kidturbo

Cool. But they still gotta come out to find that missing 600hp.

BigSilverCat

This is the dyno chart for the 480 hp 5.9 cummins in the V-bottom at the prop shaft. The numbers are pretty much what we expected them to be after the drive and transmission. We did not make a chart like this on the cat but the 6.7 550 hp qsb's made 508 HP uncorrected at the prop. We might have modified them a little bit and ended up with 729 HP uncorrected.

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BigSilverCat

It would be cool to put the dyno in the back of a truck and have a couple 55 gal drums of water and take it to a poker run and dyno anyone's boat in the parking lot.

IGetWet

Wow, they could bust a lot of balls at a poker run with a dyno like that

SKammeraad

sounds like a good little side job for someone who has the extra money to buy all the equipment. would be lots of sad people leaving after lol

BigSilverCat

Well.... I pulled the engines out of the boat and sold them last week if that answers the question..
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Cig41

Fantastic thread! Have you considered Seateks, not such a high hp per cubic inch. A little more size and moderate boost. I beleive they have a 1100hp 6 cylinder with twin turbos, weighs in around 1700lbs.

Cheers

BigSilverCat

After a lot of hard work to get the boat running, I have taken it all apart again. Between the stock Cummins marine engines and the arneson drives we were not able to make the boat run the speed we were wanting so we took out the engines and drives and are going a little bit different direction.

There is no tie bar on the Arnesons and I tried several different ways to keep them straight to each other and could not get them to stay apart once I would give it throttle. I tried just a straight hydraulic tie bar, then I put a trim pump inline, then a different high pressure trim pump and in the end had trim pumps and solenoid valves and the drives would come together when I would start going fast so I'm sure that was killing a lot of speed. I could make a big stand to go up and over the tunnel that would hook the drives together but I don't like how much leverage that would have against the trim ram so I did not want to do it. I think the fluid must have been leaking past the seal in the steering cylinders.

We decided to take off the arnesons and put on Mercury #8's. We know the arnesons will handle more power for sure but I could not keep them straight and did not want to have that problem while I was doing endurance runs and we know exactly were to put the merc #8's on a 46 skater for optimum speed. The merc drives also give us a lot more control over the trim of the boat and we have room to put trim tabs on next to them that you cannot do with the Arnesons.

We sent the Mercury #8's down to Vern at Lake Havasu and he put in a set of custom billet .8 overdrive gears. That should give us the higher prop speed we need with the lower rpm ability of the diesels. And we machined a set of standoff boxes to mount the drives on to get them a little farther back on the boat for leverage, cleaner water and it will make the tie bar clear the tunnel extension/steps better.

After all the work machining parts for mounting the arnesons and building the custom drop box transmissions to be able to use the straight arnesons. Work and detail installing them to never come off it was a tuff decision, but in the end we are doing this to win, we want the best chance we can of going fast as efficiently as possible so hopefully we are making the right decision.

We are filling in all the holes in the back of the boat and then have to repaint the transom. We debated about just putting a big aluminum plate over the holes but decided to fix it right and start over.

We are going to stay with the cummins style engine but they will be built from scratch with all the good parts to try to make a lot of hp and live. We could have used the engines we had as a core but in the end we would only be using the block and a few mounts so it was not cost effective to do that so I sold them and we will start out with a lot cheaper core engine.

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IGetWet

Wow, the amount of time and effort and I'm sure money that is going into this project....

But I know what it's like to almost have a project completed and rip it back apart, going through that now with my 1977 Can Am TNT 250cc. It's in pieces in the basement. Pretty much the same thing as your seven figure world record setting boat right?

JRider

That is an excellent idea! Boyne Thunder street party attraction!!!!! I feel bad for the Bravos!