What to Expect

[100mph]

Hello all I am wondering what to expect out of a "74 Tahiti" it appears to be same hull as member "badwee" in the image center, I have search forums but not found any posts by badwee. I have canned the original olds, and put together pretty warm 496 BBC, comp is low right now, will eventually put the blower on it but it is NA right now. The bottom is true (no hook) pump all I have done so far is replace wear ring and turned impeller to fit, appears to be an "A" in it right now, will work with it once I'm in the lake. It has become very long term project, my first boat. Just wondering how to expect it to handle, how much HP is it going to take to break 100mph with it. Just interested in what everyone thinks of the hull, or is it going to be lost cause on my end to try and run it that fast, maybe just once, but have to try so can brag rest of day right.
Thanks
Dan

[cal perf 19]

You did'nt say which hull it was 16' 17' 18' 19' ?
I had a 73 19' that had a Olds built by Mondello and came off the dyno at true 500+ hp and all I could get out of it was @ 70 mph. My boat was very heavy, it had 3/4 inch plywood layup down the sides. It was a good rec. boat but was never going to set records.
If yours is about the same I would say @ 875-1000 hp to get it that fast with a whole bunch of lightening of the boat.
Good Luck with it! BK

[jweeks123]

that boat in the badwee photos is tahiti's copy of an 18 kona. i seem to recall those being stable. probably will take 900 to reach your goal
jw

[LVjetboy]

Get it running, measure a drag reference point, then figure what you'll need for 100 mph. One step at a time. Until then, it's tough to offer a specific power to the century. Just a broad range as some already posted. Depends on where you boat. Your hull drag and setup. Whether you're talking corrected hp or actual...etc.
jer

[Jungle Boy]

900 hp to go 100 mph? 900 hp engines are not cheap, if you want them to stay together. Wouldn't it be cheaper to get a more efficient hull? Here I go about Eagle hulls again, but the 21' tunnel I run gets 98 mph with 550 hp. The 19' Sport Step hull with full interior has run into the 90's with 550 hp. These are small block powered boats, so they are a bit lighter. Just a thought.

[100mph]

Hello again, Thanks to all. My hull is an 18 footer, really didn't know there were all the variations on the tahiti line untill after I bought it and started tryin to learn more about it, seen some in magazines but there were always some differences. I'm sure a more effecient hull is avalible, like I said its my first fast boat, that why I put motor together with single carb first, hope to learn how its gonna drive before I have a lot of HP in it, as I know I'll prob WFO right off the ramp. LOL Its been awhile since I put it together but I believe the heads are 990 Chevy casting, don't rember valve size. crank is 1/4 stroke had left over from from my tractor pulling days, pistons flattop JE, cam, rods, rockers, pushrods, studgirdles, all new crower stuff, ignition msd 7al2 crank trigger, distributor low pro crab style, am hopein it will fit under blower on bds comp manifold (I believe it is 5.5 high on truck block) it's all pretty mild by race standards, but seems to have gone a little to the wild side for ski (recreational) pleasure boat. Hope to finish wireing and plumbing this spring. Maybe see everybody at the lake.
Dan