russ

Have a Baja 252 islander that I had a custom motor built. It had a 6.2 in it before this one. Brovo 1 drive with 1.50 gears.

Conditions where about 97 degrees and light chop.
Today I ran a 23P M/P 3 blade on it and was spinning the prop at 5400 RPM's and was only getting 63 MPH!!!!!!!! Prop has never been reworked

Ran a Mach sterndriver prop 4 blade and at 5100 RPM's and was running 66MPH. This prop has never been reworked.

Ran a 25P Mirage 3 blade at 5100 RPMs and was running 65 MPH. This prop had something done to it but don't know what.

Why am I not seeing more speed?

I do have a drive shower on it. Could that cause any problems.

Is the X dimention different for Baja's when they install the 6.2 in the boat?
Mesured from the bottom of the V to the bottom of the outdrive and was 5 1/2 in.

Should I have the hook taken out of the hull? There is a slight hook 16th to 1/4 in on both sides.

What would be a better prop to try. The slip I'm getting is way to much for the 3 blades. I think I need a prop that can get the hull farther out of the water. Bravo 1?

Johno

Try a Rev 4 23" pitch, worked wonders on my 24 Outlaw, will lift the the hull up & out more than the 3 blades. Call Throttle up & ask Julie whats she thinks. The have prop trest program. Have fun

GLH

Not getting the speed you think you should?
You must be new here, we all have that problem.

russ

No not new just added new power to a boat that had a 6.2 in it. Wondering if they change the x dimention between there big blocks and small blocks. If the x dimention is diff can I compinsate some by using a different prop. The Mach prop was the fastest. But is there a better prop out there than this. I don't think the 3 blade is going to work for me.

Russ

articfriends

Are you still running the same size motor? Your question is vague,and last----HAVE YOU EVER HEARD OF SUPERCHARGING?

russ

No I'm not running the same power. Added in a big block 502 that has been modified. Dont think a 6.2 could spin a 23P M/P at 5400 RPM's.

articfriends

Seriously Russ,I know supercharging isn't the answer to everything but give us a little more info on your new motor. Iv'e had the best luck with 4 blade props on my 272 baja. Where is the power band supposed to be on your new motor?Iv'e noticed on my 272 it goe's the fastest trimmed to max (but i'm sure you've realized this already)Smitty

russ

Peak HP is at 5100 RPM's. It is a carbed motor and the builder said shouldn't have a proplem running up to 5400 RPM's. The motor is putting out around 470 HP. The boat weight is around 4700 loaded. gas gear and people.

What 4 blades have you tried? Do you know if the x dimention is different when they add small block or big block? I'm thinking I need alot more stern lift.


Russ

Fuelish Pleasures

What pitch is your Mach Sterndriver? It seems to be putting you at the right rpm's. You could have it reworked to get you some more speed. I use a Mach Sterndriver on my boat and it worked better for me than the Rev 4. I am able to run 1" more pitch with 100-200 more rpm's. The Rev 4 did give me more lift but the extra diameter took more HP to spin it. I am running the 496 Mag.

articfriends

Russ,i would try a bravo 4 blade 24 pitch,see what it rpm's.If it can't turn it at least 5000 rpm's then try a hydromotive 3 blade 23 pitch,when my 272 was stock and had 450hp/415pshp it went 62mph fully loaded at 4900 (23 pitch mirage),64 mph at 5050 light load,66 mph w hydromotive 23/3 blade 5200 rpm's. As far as your x-dimension,mine is also 5 1/2 inches (2000 272 boss,originally had 502 mpi). My 502 stock couldn't turn a 4 blade 24 pitch much past 4600 rpm's(weight sounds about identical).How much total timing are you running,are they stock rectangle port heads/stock exhaust?