mickeymcclgn

Alright I have some questions for you guys about propshaft height. I've read alot of the older pages on stuff but I just wanted my situation out there so I can get some current feedback.

My new setup is a 468 efi (originally a 454 mag efi motor) it's a 95 motor and had the flat tappet cam (I believe it was the only year that they ran them it is a v belt setup for what it's worth) well it wiped the cam so I converted it to a roller motor, went .060 over on it nice heads I don't have the spec sheet right infront of me) anyways tuned it its 525 hp... B1 with 1.5 gears... The motor is stock x dim... I just came across a smoking deal on a -2 imco lower that I picked up... Now I haven't ran this setup at all.

What's the -2 going to do for me? And what about propping? Where do I even want to start? 3 blade? 4 blade? 24p? Motors rev limiter is 5400. I've read people go 4 blade with the shorty lowers others run 3. Ultimately I'd like to be able to cruise faster ride better which I think ill achieve with the -2.

Ultimately I want to know what I'll expect with this compared to the boat with the stock x dim. For what it's worth last season the boat had a 330 genIV 7.4. And stock height b1.

Thanks for any imput. I think I've given the details to atleast get me started. Getting the itch to get it all together.

Oh and I have a full dual ram hydraulic steering going on too. Lots of work to do!!

Smitty

I had a 95 24 Outlaw. Bone stock with 365 hp I ran a 21" 3 blade to 61 mph. Supercharged the stock motor, guess at 525 hp. I then ran a 26" 4 blade Bravo 1 prop to 76 mph.

I did meet a guy once who had a 240 sport and a 1 or 2 inch shortie with 600 hp and he was running low to mid 80's.

I think you will be fine the the 2" shortie. Def go with a 26" 4 blade to start and see what happens. May need to go to a 28". You may also encounter longer than normal planing time, but it should be fine once it is up and out.

Smitty

mickeymcclgn

Thanks smitty, I wasn't sure if a 3 or 4 blade was going to be in order with the height change, does raising the prop shaft height affect bow lift being that the prop is closer to the surface? I know to get the speed out of them you have to get the bow out of the water.

Keep the info coming if anyone has anything they'd like to add

Smitty

Any prop can be set up to give you bow lift. I had plenty with that stock Bravo 1 prop

stlliberator

I have a 240 with the x raised 3.5 inches. I have a 502 with about 430 horse. I run a 26 bravo 1. I also have the largest k-plane that eddie marine makes, I ran the boat for a year with no k-planes at all. I didnt have really any problem getting on plane without planes. My boat runs 70 gps at 5100 rpm, and cruises about 45-47 mph at about 3100-3200 rpm. I dont think you will be able to turn more then a 26 pitch, I would start with a 24 pitch, it will probably give you more of the all around that you need.

mickeymcclgn

Thanks for the input stilliberator, I have a set of 28" k planes I just bought as well for the boat. Parts keep piling up lol. Is your best ever speed 70 or is that a number you can hit with some frequency?

baditude

X2 on the bravo prop my 24 is 4 inch raised x-dimension and a two inch shorty with extension box. I was running a 30 pitch labbed bravo it gave mine some porpise at cruising speed but not to bad. I swithced to a 5 blade 32 and it runs alot more flat.

mickeymcclgn

Now correct me if I'm wrong but some of the added bonus to having a shorty lower (or rasing the x dim and retaining the stock lower) is less drag and as well being able to gain speed without having to trim as much so when/if its rough it will fly straighter and not shoot the bow in the sky. Now with that as badattitude said is this going to be more prone to porpoise-ing while running in flat calm water with a higher x?

Unlimited jd

Mine with the -2" had a very slight porpoise when flat calm, about 610-630hp 26" bravo 1 prop about 78 mph. @ 5600 rpm

Fixxxer22

I have not changed my propshaft height from factory or instaled a shorite. But planing with power with no tabs or anything was nuts with a highr pitch prop... I installed 280s and lay them down. They are amazing. I assume they may be hard on my transom but oh well. They are called "k-planes"