BUP

iTrader: (9)

Boat is a 1986 Cobalt 300 - has no motors but TRS drives and trannies. They will be gone and going to a current set up. This hull was the 30 Carrera back in the 80's. Specs are 26 degree deadrise, 7800 lbs dry weight, and a 8 ft beam. Its a huge 30 footer. Anyways I know the + 's having staggered motors and the few negs about them. The conversion would be transom redone / new, stringers and rear interior moved fwd. Gas tank might be a problem as a lot boats use saddle tanks. I already talked to GlassDave about the project but not in great depths. I understand the costs of the conversion. Also thinking about adding extension boxes. It already has full hydro steering.

I am thinking this boat will handle a lot better in all conditions except very low rpms with staggered engines. My thoughts are being 26 degree deadrise the hull will not roll over as much when corning with staggard engines, also in rough water it will stay hooked up better along with a more level ride. I would have to say rough water handling and corning would be a noticeable positive result along with room to work on the engines. My questions, should I do the conversion or will I not gain much improvement or even go backwards. Thoughts and any real world conversions on deep V's non stepped hulls pro's and con's. I already have to redo the transom getting rid of the TRS drives anyways. THX

professor_speed

The advantage really only lies in getting the drives closer together. weight distribution is a moot point if you move the fuel tanks from the belly to saddle tanks at the chines.(100 gallons of fuel is near the weight of a big block) if you are doing all that work save money on boxes and glass in a notch. or you could just find a set of arneson 1600's and make life alot easier,(I think there is a set in the swap shop) closer bullet proof drives and way less work. plenty of straight bottom twin engine boats with surface drives, just make sure there is no hook in the hull. my $.02

BUP

iTrader: (9)

Thx for the reply. I really did not want to convert this to saddle gas tanks because that kind of defeats trying to keep weight low and changes the CG especially when the tanks are full. I understand the gas tank under the floor might be an issue with the front motor being staggered trying to install it properly.

Anyways, just like changing things up, plus owning something different that's not all over the lake. Always wanted this or the Carrera 30 back in the day. In 1986 this Cobalt went for 130 k. That was high dollar back then for a 30 footer and out of my price range.

Also I am a dealer so pricing is better for me than full retail. I have all the Bravo stuff in stock to convert this over also along with big blocks. So I guess I am half way there, just have to make the decision which way to go with the conversion.

Jolley

iTrader: (2)

There is what is called 'modulation' inherent in U Joints that is reduced/mitigated by phasing the opposing joints depending on their angle to one another.

At work I Design and Engineer Steering Columns and I Shafts (with joints in them) and we adjust them to optimize the 'acceleration'/'deceleration' as they rotate at a constant. Sort of looks like a figure eight on the graph when looking down the shaft/.

Input at the driven end there is a constant drive rotation, this turns the other U Joint, and its driven rotation accel/decel changes based upon the difference of input / output angles (Trans to Drive Input) in a side view.

We try to make the 'figure eight as small as possible by 'phasing' the joints to minimize this effect .

I hope some of that made sense, I did not know this about U Joints before engineering school but it is worth looking up. Just want you guys safe and fast..............................

ps. Constant Velocity Joints do not do this this, thus the name.

Now for the SH!T STORM I just started. No Flames Please

Jolley

iTrader: (2)

OOp's was replying to the U Joint failure in the Geico. Must have f 'd up. Sorry BUP.