Red, Thanks for the info. My research shows about 200lbs heavier than the 5.7 engine. I think its a pretty good deal, good running engine 400 hours total that is being removed this week for a trade-in and my price is $1750 complete with all accessories.
Since the boat is going into paint shop for complete rebuild I was already thinking of reinforcing the hull. The sides are so thin, feels like there's nothing there. Moonraker got a Seacast transom but I elected to go back with good quality wood stringers. I'm thinking that maybe I should do Seacast stringers on this one. It's incredibly stong. I didn't use any foam on Moonraker but that might be necessary for the added weight of the engine on the Scimitar. Also, someone in the past has added an aft fuel tank to the boat(probably had a problem with the forward tank at some point is my thinking), so I think I'll remove that to lessen aft weight. Already considered lessening the weight of all the interior and seats using some composite materials. We all hate rot don't we? Jim What foam did you use?
Hi Jim, good to see ya here, and Yes, the SEI drives are, in my opinion, an identical make-up of the Mercruiser drives, I have ran two of them myself on 260hp & 300hp small blocks no problem, but I would be concerned about about making full power "hole shots" and running at full power for an extended period of time with the 454. The 454 has conciderable more torque than the 350, and you will be able to run a higher pitch prop, leaning heavy on the drive gears. the drive you have is probably a 1.50 ratio, thats what the Scimitar came with, but if you were going to buy a new drive, I would suggest a 1.36 ratio .. check out this link http://www.gofast.com/sterndrive_gear_ratios.htm I'm running a Gen II drive on my boat with a 1.47 ratio, I would also recomend the later model Gen II drive for the 454 power, it has a larger upper gear case, remote resivoir, and tougher gear set. I don't really know what pitch my prop is now, but I think it came out a 14 1/4 X 24 .. it was made as a Power Tech 23 pitch, but it has been modified several times to get it to perform as it does, my motor is producing 425 / 435 hp and I have turned it to 6200 several times with a drag prop, and it is turning 5000 / 5200 with my Power Tech prop, and running 68 / 71mph depending on load.
I'm not , by any means, trying to be negative, or "Know-it-All" but I would be concerned also about the weight of the 454 in one of these boats, they are Not very tough hulls, light weight, and based on the handling charactoristics of my own boat at 70 mph, and I have attaind speeds near 75 in cold water and moderate chop. I took into concideration the balance of these boats when I moved my motor / transom back just 5 inches, I reinforced my hull and stringers, injected foam all under the floor for regidity. I took almost 200 pounds off my motor with-out changing it's balance, by going with the aluminum intake manifold, aluminum exhaust manifolds, the lighter flywheel, high torque starter, aluminum water pump, and I rebuilt the back seat with 1/4 inch material, thus removing about 40 pounds there.
I'm wondering ? if the weight of the 454 would cause a porpiose tendancy at lower speeds also ... However, with 36 gallons of gas in the nose ? may confisate that ? keeping in mind these boats only weigh about 2000 pounds lake ready. I have seen boats with similar hull design with a 454 that are stable at speed, one was a Glastron, running in the 70's, but both were heavier boats ? just my thoughts.
-- Edited by OleRed on Monday 19th of July 2010 10:17:27 PM
Red, Am getting ready to buy a 454 for the Scimitar. Its got around 400 hours since new and well maintained. You think an SEI aftermarket drive will hold up with that much horsepower? That's what was on the boat with the 350.