turboz67

looks like i will be selling my 6.2's my marina has someone to buy my 6.2's with 100hrs on them they have stainless marine exhaust on them. i have them sold for 7k each. the new 383scropions set for bravo 1 are going to cost me 30k installed. they are rated at 400hp so i will need hydro sterring and new lab finished props. i already have kplanes on the boat and i plan on keeping the boat for a few more years. will the gain in top end and performance be worth the money. mercury claims 400hp out of these engines but i have to run 91octane whick i dont mind doing. how much top end will i pick up and what size props do you think will work the best with these engines. they will turn 6000rpm. any help would be nice

tony manzella

28s Lab

Bronco

I would think at least 30" lab B1's (1.65 gears).

Don't know much about the 383's, but I have been interested to find out how they perform in case I ever need fresh power. Although I rarely push the boat, my 292 with 377's (blue scorpions) can really go. I run 30" B1 labs (1.65 gears) with very solid performance. I am a little slow to plane (5ish secs) but its not a ski boat. You will be happy to have the K planes with the faster speeds.

Phazar454Mag

Note the 6000 RPM limit for the 383 stroker Scorpion so I think that you should not fit too big of a prop.

WOT operating range is: 5600-6000 RPM.

I would think a 28" or may be even down to a 26" prop depending of how many RPMs you want or can get it to spin.

turboz67

bronco what is your top speed

turboz67

thanks. but can someone tell if the gain will be worth the money that i am going to spend

4mulafastech

I would expect you would see around a 10 mph gain, so for $16k (according to your numbers), that's not bad in my opinion. That's a good jump in speed for a 292. Is it worth it? Well if the guy next to you is running 76mph and you are running by him at 80mph, hell yea!!

I would stick with a labbed 28 pitch Bravo 4-blade. If you can spin it 5800 rpm, 12% slip will give you 82 mph. You're going to love hydraulic steering. Good luck and let us know what you decide!

Bronco

Good point Phazar, I spin my labbed 30's at 5000 to 5150 rpms depending on conditions/ load. (I should have done my homework on the 383's before posting) My boat came with stock 30's and my current props I believe are merc "standard lab 30's". This winter I may have Bblades try to lab and "tweak" my stock 30 B1s to get a few more rpms... By the way my motors/ exhaust are stock other than the props (silent thunder box still on the boat).

Turbo, again I rarely go faster than 60 -65mph (lots of cruiser wake/chop where I am) but have seen any where from 79 to 81 GPS depending on the day. You get to 76-78 real easy and then let the scorpions "wind up" making sure your trim is optimal to break 80 - It will keep on accelerating just not at the same rate... I must admit, it is fun to occasionally surprise someone with much bigger/heavier HP...

rhsj2006

Turboz67, I'm impressed you're getting $7000 per engine for your used 6.2s.

Before the downturn I was going to spend about $15k to add Whipple superchargers. Estimated HP would have been 450+, but the long term relaibility of the S/C 6.2s would have been a concern for me. Your choice to swap in new motors with a touggher bottom end seems a good choice for longevity.

Please let everyone know how this works out for you.

turboz67

thanks guys. the reason that i am doing this is the marina who services my boat has a formula owner with a 28 ss, he blew the engines and wants to repower. my motors have alittle over 100hs on them, he knew that i had been asking him about the 383's. so he said if i can seel your motors would you buy the 383's . i said yes but see what you can get for them. the formula owner agrred on 7k per enfine with the stainless marine exhaust. 2nd week of september they are going to pull the engines. i just don't know if it is worth it or not. the hydro steering by hardin marine is going to cosy me about 5k installed plus the additional 16k for the engines out of pocket. i wuold like to get the 353 with 525's but i know it is going to be hard as hell to get rid of this boat. the other thing is my payment right now is only 486.00 a month . the formula dealer will kill me on a trade in if i go to a 353 loaded. so i guess i just answered my own question