the setup in the pictures. I am going to put my gopro camera under the hatch with some strangers on the pipes I added to see what the airflow looks like. I am convinced this is a big improvement. Did one short WOT run, and got to 65 mph full of fuel, two adults and normal load of covers etc. Under deck temps still rise to 150 after you are heat soaked and shut down. Once you're start running, temps go down to the 115. This is as good as leaving the hatch open 4". If this does not help overall performance, I am still glad I started this project. More to come later.

Did the FA fit right on the TB or did you have to add a bushing of some sort?

In the tubing kit I got for the fresh air, there were a number of 4" silicone couplings for the piping. To get it to fit right, I simply cut a 3/4" strip out of one of the couplings and then this acted as the bushing. The material is really pliable, and things then clamped right up. I just left the studs from the FA in place, and with the FA about a 3/16" from sitting on these studs...it fit perfect without having to modify the length of the coupling. Ran probably 2 hours of driving yesterday in some rough....for LC...condition, and the didn't move at all.

I was super happy to see the temps drop when running. With no other method to measure, this 25 deg drop in temp is simply the right direction to go. Effect on overall performance?.....too many variables to be sure.

Every +10*F in air temp is -1% power.

2 of these 496 FA's ust showed up for sale on OSO a few minutes ago $45 each: http://www.offshoreonly.com/forums/s...-cleaners.html

Port side is now done too. A little work to move the horn and work around the extinguisher, it it turned out ok, and will do the exact same thing as the starboard side. [ATTACH=CONFIG]558503[/ATTACH][ATTACH=CONFIG]558504[/ATTACH]

Nice work!!

Any new performance data?

Not yet. Heading to LC for the weekend, and will have lots of time to report back.

After cruising at 4000 rpm for about 20 minutes, under hatch temps.were plus 22 deg from ambient. This seems to be a big improvement. Was super windy with the storms everywhere, so no top speed runs. Having under hatch temps under 100 deg is a success for me though. More to come when it is hotter tomorrow[ATTACH=CONFIG]559000[/ATTACH]w

Not sure if you did this, but make sure temp sensor is right at flame arrestor screen as that is what really matters.

SB. Yep, the sensor is strapped to a bracket within a few inches of the arrestor. If anything, it is hotter there add it is closer to the engine.

Well, I have another idea in the making. Someone, in another post mentioned that cracking the hatch helps move a lot of air, and this got me thinking.
First, the idea has a few issues, such as the whole hatch being supported by the ram...not the hinge and all other perimeter surfaces. This is also an issue if anyone ever gets on the platform with it up. Quite a pain to have it up, down, a 2x4 holding it up etc. Second, there is quite a bit of engine noise.

So, I got a pen and paper out and came up with a support aystem to hold the deck up with full support and a vent hole design that would have some sound baffling.

Basically , a 2.5" spacer with a series of 2" holes drilled in it, sandwiched together for a wider support base and some space in between to cancel out some noise(a little I know). Then, some wedges to put on the sides to support the side of the deck. I think it will work well, and is totally reversible. In addition, the 2.5 inches will make the sun deck level with the sides of the boat....almost like it was designed to be like this.

I know there will be ventilation directly to the engines, but no one is ever on the boat while it is not in use, and it can also be removed if needed.

Any thoughts...? I will go and do a test fit in a week or so and get some more pictures

[ATTACH=CONFIG]563183[/ATTACH]

I got the chance to see how the parts fit, and they are going to work fine. Will need some more fitting to get the bimini top supports back in(already done...just need to install). Then need to push the vent pipe outlets back a little so they are flush, letting the bimini top slide in...again, not much work.
Then, some minor adjustments needed to make the parts easy in and out, and the engine compartment can vent all day long when hot to help prevent heat soak. There will be no reason to have the parts in all the time...just when needed. You will also note the if you look at the side hatch support that the hatch will really be level with the adjacent fiberglass. It will look like it was designed for this from the hatch standpoint...although it will be a litte more angle to it.
[ATTACH=CONFIG]563699[/ATTACH][ATTACH=CONFIG]563700[/ATTACH]

REV... love your commitment and dedication to this. Puts a smile on my face. Hopefully it will work out and i'll get to see your progress in person this summer. I'm still interested in making the trek down to Lake Cumberland.

