bertram31.com

Who has the best prices on hose? I need two 7' lengths of 5" exhaust, 5' of 1 3/4 suction, 10' of 1" bilge pump. That's the start.

I always check McMaster Carr for all but exhaust hose first...

http://www.mcmaster.com/

Mikey,
Whats the HP on those Cummins?
300hp and over are gonna require 6" exhaust.

Bruce,
After several conversations with Cummins experts including Tony Athens I was going with the 5". I was told that if I ran mufflers I should up to 6", but if I ran straight pipes, and I am, go with 5". If you have some skinny I haven't heard lay it on me quick before I spend money.
Thanks

Mickey, if you go 5", remember I have 3 5" rubber exhaust elbows - 90's - just about brand new that I no longer need. Let me know if you want them, I'll probably haul them to the resale shop later this week, otherwisw.

Mikey
My favorite "Boat Store" around here is Bluewater Ship Stores http://www.bluewatershipsstore.com
I also shop for hoses at local industrial rubber supply companies. Locally one of the places is Port City Rubber and Gasket company. This kind of store generally stocks all kind of marine rubber products including the wire embeded hoses nessessary for the suction side of pumps.

On my gassers I had a problem with the suction hose collasping and overheating my engine. The hose was a molded hose with a big spring inside that was supposed to keep it from sucking shut. The spring deterioated and the hose failed. I replaced it by welding "Short Radius" stainless 90's together then connecting the ends to the pump and oil cooler with short sections of straight hose. I promise you it will not suck that shut.

When I install the diesels in De Nada at the end of the upcoming fishing season I will use stainless pipe as much as possible connected on the ends with short pieces of rubber hose.

You doing Okay??? Running the Boston Marathon yet???
Hope so

Harry Babb

Mikey,
Every pair of Cummins engines I've installed 300hp and over, mufflers or not had to have 6" exhaust or the Cummins rep that certifies my installations would not have given them the go.
This goes for the QSB 330hp's that went into a 31 fall of 05.

I'm not trying to argue with Tony's recomendation or create a problem for you. All I know is what is required of me by Cummins on an install.

BTW, if you get everything together and decide you want mufflers, your sol for that extra inch.
Take a ride on a short exhaust boat with those Cummins and no mufflers to be sure.

I would also think about using fiberglass pipe instead of a long piece of hose. Hose deteriorates and if not properly supported will collapse or kink creating back pressure.

Bruce,
I have always heard that the 300+ HP engines need 6" exhaust. I am rebuilding a pair of 6B's for an upcoming 31 Express repower. The engines that I am rebuilding are early 90's models and the Exhaust elbow accepts a 5" hose.

I intend to install mufflers and my question to you is, should I bush up the hose size from the elbow to the muffler or use 5" from the engine to the muffler and just go 6" from the muffler to the transom?????

Can you tell me what the maximum backpressure reading can be???

Harry Babb

Damn, Bruce. Well, guys, anyone want a nice pair of S/S 5" exhaust tips? The only thing that came with the boat that I thought I could use.They will look spectacular on someone's boat, but not Dreamsicle.
Now, if I install fiberglass through the transom and then run fiberglass to the engines I would guess that I should separate the two with a small section of hose at the inside of the transom, yes, no, or can I run a continuous piece from transom to engine bulkhead?
Anyone have a nice pair of S/S 6" tips?
Thanks

Harry,
The Boston is on the list, but pretty far down. Walking with a cane now except when I get shooting pains of re-awakening nerves. Working on the new dock today to install the power and water. Some fun.

Mikey,
You can run 5" through the bulkhead then adapt it to 6". The 5" will pass easier between the fuel tank and gear on the port side. The 6" is tough to run, damn near impossible if the tank is in its original position forward and you have trolling valves. If you have the rear mounts on the bell housing of the engine and not the gear it does make it easier (this however is not recommended by Cummins)

My understanding on Cummins is 300hp or above is 6" on 6bta's and on my 89 model 250hp 6bta's is 5" because I'm putting Centex 5" mufflers on my mine, did fiberglass pipe thru the transom.

R,
DQ

Mikey,
Do you remember the conversation we had several weeks ago when I was there?

Anyway, Since you have plenty of room to work with (from what I remember) think about fiberglass and mufflers. It's what I would do if I were you. If you ever so to sell her and I can afford her I might be on the candidate list for stewardship. Having said that, I'll let you buy the 6" hardware so I can enjoy it in the distant future. The only thing I would change would the color. (just kidding).

By the way, could you also put AC and a generator?

Chiles

Rub it in, Chiles, Rub it in. Bruce is like the E.F. Hutton comercial. I'm listening.

JP, I am running the exhasut above the upper stringers so no prob there.

Mikey,
Please don't feel you have to change your exhaust cause of my comments.
If you've been told the 5" will work and that's what you want then giddy up.

Since you don't want mufflers, are you using surge tubes?

Do you have the risers built yet?

Reference this thread of pics I posted awhile back when you started the exhaust questions.

http://bertram31.com/newbb/viewtopic.php?t=168&start=25

I got an excellant price on 4" exhaust hose from go2marine.com I order the vetus brand flexible hose and i'm very happy with it. I also have a coupon code that saved me another 30 or so bucks. That i'd be happy to pass on to any of you guys

Bruce,
again, thanks. As I said, E. F. Hutton, I'm listening. Surge tubes or mufflers. Hmmm.
Scooter,
Haven't dealt with go2.com, but would love to have the coupon #. Checking prices this weekend, spending money on Monday. Does that sound familiar to anyone?

Mikey,
For a cool small diameter muffler try the centubular from vernatone. Little bit of money but very small diameter. Should have pics ready to post next week some time of our layout.