How much HP is needed from a SB ford

[mattyboy]

to spin 16 X 25 prop on 1.3 gears to 5000 ish rpm reliably???

spending all weekend boatless,and seeing some very fine setups I've made up my mind on this path




that is my goal, I know the prop handles well and I have a new 1.3 drive now all I need is the business end of the equation?

[MOP]

Matty a 1:3 is harder to turn then a 1:50, I make about 370 hp all I can spin is a 23. You being a bit heavier and geared higher would need a bunch more hp to spin a 25, I bet about 500. That would be a woop azz SB but also a time bomb!

[cutwater]

Think about this: To spin a 16 x 25" at 5000 rpm, even at 10% slip, you'd be doing 82mph with a NA small block... I would think you'd need at least 500 or more hp.

[mrfixxall]

i agree with mop i would guess around 500 hp and it would need to be a 347,your going to need the torque to spin that prop..

[penbroke]

My first thought is "lots".

Why do you want to use the 1.3 rather than the 1.61? Is it just the availability or ??


Frank

[mrfixxall]

Giving it more thought,with a 16'' prop i think you may have a problem keeping the wisky bump rail off the water

[sweet 16 1966]

Matty- you going back in time?

[Conquistador_del_mar]

If you need 500HP out of a SBF, I know you can bore and stroke a 351 to around 427CID making right at 500+HP on the dyno with a carburated motor. Many Shelby Cobra relicas have these type engines like the ones made by Rousch. Mine does. Bill

[Moody Blu']

your going to need headers for sure. If he remembers the angles and everything I gave him on the headers we designed together your good to go!
http://www.hitekmarine.com.au/ford.htm

[BUIZILLA]

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

[Planetwarmer]

If you need 500HP out of a SBF, I know you can bore and stroke a 351 to around 427CID making right at 500+HP on the dyno with a carburated motor. Many Shelby Cobra relicas have these type engines like the ones made by Rousch. Mine does. Bill

When you stroke a motor that much, aren't you going to run into problems with the piston wallowing out the cylinder over time? I hear some folks are having trouble with that.

[mrfixxall]

when you go that far with the stroke you usually use a longer rod length and relocate the rispin in the piston closer to the top of the piston to relieve the stress on the cylinder wall's..

[thehow33]

When you stroke a motor that much, aren't you going to run into problems with the piston wallowing out the cylinder over time? I hear some folks are having trouble with that.

Corvettes have 427's in them

[realbold]

Corvettes have 427's in them

Psssst...McFly, the thread title...

[BigGrizzly]

The 16 x 25 is a waste. The engine on the hornet will need to be 575 real dyno hp minimum.