Larger exhaust and running better...now to insulate

[Carl]

Splashed her yesterday with the new risers and looks like we are much morer betterer. EGT stayed nice and low, I was by myself so I didn't get to check back pressure yet. The port motor which was lagging a few rpm behind is right up to where its supposed to be at WOT.

With that I'm happy.

Downside is the wrap I put on is not going to cut it. I had a feeling and was worth a shot to at least get out and verify motors ran as they should. Guess I could add another two layers...but thinking I should just do it right by having insulation covers made. Or the HD Heat Shield Armour...which is not inexpensive and then I still need to cut and install myself.

So, is there a prefered place to have made...idea/ballpark on what they cost?

[John F.]

Sorry if I missed this, but what did you upgrade to exhaust-wise?

[Snipe]

Do you have any pictures Carl? There is a company that makes really nice wraps with just measurements. https://www.firwin.com/
Did you do the upland over exhaust?

[Carl]

I went from stock Cummins elbows with 2-1/4 ID and 3-1/2" hose/showerhead to 3-1/4" ID, dry pipe up 10" and back down to a 5" diameter shower head/hose. I was then running 3-1/2" hose to the surge tube, about 2'. I knew it wasn't right...but had the hose, it fit well in the stock space so decided to run and check out motors last year.


I later cut and swiveled the starboard side riser out 90 deg after mounting...too much work to keep tight to motor and trans. 90 degrees out put me just outside the stringer giving room for 5" hose.

I have two layers of heat wrap which is not putting me where I want to be. OK to putt around with a quick run, but need to really insulate now.

[pschauss]

Carl,

Those risers are real works of art.

[Rocky]

Large and in charge,
Great looking work Carl. Amazing how diesels love to breath with benefits! Did you reach out to Tony Athens for shielding blankets? He may have a source for you.

[scenarioL113]

The blankets are nice but they are very pricey. I know that heat wrap that you roll on works fine for this type of application. It just requires numerous layers of the wrap.
Conchy-Joe (Troy) on this forum did this a few yrs ago and he ended up doing about 4 or 5 layers of wrap and when running he said you could touch it. He has run it like this for a few seasons.

It will look like a bent mummy's leg but will be functional and not burn your decks up

[scenarioL113]

Looking at your factory wet elbow, it looks like the flange is a different size than the ones you made up for the new exhaust.

Was the bigger flange able to bolt right up to the turbo easily or did you have to make up an adapter plate or something???

I am referring to the long slots that allow the flange to rotate for positioning.

(unless I am not seeing it correctly, just wondering)


edit

FORGET IT! I see now that it just looks that way. The "dry" pipe is the same outside diameter and the factory "wet" pipe outside diameter....duh

[John F.]

Carl

I used Anchor Insulation in Pawtucket RI for the blankets for my 8.2s. They’re price was a third of one quote and half of another. Search blankets and you’ll find my post

John

[Snipe]

Looks great Carl. I used to use a few places on states island to make exhaust blankets I can’t remember the names off the top of my head but there are places still over there I would think with all the tug boat companies around.

[Carl]

Conchy-Joe (Troy) on this forum did this a few yrs ago and he ended up doing about 4 or 5 layers of wrap and when running he said you could touch it. He has run it like this for a few seasons.

I have two layers on now...I can do a couple more and see.

Meanwhile I'll price up the blankets.

Thanks Frank

[Stephan]

If you find you would like to use the firm in Rhode Island mentioned above please let me know if I can be of assistance - it's my backyard.
Nice work!
Stephan

[bob lico]

just sent a thank you to my PM , i told you the minute you had the back pressure post a year ago.i would look on E-Bay for guys selling the heat blankets on the cheap.

[Carl]

Thank you Bob, on both accounts. Ebay I found covers that will work and are brand new for less then the wrap I already bought which I'll get and install Monday. That will hold me over to play with boat till the following weekend when covers arrive.

Backpressure, knew it was wrong to stay with 3-1/2 " to get me to the main 5" run...but I was able to prove motors were in good shape and get some use in last year. It took me about 4 months to get exhaust done...it's really only a couple days work, but when it's the last item on the totem pole sometimes it's weeks before another step gets done.

All good, I should get to use and start the spiffing up the boat project after maintenance is done

[bob lico]

excellent carl i loved to hear the progress you are making, Summer is here lets splash that beauty.incidently you also avoided the flaw in the cummins sprinkler head and far worse Yammar sprinkler head and that is the exhaust water now enters and circulate 360 degrees around exhaust to cool, the cummins sprinkler head will fail in time due to the angle of the sprinkler head allowing the exhaust water to cool only 180 degrees of the sprinkler head however they are made of stainless steel and will take years to fail ,the Yanmar are a total POS. made of cast aluminum ; for those with a IQ. of more than 90 what do you suppose happen when exhaust mixes with salt water???? --------Sulfuric acid and that will destroy a cast aluminum sprinkler head in a short time . think about it

[Carl]

Yes, it was no coincidence the water going into the mixer was directed to go around the hot pipe creating a swirl effect to evenly distribute water. As you recommended the mixer pointing straight down has all water leaving the riser. Nothing to corrode, no bits and pieces to get hung up on the low spot...even though its all 316L it is better not to have water remaining behind. Also, it's a nice 360-degree cooling flow at all speeds. Hopefully I'll never have to touch them again.

