Short Circuit finally floats again

Capt. DQ · Post by **Capt. DQ** » Jul 2nd, '07, 17:20

Well finally made it back in the water 6-29-07 after almost 3 years of being on the hill, and was really worried about the engines if they were going to crank after almost 3 years, after priming them up and checked all fluid levels and push the start button they started first time and I mean they sound awesome.

But during the sea trial the engines would only turn 2250rpm to the pins, but everything was smooth and both engines turned the same rpm. I'm going to check to see whats wrong? Need to get 2650rpm out of it.

Cummins 89 model 6bta/250hp with ZF220a 1:53 gears, propped 21 X 22 with 3-cup, 3 blade.

I'm thinking props but UV I think has the same set-up, but will double check to see if throttles are opening all the way, but runs really smooth.

It sure is nice to have my B31 going again with deisels which are really nice compared to the gas engines I once had, pictures will follow shortly.

Hope everybody had a good time Panama? I will be ready for the UVI to return to Port Eads when that happens.

DQ, the happy fishermen again with a boat.

In Memory of Vicroy · Post by **In Memory of Vicroy** » Jul 2nd, '07, 17:56

Doug, glad you are back in. We did have a big time in Panama for sure. First, what kind of speed are you getting at 2250? Should be about 22 kts, if more maybe the tachs are off, easy to check with a photo tach. For sure check to make sure you are getting full throttle travel. I have the same props, but no cup and get 2650 easy, cruise 2400 at about 24 kts.

The only other thing I know of that will keep the rpm down other than overpropping and less than full throttle travel is fuel restriction on the pressure side of the lift pump.....clogged secondary for example. Clog or restriction on the suction (Racor) side will usually show as a variation in rpm.

Take your time and logically work thru it......fuel, air....diesels run. Also if you are WOT at 2250 and they don't smoke black, its a throttle or fuel restriction issue.

UV

Capt. Mike Holmes · Post by **Capt. Mike Holmes** » Jul 2nd, '07, 18:40

Doug, although it usually wouldn't hold you back quite that much, exhaust restriction will also keep you from turning full rpm. I found out the hard way on my repower that if the exhaust can't get out as it should, fuel won't go in as it should. This is sort of an oversimplification, but you need good "goes-outta" to get good "goes-inta". My problem was excessive bends in the exhaust crossover, more on the port engine. With both your engines turning the same, however, this might not be the problem.

Capt. DQ · Post by **Capt. DQ** » Jul 2nd, '07, 20:21

UV,
Tach's are matching perfect, I have the algae-x units first from the tank, then goes into Tony Athens dual fuel filtration system, with a vacum gauge, then a Walbro pump for a pass thru unit only used to prime the fuel system if ever run out of fuel. I don't think there is a fuel restriction
because the Walbro pump primes the system easy which it is locate after the dual fuel filters.

No black smoke running at all, smokes a little when cold but disapates after coming up to temp, but no black smoke at all.

Capt. Mike,

Star-side exhaust has the the stock stainless curved sweep elbow with 2-45 ell's with a 5" centex muffler, the Port-side has the stock sweeped 90 stainless with 2-90's and 2-45's and a 5" centex muffler with good water flow out the exhaust. Running engine temp's are between 180-190 up running. But with both sides turning the same rpm to the pins.
Will shoot some pictures of the exhaust system to show.

DQ

In Memory of Vicroy · Post by **In Memory of Vicroy** » Jul 2nd, '07, 20:32

Doug, next let's test the WOT out of gear....you should get about 2900, & that's a good test of your throttle linkage. If no black smoke at WOT and only getting 2250 - the SC is a heavy boat with that tower, maybe borrow some 20x20's and see what that does....you gotta hit 2600 + or something is not right.

UV

Capt. DQ · Post by **Capt. DQ** » Jul 2nd, '07, 20:42

UV

Have not done the static rpm test yet, but will do. The tower is not that heavy but it is a 67 model FBC which is a little heavier than your's I think.

