F-32 speed issues

9rock · Post by **9rock** » Thu Jun 10, 2010 10:34 am

I just purchased a f32 sedan with 250hp chrysler engines that are new and I am not getting close to correct speed. The bottom is clean and the props were just tuned. Props are 16X16. Full throttle only acheives about 3500rpm. Appears to cruise better at 3000 at 12 to 13 mph. It appears to not make any more power above 3000 just burning fuel. Any input would be appriciated.

ready123 · Post by **ready123** » Thu Jun 10, 2010 10:46 am

Is the bow trimmed down? That speed is low for that rpm, I get around 20 mph with my 318's and 16x15 props.
The props sound right... so engine power is next question.... and the reduction gearing.
F32's like to be trimmed down when on plane.

captainmaniac · Post by **captainmaniac** » Thu Jun 10, 2010 10:51 am

Props should also be cupped - not just regular 16x16s. You should be in the 18-20 range with 3000 RPM. In addition to gearing and trim as Ready outlines, tired engines, fuel flow, or a timing advance issue are also possible.

Stripermann2 · Post by **Stripermann2** » Thu Jun 10, 2010 11:30 am

The ESTIMATED Trojan specs on your boat and engine call for:

27.3 mph at 3,000 rpm
34.5 mph at 4,000 rpm
Which seem high to me...

Clean bottom, trimmed out properly, seems as though you may have to revisit your engine performance specs. As mentioned, timing, fuel, etc.

prowlersfish · Post by **prowlersfish** » Thu Jun 10, 2010 12:04 pm

Jamie , do you get thoses speeds from yours ? 7 mph less woul be what I would expect.

9rock is the bottom clean ?

Stripermann2 · Post by **Stripermann2** » Thu Jun 10, 2010 12:52 pm

prowlersfish wrote:Jamie , do you get thoses speeds from yours ? 7 mph less woul be what I would expect.

Nope. With a clean bottom, good seas, she'll crusie at 20- 21kts at 3000-3150 or so.

9rock is the bottom clean ?

9rock · Post by **9rock** » Thu Jun 10, 2010 1:21 pm

prowlersfish wrote:Jamie , do you get thoses speeds from yours ? 7 mph less woul be what I would expect.

yes the bottom is clean. I just scaped ,sandeded.and painted

9rock is the bottom clean ?

ready123 · Post by **ready123** » Thu Jun 10, 2010 2:00 pm

So you need to look at the engine.... you are not getting enough power from them.
Check the obvious timing, dwell etc: and of course is the carb giving you the fuel.

TADTOOMUCH · Post by **TADTOOMUCH** » Fri Jun 11, 2010 7:42 am

At about 3500 rpm my 1978 F-32 trimmed properly on smooth water runs about 27.5 kts or 30 mph at 3500 rpm Wide open close to 4000 rpm I get 33 kts or 36 mph. 16x15 cupped props