Incidentally, with the 20 x 20 wheels, running at my new 2300 cruise I'm running 20.5 knots with pyrometers saying the motor is happy at 750 deg F. WOT is 2600 at 23.4 knots with EGT of 800F, 850F is max reccomened by Cummins. I am going to run her a bit like this, fill the tank, bring some people on board and see if she still hits WOT. If it does I may pull wheels and add some cup...or buy another pair with cup, maybe try 3 blade.

More speed is better, but my goal on this install has always been attaining a solid 20 knot cruise, so Bingo I do believe I have hit that goal.

[EarleyBird]

Carl, though I might of missed a previous post, how many HP are your Cummins and shaft size? I might be able to assist you with wheel manufacturer, size, and pitch. MAYBE? EarleyBird

[Rocket]

Carl, I have had guys come and wrap my wheel loader and forklift exhausts at work as we are in have a lot of paper and dust in our environment. I am always surprised at how little they charge for how much work they do which is different from just about any other goods or services that we buy!

In short, try finding someone who does exhaust wraps and blankets for heavy equipment, you may be surprised.

[Carl]

Earleybird- 6 BT Cummings at 210hp running 1-1/2" shafts.


Thanks Rocket- I have more wrap coming in and blanket by the end of the week. It was my usual see if it works before dumping money into it routine. Now that I know it works, I need them wrapped or covered to really use Boat. I've been running with hatches open to monitor...they get real hot with 2 layers...real hot as in over 400°.

All good though I have plenty of thing to tend to till I get exhaust covered. And I still sneak out for quick rides...

[EarleyBird]

Carl, I have three sets of wheels. Mine motors are 270HP. I believe they will be to much for your HP. Presently they are 4 blade DQX 20X22 w/ medium cup on 1 1/2” Aquamet 22 shafts. I have another set of Hy-Torq Michigan Nibrals also 20X22 #7 cup, and same manufacturer 3 blade 21X23. Your more than welcome to try the last two mentioned. EarleyBird

[scenarioL113]

Incidentally, with the 20 x 20 wheels, running at my new 2300 cruise I'm running 20.5 knots with pyrometers saying the motor is happy at 750 deg F. WOT is 2600 at 23.4 knots with EGT of 800F, 850F is max reccomened by Cummins. I am going to run her a bit like this, fill the tank, bring some people on board and see if she still hits WOT. If it does I may pull wheels and add some cup...or buy another pair with cup, maybe try 3 blade.

More speed is better, but my goal on this install has always been attaining a solid 20 knot cruise, so Bingo I do believe I have hit that goal.

What is your High-Idle RPM in neutral? It should be above rated RPM for engine. I would think it would be 2700RPM (maybe 2750) but I am not sure tho

That nds to be checked first. You must make sure your CAV pumps are giving you what they are supposed to be. If not then the throttle stop could be adjusted to give you the High Idle RPMs you need.

After that is confirmed then you compare your sea-test RPMs you mention above.

If you are at 2600 now, then I think you are maxed out on your props as they sit.

[Carl]

Your more than welcome to try the last two mentioned. EarleyBird

EarleyBird-
I thank you very much for that tremendous offer...and I mean very much. But as you said, I know I cannot turn that much wheel with these motors. Best I could hope for is adding some cup to mine or maybe going 3 blade with cup.


Frank, yes the high no load rpm does give me the required 2850. I do however need to verify tachs at those numbers. My guess is they are right on as they have been extremely close at other rpms.


Really my first step before drifting off into faster fantasy land, I need to load up the boat and run it up. As Frank said I may be pushing all I can push. And If that is the case, I'm done and will be happy. If I need to knock a little off the pitch of the wheel for a few more rpm, I'm willing to do that as well.

[Rawleigh]

Carl: Borrow a bunch of coolers and fill them with water to load her. You can accurately figure the weight that way.

[Tony Meola]

Carl: Borrow a bunch of coolers and fill them with water to load her. You can accurately figure the weight that way.

Or you could line everyone up and have them step on a scale one by one as they get on the boat. Assuming your wife will be one of the passangers lets see if you stay married after than one.

[Carl]

I don't need to be precise, just about topped off-tank, a couple water filled coolers, a couple of people and I think I'm good.

[Tony Meola]

Carl

Measure the gallons going into the coolers and figure 8.5 ( actually 8.34 lbs) per gallon. That will give you rough weight of what is in the coolers.

Diesel weighs roughly 7lbs per gallon, but from what I understand it can vary based on cetane rating and weather. It is heavier than gas that comes in around 6.3 lbs per gallon and I do not believe is impacted by Octane rating or weather.

I don't think you are going to find running with a full load will be much different from running with 3/4 load. I find that how I run is not impacted until I run the fuel tank down to about 110 gallons. I can easily cruise at 24 knots at 2300 RPM's once I get down to half tank I can easily hit 25 knots and if conditions are right 26 knots is easy. Then as the fuel drops the cruise speed keeps on inching up.

[Carl]

My mathematical formula for the correct loaded weight will be based on the highly accurate chine above or below the water. Now I'm light on fuel, people and stuff. Enough stuff with a full belly, the chine goes under, it's about as heavy as I go.

[Tony Meola]

Carl

My Fly Bridge comes in at 12,000 lbs with a full tank. You probably come in at about the same since your hull is thicker than mine. When mine is full of fuel, the chines are underwater.

[Carl]

With the 440's and fuel I was about 14k lbs.

[Tony Meola]

Wow. Creates a much better ride. I saw the difference when I repowered. We added a lot of glass to the back end. The extra weight takes some of the bounce out of her.