big Block F-32???? better weight distribution????

TBone · Post by **TBone** » Tue Jul 31, 2012 11:40 am

I am thinking that I want to repower my F-32 in before next season. Currently it has the twin 318s, 72C(1.52:1) and 16X**.

switching over to 350 small blocks (325HP) with the same trans, spinning 16X19 wheels is an option. that will give decent fuel burn at cruise, plenty of power to move that boat at high speed.

using that theory, what about a 454(350HP) still a little more power, alot more torque, could spin a deeper cut wheel maybe 20+" of pitch.

that would achieve a reasonable 16kt cruise at a lower engine RPM....

There is the increased that some may complain about. I would think it may be better, more weight down low in the boat. wouldn't that increase some stability? What about more weight behind the CG of the boat to help alleviate the heavy bow.

If were talking about heavy bow, what about moving the engines more aft, only a about 4", and lowering the 1.5" deeper into the stringers, this would still keep the same approx. shaft angle and placement as compared to stock.

These are just ideas that popped into the brain..... food for thought.. I may not be ready to try and reinvent the wheel by moving the motors, but Im not apposed to big block power.

Tom

jav · Post by **jav** » Tue Jul 31, 2012 1:29 pm

I have diesels which are proabably comperable to big blocks in weight. They were moved aft (from where the 318's were) but how far you can move them back and down is governed by transmission output shaft locaton and oil pan clearace. In my case- it wasn't much but a 230 gallon tank under the cockpit sure helped. Also- clearance to the floor is a concern as our holes aren't very deep.

As far as a 16 knot cruise- mine never liked that speed. It didn't feel like it was fully up on top. I cruise at 20-21 knots and it feels better but the hull really likes 23-24 knot cruise (conditions permitting).

Personally- if I were repowering with gas- I'd stick with newer small blocks. Plenty of power since the boat was really desinged around 225 hp engines and their compact package will help with fitment. Be careful with too much power as 1-1/4 shafts aren't exactly beefy for high torgue demand.

edit: also- I'm surprised you have 72C gears on 318's... are you sure they aren't 71C's? If they are 71C's- and you have counter rotating engines now- the swap becomes more complicated with non-counter rotating engines.

prowlersfish · Post by **prowlersfish** » Tue Jul 31, 2012 1:39 pm

X 2 on JAV s post

On re power with 325 hp 350s good chance the props would stay the same or close to the same , as they make their HP at a higher rpm

TBone · Post by **TBone** » Tue Aug 21, 2012 1:20 pm

Jav-

Correct, they are the 71Cs that was typo.

power is FWC 250hp 360. that was typo in my brain.

obeejr · Post by **obeejr** » Thu Aug 23, 2012 8:11 pm

I have 350 Crusaders with GM blocks. They put out 270 HP.
My understanding is that in order to access the extra HP of the newer 325 HP small block motors, you would have to cruise at a higher RPM. AT 3 to 3.5k rpms, they won't generate any more power than my 270 HP motors.