bertram31.com

After listening to a few boats at PT Judith I decided to reconfigure the exhaust, moved it to the outboard stringers. Went with a centubular muffler and a bronze 6" through hull at the transom. Opened up area for two 48" fish/ice boxes..Thanks for all your suggestions. Should make for a much better layout, after looking at Brewsters boat, I realized that you can never have enough ice/fish storage...BH

That looks good Bob

Your turbo flanges should arrive at your Washington Ave address,
the first of next week.

I sanded fiberglass ALL FREAKING DAY! ! today

Will the "Peel" material that you talked about work on large flat surfaces.....and where do you get it??

H

Bob,

Looks good, where did you find the 6" bronze thru-hull fitting? I have been looking for one.

oh my god bob i hope i did not influence your decision---ha,ha .the 6" bronze exhaust are bulletproof and available from freeport marine,800-645-2565.you can get 1 lenth of 6" exhaust hose cut in half with 6" vernatone mini max muffler will be perfect fit to boat with the added surge tube insurance by way of "fiberglass shield" in front part of muffler.sort of a one way muffler in common words.

Very nice. Love the detailed prep work. Clean very clean.

Also nice job on the down slope for the exhaust. Many miss that point.

Scot, I got the bronze 6" from Hamilton marine, and yes Bob you did influence my thinking a bit....Harry...that peel n ply works great just take your time and get the air bubbles out...the better you do that the better the finish...I will get you a roll, for the turbo flanges...Bruce, thanks for the input...like you have said before..sytem by sytem step by step...doin my best at each step...I just follow the lead of the faithful.BH

Bob......you sure don't let any grass grow under your feet do you.

Its hard to believe that you have already ordered the parts, received them and installed them.

Keep up the good work

Harry

now that's the exhaust!

that was my so who saw them on the shelf 7 years ago ." dad this is the real deal" 6" bronze exhaust tough ass instead of fiberglass out the back,a real nostalgia look a true battlewagon. so i took his advise and i love the look .bob you have to agree they look tough ass on a 31 bertram!!!

Ok that's it, I want one of those. The site doesn't list them...the Buck A catalog does not list them either? I suppose I can do the old fashion thing and actually pick up the phone and speak to a live person

Is it a 17 degree flange? I believe the 4" shows 90 degree or 17 degree angle options.

Well done - that looks great. Very mean looking piece of bronze!

Has anybody had any experience with punching the exhaust through hull out through the corners of the transom?

What I have seen is the side/corner ones are more trouble than they are worth. If not done properly, they can add back pressure, lessen forward thrust, structurally compromise the transom and often stain the hull sides with exhaust soot. I think that what is pictured is just "Bertram Perfect". Walter

For the corner exhaust, check out the pictures of John Cranston boat. I believe his come out the corners.

I prefer the bronze look also. Less chance of cracking them, plus they look like they really belong there.

Hey - awesome job. Where did you get those mufflers. I have a a 31 Northcoast with 3208T (320HP) Cats. There are just straight fiberglass tubes going from engine to transom outboard of 2 large indeck fishboxes. There is quite a rumble from the engines without mufflers, but i really dont have room for normal inline mufflers. I found a marine exhaust guy in FLA that made "linear" mufflers similar to the ones in your pictures...but they were basically for much larger boats...they would glass on smaller hose sizes (6" in my case) but the outside diameter of their smallest size is still 10 inches. ...those things in your picture look like a perfect solution (if they can handle the HP from the Cats)

awesome looking job!

Joe

Joef,

I am certainly no "muffler sizing guru" but it may have more to do with exhaust volume and less to do with hp. Your 3208's are something like 636 cu in engines, that's a bunch of spent gas coming out!

I believe I recall that JP's 6BTA's are 330hp and run a similar set up, but 6B's are only 360 esh cu in.

bob this is what i did for the mini-max muffler installation. nice rumble out the exhaust but quiet in the cockpit.the cockpit floorboards clear the mufflers by only 3/4" but it is easy and it works.in my opinion i beleive the rubber exhaust keeps the cockpit slightly quieter then fiberglass.

bob don`t forget the bootstripe is going to go right in the middle of that bronze exhaust tip. make sure to prep bronze before painting .

Hey guys,
this is a budy of mines company, i didnt know they did wet exhaust of this size, i have no idea how much but it may be something to look at.
http://www.maximsilencers.com/marine-we ... -MP11.html

JoeF, I called centex and asked them for the part #s they really dont list them any where, pat pending, I just remember JPs post. Same on the bronze through hulls look on the buck algonquin site, get part #s and order from local supplier. I used the 9 degree angled ones not the flat ones. The whole system laid out really nice, now its on to the stainless elbows, and thanks to Harry I can get started, custom made turbo flanges shipped right to your door...NICE work Harry...I have already made the fish boxes Ill post some pics when I get them in.
Bob will the waterline vary alot from each boat? Or should I do a dunk and mark to get it right? By goin bronze I moved the exit point UP 2 1/2 inches...and they look tough...flap or no? to complete the battleship look.BH

Scott, part # 00tea600 for the 9 degree down, from Buck algonquin site. I ordered them from kellogg marine not hamilton, but any buck algonquin distributor should have no problem on a special order.BH

bob you ask me a question with alot of varibles.with NEW iron 6 cylinder the water line will be along the chine edge with half tank of fuel.that line is about 1/3 up from the bottom edge of the 6" exhaust hole.the problem is imron does not like salt water when painted on bronze it will in time bubble up.that being said lets go to options with a bronze flange you have the options of using a exhaust flap i chose not to because the centek minimax muffler part # 1050600 allready has a full shield in the front that stops a water surge that is why it is a one way muffler.i do not know if you have this built into yours so i can`t answer the flap question.size of muffler is determine by horsepower of engine not displacement of engine. 6' exhaust is the minimum for a 330hp cummins 6bta-m3 engine.i show you my exhaust i have no fiberglass at all nor do i have 90 degree angles what i have is 6" 316 ss 70 degree angles at bottom with high heat blue silicon joints .a custom sprinker head and 41/2" 316 ss hot pipe.you have to get that exhaust out of the engine for maximum performance. i desigh mine mine to have near 0 HG. cummins says not to exceed (3")you will have to eventually prove it to cummins for warrantee.

Bob H,

You'll like the Centek's. Since installing these the folks at the marina we used have done another 3 or 4 boats with these units. Both on 270 B series and the newest QSB's. While tuna trolling we can talk and listen to music without blasting out the pit or yelling at each other.

After about 1100 rpm you hear engine noise from the boxes, not the exhaust. Around 1600 the exhausts have a dull drone and then as you get into the turbos the noise comes from the boxes themselves. With the Bahia your going to want to insulate in front of the engins below decks, the boxes and all around to the point of your air intake source. The mechanical engines have quite a rattle to them, not to mention a significant turbo whine (its even louder if you use a K&N style intake filter).

Nothing beats carrying minimal coolers while heading offshore. Nice choice.

Thanks Bob.