wrong prop for drive?

[muskyfins]

The only reason I refer to this as a Bravo 1 upper is that was its original intent. (see picture)

I did not realize there was no difference between a right and left rotation, but AllDodge's explanation makes total sense. Thanks.

Still not sure what the 220R means?

Is gear ratio defined in the upper or the lower? I have always believed upper. The lowers are 1:1

 

[muskyfins]

I guess I'll throw in the pic of the engraving on the side. This is just forward of the serial number. Little tough to see, but it is printed "220R"

 

[Tail_Gunner]

Yes i understand the the casing but the drive ratio's on 2 & 3's are different..that is they use a different gear ratio to support the b2&3...

http://www.bluewatermarinesvc.com/pd...ear_ratios.pdf

 

[muskyfins]

Yes, different ratios, but all in the upper. The lower is 1:1.

What's confusing is that per my above posts/pics, this was a Bravo 1 upper, but seems to be stamped 220 (2.20:1???) which is an option as a B2. The label on the drive is original, so I don't think it was changed. And it is definitely mated to a B2 lower based on the distance between the prop shaft and the cavitation plate.

 

[alldodge]

The 220 is the drive ratio, if the gears have not been replaced. The R is used for XR hardened gears but the 220 does not add up for XR. The XR series drives only have one set of gears for the upper, and ratio is change on the lower with only 3 ratios available (2.00 , 1.81 and 1.65). My guess is it is at least a B2X series upper, which may also be used for diesels

 

[alldodge]

Yes, different ratios, but all in the upper. The lower is 1:1.

What's confusing is that per my above posts/pics, this was a Bravo 1 upper, but seems to be stamped 220 (2.20:1???) which is an option as a B2. The label on the drive is original, so I don't think it was changed. And it is definitely mated to a B2 lower based on the distance between the prop shaft and the cavitation plate.

Bravo's change ratios using upper and lower gears and they vary. There are many more from the past years then these but here is a pic showing you some of the recent ones

 

[muskyfins]

The 220 is the drive ratio, if the gears have not been replaced. The R is used for XR hardened gears but the 220 does not add up for XR. The XR series drives only have one set of gears for the upper, and ratio is change on the lower with only 3 ratios available (2.00 , 1.81 and 1.65). My guess is it is at least a B2X series upper, which may also be used for diesels

I would tend to believe this also except if you look at post #21, in the pic, it is clearly a B1 upper:frusty:

At this point, if it's solid and I can achieve correct WOT rpm range without over taxing the motor, I'm going to have to let this go. I have to address this stupid gimbal issue. Although I am enjoying the conversation.

In one of the photos I took over the weekend, I was able to get the serial number from the label on the drive. 0F306148. Does it look like this was stamped over some other number? It looks original to me. And in person, there's no evidence it was altered.

 

[Tail_Gunner]

I would tend to believe this also except if you look at post #21, in the pic, it is clearly a B1 upper:frusty:

At this point, if it's solid and I can achieve correct WOT rpm range without over taxing the motor, I'm going to have to let this go. I have to address this stupid gimbal issue. Although I am enjoying the conversation.

LOl easy musky think of it like this all the bravo have one universal upper case and then there loaded with the appropriate gearing. In your case it is very possible that drive started life as a b1 and somebody changed the gears to a 2.20 and then stamped the case as such..and then chnged the lower drive to a b2...common practice for backyard hacks.....I have a volvo sx single prop and would bolt up a lower dual in a heart beat but props are just to expensive so i keep it pure stock form.....for now..:lol:

 

[alldodge]

I would tend to believe this also except if you look at post #21, in the pic, it is clearly a B1 upper:frusty:

Agree, sorry its just to easy to say B2 when your talking about a B2 complete drive then to say B1X upper and a B2 lower. It works, if you really want to find out take it apart and count gear teeth :behindsofa:

We'll be here to provide support to put it back together :Cry::tape2:

Or you could pull the drive, then rotate the drive shaft and count revolutions :drum:

 

[muskyfins]

Guys,

Don't get me wrong.....I'm not even a little upset or anything. A little frustrated, but not with anyone here, just the situation.

I love you guys. :love_heart: :grouphug:

I appreciate all the input, and all in all, I love building and fixing stuff. I was just caught off guard with this and now the gimbal repair. I just need a bigger shop, more time and a box full of $100's

 

[muskyfins]

So-another update.

Put the girl in the drink and went for a ride. Achieved 37 MPH at 4500 rpm (via gps and dash tach) Using what I believe to be accurate prop math and assuming the 220R to be 1:2.2 ratio, my math works out as follows:

4500 rpm x 21 pitch / 2.20 ratio / 12 inches / 5280 feet x 60 mph = 40.67 mph before slip or about 9% slip.

Sound right? If so, then the 1:2.2 gear ratio seems correct. I'll never really know how we got to this point. Maybe after some "backyard hack" created the old frankendrive, he at least bothered to stamp the gear ratio into it.:noidea:

In any case, she runs out super smooth and i can't be too unhappy with a heavy boat being pushed by a 5.7L at almost 40 mph. She planes in right around 3 seconds and that's actually much better than I thought. So for now, this moves down the priority list.

Thanks again for all the input. My hat's off to you all.:yo: