383 stroker scorpion bravo 1
 

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

28s Lab :coolcowboy:

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.

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.

bronco what is your top speed

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

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!!:evilb:

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!

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...

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.

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

i thought about whipples also , but the bottom of the 6.2's are not built for it. so i decided to go with factory built motor from mercury

Turbo, sounds like you're keeping this boat for a while...Why not go with the Raylar 550HP LS based small-blocks?

I gotta believe you'd be seeing 95 MPH if you put 1100 HP of Raylar in a 292, especially considering you'll be lighter by at least 600 lbs. vs. iron Mercs, maybe more.

http://www.raylarengine.com/550_engine.html

of course you'll be at the outer limits of the Bravo1 but oh the fun you'd have :evilb:

All that said tho, I'm not seriously suggesting this unless you've got $$ to risk...I haven't heard of anyone on OSO or other forums that have installed the 550s in a twin configuration. Maybe Ray will pipe in with some news about customer installs, seemed like a hot topic last year when launched but quiet since then.

Are you saying that you have a set of standard 30" Bravo One props and currently run a set of Merc labbed 30" props ?

In case you do what is the difference between them from a performance and mid range point of view ?

Is the mid range satisfactory with the Merc labbed 30" props ?

i would love to get the 353 magic float has for sale, if i didi not have the 292 i would do it. I still have a 92 223ls that i am still trying to sell. i just can't understand why formula does not offer the 292 with more power, they always play it safe.

the 383's should do the job, i hope

I do think it is worth to get the 383 Scorpions and the hydraulic steering.

First of all you are getting a very good price for the old engines.

Second of all the upgrades makes your boat more fun and you can enjoy it in the years to come.

Third of all if you want to sell it at some point in the future then you have a 292 with hydraulic steering, K planes and powerful reliable engines which is an attractive combination for buyers. You will not get all of the the additional money back that you are putting into to it now when selling, but at least your boat will be very interesting to buyers so I think it is more likely that you can sell yours compared to the many "standard" 292 Fastechs out there.

Exactly Phazar, my boat came with 30" B1 non labbed and I bought a second set of labbed 30" B1's that I believe are what merc calls a "standard lab finish" from the markings on the hub. Apparently merc offers variations of lab finishing depending on the performance desired. The labbed props only added 1 to 2 mph on the top end but mid range is where I noticed the most improvement. From 3000 to 4500 rpm the boat just seems to accelerate quicker and smoother- more responsive on and off the throttles. I may have gained a bit more slip out of the hole but thats where the extended tabs really help a lot. I think the labbed props are well worth the money.

Turbo, I feel your pain. I love my 292 and even though I "downsized" to the 292 it seems I always want a bigger boat. I miss the A/C and larger cabin (although I rarely used it). I dont miss the fact that a 35 or 38 is a 2 person job most of the time. I boat by myself around 1/2 of the time and have no problems trailering (launching/ loading) the 292. Plus as you noted the great deal on the bigger boat is likely to be negated by the low price you are likely to get for your boat in todays economy. Although toys get old, lets not forget that the 292 is still a damn nice boat no matter where your come from. I have chosen to make mine special (to me) with small updates and improvments and enjoy it for the next few years.

Only you can decide if it is worth it and everyone's situation is different. Like some of the others have said, it sounds like you have a good buyer for your old motors.

Cheers and safe boating.

I was thinking in terms of mid range efficiency (ie prop slip) between the props resulting in a difference in cruising fuel economy.

Let us say your are cruising at 3000 RPM (or some other mid range RPM) with the std versus labbed props then what is the difference in speed between the props if any ?

thank you for the help. i am going forward with the 383 with the steering. the props i have now are the 28lab finshed props. do you think these will do the trick

If you can spin them at 5800 rpm, you bet! It's a good place to start.

It depends on the powercurve. The question is how much power the 383 stroker Scorpion develops around 5000 RPM ?

If it is powerful enough in the mid to upper RPM range then you might be OK with the 28" props.

Otherwise you might have to use 26" props to get the full benefit of the 383 stroker Scorpion, with strong acceleration and screaming 6000 RPM engines at WOT. I bet they will sound great at 6000 RPM :)

thanks guys i will start with 28"s

Agreed, 28's are a good place to start. I wish I had some 1st hand experience with the 383's to help you but I dont (maybe labbed 30's). Please let us know the results as I am excited for you.

4mula,Phazar, you have it right. (nice boats by the way) As you know its all about how fast u can spin the props and be in the correct rpm range at WOT w/ minimal slip, based on your normal conditions.

Phazar, I am not quite sure I understand your question correctly, but I will try. I do not have smartcraft or any other way to truly measure the results from the motors (only lots of time on boats). I have done the math with gas consumption but that is hardly precise (every day=different conditions). I can only confidently tell you that the motors feel, sound, & run more efficiently. There is no laboring when I back off and reaccelerate (to not beat up my passengers going thru some rough stuff) and when in only 1 to 2 ft of chop the boat accelerates real fast and wants to keep going... It feels more like a finely tuned sports car (Labbed props) than a quick sedan (non labbed)... hope that helps.

bronco,4mula and phazar, thank you very much for your insight on this project. i will start with the 28's . who do you guys know of that can relab the props.

You're welcome turbo.:drink: As Bronco says, I'm excited for you too! Glad you made the decision to upgrade the 292. She is going to be a pleasure to drive with that power and new steering. If you can, it would be great to post some pics of this project. Do the Scorpion's come with header style exhaust?

Regarding labbing the props, I recommend contacting Brett at bblades (advertiser here - bblades.com). He was at Mercury for 12 years and the last 6 working with props. While I don't have any first hand experience with bblades, all the posts I have read have been very positive and he is an expert on the Bravo 4-blade props.

Good luck with the project! When do you think the swap will be complete?

Thank you for the feedback, my question is related purely to cruising range / fuel economy when going on longer trips. I know they use a lot of fuel when playing around :) No problem. Just want to consider cruising range.

I am just thinking about cruising around 3200-3500 RPM, and I have heard that prop slip is often higher at mid RPMs using labbed props as opposed to stock props. I have a Northstar GPS with fuel sensors so I can see the difference it makes to get trim etc. right to reduce prop slip resulting in the best fuel economy.

But even though you don't have fuel sensors you can compare speeds at the same RPMs using the stock and labbed props, but may be you didn't notice a difference ?

You are welcome :)

I do think you will be very happy and I am also very excited for you.

I wish I could hear the sound from those engines when running WOT at 6000 RPM :drink:

I think the engines comes with 316L Stainless Steel CMI Headers, but correct me if I am wrong turbo ?

they come with cmi exhaust. i am taking the boat out in two weeks. they are going to pull the motors and put them into the other formual. the plan then is to put the steering in and then the engines. i will only put the boat back in in the spring time. that gives me some time to pay for all of this thru the winter. hopefully the wifw won;t notice.

i forgot to tell you guys. if you on you tube type in 383scorpion and there is a video of the motor running.

You are welcome, and that video on youtube is awesome!

Phazar, the lakes where I live right now are not big enough collect any long cruise data (We are in a serious drought). when I first got the lab props I did actually compare speeds at different rpms with the 2 sets of props. The difference was negligible as some rpms were a mile or 2 faster and yet other rpms yielded a slower speed than with the regular props. Over all top speed was faster. Also with the labbed props, my starboard rpms are 200 to 300 lower than the port when getting on plane (out of the hole) but they even out once I hit about 30 mph and level out the boat. I believe that this is due to slight differences in the props as this does not occur with the regular props...

I think its fair to say that there can be more slip with labbed props than regular props. At the same time, that probably varies between different sets of "labbed props" . I highly doubt any 2 props would be truly identical and any pair is "perfectly" matched. I realize this info is hardly scientific but hope you find it helpful. Cheers.