4BT 28B project

scenarioL113 · Post by **scenarioL113** » Jun 6th, '10, 16:41

We are in the water finally after 3 yrs and countless hours.

Ran like crap till we got to the slip. Valves needed to be adjusted, they were very tight on the tolerences.
The port engine had an intake valve that came off the cup, thank god it wasnt bent.
When we rebuilt the engine I thought the valves were a lot closer to spec, I could not have been more wrong. Thank god no damage was done. Once we got her in spec she came alive and I had that feeling of triumph! Not a whisp of smoke when cruising either.

WOT 2800 RPM's 26MPH as per paddle wheel (GPS broke)

2200 18 MPH up on plane no problem. (approx 4GPH per engine)

18 X 19.5 3 Blade w/ slight cup

1.5:1 gears

From a stop she comes out and up like a lion.

Its been one hell of a day!

Frank

In Memory Walter K · Post by **In Memory Walter K** » Jun 6th, '10, 16:51

Congratulations! Walter

Charlie J · Post by **Charlie J** » Jun 6th, '10, 18:29

frank
congradulations, you must be one happy camper

Mike Moran · Post by **Mike Moran** » Jun 6th, '10, 20:01

nothing feels as great to do all that work and have it all come together great job

Harry Babb · Post by **Harry Babb** » Jun 6th, '10, 21:01

Frank
I'm sure your feeling 10 feet tall! ! ! ! Congrat's to you

Harry

Harry Woods · Post by **Harry Woods** » Jun 6th, '10, 21:06

Frank,
Congratulations. No one can describe the feeling when you bring her up to cruise for the first time. You will find that the diesels in the 28 change the handling characteristics for the better. Especially when you have seventy miles to the inlet and you are sipping fuel all the way home.
Harry

bob lico · Post by **bob lico** » Jun 6th, '10, 22:06

all those years of hard work finally comes together when you hit that ignition switch and the cummins roar to life.put her into the wind and she become a entirely differant boat . best of luck with her ,take care of her.
your friend bob

scot · Post by **scot** » Jun 6th, '10, 22:30

Congradulations, those are decent numbers and the engines appear to be a good match for the hull. I am surprised a 28 will cruise along on plane at 18 mph? I would have assumed that 19-20 mph would have been the break-over on that hull with such a sharp keel.

Refresh my memory, are those engines 155hp?

Face · Post by **Face** » Jun 7th, '10, 12:12

Congratulations and thanks for posting. I have the same boat and engines but haven't put her all back together. I've been really curious about the performance numbers and your post is a big help to me. I believe these motors are 150 hp.

In Memory Walter K · Post by **In Memory Walter K** » Jun 7th, '10, 12:36

HP is always measured at WOT as I understand it. On a diesel, cruise is just 200 rpm under WOT, and run for hours. A gas powered engine's cruise is usually at about 60 % of wot. Your performance numbers/fuel consumption numbers only emphasize the wisdom of your decision, plus you now have a lifetime engine. Walter

Capt.Frank · Post by **Capt.Frank** » Jun 7th, '10, 20:39

Congratulations, I know its been a long time but you should be real proud of your work.
Enjoy the summer and all that hard work that you done.
Frank

Major · Post by **Major** » Jun 8th, '10, 08:03

Glad to hear your 28 with the 4BT's worked out so good. Those were much better numbers than i was expecting and thats always great news. Now ill have to get on the ball and get mine up and running.

So where are the pictures? :wink:

scenarioL113 · Post by **scenarioL113** » Jun 8th, '10, 13:59

Maybe after the weekend on pics and maybe a video feed!

scenarioL113 · Post by **scenarioL113** » Jun 23rd, '10, 10:04

Here is a quick video but it is not all that great, was into the wind a little bit and the boat is actually performing slightly better.

http://www.youtube.com/watch?v=idJX4uZP5u8

scot · Post by **scot** » Jun 23rd, '10, 20:35

Nice little sound coming out of the 4B's. Based on the volume of your voice it appears the noise level is not bad at all. Certainly does not seem to require screaming on the bridge.

Boat is running along nicely. Inspiring for those of us still under construction....keep the videos coming!

scenarioL113 · Post by **scenarioL113** » Jun 23rd, '10, 21:13

I am running 3-1/2 exhaust. I used my old original mufflers which are basically blown out and offering virtually no backpressure.

It is a little noisy and shaky at idle but I just have to get the kinks out and decide a less shaket idle rpm.

I would have to say the boat is no louder than when I had the 350 gassers.

The engines almost do not smoke on a cold start and when cruising the harmonics will put you to sleep.

I will be out of town for a few weeks but when I get back I will post a better video. My wife wasnt cooperating so I had to drive and video tape.

scenarioL113 · Post by **scenarioL113** » Oct 4th, '10, 18:13

*UPDATE*

Seems like the economical RPM is between 2200RPM and 2300RPM which is between 17 and 18 MPH. As long as you bring her up and then throttle back down to the above stated she stays up on plane.

I went out the other day and ran 26 miles and burned 12 gallons of diesel. Those number are not bad, I am pretty satisfied with that.

I was wondering what you 6BT guys are cruising @RPM-wise???

wmachovina · Post by **wmachovina** » Oct 4th, '10, 18:27

250 6bts in a 31,2400-25/26 kts, 2000-21 kts, 1700-17kts. Fuel burn 2400-21gph, 2000-13gph, 1700-9gph. Performance based on running data and fuel burn from cummins not flowscans

Bob H. · Post by **Bob H.** » Oct 4th, '10, 18:46

Way to go Frank, enjoy all your hard work, those cummins sound great on the video. BH

J Graham · Post by **J Graham** » Oct 4th, '10, 20:31

I have a single 330B in a B25. Tops out at 2900. Cruise at 2300/24 kts around 8 gal/hr.

In Memory Walter K · Post by **In Memory Walter K** » Oct 4th, '10, 22:20

I have 6BT 210's in a 31 Sportsfisherman. I cruise at 21-22 kts @ 2400 and burn 8 gal per hr on each engine. WOT is 2650 which I rarely do.

bertram31.com

4BT 28B project

4BT 28B project

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330B Cummins #'s

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