Bertram33 User Forum

quote:Originally posted by IRGuy Gazmo... If you have any interest in the boat in Little River, SC, "Traveler" (the first boat Doug mentions above) let me know and I can check it out for you.. the owner of the listing brokerage (Cape Fear Yacht Sales) is my next door neighbor and a good friend. Frank B - IRGuy@aol.com The weak will inherit only whatever the strong are willing to let them have! "Phoenix" 1983 FBC Cummins 6Bs - 315HP Wilmington, NC

Hi Frank, thank you for the offer, I already signed the papers on this one, first week of December sea trial, we'll see what happens.

Sorry to hijack the thread, my 33 FBC with the 3208Ts is running at about 16 knots at about 2500 rpm....it will get to 3000 rpm at wot. This is on fresh water, with half fuel, and loaded....is this too slow? It will hit 23 knots at wot (this is all GPS reading, not water reading). Should I check the screws? It always run this way for as long as I remember....

The screws need more pitch and some cup. The 3208 is set to turn max 2800 rpm. I think I was told by Bertram 21x22 pitch with a heavy cup was correct. Captain Larry Wren 305-360-4900 www.apirateschoice.com [img]http://www.bertram33.com/photogallery/p ... Choice.jpg[/img]

Do you think my screws can be modified? Can they take them to that pitch, or will I have to change them altogether?

According to the Bertram spec sheet on the prior page, the correct size and pitch is 20x22 with a cup. What size are your props right now? Turning 3000rpms at WOT isn't really a bad thing. It means the engines are not being over-loaded. You could re-pitch or add some cup, but I wouldn't go much less than 2900rpms.

With Cummins 315/330 HP 6Bs, 1.5 to 1 transmission, and 21x23 no pitch props I can run 2950 RPM so I think you should be fine with 21x22s.. but I have to admit I do not know enough about the science of props to comment on the effects of cupping. Frank B - IRGuy@aol.com Due to the recent budget cuts and the cost of electricity, gas and oil, as well as current market conditions and the continued decline of the U.S. economy; the light at the end of the tunnel has been turned off. We apologize for the inconvenience. "Phoenix" 1983 FBC Cummins 6Bs - 315HP Wilmington, NC

If your setup is stock, then 21 inches is too much diameter.

I really did not measure the props last time out of the water......would I gain anything by changing them? Less fuel use? I mean, now I cruise at 2500 rpm but I also think that it takes less throttle to cruise at those RPMs since the engines are not so loaded....

Whether or not you gain anything depends on the size of your props. Since you're at 3000rpms at WOT, you could add either a little pitch or some cup and pick up some top-end and cruising speed.

33 sportfish with 21x23 1/2 with a 3 cup. Loaded for offshore runs at 2400 and gets 23knots in good seas. Bad seas will be anywhere from 21 1/2 to 23 kts. At 2450 to 2500 rpms [ she loves that, seems to purr] i get 24 kts plus. I know I jumped into this thread but thought you guys might want some #'s. 3208 320hp. Mike

Lucky you! On my boat, fresh water and river (there is a lot of current sometimes) at WOT sometimes I cant get above 23 knots! This is on a mid loaded boat, mid fuel, jet ski on the swim platform powered by 260hp cats...

Well you just answered the question: Jet Ski on the platform. On a marginally powered boat, adding a couple of thousand pounds to the swim platform will have that affect. You could add pitch till you're blue in the face and all you'll do is run your engines into an early grave. Your boat needs to go on a serious diet if you want more speed. Also, the boat will be slower in fresh water as there is a loss in buoyancy when compared to running in salt water.

Yeap, I know....the bouyance and currents affect speed quite a lot, and the jet ski does not help, it is only 280 pounds but the weight placement is critical, although it is compensated by the fact that my boat does not have a genset currently. Overall I am happy since my boat is not so fast, but I can say it is performing as it should considering its age!

quote:Originally posted by dougl33 [img]http://www.bertram33.com/images/uploads ... cSheet.jpg[/img] Regards, Doug L. 1986 33 Bertram FBC Cummins 6BTA's Queen Elizabeth Marblehead, MA [img]http://www.bertram33.com/photogallery/p ... sabeth.jpg[/img] Off topic a bit but does anybody know all the original specs for a 1977 33' fbc? I see this chart is for 1987.