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25 Flybridge power opinions

Posted: Jul 25th, '17, 14:52
by RobCiminieri
Hello all i am back to my 25 FBC project. It is a Vdrive boat with tired 470s in her. I looked at diesels but with no fianance options the diesels are a hard nut to swallow at this time. I am thinking 350 chevys. My other option is a bracket with an outboard or 2. I know the outboard is not traditional but will get more fuel and deck area. It also clutters the stern. The boat will be used to fish like my.Bahia Mar. would love to hear some input.

Re: 25 Flybridge power opinions

Posted: Jul 25th, '17, 16:08
by CamB25
Since you have the V-drive configuration, I would stick with inboards. Outboard conversion would require a heck of a lot of structural work on the transom. It probably doesn't make sense unless you are taking the boat through a complete rebuild. You can buy 2 new fuel injected 350s for the price a single outboard:

http://www.michiganmotorz.com/complete- ... p-123.html

Re: 25 Flybridge power opinions

Posted: Jul 25th, '17, 16:26
by RobCiminieri
I do lime the invoards. The boat is so easy to maneuver. I guess the next thing is new trans or reversed rotation 350.

Re: 25 Flybridge power opinions

Posted: Jul 25th, '17, 22:19
by John Swick
Jack shaft a new 6.2L v8 to a duoprop outdrive and you will not be able to wipe the smile off your face.

Re: 25 Flybridge power opinions

Posted: Jul 25th, '17, 22:36
by Tony Meola
Not sure you can get reverse rotation anymore. Today it is all done through the transmission.

Re: 25 Flybridge power opinions

Posted: Jul 26th, '17, 05:09
by RobCiminieri
John Swick wrote:Jack shaft a new 6.2L v8 to a duoprop outdrive and you will not be able to wipe the smile off your face.
I had a friend that had a Carolina with jackshafts to bravos. Man that boat made a racket drifting in neutral. I think i will keep the inboards. I have seen some single v8 conversions and you are 100% correct. The performance is amazing.

Re: 25 Flybridge power opinions

Posted: Jul 26th, '17, 05:12
by RobCiminieri
Tony Meola wrote:Not sure you can get reverse rotation anymore. Today it is all done through the transmission.
Tony i see first mate and michigan mptorz still have reversed rotation. I think the zf trans are much more reliable from what i read. 1st hand info is always better than the hear say. You guys on the forum are a valuable resource to an old boat

Re: 25 Flybridge power opinions

Posted: Jul 26th, '17, 22:23
by Tony Meola
Rob

Reverse rotation were around for years and very reliable. Doing it through the transmission is also reliable so it would be a toss up as long as the engine you are buying is new coming out of the crate. If it is rebuilt then I would pass unless you really trust the rebuilder.

Re: 25 Flybridge power opinions

Posted: Jul 27th, '17, 04:07
by RobCiminieri
Tony Meola wrote:Rob

Reverse rotation were around for years and very reliable. Doing it through the transmission is also reliable so it would be a toss up as long as the engine you are buying is new coming out of the crate. If it is rebuilt then I would pass unless you really trust the rebuilder.
It was goining to be a rebuilt from first mate or Michigan motor. so i guess rebuilt in the crate but not by a shadetree....

Re: 25 Flybridge power opinions

Posted: Jul 28th, '17, 09:16
by ford351c594
just had to custom 383's built by white brothers performance in Tennessee. One is reverse rotation. It is no longer special cranks and rods like it used to be. Basically all it is now is a custom cam and a gear swap on the distributor and you have reverse rotation. One other thing. A reverse rotation engine should never have a timing chain in it. It should always be gear driven.


here is my horsepower and torque for less than 5k a engine...

Image

Re: 25 Flybridge power opinions

Posted: Aug 1st, '17, 14:27
by captbone
Maybe a good chance to pick up a set of engine cheap and have them redone. No affiliation, just passing on.

https://longisland.craigslist.org/bpo/d ... 69793.html

Re: 25 Flybridge power opinions

Posted: Aug 1st, '17, 14:47
by RobCiminieri
Capt why would i want those 470s?? Especially out of my boat. LOL!! Thats me. The 470s go and looking at 350s after this long grueling process of twisting my brain apart

Re: 25 Flybridge power opinions

Posted: Aug 1st, '17, 20:25
by captbone
Lol! I hear the seller is pain!!!!

Small world. Glad to see you moving forward.

Cheers!

Re: 25 Flybridge power opinions

Posted: Aug 2nd, '17, 04:16
by RobCiminieri
Thanks for remembering the thread Capt. Much appreciated. So you know my direction i think twin 350 chevys. Cheapest most reliable out. I was close to going bracket...Real close. Thanks to the almost "nonexistent" transom compaired to her sterndrive sister the purist in me will prevail which in the end my OCD will be satisfied in the later. Funny how things work out Capt.

Re: 25 Flybridge power opinions

Posted: Aug 2nd, '17, 09:37
by captbone
I think you will be very happy with the 350s. The weight amidship will make it ride the best. My 25 Bertram used to ride the best with full fuel and 6 people.

Looking forward to pics of the progress.

Re: 25 Flybridge power opinions

Posted: Aug 3rd, '17, 21:22
by kellysmall
Good choice to stick with the 350's. I did that back in 2004 with my v-drive B25 and never looked back. Same footprint, and horsepower increased from 225 to 325 each. And then, I had no problem coming into Pensacola Pass on an outgoing tide. Gained a significant increase in fuel economy also. I also took that opportunity to replace the stock rudders with new oversized stainless rudders very similar to Captain Pat's design. Made a HUGE difference in the handling. Heck, I even replaced the entire rudder shelf too. Not satisfied with all that work, I rewired the whole boat too! You can see what kind of "can of worms" you can open up with a good repower project! Keep us posted on your progress.

Re: 25 Flybridge power opinions

Posted: Aug 4th, '17, 05:16
by RobCiminieri
I definitely will. It is a new but enjoyable task. Learning a lot real quick. Owning 20s and 25s all of my experience is with sterndrive Berts. My ruddershelf has been replaced. I need to drop the shafts and make sure that is all good. The rudder mention was a thumbs up. I would love to find a source. I need to find out how to post pictures and i will share my album as it grows

Re: 25 Flybridge power opinions

Posted: Aug 4th, '17, 06:01
by Lars
Kelly, I remember admiring pictures of your boat - it looked great!
Did you have to upgrade shafts or gearbox when changing to 350's, or could you do it on existing running gear?

Re: 25 Flybridge power opinions

Posted: Aug 4th, '17, 16:58
by kellysmall
I re-used my Velvet Drives since they weren't all that old. Had to have them rebuilt, though, because on sea trial, I blew a seal and burned one of them up. I replaced the prop shafts, but I used the same size. Didn't even have to change the pitch on the props.

Re: 25 Flybridge power opinions

Posted: Aug 5th, '17, 14:04
by Lars
Thanks Kelly! I will probably be going the 350-route with Crusader PowerPaks next season.

Re: 25 Flybridge power opinions

Posted: Aug 6th, '17, 09:37
by John Swick
Rob
That racket at idle on the jackshafted boat is bearing(s) that need to be replaced.
Misalignment and lack of maintenance is common with this configuration, as a lot of the boat manufactures don't make easy access points part of their design.
No it's not perfect, but if improved performance (speed, and fuel economy) is your main goal with minimal alterations to your existing deck design/layout, that gets it done.
Outboards are great, but like everything else, there are trade offs.
Your boat has the fly bridge so your best option is probably sticking with inboards and upgrading to 350's.
All that weight down low definitely aids stability.
Good luck with your project.