kidturbo

Lower units are both off and boxed up ready to ship to Cali, and I'm back in Ohio. Believe Pat has a complete lower unit available, while I have enough new gears and shafts up here to rebuild both units. We also noticed the prop shaft on Stbd was tweaked about .050" when we fired em up on the trailer. So guess now is good time to go thru both as we did the upper drop box sets.

We won't know if the Port case is salvageable until they crack it open and see what went through that gear. Best guess, a broken tooth since it managed to get us back to the trailer without issue. Many thanks to the crew at Innovation Marine for all the support over the past few weeks. Nice to work with a group of guys who understand what we're trying to accomplish. Thing are gonna break while testing, but if you have access to tools and professionals, it's not really a set back. Just another R&D story.

While the lowers are off, it's a perfect time to easily drop the uppers an inch or two. The standoff boxes are drilled with 5 separate #6 bolt patterns, so to lower the X, you lower the whole box. They are currently in the highest setting. Finding 18" or big cupped props to test with is likely gonna be harder than just lowering the boxes. Now to dig up all the drawings and see how we came to the current height.

Crude Intentions

iTrader: (1)

The engines look awesome. Good luck when you lower the drives. Can’t wait to see the results

rak rua

Enjoyed this whole story, from start to finish (still pending).

Just to add, I love your attitude, having come this far and finally got the engines in gear and out on the water, things don't go as hoped and all you can say is "it's not a set back, just another R&D story......"
Great outlook, we all know you'll get this project done and it will exceed expectations.

Thanks for the updates.

RR

302Sport

Keep the high X and get a set of 18” diameter, 18 degree rake, 6 blades, any pitch. Change the ratio in the drop box for whatever prop pitch you end up finding. That’s the nice part of the drop boxes, you just have to find the right diameter, rake and blades then just adjust the ratio to what you need.

Also ask Pat if there’s any way to attach a vent tube on those drives, with the turbines we never had to, but it would help you put a ton getting the props to break free.

Keith Atlanta

Just curious, what is the X dim? How many inches below bottom did you gamble with? LOL, are you even below the bottom?

kidturbo

I think it's all posted on here somewhere.. Gotta dig myself, was only 3yrs ago. And no, they are certainly not below the bottom by any form of measure.

green lightning

What I have found out in my prop testing was when you have a V-bottom boat , surfacing drive, #6 type prop and in a non staggered set up you need at least a 17 1/2 " dia prop or getting on plane will be difficult . To bad you are not a little closer to New York I have a set of 5 blade 18"dia 31 pitch 20 rake props I would let you try .

kidturbo

Your not the first person to suggest the larger diameter and rake approach at current height. Along with swapping rotation from Inward to Out..18's were are our choice diameter from day one, but I never imagined she wouldn't plane on 17"s... Ya coming to FL any time soon??

What I notice was the disruption from the water pickups seemed to really be playing havoc in the area between the props. I have some other video that may show this better. TG suggested maybe not enough prop speed to plane the boat in low gear. But I tried shifting them into high while loose, and they showed no sign of trying to recover until boat speed fell off and I pulled the power.

When I tried to start off in Hi gear, 1:1 ratio, the engines [turbos] were not going to cooperate with props hooked up. Needs some tune work before that's an option. But shaft speeds I noted when they first unhooked is around 1500rpm, then I pushed em up to around 2800rpm in low gear several times. On a BBC red line at 6k, that shaft speed might be closer to 4000rpm if you let em fly. To me, that's not a reasonable option on these diesels.

Thanks for all the suggestions. Open to any and all options right now.

kidturbo

Here is a cell phone angle where you can see both drives and hear the engines a little better. They boost and start to hook, then unhook and bounce the limiter.

Look fwd to comments.

302Sport

You need vent tubes and 18” diameter props with 18-20 degree rake.