jayhawk261

Continued:

Pat I don't know what the deal was with the 24P Bravo 1 prop. Maybe it was too small? It was quite a ride! This was before we installed the hydraulic steering, and the gimbal is worn pretty bad. That is being replaced now as well.

We ran up to around 70, and then as I pulled the throttle back, not quickly just evenly, the boat pulled HARD right. We did a complete U and no amount of steering input did anything to correct it. I paid more attention to the steering the rest of the day and noticed that it was very unpredictable and wanted to go right as we gained speed. I took it off after that day and didn't run it again. We put the 25P Mirage Plus back on after getting it back form Bblades, and it didn't do that anymore. The steering was still a little sketchy at speed because we hadn't added the full hydraulic yet, but it didn't do the crazy dangerous stuff it did with the B1. After installing the steering, she drives like a dream at speed!

I'm sure with the new engine, we will need to try some other props. I'm not looking forward to the chine walk over 80. That could get a little scary!

Pat McPherson

I'm betting that your handling issues were related to the steering and worn gimble. I'm not a big fan of the single piston steering, I think it wears the gimble bushings and pins prematurely. Even if a "add on" steering system is install, I'd go with twin piston so the drive is held from both sides.

Please tell us a little more about this engine you built. It's going to make 525-550 HP at what rpm? Tyler Crockett is great to work with.

As for props:
I love my BBlades modified B1. I was not crazy about it stock; it took a lot of trim to loosen the boat up and the sweet spot was vary small.
I did run a Mirage + a lot of the time when I had less power. My boat certainly does handle better with the B1 vs. the M+ but I have not experienced real bad chine walk like you and Dave M. have with your step bottom boats. I think your boats get up on top a little more with the semi pad and larger strakes.
Dave M. and T-island both run 28p B1 props on their boats so I'm thinking that you would want to try one again now that your steering has been upgraded and gimble repaired.
Another prop to try is the Merc Revolution 4. The Rev4 has more rake and less diameter than the B1. More rake should give better bow lift and less dia should work better with how deep the props run on our boats. I'm planning to try a Rev4 soon but unfortunately the largest is 25p.

Dave M

Hey Guys,

I saw the other thread on the Pantera section.

Before I replaced my gimbal ring, my boat would pull hard to the right when I trimmed it up. GET THAT TAKEN CARE OF! VERY dangerous.

I'm pretty sure my boat would run 80+ any day of the week with a HP500 (470 HP). I think anything over 75 in a 24 is just for bragging rights. I can run 70 or so in some pretty choppy water but any faster I think you are taking a chance.

cuposterchild

This is interesting about the gimbal. I might take a look at this. I had it checked last year when I pulled the drive last winter and it was fine but I am going to start getting the parts together for the full Hydraulic conversion from the add one and when I put that on I will take a look at the gimbal. 70+ in a 24 is MOVING! Takes me a solid 2ft chop to really get her running the way I like. I am more about the cruising at 55mph and not the 80 mph top end so I haven't really tuned for top end at all....yet

jayhawk261

The gimbal ring is being replaced along with a stainless steering shaft and U-Bolt from JR Marine. It will be all new inside the transom assembly with the new power.

The engine is my 454 MAG MPI that is .030 over with 9.5 - 9.7:1 compression. I'm using Tyler Crockett's cam and tuning set up. The heads are RHS Aluminum with 2.25/1.88 valves. There is some port work on the heads. Springs and the like are from Crockett. It will have full roller rockers. We are looking at hitting the dyno next week some time. We are guessing in the 525 range right now at around 5300 rpm. Crockett says more, but the engine builder is a little skeptical. Brad Smith, the guy who does all the engines for the E-Dock crew, is doing this up for me. We are supposed to have it back in and running for the trip to LOTO for the OSS race.

If I can do over 80, it won't happen very often. My wife would divorce me if I did that to her! Whoever buys it now is going to get one HELL of a deal with the new engine and speeds.

cuposterchild

JayHawk,

I am currently running around just under 500hp with an out of the box 26 bravo. Haven't done much prop testing other than switching from the 25-3blade that came with the boat. I would think you would want to start with a 26 and go from there. What rpm's are you looking to turn. With my 454 it is reving pretty high which is why I running the 26 instead of the 28.

jayhawk261

I'm looking at around 5300 or so. All of this is theoretical of course until we get it on the dyno next week. Then we'll have some real numbers to talk about!

cuposterchild

I am very interested in your progress. I would agree with Dave M too. If you can get 525 out of that motor and are still turning lower revs than start with a 28 and see where you are at and then maybe jump up to a 30 if you can spin it. Your boat should DEFINATELY break 80 if you are able to get a true 500hp out of your motor.

Pat McPherson

Yup, I agree for the most part.
Above 70 in the rough gets a little nutty. If I had a set of those thick sit down racing bolster, I'd probably push her a little harder though. I stand in the rough at this point, I'm short enough...
On calm water, my boat handles great even at 75mph and if she had more, I'd use it...

Pat McPherson

Cup, you have the same straight V boat that I do.
You may want to consider sending that 26p B1 to Brett at BBlades and have him do the same mods he did to my B1.
From what I've experienced, it requires too much trim to get our boats to loosen up with a stock B1. The sweet spot is small to run fast without modifying the B1 for more bow lift.
You may want to test a Revolution 4 also...