I would think motown blocks and heads can't weigh much more than chevys. i'm running stainless marine dry exhaust,so i might have been lighter before the pro chargers and 504 intercoolers.

fastp29, here are the numbers for your rig

stock - 640hp, 6000lbs, 233 constant -> 76mph
mod1 - 1000hp, 6000lbs, 233 constant -> 95mph
mod2 - 1300hp, 6000lbs, 233 constant -> 108mph

It will be very interesting to see what number you get. Were your 500hp engines dyno'd? Will your new ones be?

Eceptor, 427's came from bill mitchell racing. dyno sheets were 505 hp and 515 hp. 434's dyno'ed 738hp and 750hp and climbing at 6000 rpm with 9 lbs boost and 36 degrees timing. we dropped the boost to 6 lbs and 30 degrees and made 650hp. I don't go over 6000 rpm's to try and save the drives,i'm not sure how many rpm's they will take. I have billet cranks, rods, and cams so i'm not worried about the motors. who knows what rpm i could run without the rev limiters? I don't think i would go over 100 with that hull, it can already get squirelly at 95.

Thanks for the data. When I return home from vacation I will start plotting out your data and refining that equation to fit the data.

Anyone out there actually weighed their P-29?

One motor is the only way to go around the docks and in no-wake zones. Sometimes if I'm behind a boat in a no wake zone, I find myself pulling even the one motor in and out of gear to keep from rearending someone.

Has anyone ran a Naturally aspirated motor with thier Blackhawks? I want to run 500hp carb motors, but wonder about the rpm drop upon engagement. I would figure, just the additional torque of the 383 would help overcome the stall that I get with my 350's.

My 427's were naturally aspirated. idled at 850, slip in gear and feather throttle to stay at 850 then when you take it out of gear it jumps to 1800 and you have get off the throttle and wait for it to drop under 1000 before you can put it back in gear. In tight spots i slip it in gear and take it right back out before it stalls. the nuetral safety switches are bypassed so i can start it back up if it stalls. I try not to use the port motor so i dont lose my hydraulic steering.

ok now i,m a newbie here so don't everyone beat me up at the same time. if theres problems keeping these drives slow enough to dock using one engine, then why not engauge both motors one in for one in reverse and feather the forward drive @ slighty higher rpm would this not offset the speed of only 1 at the forward position???jmtc

wow, i never thought i would see those numbers out of one of those hulls with blackhawks. i new an owner in balto that his boat was undriveable about 85 or so because of those surface drives, i owned mine for 7 years and couldn't emagine running those speeds. i would love to run ya with my phantom some day, i'm out alot and hope we can hook up on the upper bay.