DQ

Hal · Post by **Hal** » Jul 2nd, '07, 21:18

Damn, that boat has been on the hill so long, I use it as a landmark to make my turn into Island Cove! Glad to hear she's running and hope your spin up problem is an easy one to solve.

Oh, and btw, is your place where Chad took the parts to my generator before disappearing? Just curious now that I've had to buy a new one.

JP Dalik · Post by **JP Dalik** » Jul 2nd, '07, 21:26

Nice to hear she's floatin DQ.
Good Luck with her, go get some.

Harry Babb · Post by **Harry Babb** » Jul 2nd, '07, 21:34

Congratulations Doug...........I keep threatening to drive over and visit with you......

I am sure that you are proud and excited

Harry Babb

Capt. DQ · Post by **Capt. DQ** » Jul 3rd, '07, 08:20

Hal, I know what you mean about being a landmark, but no Chad did not bring your gen. parts to us.

JP, Thanks maybe when you get down here in the fall we go bust up on some Fall White Marlin fishing or something.

Thanks Harry, we talked before about how close you are, your just over there on the back 40.

DQ

litecatch · Post by **litecatch** » Jul 3rd, '07, 08:20

Doug, she looked good sittting in her slip! i have a photo tach if you need one.

Capt. DQ · Post by **Capt. DQ** » Jul 3rd, '07, 08:22

Scott, Thanks, I will call you about getting together.

DQ

Mikey · Post by **Mikey** » Jul 3rd, '07, 10:09

Doug,
Only three years!? Wow! Congrats. Love hearing that those Cummins fired on command. Same issue here. Looking forward to the day we light them off. Soon we hope.
Nose to the grind stone shoulder to the wheel . . . how do you get anything done in that position?

Capt. Mike Holmes · Post by **Capt. Mike Holmes** » Jul 3rd, '07, 12:19

Mikey, donkeys are bad asses. Around here, farmers run them with their cows and sheep to chase away coyotes and dogs. They hate anything that looks like a dog, evidently.

Capt. DQ · Post by **Capt. DQ** » Jul 3rd, '07, 15:17

Mikey it will be, (HOW SWEET THAT SOUND IS BROTHER!) when that happens for you if you have been doing all the work on the project.

There's also a story to go along with that 3-years. Believe me it has been an adventure & miracle to get to this point!

DQ

Mikey · Post by **Mikey** » Jul 3rd, '07, 19:16

DQ
We could trade stories. Five years was not my idea. I posted part of it last year but haven't a clue how to find it now. Yes, I'm doing 90% of the work. Slow but satisfying. Hope to have it splash this season. That's the plan anyway.Whew!

Rawleigh · Post by **Rawleigh** » Jul 5th, '07, 11:28

Where did you get the donkey stats Mikey?

Mikey · Post by **Mikey** » Jul 5th, '07, 12:14

Rawleigh,
The donkey lobby has it all.

Capt. DQ · Post by **Capt. DQ** » Jul 9th, '07, 20:32

Well here are the lastest sea trial #'s,

1600rpm @ 16kts.
1800rpm @ 21kts.
2000rpm @ 24kts.
2450rpm @ 29.6kts to pins

still need 200 more rpm to unload the engines. I reset the governer's @ 2800rpm and still need another 200 rpm under a running load to 2650rpm to the pins, but it sure is nice with those diesels running.

DQ

In Memory of Vicroy · Post by **In Memory of Vicroy** » Jul 9th, '07, 20:48

Shoot Doug, the SC is a blur.....you need to drop about an inch and a half to 2" pitch to get to 2650 is my guess......AJ is linear, rpm to kts from about 1800 up......look for 24 kts at 2400 and about 27 at 2650 and you are there......2400 all day long. 21x22 three blade nibrals, no cup, 1.53 gears.....

UV

Capt. Mike Holmes · Post by **Capt. Mike Holmes** » Jul 9th, '07, 21:46

Great numbers, Doug.

bertram31.com

Short Circuit finally floats again

Short Circuit finally floats again

RPM

Donkeys

Wow!

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