Quick update,
Well, this solution seems to really work well. I took the pieces that need to support the hatch on either side, and installed some rivnuts so I could take them on/off, and the spacer that is under the seat is notched so it stays in position with the hatch sitting on it. My original idea was to install these when we were on anchor, but have simply installed them and left them in place at all times. Just easier not to take the parts on/off.

What I have observed is that the opening really helps keep the engine compartment much cooler when running(around 110 deg or less), and the engines will not heat soak when the engines are hot and you stop to relax for a while. It was not uncommon to have the whole compartment at 165 deg last year, and with the venting, I can usually count on the temps to not go past 130...and will drop down quickly depending on how long we are stopped. If you are stopped for a few hours, the temps will drift back to 115 or so.

There is some noise from the engines, but that is not an issue for any of us on the boat, and it is a few more inches to step up to get on the hatch, but this is also no problem for us.

As far as any top speed numbers....I am not going to say that this is worth any speed(may very well be the case though), but is simply directionally correct to get the heat out of the engine compartment. Does it improve hole shot with a hot engine...yes. Do engines like a cooler environment...yes. Can I back this up with unequivocal data other than engine compartment temps.....no, and not really trying to as this boat is simply for family fun and trying to optimize an already great boat.

Revspan, I quickly read through the 7 pages of info. I have a 2014 292. Mine is hard pressed to hit over 60 mph with full tank of gas, 2 people, dog, etc.

What was the part number of the FA you used and the type of hold down? How did they hold up in use? You did say that you gained MPH right?
Are your 28p props Labbed? Bravo 1's?
Did you buy new props or are yours stock from Formula? I believe they came labbed.

Dave, part numbers and details for the FA are in the thread....also how I connected them.
No guarantee on speed increase.
I have mentioned this to you before. Dump the 28p props and get 26p. I have another thread on this too that you can find. I think you usually have your boat loaded up...another reason to get the 26p

The part number for the flame arrestor is in this post. I kind of lost track going back and forth to all the linked sites in this post. I thought you may have known the part number off the top of your head saving me the reread.

Also I do run my boat 99% of the time with a full tank of gas, two people, dog and overnight gear, running a Bravo 1-28 pitch. 60 mph is all I can get out of it . I'm going to try a 26 pitch prop on the boat as soon as they get to the house.

After I reread all the posts again, your top end was 66 mph with a full tank of fuel, two people, gear, running a Bravo 1-28 pitch prop. (post24) So, after you installed your flame arrestor, your air induction along with your spacer for your engine compartment, how many miles per hour more did you gain? If now you're running 66 mph, what were you running before that?

I really do not think the FA made any real difference. The quoted speed differences would have been in different conditions etc. I, like you, have been searching for the magic unicorn for the 6.2 powered 292. Fact is that they are borderline on torque to push any 28...labbed or not. It is only when you have a light load, and perfect conditions that the 28s are the right prop for this boat. Like you, I usually have mor fuel on board, and at least two people...normally more. This makes the planing capability for the 26p soooooo much better.
I Now have 26p for most conditions and a set of 28p labbed props that were tuned for my boat that actually got me close to the 69mph mark......with two people and a pretty light load. These props will stay in the shop most of the time.

Who did the Lab work on your props? Can't find where you welded extensions to your trim tabs.

The Cat exhaust manifold weighs in at about 110 lbs. each or 440 lbs total. That's Manifold, Catalyst and 2'' risers. With a gallon of gas weighing in at 6.3 lbs, that equates to 70 gallons of gas sitting on the ASS of the boat!

Hardin Marine sells a device that cuts out the O2 sensors. Whipple flashed your PCM. Both have Pro's/Con's, BUT your able to get ride of the weight. Hardin Marine and Stainless Marine are in Fl. Where I'm at. Both have there own manifolds. Hardin makes theirs out of state, while Stainless is in house. Stainless Marine Manifolds are 8lbs each! THAT is one hell of a difference.

No matter what route I take, I'll keep the OEM manifolds. When I sell the boat, the new owner can put it back stock if they like....

Links below.

Hardin Marine - Max Volt Catalyst Eliminator Computer

https://whipplesuperchargers.com/index.php?dispatch=products.view&product_id=273