83 scarabII with kaamas - turd!!!
 

its my first big boat, i have had a few v drive flatties and a ditch pump or two. i always liked the older scarabs with all the teak, found a good deal on a real clean 1983 scarabII 30 with kaama drives, twindisc trannys, and harland marine SBC 5.7Ls. it was a special build from scarab. i have the build sheet. i like the surface drives and the roosts but man its a turd. 43mph on gps. its over proped, the motors will only turn about 3900 rpms with no gain in rpm after about 1/2 throttle. Qjet carbs.

i want to add some more power (heads, cams, intakes, carbs) on stock short blocks, but im scared its going to hurt the value. i think i can build alittle over 400hp safely with stock short blocks. i would buildi the motors around the props i have, 16.5/28 4 blade choppers, or just through some 177 blowers on the stock motors....

give me some input.....

decent motors won't hurt the value. .. 400 hp on a na 383 is easily doable, but 800 hp still isn't much for that boat. It may be cheaper in the long run to look for a couple takeout BBC's. people are heaving a hard tome selling motors right now, so there are deals to be had. How many hours on the motors? By the time you freshen the bottom end X2 throw in some more stroke, pistons, rods, (if you dont do that and just toss blowers on top of unknown short blocks, your asking for headaches) buy 2 sets of heads, cams, valvetrain, intake manifolds etc... you have spent more than a couple low hour 496's just went for.

I agree 100%. You can move a big 30' tub decently with a pair of small blocks (but I have no idea why it became so popular in the early - mid-90's... does the factory really save that much by installing small blocks???), but at the end of the day I think you'll be extremely underwhelmed until you put a pair of BBC's back there!

http://www.offshoreonly.com/classifi...o31733-en.html


http://www.offshoreonly.com/classifi...o32258-en.html

the motors have low hours and run and sound good. i could spend about $2500 on top ends proven to make 440hp on stock 350ci short blocks and not go through the trouble of doing a swap to big blocks.

holley 750 vac secs, professional products hurricane intakes, pro comp aluminum heads 210 runners, 488/510 234/244 @50 cams lifters chain sets , cheepo roller rockers, push rods, gaskets, oil and elbow grease.

i would be doing all the labor my self. altho a pair mpi bbc would suite it well, sbcs with these cams would make some niose. stock bbc just go potato,potato,potato,potato

what kind of speeds would i get out of a pair of 454 mpis? i would think it would be alittle faster with the weight savings from sbcs with the same power......

the main goals are more speed, and the best resale value.

the motors have low hours and run and sound good. i could spend about $2500 on top ends proven to make 440hp on stock 350ci short blocks and not go through the trouble of doing a swap to big blocks.

holley 750 vac secs, professional products hurricane intakes, pro comp aluminum heads 210 runners, 488/510 234/244 @50 cams lifters chain sets , cheepo roller rockers, push rods, gaskets, oil and elbow grease.

i would be doing all the labor my self. altho a pair mpi bbc would suite it well, sbcs with these cams would make some niose. stock bbc just go potato,potato,potato,potato

what kind of speeds would i get out of a pair of 454 mpis? i would think it would be alittle faster with the weight savings from sbcs with the same power......

the main goals are more speed, and the best resale value.

hp yes, torque? Mind you I am not saying anything negative about your engine building, but you repeatedly said resale. If you were boat shopping would you weigh stock merc bbc power over some small blocks some guy you dont know whipped up in his garage?

Personally I think you'd be better off putting the $2,500 + w/e you can sell your longblocks for, and getting a pair of big blocks.

If you want to go the elbow grease route you could buy a set of Merc 454 330Hps, add some milled 049 or 781 heads, a cam and intake, and be going somewhere with some reliable Hp for around the same price.

Chris cat
 

buy my boat and put the power and arnesons to that scarab, then you will see god:drink:

On my boat I gained 5mph from going from 300hp 350 to 310hp 454
and was much happier all from the added torque.
Boats need torque ,the more they weigh the more important it is.
Dont think youll ever be happy with small blocks on something that heavy.

Weight difference between 350 and 454 is about 160lbs per engine.
Throw aluminum heads and intake on the 454 and weighs about same as stock 350.
Even if you dont the difference is less than a couple extra passengers and a full cooler.