Staggard driveline long shaft takes more HP
 

Ever since day one with my Bertram I can not sync motors, always 200 - 300 rpm less with port engine. changed everything over between engines to see if different, No. latest poker run noticed a little vibration on port driveline around 3,600 Rpm, so I pulled driveshaft and freeked out how heavy it was. didn't weigh before I left at driveline specialist but he also stated very heavy for application. Im awaiting for his response. May retube with lighter material. still in a confused state. Starboard shaft is only like 16" long and just a slip joint and two flanges.

My Question to the forum gods. Will it take more Hp to spin the long shaft verses shorty shaft.:lolhit:

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One of the offshore race teams set me up with Dynotech
Pricey,.. but they know there products. bout $800 per engine

Doesn't answer your question,.. but fyi if you ever need another source for parts

I would think not. Even being heavier, longer etc, once it's rotating shouldn't be a difference... Maybe off base here but physics wise, shouldn't cause horsepower loss especially to the tune of 2-300 rpm.

Port engine spins apposite of wheel, where as starboard spins same as wheel.that was another thought was tossed at me today. Awaiting drive line guru to call me back with his results. I need it back by Friday. I'm also trying a new set of bigger B4 props . This will be my fifth attempt to find the perfect wheel.

Driveshaft angles equal (parallel flanges)? Crosses not in phase (can happen if you have slip joint and put back together wrong)? These things can cause more losses, vibration, even driveplate and gear issues if off significantly.

No.

Agreed, Will follow up on what you listed. Thanks falcon

Curt- The jack shaft may have been upgraded because of the diesel engines that were in the boat when you bought it. I would see if aluminum shaft is an option.

Wannabe

If the diameter is small the rotating mass is also. A lighter larger diameter lighter shaft can have a greater turning weight than a small diameter steel shaft.

Did you try switching props from side to side?