I saw some of the pics on x-dimensions,been working out the bugs of my boat and the set up.Have a 77 Excalibur,604 b.b.,merc 1 trans,i believe trs drive but never worked on these before.measured from imaginery stright line of hull bottom to center of prop shaft,got 51/2 inches.someone told me to lift up the tabs and let it eat but it pulls the bow way up and porpoises,also almost impossible to get on plane with tabs up,boat has 23p 3 blade cleaver.with tabs down boat runs stright as an arrow,nice ride,corner hard rpm's will rise 2 or 3 hundred.some have suggested 3 blade mirage or a 4 blade prop and i think i could use bigger pitch but do not know what fits this drive. Any suggestions would be appreciated,by the way it is a 24 ft. v bottom with narrow 7 ft. beam

Exactly the same hull as my 77 Martini. With that much power you should be able go like crazy but not with the old cleaver stuff that they came with. I'm running a 29 Spinelli (that was reworked several times so I think it's only really about 28) at 53-5400 on the right day -- 80+ on gps. But my backup prop (and it runs just as fast but doesn't handle or perform through the whole range nearly as well) is a 27 Mirage. If you can get the hull up and loose you should be able to run flat out with tags full up. I call the X-dimension the distance between the drive output centerline and the keel. I have the TRS drive and I'm sure you do too. My X-dim. is 18-3/8" (but I did raise that 2-1/2" form stock) For more details or pics. you can e-mail me at my profile address. --- Jer --- PS-You got lots more cubes than I do so I would think you would want to start with at least a 27 Mirage. But check the hull for "hook" before you spend too much money.

I ran a stright edge down the hull in several different places,i noticed that the last 4 ft. of the boat tapers up at a slight angle but no real hook in the hull,at what speeds does a boat usually
break loose ? The boat has only been between 35 and 40 because i feel i am severly underproped.More info. on what a hook is and where it would be located if i had one would be appreciated.

OK, you got me really messed up here. You got a fantastic (even if it might need some help) old hull and over 600 cubes and you don't run over 40??? One of us is not on the same page here. Don't bore the OSO Board here while we sort this out. You can e-mail me direct at [email protected]. --- Jer

Its good to here some tech info on that style of hull.I have a 1977 Magnum 25 same design of hull as the Excalibur. My boat has a warmed over 365 hp mag approx 400 hp now. Has gone 61mph on gps. Porpuses like a mother in calm water over 30 mph with tabs up.Tonight Im going to mesure X dimension and repost. Damn good to find other old turds(kidding) going straight at speed

Measured distance from the TRS bullit (nose cone) in the full down position, to the bottom of the transom flat 5 inch pad, is 5 3/4 inches.Also from the drive center ,taken at the mid point of the gimble swivel (half way down the bulge on the gimble ring) to the flat spot again, I got 19 1/2 inches. Would rasing the drive stop porpousing?

Are you guys telling me that you can't get your tabs up at speed? Have you tried keeping the drive trim all the way down and pulling the tabs up at wide open? You should definitely be able to get the tabs up without porpoising. After the tabs come up, you should be able to get some positive drive trim as well. THen you should be aired out nicely and running fast - you will need to prop to 5000 rpm (on the 365hp 454).

If you can't get the tabs up, then I would look towards a Mirage prop. Maybe the stern lift of the cleaver is causing this.

Although I don't have ALL that much experience with the "pad" version of these hulls it almost sounds like we've got a "rocker" problem here as opposed to the "hook" situation that I had. In my opinion, the last 4' of the hull and strakes must be dead flat! If not, my advice would be to correct that before spending money on props or any other bolt on fixes. But I also believe that you won't ever get it to really run with a cleaver. If the porpose still persists, you can create a "cup" (just like on the trailing edge of a HP prop) on the back, horozontal edge or the strakes at the transom from a good grade epoxy with fiber filler. Give a little more "cup" on the left (port) strake if it's RH drive to help compensate for prop torque when you get it up and really running. Also Andy, Sounds to me like you're plugged in high enough so I wouldn"t start there. Luck! --- Jer

A 26"pitch bravo1 will get the boat on plane really well it is an excellent choice for all around performance on this hull. With that large displacement engine you may need 28 or 30pitch to get the rpms down but I would try the 26 or 28 first. The problem with the cleaver is that hull responds well to a larger diameter prop and 14.5" is not enough with the cleaver or the mirage. You can use standard or solid hub bravo props on the TRS just not the XR hub. I don't think that you need to raise the drive until you dial in the boat where it is now. If you don't have external steering you may want it soon, the deep V narrow boats become a handful in the rough after about 65 or so. Good luck. The Ironman.

I didn't say the boat would not go any faster than 40 but why push my b.b. to 6000 to get some speed when i know it ran 56 with the 454 and the same prop at 5500 rpm.i just don't want to
have the boat do funny things to start if i don't have too.First time
playing with a boat. Been pushing my Porsche at over 200 for years but i know the car well.How's 900 plus horsepower out of a
200 c.i. motor.Like to do things right the first time if you know what i mean,don't like chasing ghosts to get things right,a little research never hurt anyone.motor only has about 10 hours on it,still braking in good,so i'd like to do some prop changes and get in the ball park before i turn the rpm's up.