Prop Selection & Build Process
 

First off thanks to Paul from Razors Rdge Performance and Laz from Mesa Balancing.

Basically i'm looking a prop for my V260. I was currently running a 24p Hydro with my 7.4l MPI that decided to have reversion issues that resulted in a new motor.

the motor was dynoed at 560hp with over 500lbs of torque from 3000rpm-5800rpms.

so what i need is help with deciding what prop i should go with..i want something that will plane easily and still run good if i have to carry passangers. the boat doesn't have trim tabs, but i might install later, and yes i do have hydraulic steering.

i'm located in Bermuda and shipping is very expensive and not to mention the 35% import duty that is added as well. FYI it's 55% on all boats and 150% on cars, so i hope u understand my situation.

thanks
q

Since you have a prop, try it and see what your numbers are and go from there. I had a single 700hp in a 28' Donzi and ran a 4 blade bravo one 28 pitch. Tabs and Hyd steering would also be a nice safety upgrade.

Thanks VV,

qaberdeen, I would start off with something in the 28 range. I would also try a Hydromotive prop, they seem to work well on the Velocity.........

Give the factory a call, they would prob. be able to get you pretty close to where you need to be!!

Dkerns, i was thinking about that, but have u had any experience with the bravo 1 props, i only ask because i still need to get a few accessories and i want to order from one place..

qaberdeen, I haven't tried a Bravo 1 on my boat........some of the other members may have!! Like I said, give the factory a call, they would know!! Keep us posted on your motor swap!!

My 260 ran great with a Hydro. With @425HP I ran a 26 Labbed Hydro @5200 RPM, @ 75 MPH GPS. My 290 did not like Hydros though, so I ran a 28 Bravo 1.

When you get your boat dialed in it is going to run really fast with the new engine. You might even say "fun fast" Get that hyd steering going as soon as you can.

Prop selection
 

I have a 99 260 with a 500 bulldog and am running a 30p bravo

Thanks Fellas for the input. VV i do have the Hyd steering single ram. once the engine arrives, i will post more pics. waiting for the cargo ship to cross d Atlantic. JAB r u running tabs, and just curious how long it takes to get up on plane with passengers with the 30p prop. hers's a few more pics

Prop selection
 

The boat gets up on lane just fine with the 30p

I found in my pile a 15"x30" 4 blade Mach Stern Driver prop. Came off my 28zx Donzi.
If I recall this was a real fast prop. Looks good except one small chip in one blade. Don't know if it's even worth fixing it is so small. If this is something you might be interested in and can use it, you are more than welcome to it, I don't need it and is just sitting here on my wifes granite countertops.

http://i265.photobucket.com/albums/i...0/DSC_0042.jpg
http://i265.photobucket.com/albums/i...0/DSC_0045.jpg
http://i265.photobucket.com/albums/i...0/DSC_0043.jpg
http://i265.photobucket.com/albums/i...0/DSC_0044.jpg
http://i265.photobucket.com/albums/i...0/DSC_0046.jpg

Thanks VV.Where r u located..

also does any one have trouble with rain water getting in the corners of the engine compartments and settling..

q

some more pics'

Oklahoma USA

gaberdeen,I have several different props that you are welcome to try.I have a friend that lives there in Bermuda and I could ship some blades for you to try,he lives in I do believe they call it Hamilton,he is part owner of the Sonnesta Beach Hotel is that near you.I think something in the 28 range will be close but you never know until you try them.If you need something let me know.
Bill

Hyper1, That sounds great, have u ever been to Bermuda. it's a beautiful place down here. yeah i'm about a 5-10min. drive from either location and that's doing 20mph.lol and the island is only 21sq. miles long and 3 miles wide.. so basically eveything is close and the water is even closer.. :-) My engine should be in Bermuda Next week so i will stay in touch and post more pics soon..

q

My 26/280 didnt like hydros as it lifted the stern to much. I run a B1 labbd 32 with big power. But these guys have a better idea then I. Im running a similar set-up to a couple other that knew it works.
-Mike

Just thought i would add some racing footage from bermuda. It's 1 or 2 Velocity's in there...
Click on Round the Island boat Race with the Yellow Bat Boat on front

http://www.bermudasportsnetwork.com/...mid=62&catid=5

Hopefully this will work

:ernaehrung004:I just took delivery of my engine and it's sitting in the garage..so hopefully i will have some pics later today. :ernaehrung004:

Nice cant wait to see
-Mike

Thanks Sick,

Here's what i have thus far..

Wife's gone out, so i've got to deal witht the kids. so i guess it's going to be a late one in the Shed..:food-smiley-007:

Out goes the old :angry-smiley-038: here comes the new:angry-smiley-038:

As you can see, i still have a bit of work to do. so, i'm going to need help putting this puzzle together.

first off i going to need a thermostat, it looks like it was set up for the serpentine belt system like d old motor, i was wondering if i cound run the ss water crossover system instead of the water pump in the middle with the serpentine system or which option would be better like individual belts.

By chance would any know what would be the best thermostat unit to use. also i went with the EMI Thunder exhaust

thanks

i was thinking something like this ?

I am running the one on the right!!! I would also try to keep the circulation pump on it if it was mine!! Just my .02!!

Thanks DKerns,
I was thinking the same thing. it's just that we import everything and our local marine doen't carry much and if they do it's triple the US price.. do u have any pics of yours so i can see where the hoses go. also i was thinking of of these pullies but i not sure if i want to go the route. but they r the Hardin Marine billet set. has anyone had any experience with them or would the originals will work better. also has anyone used the SS thermostat.

also does anyone know where the hose on top of the circulating pump go..sorry for the questions :-)

Fellas, wanting some ideas how i could plumb the engine using the serpentine belt system and the recir pump with out drilling the intake..
so, can i just cap off the top of the recir pump and run the belt system as normal using the SS mer t- housing (above) and 142 thermostat. will the exhaust still get water and not over heat. i was told to drill the bottom of the intake underneath where the thermostat would go. i guess what i'm taking about is where the bypass hose would go(from top of recir pump to bottom of intake housing. i guess this is a jumper for water to the exhaust areas i think)

i really don't want to drill anything at this time so if u have any suggestions, please advise
thanks

q

For the newer merc style thermostat unit on the right above you need to plumb the circulator pump bypass to the intake manifold to allow the water to circulate in the engine when the T-Stat is closed. It's purpose is not to provide water to the exhaust manifolds as the design takes care of that. Different story if you're using a cross over and no circulator pump.

If you don't want to drill you'll need to find the older style 2 piece thermostat housing which allows the pump bypass to be plumbed into the lower section of T housing. I use a single belt set up on my 500 EFI's with Merc. part 849927T1 but there are probably others that will work as well.

Thanks Revelocity,

it looks like i will be drilling to be on the safe side..what about the safety sensor, at least that is what i think it is, as u can see i missing one on the other side of the intake, anyone know where i could get one. i believe the # on the temp sensor was 66 and i also saw S1 not sure if that means anything..

and any suggestions on a good fuel pump i was thinking the Holly pump with regulator. but i'm open for suggestions, needs to be a min. of 6 psi's and would the stock one work as well..

thanks Q

I am thinking about going with the Holley Blue Pump, any suggestions,

thanks

qaberdeen, I am not sure what/why you would have to drill the intake to use the updated Merc. style therm. housing. I didn't have to do anything extra to use mine. The large hose nipple on the front (left fron if looking at the front of the motor) is from the circ. pump, the one directly across from it is for the incoming water from the sea pump, and the two smaller ones on the rear of the housing go to the bottom of each exhaust manifold. Saved what seemed to be 5 lbs. and 2 extra hoses. Really cleaned up the front of the motor!!

As far as the fuel pump, I am not a fan of the holley pumps because of too many problems (on cars anyway). If you have the ability to run a mech. pump, that is the way I would go. If not, I would recommend an Aeromotive pump! Again, just my opinion!!

As for the pulleys, looks like a pretty sweet set up to me!!

I don't have any clear pics of the therm housing and mine is a small block!!

Thanks DKerns,

i was thinking the same, but i'm still having mixed feelings of drilling, but the engine builder said to drill it, but i was just seeking some different opinions.

oh, thanks for the pics, the engine looks sweet...

q

As far as the prop question, I have almost the same horsepower in my 260 and run a labbed 28 P Bravo 1 prop by BBlades.

The issue is that you won't have water circulating through the engine (it has no place to exit the engine) until the thermostat opens which leads to uneven heat distribution, hot spots (heads) and in rare cases steam pockets while the engine is heating up. That's why Mercury and Merc Racing engineered a bypass as a safeguard on their motors.

You can experiment by drilling a hole or two in your T-Stat to allow some water to flow through to help mitigate the issue. Too much hole flow through and the T-Stat might not open so work your way up.

ReVelocity,

Should i use the standard connecotr that was on my 7.4l MPI and hose

Revelocity, I am not doubting you, but what "bypass" is required?? I ordered all new hoses for my boat when I put it together and there were no bypass hoses. I also put a motor in a 98 boat recently that had the same therm housing O.E. and didn't have any bypass hoses and didn't have a hole in the thermostat.

Looking at the newer 454's like qaberdeen had in his boat, they don't show any bypass hoses either?? Looking for positive info so I know what I need/should do!! I also don't want to mislead qaberdeen!!

This is a pic of the bypass coming up from the recir pump.. although this is not my setup, my engine came with the connector on top of the recir pump, and when i enquired about it, i was told to drill the intake manifold for the bypass hose..

thanks again for the comments.

Dkerns,

am i going to use #24 in your pics for my applicaion. it's the cooler power/steering oil cooler..

thanks