Gear Jammer

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PeterPalmieri
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Gear Jammer

Post by PeterPalmieri »

What do you guys know about this boat?

Seems to have very nicely laid out cabin and prop pockets. Haven't heard about it from this site.


http://uk.yachtworld.com/core/listing/b ... ess=Public
1969 31 Bertram FBC "East Wind" hull #315939
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mike ohlstein
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Post by mike ohlstein »

Too bad about the prop pockets........

No longer a 'Bertram weather' boat.
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1973 FBC 1286 0273-315
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In Memory of Vicroy
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Post by In Memory of Vicroy »

Yeah, don't need 'em with only 320 hp a side, and must be a problem with the cruise speed with the 1.5 gears...don't most of you guys with the Yannies use 2:1 gears? Somebody spent a lotta money on that puppy tho. Three years ago the asking price would be over 200K, guess the market's that soft.

UV
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Rawleigh
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Post by Rawleigh »

Do you really thing that change in angle will adversely effect its handling?
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1966 FBC 31
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Charlie J
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Post by Charlie J »

uv
iam running 1.5 gears with the 230 yanmars
1968 hull # 316 - 757
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In Memory Walter K
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Post by In Memory Walter K »

For all the prop pockets must have cost him, he didn't seem to gain that much speed. Am I wrong? Beautiful interior.
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In Memory of Vicroy
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Post by In Memory of Vicroy »

Yeah Walt, shoot, I run 24 cruise with my ole 250 Cummins and I know I weight just as much. He must not have it propped right, with a 32 kt top end she should cruise at about 27 at least?

UV
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amuh60
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Post by amuh60 »

I kept my boat a few slips down from it last summer. Looks very nice in person. I am sometimes in Panama City, Let me know if anyone wants me to take a look for them.

-ANDY
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PeterPalmieri
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Post by PeterPalmieri »

Personally was just admiring a well done interior
1969 31 Bertram FBC "East Wind" hull #315939
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bob lico
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Post by bob lico »

mike o remember our long discussion at the yard last week on proper proping with pockets , well behold for there it is . this and a ocean yacth could play bumper cars coming in the inlet with 6-8' following seas.
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mike ohlstein
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Post by mike ohlstein »

Rawleigh wrote:Do you really thing that change in angle will adversely effect its handling?
Ask Randall how many times we've had the props out of the water at the 'stock' shaft angle.........
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Bruce
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Post by Bruce »

Charlie,
You should be running a 2:1 gear on those 4 bangers. Somebody short sheeted that install.

Those engines are the 315 in that boat 6LP, no need for a prop pocket running a 2:1 gear box.

I've done two 31's with pockets. One was the QSC Cummins 330 1.5:1 gear. While I didn't tweak the prop as much as Bob has, I saw no performance gains over the Yanmar 315's 2:1 gears for the cost of doing pockets.
I've posted pics of this one on the board before.

The second involved a pair of 370hp Yanmars and half way thru the project creative(safety for me) differences caused me to tell the owner to take the boat and go **** himself.
Luckily the job was not contracted and just time and materials.

Never saw it run, but I suspect someone got hurt or there was property damage at some time with it if it ever ran.

Based on my calculations of what gear/prop combo the owner wanted for top end speed, the boat was going to see a 6 to 10 knot idle speed.
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Post by Craig Mac »

the interior and prop pockets makes me believe that cabrerra did some of the work
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bob lico
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Post by bob lico »

bruce when you put those prop pockets in you will have to go way way beyond tweaking to get any additional speed to warrant the price of glass work . the post on shooter with 440hp yanmars and this gear jammer with 315hp clearly illustrates what i am about to post; you want pockets no problem you have to reach in your back pocket and come up with $8000.00 in cash and you will get 110% overproped, 21dia., 5 blade, 5 degree rake,special cup beyond #5 , and pitched to produce correct engine rpm plus 50rpm under full load at wot. 5 blade is the absolute minimum .perfection would be 6 blade.as the boat goes forward churned up water is being funneled into the pocket .this white water is filled with air bubbles and then you are "just spinning your wheels".all that work to reduce prop. shaft angle you negated by not following up on desigh . rather silly my boat goes 2 knot faster at wot. and 4 knots faster with 1/3 better fuel enconomy in a much heavier boat with very usefull full lenth,full depth hatches on both sides of cockpit by way of no prop. pocket which really do away with all that valuble room.
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Capt.Frank
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Post by Capt.Frank »

The interior looks like a few cabrerra boats that I've seen. One had 3126 cats the other 315 yanmars.
1976 FBC
3208 NA
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Charlie J
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Post by Charlie J »

bruce
i will double check, thanks
1968 hull # 316 - 757
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ZeroCavity
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Post by ZeroCavity »

It is a Cabrera boat.
1965/2007 Bertram 31
Craig Mac
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Post by Craig Mac »

Looking at the pics again--I am not so familiar with prop pockets-but those look very shallow
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bob lico
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Post by bob lico »

not only shallow but worst yet instead of making upside down u they cut the most important area between the chine and strakes this is where the boat lays on in a hard turn (like avoiding a log in front of boat) . that boat has to go to captain patrick and put a o to 6" tapered keel starting from 6' back from bow all the way to transom or keep it in bay!!!!
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